LS1TECH - Camaro and Firebird Forum Discussion

Camaro and Firebird: Intake Manifold Reviews and How to Replace

Replacing the intake manifold can increase your Camaro or Firebird's performance tremendously, and also make it sound better.

By AJ Mawley - April 11, 2016

This article applies to the Camaro and Firebird (1998-2002).

Replacing the intake manifold with an aftermarket one allow your Camaro or Firebird to breath more air into the engine, which results in an increase in performance. Having a less restrictive intake path allows the engine to work less getting the air in, which results in less gas consumption, too. Another benefit to replacing the intake manifold is how it makes your car sound; you can expect a nice intake roar to your car instead of the whisper from the factory unit. Swapping an intake out is not easy, but the results are immediate and well worth the effort.

Figure 1. An intake manifold.

Table of Contents

How to Replace Your Intake Manifold

Camaro and Firebird: How to Replace Intake Manifold

Materials Needed

  • Phillips screwdriver
  • Flat head screwdriver
  • Metric socket set
  • T-20 screwdriver

Step 1 – Remove airbox lid

To remove the airbox lid, you have to remove the two sensors attached to it first. Remove the MAF sensor and the air temperature sensors by pulling their tabs and pulling them out. Then release the two metal clamps on the front of the airbox lid, by the grille. Loosen the worm screw attaching the tube to the throttle body. Pull the lid out towards the car to remove.

  • Release metal clamps
    Figure 2. Release metal clamps.
  • Disconnect sensors
    Figure 3. Disconnect sensors.

Step 2 – Remove throttle body

Before removing the throttle body, you have to first remove the throttle cable. Slide the throttle cable back, as it would move if you were stepping on the gas pedal, then pull cable out, away from the throttle body. Unplug and remove the two electrical harnesses connected to the throttle body, then use your T-20 Torx driver to unbolt the throttle body from the intake.

Throttle Body Removed
Figure 4. Throttle body removed.

Step 3 – Prepare to unbolt intake manifold

Next, remove the EGR pipe on the top of your LS1 manifold, which comes off my removing the 8mm bolts holding it on the manifold. You will need to remove the EGR tube from the driver's side exhaust manifold and passenger side head. Then, disconnect all eight fuel injector connectors by simply unclipping them from the injectors. Remove the big rubber vacuum hose from the intake to the brake booster, then remove the rest of the miscellaneous hoses and connectors on the front of intake manifold.

Figure 5. There are eight injector conectors which clip on (red circle).

Step 4 – Remove the intake manifold

Now, simply unbolt all eight 10mm bolts from the top of the intake manifold. Move the manifold slightly and disconnect the sensor as well as the small vacuum hose on the back of the intake manifold. Once those are free, slowly lift up on the intake and pull it towards, but be careful of the still connected fuel rails. Remove the four 10mm bolts holding the fuel rails on and pull up on the fuel rails to remove the injectors from the intake. If the injectors have never been taken out before, you may have to tug pretty hard to get them to come free from their ports. Now the intake is free from the engine and can be completely removed.

Intake Removed
Figure 6. Stock intake removed, leaving room for new high performance parts.

Step 5 – Install new intake

Now, follow the manufacturer's directions on installing your new intake. The basic steps will be the same for all of them, such as inserting and bolting down the fuel injector rails, and bolting the manifold back on. Proper torque and not over-tightening is very important, especially for composite manifolds. Torque the intake manifold bolts to 7 ft/lbs in the sequence shown below. Reconnect all hoses and connections that were removed. That's it, now you can enjoy that instant power boost!

Intake Torque Pattern
Figure 7. Intake torque pattern.

Intake Manifold Review

Due to the popularity of the LS1 engine platform, there are many great options for upgrading the look and performance of the intake for your application. Depending on the rest of your engine combo, you will want to strategically choose your intake inlet diameter and throttle body size to take into account any future power needs. Check out some of the most popular options below for your LS1 intake.

LS6 OEM Intake
FAST 90/92mm
FAST 102mm
MSD Airforce
Edelbrock Pro Flo XT
Price
 $300-400 (used) $900 $900 $900 $630
Ease of Install
 Easy Medium Medium Medium Hard
Usage
 Great for most stock displacement motors Great for all stock displacement motors Great for larger displacement motors Great for stock and larger displacement motors Great for boosted motors
Gains Over LS1 Intake
 20-25 rwhp 25-35 rwhp 25-35 rwhp 25-35 rwhp Depends on boost
Warranty
 No warranty Limited 1 Year Limited 1 Year Limited 1 Year Limited 1 Year
Best Quality: FAST 102mm

Best Value: LS6 Intake

LS6 Intake

Price – $300-400 (used)

Ease of Install – Easy

Usage – Most stock cubic inch LS1's

Power Gains – 20-25 rwhp

Warranty – None

The LS6 intake is the most common budget friendly upgrade for LS1 owners. It provides a great power upgrade while maintaining a stock look, and tuning it is easy. Also, quality control is great, as it is a GM factory part. However, you will have to settle for a used intake since new LS6 intakes are no longer in production.

FAST 90/92mm and 102mm

Price – $900 + new throttle body

Ease of Install – Medium; a new throttle body is needed.

Usage – Most stock cubic inch LS1's and wild builds

Power Gains – 25-35 rwhp

Warranty – Limited 1 Year

The FAST intake is the best selling aftermarket LS1 intake for a good reason. It provides great fitment and a nice improvement over an LS6 intake. However, this comes at a cost. A new intake and throttle body is about $1,300 and you will not see much of a gain over an LS6 intake unless you also have aftermarket heads/cam combo. Also, note that you can get this intake in two flavors, the 90/92mm throttle body size and the 102mm. The 102mm works well on all engines and is the most common choice for upgrades nowadays.

MSD Airforce Intake

Price – $900 + new throttle body

Ease of Install – Medium

Usage – Most stock cubic inch LS1's and bigger cubic inch engines

Power Gains – 25-35 rwhp

Warranty – Limited 1 Year

The MSD Airforce is the hot new intake that only hit the market in 2015. Its main goal is to compete with and make more power than the popular FAST intakes. Most dyno tests show a small improvement over a FAST intake. However, there have been some fitment and hood clearance issues, so look out for those. This intake will also require a new throttle body.

Edelbrock Pro Flo Intake

Price – $630

Ease of Install – Hard; you will need to notch your cowl and get a new hood.

Usage – Boosted applications

Power Gains – Depends on boost level

Warranty – Limited 1 Year

The Edelbrock Pro Flo is the intake you will most likely see under the hood of a high HP boosted LSX engine. Due to the tall runner and other design cues, this intake is perfect for boost, but not the best for naturally aspirated applications because you will lose lower end power. Also, keep in mind that this intake will not fit under the stock hood and will require cutting the car's cowl around the intake. This intake is recommended for high HP race applications only.

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