Hello everyone!

I'm finally getting close to finishing the list of parts I need to improve my L98.

I'm not having any ring problems, so I plan on using the stock pistons, rings, distributor, & crank.

Here is the list of parts I plan to buy or have
already purchased...

TPIS BigMouth intake
Double roller timing chain
ZZ4 hydraulic roller camshaft
Hedman shorty headers w/AIR
AS&M Long Tube Runners
Comp Cams Magnum 1.52 roller-tip rockers
Hydraulic roller lifters
Dart Iron Eagle 180cc heads 2.02 int/1.6 exh
Custom PROM

Other mods I have already done to my car are listed in my sig.

I'm going for strong low-end & midrange HP & TQ.
I'm getting too old to go a zillion miles per hour

Can anyone give me an estimate of how much HP & TQ the above combination would give me?

I don't have a huge budget, but any suggestions would also be appreciated.

Thank you!

 

My 89 L98 makes 245rwh and 330 wrt. So those numbers are about 300-310 horsepower at the engine and 370-390 at the engine for torque. Mod list below.

FlowMaster Cat-Back w/high flow cats from Cat-co, EdelBrock TES Headers, EdelBrock High Flow TPI Intake Manifold, EdelBrock High Flow Intake Runners, EdelBrock Air Foil In Throttle Body, Throttle Body Bypass, TPI Intake Manifold and Runners Ported by TPIS, TPI Plenum Ported, TPIS Adjustable Fuel Pressure Regulator ,TPIS- ECM Reprogrammable Chip, Gutted Air Box, K&N High Flow Air Filter, ACSD 82-92 Camaro IROC TurboHood, HyperTech Chip Stage One, HyperTech 160 Degree Thermostat, Re-mapped Injectors, MSN Ignition, Blaster Coil, Accel High Performance Rotor, Wires,Beefed up Alternator, Mass Air Flow Sensor [cut out fins], 3.42 Rear End.


Anyways to be sure you have to get it dynoed. A guess is a guess. But id say 265-280 horsepower at the wheels if you get a good exhaust cat back system, and have the intake and runners ported. Hope this helps.

 

I would be suprised if he didn't see over 300 rwhp, easy. Those are nice heads and will help his combo alot.. The TPI will be the bottleneck.

 

I dont know. That tpi setup really holds back horsepower. I would go with a different intake.

 

Thanks for the replies!

I am wanting to keep the TPI, so I went with the TPIS intake because I heard it flowed the best.

I will agree that, if I wanted maximum HP, another intake (SuperRam, HSR, etc) would be a better choice.

I'm was hoping to get close to 300rwhp, but I wasn't sure if my combo would come close.

Thanks again.

 

The 245 rateing is wrong . It's at the motor ,not the wheels. The stock L-98 cars I see get around 200ish at the wheels on a chasis dyno.

All the stuff in my sig got me 251 rwhp and 318 rwtq with no tune . You should best that by maybe 10-20hp then with a tune could be more.

 

Are you talking to me? My car has 245 at the wheels with my mod list. Re-read my post.

 

I see now .

 

But it sure accels in torque

 

Which results in

 

i'd go for a bigger cam than the ZZ4 if you want closer to 300whp. also to port those heads out.

with that ZZ4, i'm thinking your good for 250-270whp

 

if you don't surpass the 300 hp mark, you will be really close. my combo is as follows..

aluminum 180cc brodix heads
zz4 cam
stock valvetrain
stock tpi components w/24# injectors and afpr
1 5/8 slp headers, 3 in i pipe, dynomax muffler
custom chip
fully smog compliant

I produced 272 hp and 372 lb ft through a t56, and I feel that I have a little more in it if I adress a few things.

 

Nothing wrong with a modified TPI!

 

90firebird,

Maybe an aftermarket intake/runner combo would get you to the 300HP mark? I've read that the stock ones are pretty restrictive. Since you are running a better set of flowing heads, it may be best to get more air to them. Just a thought ... but I'm no expert

If your making 272 hp and 372 lb ft at the wheels, what do you think the ratings are at the crank?

Thanks to everyone for the info!

 

Around 312 hp and 427 lb ft with a 15 percent loss from the manual.

 

JulieGTA (91 GTA) on the SC Area board made 253rwhp@330rwtq with bolt ons. Edelborck runners, TPIS manifold, stock throttle body, 1 3/4 headers with dual 2 1/2 cats and 3.23 gears