cals400ex

my friend has an 87 iroc 5.7 and wants to get a little more ***** out of it. his mods are borla cat back, headers, msd ignition, k and n filters, fuel pressure regulator, and air foil. he wants to add something that will give a noticeable difference. he does not want to spend a couple thousand though. we understand it may not be cheap though. he also wants to leave the stock torque convertor on. what are the next mods he should be getting done to receive adequate gains for the price? thanks

stevem

how about a 1.6 to 1 ratio roller rocker???

Sitting Bull

Maybe 3.42 rear gears? Good combo for town and country driving.

iroc4ever

nitrous??

guywidiroc

Have the heads ported along with port matching the plenum, runners and base. Itll run good after that.

slayer6x6

if so, check piston to valve clearence

cals400ex

thanks for the replies. we did consider the rockers but did not know if they would make a difference or not. we also did not know how hard they were to install. he kind of wanted to stay away from nos. we were also thinking of the runners, base, plenum, and heads but we were not sure if all these were needed or not. out of these, which is needed most or which is restricting him the most? as for the gears, i think he has the weird 9 bolt that they only made for one year or something. i think it came with 3.21's. gears were an option also but we were not sure what difference they would make. i was surprised no one mentioned a cam. he does want to leave the stock convertor in but that could still handle a healthier cam. other suggestions?

RedIrocZ-28

Sure the stock convertor could handle a healtheir cam.... It'd be nearly pointless to do a cam without a convertor though. Look at it this way.... Say you wanna get new tires to go raceing in. I would get slicks and know that I was gonna hook up.... a cam without a convertor is like getting some 165 R65 14's. Sure ya have some new tires but they aren't doin ya any good... Get what I am saying? Hell I'd rather swap out a convertor than a cam. The convertor would take less time AND effort.

Besides, a decent convertor like mine was $412 out the door. Its good for about a 2400 stall speed. Trust me when the car hits right around 2500rpm holy watch out old ladies!

On the other hand a set of 1.6 rockers with a cam and a convertor along with some gears would be sweet I guarantee low 14's but probably 13's

TheGreatJ

The Borg Warner 9-bolt was made from 85-89 (I think) and is significantly stronger than the 10-bolt that most of these cars have. The ratio is either 2.77, 3.27, or 3.45. You can get gears for it at 9bolt.com

Don't get a cam unless you port the heads and intake too while you have it apart. It won't do you much good, since the intake tract is the big restriction on TPI motors. I'd say port the plenum, runners, and intake yourself (cheap but time consuming) and get some 1.6 roller rockers (you'll need to check the piston clearance and probably get high-rise valve covers for these). That should wake her up a bit.

kandied91z

or if the engines in good condition throw a small amount of nitrous on it with the right safety features and call it a day.

i know a 75 shot on mine put me in the low 13's without ever opening up the stock 100,000 mile engine. once you break into that engine your going to start having trouble. unless you already do then i guess it wouldn't matter.

cals400ex

so this convertor thing i do not fully understand i guess. are you saying, the more you hook up, the bigger convertor you need? if so, i get that. as for the times, he can already run 13's but barely. he runs about a 14.1 with crap tires. he has some slicks but has not used them yet. he can not hook up at all but that car has torque for no engine mods. it has a decent amount more than my lt1. highend is where he is getting beat. maybe the gears he has are 3.27. i know that they are 3.2 something. i will ask him. the engine is in good condition. the problem with nos is that we really don't go to the track much to use it. maybe twice a year. we just get on it on the roads. also he said he does not want to refill the bottle. great suggestions; i am still a learner so more would be great!!

kandied91z

true, you just don't have alot of options for "cheap", possibly change the intake setup and try to get maybe 50 or so horsepower as the tpi is restrictive??

if you want to leave the engine alone your extremly limited to a power adder......otherwise the sky is the limit, that an a bilfold.

CamaroFreak87

I'm gonna have to say to get a new intake. a Holley StealthRam or a modified LT1 intake. they're about the same price, I think the stealthram is $500 and the LT1 intake is $400? I don't remember. plus gaskets, would be about $50?

proamature

Change up to 373 gear, go with a 2500 converter, and custom y-pipe, with high-flow cat. swap in a set of sportline springs. might do some rear suspension tweaks also... and get some damn subframe connectors.

or nitrous it.