Small Block & Big Block Chevy Specific - Any L98 TPI Experts?

Few basic L98 questions. I'm about to pick up a 93 LT1 and a friend is selling his 86 Corvette. 100K miles, auto, Black/Black... Wants 4K. Should i say fuck the camaro and go with the vette? How hard is it to mod a TPI vette? Can i make good power with it? Does the L98 need some special heads or can any SBC head be used? Thanks

All it really comes to is preference between the two cars. Would you rather say you own a Camaro, or a Corvette? Which one do you think looks better? Drive both, which one will drive and handle better for YOU?

If you're looking for something simple to to tune up and play with, have basic mods to go fast, the Vette is a good choice. It is still Gen I SBC and doesn't require anything more than basic parts to work on, and parts are plentiful and cheap. The L98 in the Vette is also 4 bolt main VS the F-body's 2 bolt main LT1.

The LT1 will also have the opti spark which can be costly to replace for someone on a budget, and is Gen II SBC. With basic mods such as full exhaust, changing the intake runners and intake manifold on the TPI with some home porting on the TB and Plenum, along traction will net you into 13 second time slips for sure. TPI is also the king of street light to street light racing with it's low end TQ.

Modding an L98 is no different than making any other SBC 350 go fast, you just have to remember that it's RPMs are limited to well below 6,000. So don't go buying parts trying to rev to the moon. STOCK, the TPI intake starts losing power around 4500 and is what I'd call dead by 5. Doing what I mentioned above will help you make power to 5K instead of it dieing 500RPMs sooner.

Either way, you're making a good choice though, so don't stress.

PS, the 93 F-body is not the most sought after of the 93-97 cars. It is the only year that the F-body didn't have an electronically controlled transmission (4L60-E) and it also uses Speed Density instead of MAF.

PS, the 93 F-body is not the most sought after of the 93-97 cars. It is the only year that the F-body didn't have an electronically controlled transmission (4L60-E) and it also uses Speed Density instead of MAF.

The 93 is also batch fire instead of sequential (came out the following year). Also is a chip car, same as the vette.
The Vette you can swap the TPI for a mini ram, and get close to the perf of the 93. Mini rams are pretty expensive, but if ya wanna make power with a L98, thats the way to go.

But a Holley StealthRam can be had for about $530 with fuels rails and regulator.

But a Holley StealthRam can be had for about $530 with fuels rails and regulator.

Yeah, but they dont fit under the stock hood. So add in the money for a new hood, and the miniram gets more appealing

Yeah, but they dont fit under the stock hood. So add in the money for a new hood, and the miniram gets more appealing

I forgot it dont clear the on the vette's.

I would go with the Vette. I like the old school TPI's. They do have their limitations, but eh. The 1st v8 I ever had vas 86 Iroc with the old ass TPI. They are realy easy to work on. Also the 93 is that Damn Opti Spark(I think).

I'm going to test drive the vette tomorrow so we'll see.

EDIT : Does anyone know of any guide to modding the L98? What are the biggest heads you want to run? 195cc? Summit has some nice LT's for the C4 for cheap. Also a lot of parts for this car are really fucking cheap.

Also.. What would a 383 L98 put down?

I had a 383 L98 in my old thirdgen I used the LPE Superram intake, LPE cam, and some home ported GMPP Corvette heads. I would choose the mini ram if I could do it all over again though. It was a torque monster but didn't make much hp. I say get the Vette and do an LS1 swap down the road.

pretty much the modding can be aftermarket runners and throttlebody.even larger injectors.i had built a tpi for my throttlebody 3rd gen.with the 86 you have a mass air flow system insted of speed dencity.that to me is best.speed dencity is harder to tune and i din't have the stuff to swap to mass air flow.if you are on a budget i would start with headers and work your way up.larger runners,injectors,adjustable fuel pressure regulator and throttlebody.my old setup had a standard bore 350 with slp runners,bbk adfpr,bbk 58mm t/b,ported plenum and intake and stock injectors.it ran a 8.30 in the 1/8th.pretty decent considering how much a 3rd gen weighs.of course i had aftermarket heads and a lt4 hotcam.you already have a set of heads,or are supposed to have,on the l98. they had the aluminum heads that are used on the zz4 engines now,that pump out 355 hp.i would go with the lt4 hotcam myself if it was my car.and yes it will fit in 1st gen sbc.unless that car doesn't have a roller cam from the factory,then you couldn't use it.then again,why not just buy the zz4 engine and add larger tpi stuff to that.

i like tpi - own a 90 and 85 vette. they are good at lower rpms, but the way i figure it is how much of my driving is over 5000 rpm? for me probably .001 percent so I don't worry much about it understanding the limitations of the motor. it is a cool cruiser and a lot of people look because it is a vette.

What heads are on the Corvette? Half way through 86 they switched over to aluminum heads. And while GM only rated them like 10HP more, they run MUCH better with the aluminum heads!

What kind if heads are too big for the TPI? Are Edelbrock Victor JR's too large for it?

If everything else is left stock, then yes absolutely. The biggest limitation of the L98 engine is the TPI intake. It just refuses to breathe above 5000RPM. You need engine components that are designed for that powerband of 1000-5000RPM. Upgrade the intake to something better like a MiniRam, SuperRam or StealthRam (may require hood modifcation on Vettes) and you just build it like any other SBC 350.

If everything else is left stock, then yes absolutely. The biggest limitation of the L98 engine is the TPI intake. It just refuses to breathe above 5000RPM. You need engine components that are designed for that powerband of 1000-5000RPM. Upgrade the intake to something better like a MiniRam, SuperRam or StealthRam (may require hood modifcation on Vettes) and you just build it like any other SBC 350.


Thanks marc. I'd consider doing the stealthram and some hood modifications.

with my ported stock plenum and lower intake my car still pulled over 5000 rpms.but that was me.i liked the power of the tpi system.but i like my carb setup even better.lol

I have my '87 corvette running high 12's with only exhaust and an old used blower! :)

How hard is it to mod a TPI vette? Can i make good power with it?

Go with the C4-Corvette, not hard to mod at all, Click Here (http://challengevideos.com/event5/JD/doutten11.28.115.mpg)....; ;)