dj haf

i was curious to know all the free mods i could do for my iroc-z. it's a 1990 5.7 L A4 IROC-Z and all it's got is a flowmaster exhaust the first owner put on.... everything else is bone stock

i want to do all the free mods i could possibly do before i take the car to the track so i could see what it would run. then i'll start modding the hell out of it

Sitting Bull

It should do mid-14s stock.

Go to www.thirdgen.org and look through the Tech Articles. There are TONS of things you can do for cheap

dj haf

tru... thanks man

by the way... since it's automatic, should i just leave it in "D" the whole time im running it, or should i manualy shift it? this is my first automatic car so im not sure wtf im supposed to do lol

and another thing... how should i launch and at what rpms? i haven't had a chance to try myself due to the fact my breaks got rusted the day after i purchased the car (because my drive way got flooded after being rained on for 2 days no stop) and i need to replace them probably tomorrow if i have the chance

damn... i think i got off subject here, lol, but yea, i saw some of the tech articles and im sure there's more you can do to get some free hp... anyone got a really good free ram air mod? not sure which one to do off the thirdgen.org site... thanks for all your help guys!

Rage

http://www.skulte.com/ramair.html

There you go. Simple, yet effective.

firebirdjosh

I did an open air filter and now I am doing Ram Air. A cone filter made a huge difference in my 2.8L, so for a 5.7 it must be even bigger (assuming they have the same airbox).

kevinz85

One of the first things i did to my 90 was cutout the air boxes.. if you need some parts for that car shoot me an email

teke184

if the brakes got rusty, just go out and use them a few times...the rust will clean off, it is very comon for the rotors of a car to rust if they just sit around. it may squeal for the first few stops...but it stops.
worse comes to worse...have them turned for like $10 per rotor.

as for the tranny. it is fine to leave it in OD, it has no affect on how the tranny shifts, or behaves when driven around town. and as far as i know the tranny won't shift into OD above a certain % throttle, the kind associated with "spirited driving"

free mods off the top of my head:
-ram air or at least cut air box
-ported intake Y (remove some small restrictions in the plastic Y behind the filters)
-throttle body bypass
-port the plenum, remove bumps just behind the tb, and enlarge the ports for the runners)
-bump the timing from stock 6* to 10* or so and run 93 octane
-remove air pump, or just remove belt
-gut the cat
-box the lca (no hp gain but may help traction)

iroczinoz

Depending what gears you have in the transmission but seeing as it is stock then they will not be over 3.45.

I personally would not leave the car in OD driving around city keep it in D. I would use OD when you are at about 50mph +. I have spoken to a few people and leaving it in OD under 50mph is not the best for it.

Another good mod is to put in Vette servo. It is not free but not that expensive either $30?.

Damen

I have to agree for leaving it in D around town. I find that in OD since it changes the shift points, it shifts to a higher gear too early, and I lose a lot of power from around 38-48 mph. I leave it in D until at least 45, usually 50. Admittedly, I only do this when I plan on doing my quick launches/massive acceleration. For casual driving, OD is great and saves you on gas. In my experience, anyway.

doug791

explain what it does that could cause harm. I use it sometime because it lowers shift points and saves gas for when im cruising but if im doing damage id like to know why.

iroczinoz

Why is it bad I let you find out and ask around cause I don't have the explanation you probably are looking for. But I all trannie places I have spoken to say it is a no no at 60kph and less to use OD. They all told me to use it at 50mph +.

I am not going to argue with places that have been building transmissions for over 30+ years.

Difference in OD and D is the tranny has very different pressures in D and OD.

Can you also imagine driving around town a LS1 in 6th at 60kph!

Pro

If you need more power just give it gas and downshift.
Otherwise leave it in OD to save on gas and rpms (ultimately life of the motor).