L98 upgrade quest
#1
L98 upgrade quest
Hey I have an 89 trans am..I just bought a L98 out of a 89 gta with 75k. While I have the engine out I wanted to know what parts need to be upgraded and what part to buy to achieve high torque and 350 plus hp...also wanted to swap in a manual and would a built T5 hold or should I go T56?
#2
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Car: 87 GTA flame red
Engine: 5.7 l98 cranes 2032 and chip
Transmission: stage 10 700r4
Axle/Gears: 3.27 axle
Re: L98 upgrade quest
do cam and at least porting polish of the heads and go with the t56 much stronger
#4
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Re: L98 upgrade quest
Intake - depends, but you don't have to.
You said 89 L98 engine, so that would be a roller cam.
There is a link in my signature to a very good cam designed specifically to work well with TPI.
You will either need to get the stock L98 heads reconditioned and modified/upgraded for more valve lift, or replace the heads with aftermarket high-performance. Which, depends on your budget.
You can get 350 hp from your L98 the hard way (read - expensive), or you can keep things simple and use a power adder like a N2O system along with a few supporting modifications.
If you're going to use the stock heads, then they will need new guides, the guide tops trimmed for more valve lift (bigger cam), a 3-angle valve-job, and probably a light resurfacing. For power gain you will want to have them ported.
There is information in my signature about economical valve & spring upgrading while reconditioning factory heads.
If you're going to be using a 0.038" fel-pro type head gasket, then you'll probably want to get your block decked to eliminate the factory 0.025" piston-to-deck clearance, or you would end up with too much clearance and lose compression in the process. Otherwise you want to stick with a 0.010" steel shim head gasket. It's cheaper but you have to get the block surface extremely clean to ensure it will seal, and it may limit you a bit on total power with a power-adder.
Either way you go you will want an effective exhaust system.
I always recommend stainless headers and cat-back systems. I think Dyno-Don's headers are one of the favorites around here.
If you're planning to use any kind of power adder, then get the larger 1.75" primary headers and 3" collectors.
Basically, useful suggestions for your power goal are the typical: heads, cam, exhaust, and maybe a power adder.
Some people prefer to go: aftermarket heads, much larger camshaft, and a larger intake system like the Holley Stealth Ram.
It will come down to your preference and budget.
If you wanted to keep things extremely simple you could reach your goal with just headers/exhaust and a simple N2O system.
You said 89 L98 engine, so that would be a roller cam.
There is a link in my signature to a very good cam designed specifically to work well with TPI.
You will either need to get the stock L98 heads reconditioned and modified/upgraded for more valve lift, or replace the heads with aftermarket high-performance. Which, depends on your budget.
You can get 350 hp from your L98 the hard way (read - expensive), or you can keep things simple and use a power adder like a N2O system along with a few supporting modifications.
If you're going to use the stock heads, then they will need new guides, the guide tops trimmed for more valve lift (bigger cam), a 3-angle valve-job, and probably a light resurfacing. For power gain you will want to have them ported.
There is information in my signature about economical valve & spring upgrading while reconditioning factory heads.
If you're going to be using a 0.038" fel-pro type head gasket, then you'll probably want to get your block decked to eliminate the factory 0.025" piston-to-deck clearance, or you would end up with too much clearance and lose compression in the process. Otherwise you want to stick with a 0.010" steel shim head gasket. It's cheaper but you have to get the block surface extremely clean to ensure it will seal, and it may limit you a bit on total power with a power-adder.
Either way you go you will want an effective exhaust system.
I always recommend stainless headers and cat-back systems. I think Dyno-Don's headers are one of the favorites around here.
If you're planning to use any kind of power adder, then get the larger 1.75" primary headers and 3" collectors.
Basically, useful suggestions for your power goal are the typical: heads, cam, exhaust, and maybe a power adder.
Some people prefer to go: aftermarket heads, much larger camshaft, and a larger intake system like the Holley Stealth Ram.
It will come down to your preference and budget.
If you wanted to keep things extremely simple you could reach your goal with just headers/exhaust and a simple N2O system.
#5
Re: L98 upgrade quest
I have a little money to spend...I really like that HSR.... would that work with the L98 heads or what aftermarket heads will work better? Also what cam will work well with that combo
#6
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Re: L98 upgrade quest
Start looking for aluminum heads with intake ports in the 170 to 180cc range, and combustion chambers in the 64cc range. Things like fast-burn chambers, angle-plugs, and wet-flow technology are advantages to look for in a head.
When looking at head port flow numbers look for strong flow at 70% to 80% of your planned maximum valve lift.
The HSR has a runner length/size around the same as an RPM air-gap intake manifold. The cam in my signature will work just fine for that as well. If you use a bigger cam you will start running into more difficulty with getting the tune correct.
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#8
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Re: L98 upgrade quest
the link that says camshaft :
http://www.lingenfelter.com/mm5/merc...egory_Code=C30
do you have signatures turned off?
http://www.lingenfelter.com/mm5/merc...egory_Code=C30
do you have signatures turned off?
#10
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Car: 91' Firebird SOLD
Engine: 350 TPI +bolt-ons
Transmission: 700r4
Axle/Gears: 3:42
Re: L98 upgrade quest
That cam will not work with stock valve springs. I would personally go the vortec route. Vortec heads and Scoggin Dickey Tpi lower intake. Supposed to guarantee 300 hp.
#11
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Car: 91' Firebird SOLD
Engine: 350 TPI +bolt-ons
Transmission: 700r4
Axle/Gears: 3:42
Re: L98 upgrade quest
Probably only cost about $700 to go the Vortec route.IMO, boost is where it is at.
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