What are some good ways to make the L98 crank out some more power? THe stock motor is a bit of a slug. I'm leaing towards motor mods rather than other things
thanks

 

ok, there's a whole slew of things to do... But first we gotta get some things straight
1.) What year vette is this?
2.) Stock Motor? Any mods to anything at all?
3.) Manual or Auto Tranny?
Answer those three and we'll go from there.

 

Check out the "Results of L98 Mods Data" on my site, link in sig. below.

The data is taken from a magazine article some years ago and shows what you can expect from various mods to a TPI motor.

 

:crazy:
What is your definition of a slug? What year is your car?
If it is a slug,, you probably need to rebuild the engine, I t probably hasnt been taken care of..........IMO :nonod:

 

Intake, cam changes to an 89 will wake it up. The stock intake is too restrictive for a 350. So replacing with a Miniram/StealthRam/Superram is your best bet for any serious HP. If you like the stock look though, Joe90 and Vic89 have excellent setups, run a search.

Then the cam needs to be changed, stocker is too short in duration. Of course some valvetrain work has to be done when you change cams.

Then the exhaust, the stock exhaust manifolds are just as bad as the intake manifold, and headers are the only good way to fix it.

Costs ALOT of money, especially if you cant do all/most of the work yourself.

 

If you think C4's L-98's a slug, try driving a stock C3 :lol: At least the C4's benefit from better gearing and fuel injection.

When attempting any modifications, it's best to take a balanced approach. There are few majic pills, one restrictive part that, if removed or modified, will wake up the car. Instead, you need to look at the entire system and understand that it's only as good as the weakest link. Then, realize that the engine is a giant pump, and the more efficiently you can make it pump, the more power you'll make.

That said, as pointed out above, the exaust and intake are great places to start. Then the heads and cam. But watch out. Because if there is one thing the stock L98s do well, it's make good power and torque down low, where you can use and feel it. You can end up with better overall horsepower numbers, but you run the risk of achieving them at a higher RPM, where the power isn't as easily felt.

My C3 for instance, makes a lot of power up high. At 3000 RPM, it feels like a switch is hit, as the engine gets on the cam. Up until 3000, it's peppy, but that's not where the power lies. And it's nowhere as fun, around town, as my C4. Of course, this is as much a function of my C3's weak 3.08 gears.

Which brings up another point: For seat of the pants difference, it's hard to beat swapping out gears, if you're not opposed to a slight fuel mileage penalty.

Ultimately, my advice is this: If you can afford it, pull the motor, tear it apart, and have it gone over by a competant machine shop. Then, sit down, think about your priorities, and build a motor with advice from the people here. They know what works and what doesn't. Also, if your cars are subject to emissions regulations, as mine are, that is something else to consider.

Crate motors are another excellent way to go, with plug and play performance at a cost that is comparable to doing the job yourself. But in the case of the crate motor, you have GM expertise and a warranty to boot.

Good luck with it.

:cheers:

 

I think the stock motor TPI is kinda peppy.

It has very nice street matters and is Torquey.

Vic