performance options for L98

**sledog** · 11-23-2005, 08:14 PM

i have a L98 that is making some bad noises, I suspect a spun bearing. I want to do some performance upgrades to the engine while out of the car. I have convinced myself to stroke the engine, but that is about it. Does anyone have any recomendations? I still want the car to run on pump gas, I plan to use the car as a daily driver so nothing to wild but something better than stock. Any suggestions would be greatly apreciated. BTW the car is a 89 corvette convertable. Thanks Guys!!

**91Z28** · 11-23-2005, 09:01 PM

Ditch the stock TPI for one of the aftermarket intakes. I'm not sure which ones will clear the hood on a corvette, perhaps a TPIS miniram.

**sledog** · 11-24-2005, 05:00 PM

Originally Posted by 91Z28

Ditch the stock TPI for one of the aftermarket intakes. I'm not sure which ones will clear the hood on a corvette, perhaps a TPIS miniram.

Cool 91Z28 I'll look into it.

**hammertime** · 11-24-2005, 07:59 PM

Originally Posted by 91Z28

Ditch the stock TPI for one of the aftermarket intakes. I'm not sure which ones will clear the hood on a corvette, perhaps a TPIS miniram.

Great suggestion. The TPI intake makes excellent power up to about 3500-4000 rpm, but after that, it becomes a bottleneck. At the very minimum, consider larger runners and baseplate for the TPI, plus a throttle body and porting the plenum to match. A stroker will move too much air for thr stock setup.

Miniram is an excellent choice if you plan to spin it very fast, similar in design to the LT1 intake by the looks of it.

Good luck!

Hammer

**sledog** · 12-01-2005, 09:46 PM

thanks for the reply Hammertime. I have been doing some searching on the net for more info. It seems that the sky is the limit as far as options. I checked out one site that claimed a possible 100+ Hp increase with that miniram setup with some other mods to the motor.

At least I have a few months to decide which way to go before I yank the motor from the car.

**Street Lethal** · 12-02-2005, 12:30 AM

Originally Posted by sledog

I checked out one site that claimed a possible 100+ Hp increase with that miniram setup with some other mods to the motor.

I wouldn't be surprised if it was TPIS themselves, who claimed 100+ horsepower. Although possible, those "other" mods will need to really compliment that intake. I wouldn't bother with the miniram though (too expensive)....

IMO, the Holley Stealth Ram is the better choice. That, or John Millican's concept of the LT1 intake for the L98 (although John does not run the company anymore, the new owner is working on some things to make the LT1 swap better than ever)...

Two inch cowls look awesome on C4's, too.

**sledog** · 12-09-2005, 09:36 PM

I might also have another option, I have a 350 vortech out of a 98 gmc with about 6000 miles on it. Does anyone know if I can mount the stock tpi unit from the L98 onto the vortch block and heads. I still would go ahead and stroke the motor though

**Street Lethal** · 12-09-2005, 11:06 PM

Originally Posted by sledog

Does anyone know if I can mount the stock tpi unit from the L98 onto the vortch block and heads.

Stock one will not bolt up. Just FYI though, Holley makes their Stealth Ram (TPI intake) for the vortech heads now as well...

**Redphoenix1998** · 12-10-2005, 01:10 AM

If you want to bolt the stock vortech's onto a TPI, you have to go to Scoggin-Dickey and get the manifolt that they make for vortech heads. They are the only one's I know that makes a manifold to run Vortech heads on a TPI. While you're at it, look into the Accet superram or the Holley stealth ram but get the plenum only and not the manifold because if you go with the Vortech heads the manifold isn't necessary. Also as far as other mods, look into stroking the block out. Cam, do some research and find one that fits you. With stroking, you'll have a lot of lowend grunt but with the valvetrain being done with heads, you'll have a nice topend as well so look into a good midrange cam. I have a project 85 Z28 that I'm working on right now so I'm pretty fresh on L98 mods