First pardon my poor typing skills

I have a 90 vette with an l98 motor with the aluminum heads and an automatic., it ran fine but i wanted it to go faster, looked for a crate motor, couldnt find one without eliminateing computer. so i took it ot a local shop and he promised me 400 horse with a 383 stroker custom build


build sheet says

bored .030 ballanced full recon on heads 2.02 stainless 1.6 ex 3 angle bowlhawged milled .0019 103523750571 eagle crank sir7000bblw eagle full float rods h90cp 0.30 speed pro pistons 9.5-108-5032-8 comp roller cam 2148 roller lifters prw roller 1.5 rockers direct fit headers

they also put in a new water pump o2 sensor, oil sensor and radiator.
cost to do teh whole job from pulling the motor to instalation was $5,300. does that seem reasonable for 400 horse sttroker?
do the listed parts seem liek they would ad up to any where near 400 horse?




ok, after all that, its runs good, but it has no real power, the mechanic has tried two different "chips" and says he beleives the chip is the problem, sound reasonable? now with the second after market chip, it runs like crap, and wont idle, bogs down where it should have its most power

they have been messing with the car for overa month, and even removed the motor a second time to put in a less agrresive camshaft (cus the first chip maker told them that was the problem) it only got worse at that point.

so what IM asking is first did i get ripped, second will i see anything clsoe to 400 horse, third do you think its likely jsut a chip problem, and lastly, this was suposed to be a PRE forced induction set up, i had planned to get my out of the hole power with the strokers increased torque, giving the turbo time to spool. will this set up work in that fasion? lastly, does the ECU control the transmision, or do i really need to upgrade to a better converter?

and and all advice/answers will be appreciated.

I hope i dont appear to stupid, i have ben out of the car game a LONG time, and never had anythig fast and fuel injected,

 

$5300 isnt bad at all. With a non long tube runner intake you may see 400chp
WItht the TPI probably not as it chokes the motor but you should make great torque once its properly tuned.

Dont know who told you the computer had to be eliminated to make power there are some pretty quick cars here with the stock computer, just well tuned.

Injectors upgraded?

Do you have cam specs that # doesnt come up in google.

What intake do you have now?

Chips....that thing needs a custom tune to get it right. Couple guys here are very well adept at them. Mseven is pretty popular here.

Guy sounds like he may not have a total grasp on moddign EFI

 

Talk to Mseven or PCMfor less. Find out which software they want you to use to scan the car with. Get a laptop, cable and software. Make some scans, send them in and they'll send you a new chip.

The intake will choke your HP, so it might get to 400chp with a carb, but you should have a real torque monster there!

 

so, i didnt get screwed.
I think on the chip deal, my mechanic was getting screwed. He was asking for a custom chip, they sent him an off the shelf "superchip" thats why they had him swap out the cam.

I have directed him to boos performance for a true custom chip, im hopeing he goes that route..

so i guess if thsoe two questions are answered, then my main questions are.

is this a good set up for a mild turbo, maybe 6 psi?
and does the computer control the transmision, or do i need a higher stal lconverter and a shift kit to get the performance im looking for out of the hole?

My desire with the rebuild wasnt to go 200 mph, but t do 25 mph... sideways. Im hopeing that the turbo will feed whatever top end needs i develop later and push me into respectable (non rollcage) times on the track.

 

how much does such a chip normally cost? will the long tube runners be compatible with a turbo, and would i ever be able to see 5-600 hp from such a set up with a turbo, or will i be forced to swap out the TPI (dont want to)

dont really have the money to swap the fuel system, and may have to skip the turbo if it wont work, and jsut burn up a set of tires every year at the stop lights.

 

You can do a Miniram a lot cheaper than a turbo. It will let the heads and cam work like they should. It will make power with a pro tune.

 

guess i need to price the minni ram, I dont really wish t ogive up on the turbo, but my budget is already drained, with the car, the motor, and well, the stereo, ive sunk a ton into it already

 

Welcome to the world of the C4's drained bank account LOL.

I just starting my self getting my Vett money to build back up after my rebuild it worth in the end.

My 1st Motor the 355 nightmare one of the big issues I had the guy who built the POS trans 700r4 put the wrong stall convetor in he told me it was a 2200 stall but after pulling all back apart I found out it was a 1500 Stall that killed the car power.

The motor never had a chance to step up to it power band before it kicked in so the car was a dog.

My 2nd motor is a 383 after the 355 ate it self and I also put a New 700r4 and a 2500 Stall convertor now the car hauls.

But like others said If you have a 383 you need heads cam and intake system, Exhaust, to macth to get all to work together, Dont for get about the correct stall for the trans.

With out the right combo you just have a stroker motor that can't breath or a trans that woun't let it get up into the power band where it needs to be to low of stall is bad to high is bad also.

 

who needs a stall convertor?/? Its what my left leg is for, along with my right hand, to change the gears.

 

Your Speed Pro pistons are cast hypereutectic. They will work for a short while with your planned turbo project, but they should be forged if you want the motor to last and make real power. You can make good power with the right combination of parts (and your current pistons) without having to turbocharge the motor which really takes some knowhow and precise tuning.

 

A custom tune can be a couple hundred bucks more or less
For example I provided PCMfor less a list of the engine mods on my 383 and had a couple things taken out (AIR, EGR), it was $200 and the tune was close. Never got a chance to take it to them for a dyno tune (would have been a bunch more).

 

Need the specifics on the engine. What are the cam specs, lift, duration @ .050? What is the compression ratio?

It appears that you're running something setup for forced induction. Knowing the cam specs and compression ratio will confirm or refute this. If so, you'll be down on power until you add the turbo or supercharger.

 

Scan and post the build sheet.

 

A lot of info here already, I think I will ahve t wait till after the car is running well with no check engine light to figure out a lot of this stuff. I may jsut ask for the stock chip back.

but to be clear, i should have a stall converter of about 2500 stall put in?

I thinki best take it one step at a time. will give the mechanic one last chance to get the chip right, then i will ask for part of my money back. I may be able to get him to install or at least pay for the converter if that is what I need.

If the computer dosent control the shiftpoints and stall, then a good converter and shift kit could make a WORLD of difference

 

cam is 08-502-8 comp cam

218 and 224 % .50
compresion is 9.5
pistons are speed pro
Looks liek i got screwed there, If i put boost on these pistons and it runs lean im going to be SUNK!

 

I think i need to slow this way down. get the car running, hoeully with a new converter, and then see where to go from there, probably start a new thread and list waht i have, then take it step by step through the process of what to add, do a LOT more research, and not trust a mechanic jest becosue he is well recomended,

 

The info I was looking for is not here. Sounds like you are In good shape moving forward though.

 

Good to see you back in the game.

In your absence, there have been many, many 383 build ups in various hot rod mag's. 400 horsepower is no longer the magic number it once was. The recipe is out there; nowadays, it's like following a Betty Crocker Cookbook. A custom 383 with the potentential for less than 400 horsepower? Not too likely.

Speed Pro does make a forged piston for your application...not saying you have them, but it is possible ???

Not a L98 expert, but from my reading, the airflow into the engine (and the horsepower out) is limited by the stock intake which was designed for low and mid range torque on a smaller and (comparitively) low output 350. The aftermarket offers higher flowing intakes better suited for a a larger 383 with a (much) bigger cam than the stock L98 piece and heads upgraded with (significantly) larger 2.02 valves. Ask your builder if he thinks your 383 due for an upgrade in this area ?

Let us know how it all works out...someday, someone else is going to build a 383 and hopefully they can learn from your experience. Good luck.

 

Tiny cam, typical compression ratio, and I'm stock intake. All of that would add up to a 383 that's realistically making 325-350hp.

You need a new shop that knows how to build an engine versus swap parts.

Step 1: Define goals, usage, desired horsepower, desired rpm range, etc
Step 2: Select components
Step 3: Build engine
Step 4: Tune

Some random thoughts...

You may or may not need a new torque converter. 2500 wouldn't hurt, but the cam is small enough that the stock converter should be fine.

Based on your description of how it's running, I wouldn't be surprised if the base timing is significantly off. With your setup it should be around 8*-10* BTDC.

What codes are being thrown?

Lots of us running 500+ hp with the computer. The cam in mine is 230/236 @ .050 and the lift numbers are .622/.624. Idles at 800 rpm, revs to 6500

 

I had asked for 400 horse on the motor. he said he would get me close, 325 is not close.

I am probably going to upgrade to an aftermarket intake set up probably the eidlebrock one.

id go with a mini ram i i could ind one used, but i cant, and probably will .never rev the motor over 5500 or 6k anyhow.

i don't think im going to touch the cam, unless i can get him to do it for Free.

I am sure now that ive went with the wrong builder, but i think he has tried to give me as good as he can for the best price, so im not going to bad mouth him, he just wasn't the right man for this job.

my focus now will be on where to go from here. I have the heads i have, and the cam and pistons i have. im going to use the money i have left to swap out the intake and some other bolt on mods, see where it gets me.

I am thinking that even at 350 horse, it will be a wild ride, and maybe i might need some time learning to drive the monster beore i make it a monster.