msgZ28

I am about to buy an absolutely pristine '89 IROC-Z T-Top car that had a 5spd manual swapped in (money down to hold it, just waiting to sell my current car). Other than the transmission, and maybe a catback (?) the car looks dead stock. That of course means that it's a dog. No offense intended, but I'm coming from a CTS-V (traded for a minivan....damn kids), and before that a 2000 Z28 with a 408 stroker. I intend to swap in an LS/6spd combo in a few years when money allows it and my '79 Z28 project is back underway. So really, I'm looking just to prod this old dog a bit to hold us over.

As this will be a daily driver, what can be done suspension wise, engine wise, driveability/comfort wise that is relatively cheap? I have a budget of between 750 and 1250 dollars, depending on what my Jag goes for. Would subframe connectors or a strut tower brace be worth the money? Any "anti-rattle/squeak" thing that would dramatically make it more enjoyable for the 20 minute drive to and from work? And of course, what can be done to the engine that will wake it up a bit? I don't want to lose a race to our new Town and Country. Labor shouldn't be an issue as I am a mechanic for Mercedes and have access to lifts and tools and all that jazz. Only welding will be a real expense.

I appreciate everyone's help, and Merry Christmas!
Adam

darbysan

Two things come to mind. 1) Change rear gear ratio to 3.23, 3.42 or 3.73 ( if your's is lower). 2) Swap in a hotter cam, like the LT1/LT4 or LT4 hot cam. Can't get too aggressive with the ECM, but those should work fine. Beyond that, you will need to get into Headers, Intake porting, etc to increase flow.

Can't answer the strut brace/handling questions, but I'm sure others will chime in.

TTOP350

iTrader: (8)

How I wake my cars up

Justin89Formy

iTrader: (26)

I have a great starter....LT1 roller cam. Specs:

202/207 0.450/0.460 lift 116 LSA (the bigger of the f body LT1 cams)

looking for $75 shipped.

msgZ28

I'm not sure what the rear end ratio is. I didn't ask, and I doubt the current owner knows. I will have to do the count thing when I get it. With a new cam, do I need a new chip/tune?
You let your car sleep pretty late. I wish I could sleep in like that.
Is that for the cam only? What do I need to install it? Will I need lifters and rods as well? Also, again, will I need a new chip/tune? What power gains will I be looking at with that cam?

Thanks guys, keep the ideas coming!

darbysan

Std ratio for that year for an Iroc 350/auto was 2.77, with 3.27 as an option. If you have the 2.77, going to 3.27 or 3.42 will feel like a new engine has been installed. That may be enough of a performance boost to satisfy you for now. The Cam swap will add maybe 20-25 hp.
You already have a roller cam motor, so nothing needed besides gaskets to do the LT1 swap, although a new timing chain, and maybe valve seals, would be worthwhile insurance.

For all the hassle involved with a cam swap, I would try the rear gears first.

Caveman305

iTrader: (8)

suspension is simple

Jegsters SFC's $180(maybe get them cheaper), bolt them in then have them welded up

Founders Suspension parts, upper and lower Panhard bar, LCA's, and front strut mounts $367.75

Strut tower brace of your choosing $100-140

that will firm the car up and then some

11ellswray

iTrader: (1)

I would do suspension and supporting mods first, you have already expressed interest in going with a entirely new drive train so i would focus attention to the things that you are going to keep around after that swap. Such as rear axle/gears, rear suspension, brake upgrades etc

gta_knight

Im getting ready to drop a 350 in my car, ive been talking about swapping in a new Cam in another thread but after reading this i might just keep that stock and look into changing the gears instead.

I think my LSD is wearing out anyway as only one of the rear wheels spins most of the time and rear end doesnt kick out sideways very easily.

Id love to know more about the process as ive got no idea about it, is it just a case of opening up the rear end and taking out the current gears and putting in new ones or is it more complex than that ?

darbysan

For a novice, it can be a little tricky. You need some good dial indicators to get the shimming perfect, and you may need a press to install bearings. If you don't get the gears shimmed perfectly, you will have a whine. For the money and hassle, it's worth having it done at a professional shop.

gta_knight

Ah right, i thought there míght be more involved. Something for me to look into once its all running right then the axle could be done at a later date

NufNuffZ28

iTrader: (10)

With only a $1200 budget, do some free mods, headers, and 100 shot!

msgZ28

I know I can't throw nitrous at it, my wife would kill me. So how about this:

LCAs and LCARBs
'Wonderbar'
SFCs
STB
Polyurethane bushing kit
LT1 HOT cam(?)
3.23 rear end
Home port/polish of heads and intake.

Should come up around 1200. Don't know how long I can have the car down for the head/intake work though.

subroc

iTrader: (2)

I have poly everything in the suspension. as well as aftermarket rear LCA and panhard bar. Tokico Illumina shocks and struts along with founders strut mounts and weld in subframe connectors. With all this done the car handles like its on rails. If you have the extra cash spring for Bilstein or Koni Yellows. My Illuminas are great but they're are better out there. But not for the price i paid.

As for cam...i had a LT4 cam in my former 305 with high flow runners and base as well as headers and a 3 inch exhaust system and the motor only managed to put out 216 at the wheels. Granted that means it was making 250+ at the crank which is really good for a 305 but id skip the cam and just do suspension and gears. If you want more after then i would be thinking exhaust.

cuisinartvette

Being used to the power youve had even with a larger budget just make it drive/look good and save the $ for the swap. Youll never be happy with the tpi motor.

msgZ28

Well, I've been talking about this car, so I guess it's time to show it off. Here she is:






It's absolutely 1980's craptastic and slow as an octogenarian cripple, but I'm loving every minute of it.

86redIROC

"slow as an octogenarian cripple" LOL! funny but true!

Zane M

iTrader: (1)

Nice car. Congrats!

Kennerz

On a budget like that I would do the following:

Engine:
-Muffler shop (usually cheaper) 3" catback with a good high flowing muffler (magnaflow,dynomax,etc..)
-K&N drop in filters
-Fresh plugs & MSD wires(or equivalent large 8mm, or 9mm wires)
- MAke sure distributor cap and rotor are in good condition, maybe do a high voltage coil
-fresh fuel filter
- Custom chip (see if you can find the ARAP bin(factory hot tune))
- Free mods (modded iroc air box, port the plenum/remove egr walls)
-Adjustable fuel pressure reg

All the above can drop you into the low 14's high, high 13's while on a budget.
Suspension:

- Best shocks you can afford(koni/bilstien 1st, then tokico,last KYB)
- Good springs (Ground control.guldstrand,global west,pro-kit, cut replacement moogs)(I have the pro-kit and don't like the rear springs- too soft, however the fronts are good)
- Stiff either GM 1LE, or energy suspension sway bar bushings and end-links
- Poly trans mount
-poly torque arm mount
- Astro steering shaft
- Steering gear/front link rebuild if needed
-Fresh HD brake fluid
- Check wheel bearings
-subframe connectors

It all adds up but on the cheap you can do most all of that for arround your budget.
Use rock-auto and the clasifieds on here,ebay,jegs,craigslist and you would be surprised how much you can get done using your own labor.

Do all this and your old car will perform much,much better. These are the basic beginner mods to have a car that runs alright and is not spooky handling.. of course if you have to fix more unexpected stuff your budget will be blown..

Very nice iroc btw, clean car.

Then you must either stop there & try to be happy, or jump in both feet with the mods to see much more improvement & it will cost much more.

Adding a small cam to stock heads is not worth it in my opinion, I used that cam(LT 1) before in my car when it was near stock and the gains were not worth the effort, more like a XE264HR, or XFI268 comp cam, but you need all the supporting mods to make those worth it as well. Cost wise it's a losing proposition to chase power with a TPI.. it will never be an LS. HOwever the modded TPI's are great street motors IMHO. Good luck..

jrhaus76

First, nice car.

Second... gears. Count your bolts on the pumpkin. 9 or 10? Next, Look at your SPID sheet and research all the codes. If you have 9 bolt rear and 2.77s you're looking at a good bit of work to swap gears. 2.77 is a 2 series carrier. Anything over 3.08 is a 3 series. Easy swap, just either time consuming or costly. I went the costly route bc I hate waiting and searching. $500 later I had a rebuilt 3 series from 9bolt.com. I swapped the 2.77 for 3.70s.

Third... If you monkey with anything, get a custom chip. These cars are very finicky when you change airflow. I adder k&n drop ins, headers, a real Y pipe, no cat and flowmaster cat back. It's was crazy lean. After the tune, it's a monster.

I did all that at once, so yes... my car went from feeling like a pig to, well compared to my last 3 cars... a slightly faster pig! (2000 Corvette, 2007 Corvette, 2010 SS Camaro with plenty of mods).

Finally... You have a 350 with TTop. You NEED subframe connectors and a strut brace. That will at least make it so your car doesn't feel like it's twisting in pieces.

With your budget... start with making the car safe. SFC, brace, tune up, go through the brakes...

After you're comfortable, start with other stuff

Johngypsy

Hi I know it's been a while. But how far have your come with fixing up a little? On your Iroc?