Ive got a friend with a 89 Camaro IROC-Z that originally had an L98 motor in the car... So I figured this would be a good place to look for some help, seeing as he can't get much good advice on thirdgen.org and theres gotta be many more members and useful help here. So I told him I would post for him here... So lets just says this is an 89 C4!

He had the engine replaced with a ZZ4 after I had one put in my 74 corvette and had such great results with... At the same time he installed a T56 transmission and rebuilt the rear end. Also went with shorty headers and hi-flow cat. Car was fairly quick, but after a few years his dad went and had a Vortech SC Kit installed(w/ Aux fuel pump and boost retard), keeping the TPI setup with SuperRam lower, and SLP runners. Stock TPI upper and TB. Well long story short, the car never really got a great tune(never was on a dyno, only had a mail order tune) and it blew the motor.

He is looking to get another crate motor, possibly eliminating the SCer and trying to shoot for similar HP... Not really sure where he was seeing as it wasnt on a dyno... I am guessing with a ZZ4, 355hp, losing maybe 20hp with the TPI setup bringing it down to 335hp and I dunno probably 125-150hp with the SCer? So around 460-485hp...
Is this a good guess?

We've found a few replacement crate motors in this range...
Blueprint Engines SB-Chevy 396ci 500HP/525TQ ~$5900
Blueprint Engines SB-Chevy 383ci/ 430HP/ 470TQ ~$5600
Blueprint Engines SB-Chevy 383ci/ 430HP/ 450TQ ~$3700
GM Performance Parts ZZ383 Engine 383ci/425HP/450TQ ~$5100
Patriot Performance SB-Chevy 383ci /450HP Engine ~$4500
Patriot Performance SB-Chevy 383ci /500HP Engine ~$5200

The shop doing the swap is pushing for him to do the GM ZZ383 but he hasnt spoken to him about the other engines yet.
The other thing the guy is telling him to do is KEEP the TPI...
This is one of the major questions we want to try to get answered as im sure many of you guys here have battled with.

In order to go with one of these engines and be in that HP range, can we still use the TPI with a good tune??
He's willing to track down the rest of a SuperRam, but is it just better to go a carburetor?
Neither of us have much knowledge of the original OBD1 computers, so if carb setup, will it be able to be setup so all the gauges and no check engine lights come on??

The only other question is most of those crate engines say they will not work with EGR, is that something just in the manifold, so if keeping the TPI it would be OK?? Since the crate motor probably just says that since it comes with a manifold that'll be replaced?

What would you old L98 / OBD1 guys recommend to do with the car to get it back up and running?? hes pretty open to anything right now, just wants to get something with a warranty on the motor...

Open to any suggestions, recommendations, etc...

We really appreciate any and all help guys!!

 

in short...depends. The super long runners support excellent torque but will ultimately choke upper RPM power. even a modified TPI setup may have some issues supplying that kind of power in the upper RPM ranges. on a street car that sees little drag duty this may not be as big of an issue as it seems. with a very competent tuner and some dyno time it will be just as if it came from the factory that way.

is it better to go carbed? not really. you can always do a Miniram/LT1 style intake instead. if he's already looking into about 5k for a motor another 1k on a good intake/tune is nothing. The Miniram would be expensive but converting an existing LT1/4 intake is not bad at all. Many users here have gone that route.

 

All of those engines have either too high Static Compression or crappy hyperutectic pistons... Some of them have both.... He is right back in the same boat he was in with the ZZ4. It may last a while depending on how good the tune is - but eventually it's going to be a pile of parts once he starts actually running it hard.

Have your friend find a real engine shop that will build him an engine built specifically for the supercharger. 355 cubic inch with 5.7 rods would be ideal. 4bolt main block, 8.5 to 9.0Compression, forged pistons, forged rods and forged crankshaft. Cyl heads with good exhaust ports. A camshaft with at least 15* of duration split (bigger on the exhaust) and long centerlines to cut down on overlap.

Everybody has an opinion on the intake system but TPI on a 383 inch engine equals a 4500RPM HP peak. Thats a complete non starter IMO.

An LPE Super Ram with a little port work will get you to about 5500RPM peak but it will at least still pull till about 5800-6000RPM and would be a much better option but still not the best.

Since he has the supercharger I don't see screwing around with intake manifolds that were desgined for low RPM TQ on mild normally aspriated engines. I would suggest a short runner free flowing intake like the mini ram. Maybe a converted single plane intake like the Victor EFI.
Will

 

Thanks for the info Fubar...
I checked into that Miniram and wow, that looks like a really nice system!! And pricing wasnt terrible... 900 for manifold, 360 for fuel rail/lines kit, and 190 for the EGR kit if he wants to keep it. Should he eliminate the EGR??

As far as the tune, we found 2 places locally willing to tune it... Tune Time Performance and Big Daddy Performance, which is nationally known tuner esp for Mustangs but can/will do the tune. Anyone have any experience with either of these tuners?

Thanks for the reply rklessdriver... My fault, I should have been more specific, he actually wants to eliminate the SCer.

What kind of HP loss do you guys think that with that Miniram will have with those motors above??
Also, should he just eliminate the EGR seeing as hes not going to pass emissions anyway and go historic plates in a 3 years anyway.

Thanks a lot guys!! gonna do some more research on the miniram for now

 

A miniram style intake will see some loss of low end power vs. TPI/Dual Plane intakes but will flow more than enough for these motors at the top end. he will see no loss of peak power at all.

It is possible with the right parts and tuning for some built engines to pass emissions testing depending on your location. I would not bet nor bank on passing however. if he needs EGR to pass his visual in states that require it i would install it.

 

On a 383 or 396 in the over 400HP and 6000RPM (or better range) - A mini ram or converted single plane is going to be the perfect intake manifold.

If the HP and RPM were on the low end of those recomendations the Stealth Ram would also be a good choice.

IMO those are your 3 options at that power level. I wouldn't even consider putting anything else on such an engine.

The GM ZZ383 is the best engine quality wise out of all of those. Blue Print and Patriot have well known QC problems as well as IMO really optimistic HP claims....

A ZZ383 with a mini or Steath Ram properly tuned in a 3rd Gen F body would be a mid 12 second car.
Will

 

Thanks for the replies again guys... I filled him in on some of this stuff but he was traveling for work so only had a few minutes.

Im thinking if it were my car I would do the TPiS Miniram, eliminate the EGR, and one of those crate motors...

How are the YearOne crate motors?? Check this one out
500hp/480tq and only $5k.. Looks like a way better option than the blueprint 500Hp for $5900

Also, any thoughts on the FAST EZ-EFI systems?? Spend the ~$900 on that and let it self-tune or really better off going to a tuner and have them Dyno tune it??

Thanks again guys!!

 

I think they are 50-75HP on the optimistic side of that 500HP....

With the low valve lift - that tells me right away the cam is a flat tappet hyd. The heads are Chinese as is the intake manifold. Cast crankshaft.... Making an honest 500HP with that stuff is a pipe dream.

Not to mention in todays world of ever declining ZDDP levels in everyday oils - a flat tappet cam is lots of potential problems I wouldn't want to deal with in a $5,000 motor.

The factory ECM is more than capable of being tuned for the kind of power he is looking at. While I like FAST and DFI in race cars.... they are a waste of $$$ in this case.
Will

 

http://xtremecarzone.com.au/index.php?showtopic=386

 

Very Very interesting article!

Looks like the MiniRam and the StealthRam are the best options for what hes looking to do, but what are the chances of finding a StealthRam for a decent price!? LoL at $2500 thru Summit the Miniram and having it tuned seems to be a bargain!


Any other comments/suggestions on the engine choices?? Or intake systems?

 

Looking in wrong place
New price
Intake $330
http://www.summitracing.com/parts/WND-7540/
Fuel rails w/ AFPR $245
http://www.summitracing.com/parts/HLY-534-186/
Maybe $150 for fittings and s/s braided line for rear entry rails
Reuse all other stock components inc harness and stock ECM (w/tune )

Used HSR 's always for sale for good prices over on 3rd Gen FS
http://www.thirdgen.org/techboard/en...ts/index2.html

Bought one there late last year for $250 complete