Free mods

alright im just wondering what else i can do to my 89 Formula L98 without spending some real cash. Mods so far are
modded air box, K&N, descreened MAF, TB airfoil, Flowmaster exhaust without cats and threw in a cut out for the track, 700R4 out of an 89 vette with shift kit (dont know if the vette tranny is any different it was already in the car)
Any suggestions? I live in Texas and emmisions arent really going to be a problem.

You could take the top end apart and port the hell out if it. That should give you a little more breathing ability up top. Other than maybe removing the A/C and what not to lighten the drag on the motor, I don't know of too many more "free" mods that can be done, that will increase power output.

Will

"Free" or cheap mods

-Remove cat
-delete EGR
-relocate MAT sensor
-remove air box, replace with cone filter
-descreen MAF
-port MAF
-increase timing
-tb airfoil
-tb coolant bypass
-increase TPS voltage
-remove A/C components, run smaller belt
-headers
-afpr
-port TB, Plenum, Runners, Manifold, and Heads. Gasket match.
-new plugs, wires, cap and rotor
-sticky tires. (TPI motors make torque, take advantage of it)
-shift kit

Thats all I can think of right now. Hope it helps.

Oh one more thing. You may have read it but I have a issue of High Performance Pontiac where they did a trackside TPI tune up on a stock 1988 GTA with a L98 and 700R4. They added et streets, increased timing to 13*, added a afpr, removed the air box and added a cone K&N, descreened the MAF, ported the plenum walls, and added a tb air foil. They went from a stock run of 14.79@94.68 to a best of 14.19@96.88mph. They feel that if they had more time to play with the timing and fp, plus a track that wasnt so sticky they could have gone 14.0 or a 13.99 even. According to the article fresh glue was laid during the test and tune at Raceway Park, it was a bit more rolling resistance than a stock car could handle. Not bad for a cash outlay of $300 and one afternoon at the track.

P.S. I have the mag here in front of me that's how I remebered it all! LOL! :D ;)

You could also bypass the coolant running through the throttle body. That will keep the intake much cooler and might net you a few ponies

while you're doing the TBB put in a lower thermostat

i did the "gut the airbox" 1 step farther and gutted out some of the restrictions in the intake Y.

not sure if the formula intake is the same as the camaro...:think: so maybe that won't work

"Free" or cheap mods
-Remove cat
-delete EGR

Can't do either in Texas (well, not in Houston)

-remove air box, replace with cone filter

Works better if the cone is fed outside air.

-descreen MAF
-port MAF

A descreened MAF will flow more than the TPI can use, no need to port the MAF.
45°. 0r 90° bends in the air path cause severe turbulence which the screens minimize.

-increase TPS voltage

How do you increase the voltage other than adjusting for max voltage without loosing the min voltage of 0.54?

Don't forget weight reduction :D

- Justin

Can't do either in Texas (well, not in Houston)

Works better if the cone is fed outside air.

A descreened MAF will flow more than the TPI can use, no need to port the MAF.
45°. 0r 90° bends in the air path cause severe turbulence which the screens minimize.

How do you increase the voltage other than adjusting for max voltage without loosing the min voltage of 0.54?

If you can't do it in Texas then I'm sorry.

Yes it will work better with outside air, but not everyone wants to cut up there car. You have to cut the air filter tray for it to work properly.

A descreened MAF will not flow more than the TPI can use. Removing the screens increases throttle response and lower's et, it's been proven many times!

Increase the min .54 volts. Myself and three others have done it here, all saw improvements in et. I went from 14.93 to a 14.80 by increasing voltage to .60. Runs were made on the same day within an hour of each other, so no change in weather or anything else.

I don't know if cutting up the stock air box will net you the same effect but I picked up a cheap CAI pipe at like Autozone or some store don't remember where meant for a civic. Its just a straight chrome pipe with a bend at the end. It went right on the MAF and goes right to where the stock air box was. slapped a cone filter on there and noticed a SOTP difference in throttle response. Also don't forget about an MSD or accell coil and HEI module while you are doing the ignition upgrades. :)

so what does everyone think about going from a 3.23 rear end to a 3.42? ive got one laying around here so i figure why not pop it in right? what kind of time differences do you think that will make?

Maybe a couple of tenths, depends. But it's a better gear than the 3.23 for racing and on the street it's better than 3.73's..for gas.

My car must be a freak, because I have only done a few mods listed and it runs in the area of stock LT1's (13.8x@100.2x mph).

so what does everyone think about going from a 3.23 rear end to a 3.42? ive got one laying around here so i figure why not pop it in right? what kind of time differences do you think that will make?

Do you have the 9-bolt rear end? If so you don't have 3:23's unless they are aftermarket. :)

so what does everyone think about going from a 3.23 rear end to a 3.42? ive got one laying around here so i figure why not pop it in right? what kind of time differences do you think that will make?

I don't think it'll be much of a difference at all to be worth doing..

Do you have the 9-bolt rear end? If so you don't have 3:23's unless they are aftermarket. :)


umm thats a good question...its the stock rear end, i dont really know what came in these cars, i thought it was a 10 bolt but ive never got under there to find out. and i know they arent aftermarket, everything ive found tells me they are 3.23s though

umm thats a good question...its the stock rear end, i dont really know what came in these cars, i thought it was a 10 bolt but ive never got under there to find out. and i know they arent aftermarket, everything ive found tells me they are 3.23s though


Count the bolts on the diff cover. That will tell you for sure. Here is a link to 9-bolt information to back up my previous statement. :)

http://www.9bolt.com/

its a 10 bolt, just crawled under there and counted. so whats better 9 or 10? i know with a 10 bolt if you want to go like 4.11s the teeth get kinda small so im guessing thats the same way with a 9 bolt. What does yours have formula350 and what year is your car?

its a 10 bolt, just crawled under there and counted. so whats better 9 or 10? i know with a 10 bolt if you want to go like 4.11s the teeth get kinda small so im guessing thats the same way with a 9 bolt. What does yours have formula350 and what year is your car?

As far as whats better? people will argue all day bout that. Originally the 9-bolt was supposed to be stronger and thus was a performance option. However I "thought" that it was standard behind all L98's. I'm asuming that yours is a Formula350 since you mentioned L98. Mine is an 89 Formula350 with the 9-bolt and 3.27 gears. The 9-bolt has a larger ring gear I belive is what the main difference is and it was made in austrailia by Borg Warner from what I have read. Anyway a 10 bolt is not bad by any means mostly because parts are easier to obtain and lots cheaper. :D

it can be done, its worth maybe 8hp at best, look on ebay for the kit and then if you look at it long enough you can just make one yourself

it can be done, its worth maybe 8hp at best, look on ebay for the kit and then if you look at it long enough you can just make one yourself

It can easily be done, but it's prolly worth closer to .8 hp than 8 hp. You'll see a small drop in temps, but the intake will still be warm from ambient air.

- Justin

It can easily be done, but it's prolly worth closer to .8 hp than 8 hp. You'll see a small drop in temps, but the intake will still be warm from ambient air.

- Justin

Agree.... I did it on my L98 and noticed nothing. The only reason I did it was because I was replacing the water pump that hose was rotten anyway... ;)


BTW isn't 97 a 4th gen? :p :D

i ment .8, i just missed the period. But you never know, some people dont see a difference in little stuff but then some people do

i ment .8, i just missed the period. But you never know, some people dont see a difference in little stuff but then some people do


Very true, and every car is different. On an LT1 it MAY make a bigger difference but there is only one way to find out. ;)

My car must be a freak, because I have only done a few mods listed and it runs in the area of stock LT1's (13.8x@100.2x mph).

Mines a freak too . I beat a '95 LT-1 Z-28 by 1 1/2 cars from a 35mph to 110 mph run . All I got is K/N , Air Foil , 175* fan switch .

well thats what happens yeah, even if the 95 was an auto and youve got a 5 speed he would have run you down after that. happens to me everytime, i jump about a car on a stock lt1 and then it runs me down after about 95-100. thats just the difference in an lt1 and a TPI

Mine is Auto . 350's came with auto . 305's had the 5 sp .

I pulled to 1 1/2 cars lead to 110mph then shut it down .

I heard stories that the L-98 is underrated . It should say 260hp , not 245hp . Plus aren't 3rd gen's lighter than 4th gens ? 200-300 lbs should make a little difference .

L-98's :bow:

Mine is Auto . 350's came with auto . 305's had the 5 sp .

I pulled to 1 1/2 cars lead to 110mph then shut it down .

I heard stories that the L-98 is underrated . It should say 260hp , not 245hp . Plus aren't 3rd gen's lighter than 4th gens ? 200-300 lbs should make a little difference .

L-98's :bow:

Yes the 5spd was not available from the factory with the L98. But you can swap one in like I did. Not all 305's had the 5spd. From what I have read the third gens are lighter thand the 4th gens but by how much I don't know. The L98 had more torque than the LT1 but the LT1 breathes better at high RPMs and has slightly higher HP ratings, which would explain why they will pass you up in the long run. With slight modification the L98 will hang right with an LT1. :)

-Remove cat
-delete EGR

Can't do either in Texas (well, not in Houston)

Actually it's a federal offense to disable or remove any original smog equipment placed on a vehicle from the factory in any state. Some states are not looking as hard though. I can't remember what the fine was up to now though. I think it was a minimum of $1,000 up to $10,000 and/or 5 years in prison.

I believe.

I realize 350s only came with an auto, but you never said it was a L98 car, and if you did i didnt see it. I dont think third gens are under rated, my car with only the exhaust put out 245HP and something like 360 ft lbs of TQ on a fresh motor