jaberwaki

So You Wanna Be Fast....
by Jaberwaki
(a guide for newbies to what it takes to build a fast F-body)


Being fast is much, much more then just making a lot of power. There are SEVERAL topics that make up the ability to be fast at the track. We will discuss the things that you can directly affect.

We will split the topics up one at a time, and even get part-specific, defining what a part is and what it does.

Part I: Power
A. Nitrous Oxide
B. Heads/Cam
C. Bolt-Ons
D. Short Blocks
E. Fuel Systems
F. Forced Induction

Part II: Drivetrain
A. Manual 6-Speed (M6)
B. Automatic 4-Speed (A4)

Part III: Chassis/Suspension
A. Chassis
B. Suspension


Thread for comments/discussion: https://ls1tech.com/forums/new-ls1-owners-newbie-tech/361892-so-you-wanna-fast-jaberwaki-s-2nd-writeup.html

jaberwaki

Part I: Power

Power is the newbie's wet dream. It is what Vin Diesel said he needed to twist the chassis off the line, and you want a twisted chassis don't you?

In its simplest form, the motor is nothing more then a power-making air pump. The more air in, the more air out, the more power you make. That is not everything by a long shot, but it will help you figure out if a mod will help or hurt.

There are A LOT of ways to make power -- more importantly, increase power output from your motor. Here are some of them.

jaberwaki

A. Nitrous Oxide

Nitrous Oxide (or N2O) is a chemical oxidizer; it is two parts nitrogen and one part oxygen. The oxygen is the part that makes power. Gasoline combines with oxygen in a combustible mixture. The more of both gasoline and oxygen you have, in the proper amounts, the more power you make. So why not inject pure oxygen? Simple: pure oxygen is much, much more intense of an oxidizer. Having about five times the intensity that N2O provides, pure oxygen would melt your motor.

Bang for buck, N2O is the fastest way to make power. That being said, N2O has a bad reputation for giving more BANG then people expected. Let me go on record as saying, this is not the N2O's fault. The fault is on the person trying to get away with spraying nitrous and only having $500 total to put into it. Nitrous is a SAFE power adder, if it is both set up correctly and used properly.



Setup Types

There are 3 major types of nitrous setups.
1. Dry
2. Wet
3. Direct port

As with most choices, there are pluses and minuses to all of them.

Dry:
A dry shot relies on the car's MAF, PCM, and fuel system to add the proper amount of fuel to balance the nitrous out. That is, the nitrous is sprayed in front of the MAF, which recognizes a sudden spike in O2 and signals the PCM, which decides the proper amount of fuel needed to balance the mixture. It is the cheapest of the setups to purchase. It also leaves no chance of fuel "puddling" in the intake. The weak point in this system is the car's fuel system. The dry shot is limited to the car's ability to increase fuel. Often a shot will find the weak spot in the fuel system, be it the injectors, the fuel pump, etc. Spraying N2O without the fuel to support it equals the kiss of death for your car.

Wet:
A wet shot does not rely on the car's MAF, PCM, or injectors to provide the proper amount of fuel to balance the mixture. It has a separate fuel line with its own jetting that is set up to spray the exact amount of fuel needed to go with the size nitrous shot you are using. In some cases, this may require you to step up your fuel pump, but you need not worry about your injectors. Some drawbacks are that with a separate fuel line and the fact that the spray is happening AFTER the MAF, any trouble with the system will go unnoticed by your PCM until it's too late. If your nitrous stops spraying but the fuel does not, then it will puddle and possibly introduce you to your hood-- the hard way... If the fuel side cuts out but the nitrous side does not, then you will go drastically lean and blow your motor. Threat of these things can be minimized. Buy GOOD parts, not the cheapest you can get away with.

Direct Port:
A direct port setup mixes the N2O and fuel, and directly injects the mixture into each individual cylinder. It is by far and away the safest and best way to use N2O. It does have one major drawback... PRICE. The direct port system by itself, can cost north of $1500. That does not include any of the supporting parts, that really are must-haves with ANY nitrous setup.


Accessories

Not just the base kit. If you plan on running N2O and would like your car to last more then just one or two runs down the 1/4, then you should compliment your base kit with the proper accessories. These include:

- RPM Window Switch: It will turn your nitrous kit off and on at preset RPMs, 1. so you don't spray under low RPMs, which can blow your motor; and 2. so you don't spray right into your rev limiter, same reason.

- Fuel Pressure Safety Switch: If your fuel pressure drops below a safe range while spraying nitrous, the safety switch will shut the nitrous off to keep from running the engine too lean.

- Bottle Pressure Gauge: It allows you to safely monitor your nitrous pressure from the passenger compartment.

- Throttle Position Sensor (TPS) Switch: Also called a WOT switch, it only allows your kit to turn on when you are at Wide Open Throttle.

- Automatic Bottle Heater: It will keep your bottle at the correct temperature and pressure to ensure that you are spraying the correct size shot. This is especially important in a wet shot setup, as the shot of fuel will not adjust to the lack of nitrous from a cold bottle.

- Purge Kit: This vents old nitrous left in the lines from the last time you sprayed, and keeps it out of your motor.


This is not everything there is to know about nitrous. It is only a quick, down and dirty introduction to entry-level knowledge that you should have before you go the N2O route.

(As a side note, it should be said that referring to nitrous as NAWS or NOS is a good way to get made fun of at the track, and could even get your *** kicked.)

jaberwaki

B. Heads/Cam


Heads and cams are like peas and carrots. They belong together, should be bought together, they rely on each other; so we will discuss them together.

In the beginning of this thread, we said the motor is a power-making air pump. Well, your heads and cam decide just how much air gets in, and how much gets out. Most often referred to as the heart of any race car, the head and cam selection is a huge factor in just how much power your pile is capable of making.


Just because you buy the biggest cam on the market, and the biggest-port highest-flowing heads on the market, does not mean that you will make a ton of power. It does not work like that. When purchasing a H/C package, you want a setup that is:
1. Matched to each other's strong points
2. Compensates for the weak points
3. Best suited for the displacement of your motor

1. Matched to each other's strong points:
Every head has its strong points and weak points. If you have a set of heads that flows particularly well on the intake side, then your cam selection should take that into account. If it has excellent port velocity, then your cam should again be geared to exploit that. For example, if your heads make the best flow at higher lift, then your cam should have the lift numbers to get it there.

2. Compensates for the weak points:
Like the strong points, every set of heads have its weak points. It is my belief that the cam should compensate for the shortcomings in your heads (since cams cost less). For instance, if your heads do not flow as well on the exhaust side, you may want to consider a cam that has a longer exhaust duration, to allow more time for the waste gasses to escape.

3. is Best suited for the displacement of your motor:
If you go out and purchase the biggest-port highest-flowing heads, and the most monstrous cam you can find, and slap it on your stock 346, what will you have? The baddest, fastest 346 this side of the Pecos, right, buddy? WRONG... you will have a over-priced, under-thought pile, that won't hold an idle, falls on its face, and never makes power in any usable power band. Good luck with that... What you want, is the highest-flowing smallest-port heads suited for your cubes, and a cam that makes the very most out of them.


I will not get vendor-specific. The choice, in the end, is still yours. I would advise that you ask a ton of questions, to a ton of sponsors, and go with the one that has the best results on hand, is willing to be up front and answer your questions, and puts technical information in words you can understand and will help you match a cam for your needs.


The subject of cams alone could fill this website to its brink. This is not a tell-all guide to buying a heads/cam setup; just some basic knowledge and tips that you should know before you drop $3000 on a H/C setup.

jaberwaki

C. Bolt-Ons

Bolt ons are any part that assists in the making of power, that does not touch oil. It is common knowledge that they are the starting point in modding your car, so the fact that you should complete your bolt-ons should go without saying. Let's look at some of them and what they do.

Lid:
A lid replaces your stock lid, which was designed with comfort, not power, in mind. Simply put, an aftermarket lid does not have the restrictive air silencing fins and baffle found on the stocker. It allows more air in, and is a "must do first or second" mod. A lid is a lid, don't ask which one is best.

Cold Air (Ram Air):
The factory placement of the lid is poor for two reasons: the amount of space that air has to get into the lid is minimal; and placing it right on top of the radiator all but insures that you will have hot air entering your motor. A cold air (or ram air) kit fixes both of these problems. Either drawing cool air from under the car, or sealing your factory ram air to the cool outside air. Both methods ensure that enough air is getting in, and that the air that gets in is not hot.

Headers:
Headers replace your stock exhaust manifolds. They assist in the evacuation of spent gasses from your heads. They do this two ways: 1. first, they are free-flowing, which is to say they do not restrict exhaust flow in the slightest. 2. being free-flowing is not enough - GOOD header designs take it one step further by creating something know as the "scavenging effect"; that is, the flow of one header primary as it travels to the collector, creates a void or vacuum in the other primaries, effectively sucking out the exhaust as it is released from the head. I have always preferred "steeped" headers, for this very reason. Steeped header primaries get larger as you move away from the head's exhaust port. This greatly increases the scavenging effect, and increases your power potential.

Underdrive Pulleys:
Most commonly the crank pulley; it is simply a smaller pulley. 1. The rotational mass of the pulley is less, and therefore lighter and easier for your motor to turn. 2. It effectively reduces the amount of power required to turn the rest of the accessories, much like shifting to a lower gear.

Electric Water Pump:
Following hand in hand with the underdrive pulley, the electric waterpump gives the motor one less accessory it has to turn, thereby freeing up a few more HP. Although there is debate as to how much, no-one (who isn't a moron) disputes that it does free up at least SOME amount of HP.

Manual Rack-And-Pinion Steering:
Along the same lines, the MRAPS gets rid of yet another accessory, thereby freeing up power. It also weighs considerably less then the stock power steering system.

Exhaust Systems:
While there is A LOT of bullshit that flies around the Internet about "this exhaust sounds better then that one", this post is not for posers who want to whine about rasp. The very best-flowing exhaust there is, is a true dual X-pipe or H-pipe setup, with or without bullet mufflers. The next best thing is a cutout in the I-pipe. No cat-back out-flows a cutout; no Y-pipe setup out-flows true duals. Period.

Intake and Throttle Body:
I put these together because much like heads and cam, they should be matched. Again all bullshit aside, the best is the LSX 90mm intake and a 90mm throttle body. They are very expensive. A cost-effective second place is the LS6 intake and a ported stock TB. Either of these two choices are worth it, and have been dyno-proven time and again.

jaberwaki

D. Short Blocks


When you're ready to play with the big dogs, it is time to refer to older wisdom: "There's no replacement for displacement."

I will not speak to which vendor, or even which short block, is best. But there are a few staples that any good short block should have:
1. be completely balanced and blueprinted
2. forged internals
3. warranty on craftsmanship


1. it should be Completely Balanced and Blueprinted
This means that every part of the rotating assembly has been weighed and made to be in perfect balance with like parts; for example, all pistons weigh exactly the same within a tolerance of +/- 1 gram. This ensures that the motor is not vibrating itself to death. A perfectly balanced motor will always make more power, all else being the same. Blueprinting means that every clearance and tolerance has been checked, rechecked, and documented for you on a build sheet.

2. it should have Forged Internals
Getting a new short block is something you do not want to have to do twice. Forged internals will last longer, withstand more abuse, and support more power. Do it once, do it right.

3. it should have a Warranty on Craftsmanship
This should not be a hard one to understand. If a company will not stand behind its product, then why would you?Do not be fooled by a vendor who says no-one gives a warranty on short blocks. Yes they do, and if that vendor will not, then find one who will. It should be noted on the side, that this does not, nor should it, apply to power-adder cars (nitrous, forced induction). Too many things can go wronge in a power-adder setup, to ever hold the motor totally responsible.


Having a potent short block will most definitely make you the guy on your block to beat.

Ensure that you have the short block built for your specific application. Most builders do not have cookie-cutter short blocks. They build yours for your goals. Are you looking to be a naturally-aspirated (N/A) monster? Then a 427 mill with high compression may be your best bet. Or are you looking to be king of boost? In that case, perhaps a bulletproof low-compression iron 408 would suit you best. Tell your builder what you want to do with the short block, and they can help guide you to the one best suited for you.

jaberwaki

Part III: Chassis/Suspension


Okay, you are ready, right? You now have a 500+ rwhp car, with a bulletproof drivetrain. You slap on your slicks and head to the track. On your first run, the track is cold. The 3rd amber lights, and you floor it.... What used to be your tires, is magically transformed into two pillars of billowing smoke. You lose to a cam-only F-body in the next lane.

Frustrated, the next time up you perform a burnout that John Force would envy. People in the stands, stand and cheer and whoop and holler. Determination furrows your brow as you stage. As the bulbs start to drop, you bring your rpms way up... 3rd amber, you peg it. Your teeth feel like they are going to fly to the back of your throat, your rearview mirror pops off and is only stopped by the cable holding it. The front tires head skyward as the track is lost from view for a brief moment. "Wheels up BABY" you scream in your head as you hit second and the track returns to view. You steal a glance at the next lane, the other car is WAY behind; you would look at him in your rearview mirror if it was still hanging properly. You cross the traps well in excess of a 120mph... WOOHOO!!! You hit the brakes and make the turn around. At the ticket booth, there is a older guy looking hard at your ride. As you pull up, he starts cussing you out... you get kicked off the track for the day. 10 seconds... no roll bar... DOH!!! You take your ***-chewing like a champ, only because he hands you that timeslip.

You take your car home... But after a week of driving, you start to notice the car pulling to one side... you get out and inspect. Sure enough, your brand new tires are worn BADLY on one side. What gives? Hey, remember at the beginning of all this, I asked if you wanted a twisted chassis? Well, congratulations, oh master of the clutch dump... You now have one. Hell, you didn't like your now-$80,000 car anyway, right? Yeah, let's keep this from happening too. And while we are at it, we are gonna stop that first race from being a loss too....

jaberwaki

E. Fuel Systems

We have talked a lot so far about air, so now let's turn our attention to the other half of combustion: FUEL.

Having a fuel system that will support the motor that you are building is paramount. What good is having a motor capable of making 700 hp, but being limited to 500 because your fuel system will not support any more then that? It is very hard to go overboard when planning your fuel system. Because it is adjustable and PCM-controlled, having more then you need is not a bad thing. Once you know how much HP it will take to run the timeslip you want, then that day start putting together a fuel system that will support that amount of HP.

As a general rule, you do not want your injector duty cycle to be over 80%. By the same rule, it is best that your fuel pump be able to handle 120% of the RWHP your motor is making. Add to that an adjustable fuel regulator, a fuel pressure gauge, and tuning to dial it all in, and your fueling department should be covered.


F. Forced Induction

Apology (no boost)

I will go ahead and extend my apologies; I am not including Forced Induction in this write-up. I am not one to write about things I don't have clue one about. I do not know enough about boost to make an informed write-up on it. However, plans next year have me building a boost car for a friend. Perhaps after that I will add to this.

So for now, that is all I am going to write on the subject of making more power in the LS1.

jaberwaki

Part II: Drivetrain

Chances are that you will never have your 100 shot blow the welds on your intake. And even though you could not get your dream car (you know, the 10-second Jetta), chances are that if you applied some of the above "power section" to your car, that your car, much like a caterpillar in a cocoon, is going to blossom and do something wonderful for you the first time you hook all that new-found power to the track on a sticky tires....

It's going to break. That's right chucklehead, it's going puke out parts of its drivetrain like someone threw a grenade under your car. Congratulations, everyone in the stands are now pointing and laughing as the stock Honda Civic with a "Type R" badge that you lined up with, goes on to whip your V8 with a hella fast 15-second timeslip. Don't you feel like the MAN?

Let's avoid this little mishap, shall we? In this next section, we are going to talk about your drivetrain: the parts that transfer your motor's power into foward motion. Since there are two types of drivetrains that come with LS1 F-bodies, we will talk about parts as they apply to each of these.

jaberwaki

A. Manual 6-Speed (M6)

First, let me congratulate you on buying the stronger of the two stock transmissions. With minimal changes, this tranny in near-stock form has been deep into the tens. And in built form, it has propelled an F-body to mid-9-second glory. Now for the bad news. You also possess the single most part-destuctive force known to civilized man. FACT. M6 cars break more **** in the drivetrain then most A4 boys ever dream about. To avoid this (as best we can), we are going to talk about parts that are made ultra-tough, just to stand in defiance to this cruel tyrant called the M6 tranny.


1. Clutch

It's time to man up and start giving your left leg a serious workout. Your stock clutch (yes, even if it's a Z06 one) is weak. It is the skinny guy on the beach that all the other clutches walk by and kick sand in the face of. It will NOT hold much more than stock HP, and it won't even hold stock HP for long on sticky tires. If your plans are to run 11s or faster, then you can forget those oh-so-cheap Stage 1 and Stage 2 clutches. I hate the term "stage" because people get wrapped around the word and forget to think about what they are really buying. So you wanna be fast? Well, you have two choices of clutches:

Twin Disk
A Twin Disk clutch is very strong; it will most definitely get you where you want to be. It will also do so while retaining a very comfortable pedal feel, and streetablility. Sound good? It is. However, as always, with the good news comes the bad. It is well over $1200 for a respectable twin. If you want that comfort, you've gotta pay for it.

Sintered Iron Disk
Wow, just saying its name makes it sound manly, doesn't it? That's because it is. It's a MAN's clutch. Little pansy boys, who like to complain about too much rasp or the clanks and rattles that solid end links make, need not apply. If you do not love the feel of a race car, then DO NOT buy this clutch! But, if you want a clutch that will kick your car in the *** and say "giddy the *** up pony!", then this is the clutch for you. Your reward for having *****? How does paying $400 less grab ya? Yeah, that's what I thought.

For information on how the clutch works, and the supporting hydraulics, please see my earlier write-up on this topic: https://ls1tech.com/forums/manual-transmission/156608-clutch-prob-post.html


2. Driveshaft

First things first, you need to say to yourself over and over and over again: "ALUMINUM IS FOR BEER CANS, NOT DRIVESHAFTS!!!" When it comes to driveshafts, I will stand on this statement every day and twice on Sunday. If your plans include a lot of power and sticky tires, then you have three choices for driveshafts.

Steel
Steel is real. Steel is strong. Steel is easy to balance. Steel is afforable. Can anyone guess what kind of driveshaft I have? Thats right, steel. Steel, however, is not perfect; it does have two troubles. 1. It is heavy -- against its
lighter counterparts, it does produce slightly more parasitic loss. 2. In the rare occasion that they do break, they take a lot of stuff with them.

Chromoly
Chromoly... without going into a chemistry class, think of chromoly as having all the plusses of steel, and add to that it weights about 50% less. So why doesn't everyone have one? Price -- ah yes, the almighty dollar. These things are very pricey.

Carbon Fiber
All right! A real use for carbon fiber, other then making ricer hoods! Carbon fiber is light, very strong, and looks GREAT. One major asset that carbon fiber has that the other two do not, is that in the rare case that it does break, the fibers splinter and crack into what is best descibed as a broom. This means that as you are hitting the brakes and your broken driveshaft is still spinning, it is NOT hurting anything else. Hell, it might even clean off a thing or two.


3. Rear End

Let's face facts. When the General was building the F-body, he put no thought whatsoever into the choice of the 10-bolt rear. This rear is not even strong enough to hold the stock HP, and is one of the first things to break when a new F-body racer heads to the track. In the case of the M6 tranny, please do not make a $2500 mistake. If you have spent a week on LS1tech, then you have heard the words "12-bolt" and "9-inch" when it comes to rears. If you have an M6, then I want you to forget the first of those. You are about to spend $2500 on a rear; do you really want to break it? 12-bolts are for automatic cars. They last a long time in an auto. But you own the sledgehammer of parts, the T56, breaker of rears. For you, there should be only one choice -- the mighty mighty 9-inch.


Rear end parts... Now that you have chosen the correct rear, it's time to pick the parts you want in it. Most every place that sells these rears will give you these choices.

Posi-Traction: The best choice for a car that will not see much track time but still wants a super-strong rear.

Detroit Locker:The best choice for a car that will see a lot of both street and strip time. It is more noisy than the posi, but it is also stronger.

Full Spool: So you got a RACE car, huh? Well, this is what you want. Full spool is the least street-friendly of the choices, but it is hands-down the strongest.


Axles: The simplest way to approach axles is: the more splines, the better.

Gears: This is mainly a matter of personal preference. 4.11s are perfectly streetable while also performing well at the track. Numerically higher gears lean more to track use; lower leans more to street cars.

jaberwaki

B. Automatic 4-Speed (A4)

Welcome to the wonderful world of the 4L60E transmission. Let me be the first to congratulate you on entering the world of the broken trans. The 4L60E is not the cruel tyrant on drivetrain parts that its M6 brother is. It is most definitely MUCH more parts-friendly. Too parts-friendly. So friendly, in fact, that it will break itself before it will break other parts. How noble... The problem is that it does this far too often, and even in full built form, this transmission is just NOT very good for real drag racing. Most in search of 10-second and quicker timeslips find that they are just not able to do it with the 4L60E tranny. They usually end up with a TH350, TH400, or 4L80 (the 4L80 being the only one of those which has overdrive).


1. Torque Converter

Selection of your TC is very important. It has much to do with how quick you come off the line, and your 60-foot. The general rule of thumb is: a 3200-3500 stall for the LS1 street/strip car. If you are gearing your car more for drag-only, then 3600-4400 will be more your speed.

Another important number you will see is STR. Without going into a math class, the STR of your TC is part of the torque multiplication that happens in your TC. The higher your STR, the harder your TC hits off the line. You wanna get that 60-foot down? Then get that STR up!


2. Rear End

Since you have the more gentle of the two trannys, the 12-bolt is all you need. Simply apply the same principles as the M6ers do for their 9-inch selection.

jaberwaki

A. Chassis Parts

To keep your chassis happy at this power level, it still only takes a few pieces.

Sub-Frame Connectors
SFCs are nothing more then mild steel or chromoly bars that are welded to both your front and rear subframe. This will greatly minimize chassis flex, and will also assist in the lifting of the front when you launch. They really are one of the first five mods you should do.

Roll Bar/Cage
Under the incredible stress from a drag launch, a roll bar/cage will go one step further in adding to chassis strength. But that is not the reason you install it. You install it to save your life if something goes wrong at the track and you find yourself riding on your roof at 100 mph. Oh yeah, and it will help you avoid getting kicked off the track. If you run faster than 11.49 seconds, then you need a roll bar. Faster than 9.99, then you need a full cage.

K-Member
This part is not so much about strength as it is about losing the weight that your other chassis mods added. You want your car to be strong, but you also want it to be light. This part will more than make up for the extra weight.

jaberwaki

B. Suspension Parts
To keep your tires planted to the ground, you need to upgrade your suspension.

Shocks
Shocks control the up and down motion of both the front and back of your car. Ideally in a drag race, you want your front shocks to allow the front to rise very fast, but to come down slowly. Your rear should assist in transferring weight at first, and then push the rear end toward the ground as forward movement begins. You need adjustable shocks to do this. It would be better to have two-way adjustable shocks if you can.

Springs
Your front springs should be weight-specific. If your car is heavy, then you want a stronger front spring to assist in bringing the front of the car up. If your car is a tin can, then you can go lighter on the front springs. For a stock weight car, I would go with a 300lb front spring; for a really light car, 275lbs should be plenty. There is some debate over the rear springs. Many have gotten their best times on stock rear springs; others use what I use, V6 springs.

Lower Control Arms
LCAs are very important for several reasons. They control wheel hop -- the violent bouncing of your tires as they try to grab traction. And as weight transfers from the front to the back, the LCAs apply downward pressure to the axle housing, planting the tires and aiding in traction.

Torque Arm
The TQ arm does a few vital things for your whole setup. 1. It (along with the LCAs) is the pushing point for your rear end. 2. It acts as a ladder system to assist in weight transfer. 3. It can affect and change the pinion angle of the driveshaft as well. If you intend to race a lot, then you want a chassis-mount torque arm, not a tranny-mount torque arm.

Rear Sway Bar
As the power of your motor is translated through your drivetrain, it create a natural torque to one side; that is, the body tries to twist to one side. A drag solid-end-link rear sway bar, will combat this effect and assist you leaving the line straight and true.

Pan-Hard Bar
As power is sent violently to your rear, the rear end has a natural tendency to move side to side (known to some as the traction shimmy). Your pan-hard bar combats this. If you get an adjustable one, then you can also use it to center your rear end.

jaberwaki

Well, boys and girls, that's about it for the basics. This write-up does not make you an expert by any stretch of the imagination. It does, however, give you a base of knowledge for what it takes to be fast. As you can see, it's much much more then just making a lot of power.

300bhp/ton

A simple mod guide for beginners – what to do first

So you’ve bought an Fbody, but it’s still not enough. Well it’s time to start modding then isn’t it!

First off, what do you want from the car?

-Drag
-Circuit
-Street
-or a combination?

What you decide upon should dictate which mods to do and in which order. Remember be realistic with your goals and you’ll end up with the car you want.

This is a simple guide for making a faster street car which will see some ¼ mile action. Of course there are many variations and alternatives (too many to cover in this post). However following this guide will make your car faster, more fun and sound better. And hopefully help avoid wasting time and money on mods which are not needed and show little results.


1. Ok then your first mod. This is always open to debate, however I see two options as the only sensible choices. We’ll start with the cheaper one.

LID – quite simply replace it with an after market one. “What is a lid?” I hear you say. Well it is basically what it says - it’s a lid! The top of the air intake box. After market ones are smoother inside and do not have the factory sound baffles.

Why? – It’s fairly cheep (~$95 new) and will improve throttle response and increase BHP.

Which one? – Any, a lid is a lid. Some fit better and some look better but that’s about it.
-MTI
-SLP
-TSP
-Whisper

To name a few. Check out the sponsors’ on the left --->

The stock paper filter is fine up to about 500bhp and will filter better than any of the foam or cotton weave ones. So there is no need to get an after market filter if you don’t want to. If you do, then you might see a very small gain. But for the cost of a K&N filter the $/HP ratio is not too great.


2. Mod number two.

EXHAUST – Either as a catback or combined with headers and new mid pipe. Let your wallet decide.

Why? – Increase BHP and throttle response and still represents good value for money in the $/HP game. Also an exhaust has the GRIN factor, there is as much justification for getting one for the sound alone.

Which one? – Basically any. But remember a freer flowing exhaust will show more potential once HP levels start to get serious. If you plan on keeping the car then stainless steel is worth considering. There are lots of choices, however these seem popular:
-SLP Loudmouth
-Hooker Aero chamber
-GMMG
-Magnaflow
-TSP Rumbler
-Stainless Works chambered exhaust

For sound clips why not try www.ls1sounds.com

True duals always seem to hold an allure. There are several kits out there, many dump before the axel so they will be very LOUD, you have been warned. Custom kits can be made by exhaust shops. However if you’re going to the trouble of duals, you might as well do the headers at the same time.


3. For the AUTO guys only

STALL – This is often an over looked mod, but can be worth quite a bit at the drag strip.

Why? – It allows you to hold the car with the foot brake at higher rpms. This means you can launch the car better improving ET’s. It can also improve in gear response as well.

Which one? – This is a very big debate. Be realistic here, as a stall to inclined for track use will just be a pain on the road. Speak to the sponsors and other members here and see what they are running. Makes include:
-Yank
-Fuddle
-TCI


4. Now we’re talking.

HEADERS & MID PIPE – These are the exhaust manifolds and the exhaust that goes between them and the rest of the system.

Why? – The stock manifolds are cheap mass produced items. They do not flow particularly well and do not promote scavenging. So aftermarket Long Tube headers will increase BHP and once again throttle response. The stock mid pipe is also very restrictive along with the stock CATS. Basically they need replacing.

Which one? – There are 3 main types of aftermarket header. Shorties, mids and long tubes. Unless you have a specific reason for the shorties or mids. Get the long tubes. They all offer similar gains, but the more you spend the greater potential they have once you start getting serious about your mods. Once again stainless steel is worth considering, if not that then coated is an almost must. Brands that seem to be well respected are:
-Pacesetters
-Jet Hot
-Hooker
-QTP
-Kooks
-Stainless Works

There are many others however, so a little SEARCHING and research will go a long way.

The mid pipe is in many ways more of a complex choice. If you are running an off the shelf catback you’ll be wanting a replacement Y pipe. 2.5” diameter will be fine for most mild setups and some people have seen very impressive numbers, however it’s flow rate is a little restrictive for a 5.7 litre V8. A 3” Y pipe is probably a better bet and will be fine with up to 400-450bhp. After that you are onto 4” Y pipes, these are very bulky and can have serious ground clearance issues. Now to the CATS, if you like you can remove them and run a OR/Y, or Off Road Y pipe. Remember this is illegal for road use, so only get one at your own risk. Catted Y pipes are available from most of the headers makers as well as a few others. They will cost a bit more but they will keep you legal. Normally the removal of CATS will see some HP gains, but they are likely to be minimal on most setups. There are some free flowing high performance CATS that will have next to no effect on HP, so they are certainly worth considering.

If you decided on duals then you’ll be wanting either a H pipe or an X pipe. Both basically do the same thing. The X should offer a little more high rpm HP and the H a little more low rpm torque. They also have a slight difference in sound between them. And yes you can still run CATS with a dual setup.


5. Now comes decision time. Either try and get more BHP from the engine, or improve the rest of the car? Remember deployable HP is often more important than dyno numbers.

FINAL DRIVE GEARS – These are the gears in the rear axel. The higher the number the faster the car will accelerate, in simple terms. However maximum speed in gear will be reduced, so cruising MPG will usually drop, and interior noise may increase, because you will running higher rpms.

Stock ratios:
Automatics 2.73:1
Optional automatic 3.23:1
Manuals 3.42:1

Why? – Because they should knock up to 0.5 second off of your ¼ mile ET.

Which one? – There are lots of makes, most are high quality but some are more renown for being noisier than others. Check with the sponsors for available brands.

3.73:1 and 4.10:1 seem to be fairly well accepted. Especially with the manual transmission cars. Remember with an auto you only have 4 gears, so a set of 4.10’s will severely increase your cruising RPM.

N.B. There is one issue with gears. And that’s the weak 10 bolt rear axle. If you continue to mod – it will break and need replacing with a stronger alternative. At which point the gears you bought for the 10 bolt are redundant. If you think a stronger rear axle is in your future maybe stick with the stock gears until then.


6. This is for the Pre 2001 cars only.

INTAKE MANIFOLD – From 1998 – 2000 the Fbody used the LS1 style intake manifold, from 2001-2002 the LS6 type manifold was used.

Why? – The LS1 style intake is quite restrictive in comparison to the LS6, by swapping it over you will see gains in BHP and better throttle response. If you already have an LS6 style intake manifold then there is no real reason to change it yet.

Which one? – There are many aftermarket intake manifolds. However for the cost the LS6 style one probably represents the best value for money. They can be bought new or seconds hand. GM Performance and SLP both offer it with the EGR fitment so it can be a direct swap over. Some of the other aftermarket intake manifolds will require a larger TB and other supporting mods. There really is little point in going this far unless you are doing more serious mods such as forced induction or a more aggressive cam and better flowing heads. They will produce gains on a lesser modified engine but the $/HP ratio will be far lower.


7. More air in = more BHP

THROTTLE BODY – Now you have improved the rest of the induction system and the exhaust system it is worth looking at the TB. The stock unit is not too bad, but as always improvements can be made. You have two choices:
-New bigger TB
-Ported stock one

Why? In theory a bigger TB should help, however they are quite expensive and will often show only minor gains on a still mildly modified engine. Also there have been reports of people having trouble with some of them. The better bet for most is a ported stock TB, these will show gains in HP and most importantly have a dramatic affect on throttle response. Often the throttle response gain will be better than a stock larger aftermarket TB although the HP gains will probably be similar. But the price will be a lot more wallet friendly.

Which one? Well you can do it yourself or there are several people who will do it for you. Check the sponsors and have a SEARCH around the different forums.


go to part 2

300bhp/ton

8. By now you will have made a massive improvement in engine BHP and also how that power is transmitted to the rear wheels.

TUNE – This is often the most over looked modification. However it is one of the most crucial. You can have a tune at anytime, including stock. However it is often worth doing it after a series of mods, especially if no more mods are planned in the immediate future.

Why? - As it will yield extra HP, improve driveability, potentially improve MPG and ensure that everything is working and is safe.

How? – There are many options in terms of handheld tuners and chips. These all ‘can’ work, but are by no means the best option. Proper computer software is the best option combined with a rolling road (often called a ‘dyno’). This way all variables can be monitored, altered and maximised. Many dyno shops will already have tuning software, however they are available to buy and are not stupid money. Plus they can then be utilised in the future if more modifications are performed.


9. By this time you car will be a totally different beast on the road. So other ‘supporting’ modifications should really be looked at. The stock brakes and suspension are pretty good, but they where only designed to handle less horse power. Upgrades in these areas can be done at anytime and will only ever be a benefit.

Shock tower braces and control arms will all help. As will safety devices like driveshaft hoops which are often mandatory at many ¼ mile drag strips.

In addition different wheels and tyres such as DR’s (drag radials) or Street ET’s can be used. Both will improve grip and lower ET’s however both will apply more stress on the drive train and probably put you one step closer to needing a stronger rear axle.

There are also lots of additional mods which may improve the car as a whole but will not necessarily yield any BHP or improved ET’s. These would include shifters for the manual guys and CAGS override to prevent the skip shift activating. Along with transmission coolers for the automatics and additional dials and gages to monitor fuel pressure, air intake/oil/coolant temps and so on.

Things to avoid, or at least to research first:

FREE MODS – There are plenty of these for the Fbody. Some are worth while, most probably aren’t. People often claim “well every bit helps”. But does it?
-TB bypass
-!AIR
-!EGR
-De-screening the MAF

And several of the others will be unlikely to produce much or any additioanl HP. There are other reasons people do them however. So do a search and check it out if you’re interested. However leaving them be will not be any major cause of alarm.

MAF - The stock MAF will be fine for most people and does not need replacing or anything doing to it. 500bhp should be no problem for it. Replacement MAF’s are not cheep and can cause problems. Only go down this route if you know what you are doing.

SMOOTH BELLOWS – Not really going to affect anything. The principle behind it may be sound, but in all reality talking you shoes off before getting in the car will likely have the same effect on performance. If you want to do it, then the ‘Fernco mod’ is an option, or just buy some ducting (silicon or flexi-tube) and do it yourself for only a fraction of the price.

CUT-OUTS – These are a great cheap way of by-passing the stock exhaust and will see some good gains in HP and a lot more in noise. However, if you buy a good catback and do the headers & mid pipe the gains will then be minimal, maybe even as low as 1-2HP. You then also have the issue with possible leaks and restricted ground clearance. If you plan on any exhaust mods give a second though to buying cuts-outs.


CLIFF NOTES:

1. Lid
2. Catback exhaust
3. Stall (auto only)
4. Headers & Mid pipe
5. Rear gears (optional)
6. Intake manifold (pre 01 cars)
7. Ported Throttle body
8. Tune


go to Part 1