I just spent months searching for the right third gen. I found and purchased a very clean Blue 1990 IROC-Z 87k miles bone stock. i have always had a love for third gen camaros and this is almost 100% perfect. I want to achieve a very reliable 300-ish rwhp but i have not idea where to start with performance parts. i am considering AFR 195cc heads and a decent comp hydraulic roller cam. any advice for the build is welcome but i am really wanting to keep stock like driveability. i know 300 rwhp should not be hard to make but i am fairly inexperienced with older SBC's. I have worked mostly on LS1,2, and 3's and the power gains are very easily achieved. my main concern with the TPI is tuning.what do i need for tuning the TPI? what are some weak components to consider? thanks in advance for any advice.

 

I would recommend you do a search on this site for l98 upgrades. Do the easy stuff first, headers, 3" exhaust, free flow cat, etc. There is a lot of additional info on this site. Search is your friend. I'm not trying to blow you off, but your question has been asked and answered on this site a couple hundred times.

 

Consider that you are starting from a much lower base (<250Hp at the crank )
and vastly inferior heads to those installed on a LSX.

As noted , plenty of TPI build reading on here
https://www.thirdgen.org/forums/tech...pi-carbed.html
https://www.thirdgen.org/forums/tpi/...400hp-tpi.html
https://www.thirdgen.org/forums/post...718-post9.html

 

thanks! I know to search for the info on the forums as well but I am working with terrible internet here in Afghanistan so it takes forever to load pages but all the same I appreciate the info

 

Is yours speed density or maf?If it's speed density your biggest Problem will be the Tuning needed to make it run right.Also a good exhaust system.

 

Before I switched to carb, I made 305 rwhp/340rwtq with a modified TPI setup. I'll tell you exactly what I had on the car.

Custom cold air intake (basically an open element filter and unobstructed 3" pipe into the plenum)
Gutted MAF
Dyno tune/custom burned chip
fully ported/ground plenum (all obstructions behind the intake ports ground down)
port-matched SLP intake runners
fully ported STOCK intake manifold (alot of work was done to this piece)
30lb/hr injectors
AFR 180cc Street Eliminator Heads
Comp Camps 08-503-8 cam (224/230@.050)
1.6 Roller Rockers
MAC shorty headers
Mufflex 4" exhaust
AC/Smog/Cat delete

It also made power to 5500 RPM, almost 1000 rpm improvement over the stock TPI intake pieces.

 

Not trying to be a jackass, but what were the timeslips looking like?? Power seems way low for that setup. Should have been closer to 350 RWHP.

 

thanks I appreciate the info and list of mods. basic direction I am going for now will be exhaust, intake, and heads and a good tune. I am also about to start a 5.3 liter turbo build for my 89 RS so I will tinker here and there and hopefully have a decent build thread started on that here soon. My corvette is priority though to get a new A&A S/C set up. it sucks having too many projects going on but I am only in the states about 5 months out of the year so I want to enjoy driving them more than work on them. I am an EOD Tech/ Operator (bomb squad) in the Air Force and my job takes me all over but also affords me the opportunity to fund my passion for cars, although its still like a champagne taste on a beer budget. thanks again for the info.

 

well it is a 1990 5.7 tpi so I am not really sure but I thought the speed density was like 91-92 tpi and 93-94 lt-1? maybe someone can educate me.

 

1990 is gonna be speed density. MAF was used 86-89, SD from 90-92, then MAF again (better designed) on the LT1 used 93-97

SD is better for making power (so i hear), but MAF is more forgiving of upgrades without requiring a re-tune

 

To be honest, we were all floored it made 300+rwhp. Considering the breathing capabilities of TPI (or lack thereof), without the added torque of, say, a 383, we were figuring 260-280.

The car went consistent 12.8s at around 107mph. 2400 stall, running 1.7-1.8 60fts.

 

Except 92-93 LT1 is speed density!

 

My 8.8:1 compression 350 with small reed custom grind cam, ported vortecs, edelbrock 3817 base and stock runners pushed a 5, 500 lbs 3.08 geared G-van with a S10 2, 600 rpm converter to a 14.1 @ 101 on a 2.1s 60' while making nearly 360 rwhp.

 

true, always forget about that....