i'm wondering what my 89 IROC ran stock. it's an lb9/auto with 2.73's. hardtop car. i want to say it was in the 15.6 range.

my mods are as follows:
-3.45 posi 9 bolt w/ lca rb's (spare rearend for my sportcoupe, it's going in monday )
-hedman shorty headers
-blowmaster 2.5" catback (not my choice, lol!)
-under drive pulleys
-accel plug wires
-msd cap/rotor
-k&n filters
-opened up air box
-tpis air foil
-afpr (not sure what its set at, the fuel pressure guage the guy put on it doesn't work)
-275/50/15 mickey thomspon et street radials

i know the car has the crappy camshaft and i have every intention of putting an lt1 camshaft and a set of 1.6 rollers on it. i'd also like to go to a 22lb. injector and start doing some tuning, but i don't know what tuning equipment to buy. (come on, i'm the carb guy, lol!) i also think a 2500 stall speed converter would do this thing some good, but i'm not gonna mess with that just yet.

the goal here, is to beat the guy i bought the car from. he never ran it once he put the headers on it. i told him not to sell it to buy this other car he bought. it's an 89 l98 powered forumla, and i believe it to be bone stock. it's not in the best of shape and i think it ran a blazing 15.1 last time he was out with it (about 3 weeks ago). but anyhow, i've got the IROC back in great running shape and i'm wanting to prove a point to him. what do you guys think?

 

Sounds like a good plan! I would maybe go 2800 stall being that is where peak TQ is I think.. It should leave real hard!! Maybe get a Dyno Max Intermediate 3" - Dynomax is the only one I know that sells their parts
seperate. Maybe throw one of your old bullets on!
I would aslo advance Timing 2-3* at the track, run cooler thermostat to stay away from pre ignition. Also pull screens from Mass air..

My L98 bone stock first day at track - started out at 14.8 - removed Mass air screens, air box silencer, and advanced timing. Got down to 14.3 that day.

As for tuning Equipment, I have Pocket Programmer for burning and Tunercat for editing, Tunercat has awesome programs and very easy to use - but there are free editors out there as well like tunerpro. You can do it very cheap if you want..
Prom chips are 4-5 dollars each and can be reused 1000+ times.

 

i'm thinking a magnaflow catback would be my best bet. i want something really quiet at idle, but lets you know it's there when i stomp on it.

i put the 3.45 rear in her last night, holy crap what a difference! it feels like it actually accelerates below 3000 now! and, from a dead stop, i can squal tires, where before i couldn't. while looking under the car, i found it's got aftermarket lca's!!! i'm gonna put them on my sportcoupe, cause it can use them more than the IROC can.

how much timing did you give it?

 

It wouldn't even chirp the tires before?? ouch.
What do you think this TPI setup is worth with your mods on it? Basement 14's?
haha, modding your daily driver eh? tsk tsk, you sir, are hardcore.

 

i think it'll run mid 14's once i get it all together. my little bro is putting in my great shape black interior from an 88 parts car i have out back right now, so i'm limited to working on my sportcoupe till he gets done, lol! (hehe, darn, gotta work on the racecar instead of the daily)

everything's got mods, lol! the tow truck (91 dodge d250 with cummins) has a 3" straight pipe and 4.10 gears!

 

Magnaflow doesn't make a catback for thirdgens, but the LT1 exhaust can be made to work. LS1 also, but the LT1 is basically the same for less money.. I think there are different tips. I just put one on my car this weekend. Not as loud as my old Flowmaster. Didn't have time to finish up with welding the tails and new hangers but I'll have sound video next weekend.

 

these were my basic mods on my L98 and i went very quick. 2800 stall is perfect! even with 2.73's but with 3.45's that car will leave good. work on suspension abit to get it too launch great. it will run hard. My car also liked 8 degrees base timing or 2 degrees over stock.
pulling the screens out the MAF may make the car run richer as more air will be goin thru and the computer may adjust to that. i know my TPI car ran abit on the rich side and i think that helped when i went to HSR. the tune was just about right.

i'd keep fuel pressure at near stock. 43-45 psi or so.

sounds like a good plan.

As far as tuning equipment goes, i'd stick with Moates stuff. i got their ALDL cable, Burn1 chip burner that comes with Tunerpro RT, and i pretty much can handle any basic tunning needs. didnt cost all that much either

 

my friends 91 formula lb9/700r4 with just a cai it ran a best of a 15.6 some argue and say it has a better cam then the earlier lb9's but i believe its the same since every l98 style cam lb9 i ever seen has only been 5 speeds and the tachs redline at 5500 instead of 5000 like most lb9's

 

hehe, if you'd seen the other stuff i've fabbed up, you'd know that modifying a catback is not an issue, lol!