PhLaXuS

Okee...

I've read all over the place and aside from buying the actual books I need (which I'll probably do in the next few days), I cannot find answers to a few questions on twin charging a 383. I'm really just wanting to know if this setup looks like it would work:

·Forged 383 with 8.5:1 CR
·Decent aftermarket heads
·Stealth Ram
·A pair of T70's (or possibly a T70 & T64)
·Air-to-air intercooler
·15# boost (total; after the intercooler)
·93 Octane pump fuel
·Upgraded ignition (obviously)

Anyone know if this combo would work without killing the engine & are there any estimates on the power output? I'd like to get 800 HP or so @ 6000 RPM. I think this setup should allow even more than that on 93 octane, but I'm not really sure at this point. I may even run some water injection, but this could get a little tricky as I will have to inject it into the compressed intake somewhere after the turbos.

CrazyHawaiian

I dont think you're really gonna get solid numbers until the motor is built and you're tuning. When planning it out you should build the motor first and get the specs, then worry about everything else. Once you know the specs of the engine then you can calculate stuff and find the best matched parts for the combo. Depending on how your motor flows, those turbos might not be the best match, or they might. It would all depend on the specs of the engine. Then once you got the combo built, you're gonna tune it, and thats when you're gonna find what the motor likes (as far as the boost limits and detonation) and power output.

PhLaXuS

Well that's the tricky part. I was going to build a nice 400HP N/A 383 and then maybe a year or two later pop one or two turbos on top...but that will be hard if I build an engine with an 11:1 CR. I'm trying to look even more forward than the next build. I really don't have the resources to rebuild, test, rebuild (if needed) and then toss a turbo on.

CrazyHawaiian

Generally speaking the higher CR will limit the ammount of boost you can run before seeing detonation. You can still turbo the engine, just cant run some high boost number. Maybe you should make a compromise on the pistons you select, give up some CR for the initial N/A build in hopes you can boost as much as you want later on down the road.

browncamaroz28

iTrader: (1)

if i was you i would do like a 9.5:1 CR and then you will be able to drive the car get some decent hp numbers and later be able to turbo it. if you really want to run 15 psi you can just get a two stage boost controller, and have the initial boost set at about 2-3 psi then when you want to go you can flip a switch that will activate the boost controller and a water/alky injection kit to reduce detonation. all that wouldn't really be too hard its just a few wires and a switch and then you will have a streetable monster...... would be in your future

Dustin Mustangs

iTrader: (1)

You can top 800hp with one t70....I think you need to look into some smaller turbos unless you want a ton of room to grow. Just my 2 cents.

browncamaroz28

iTrader: (1)

yea i forgot to mention that, my friend has a t70 on his all trac celica, and he makes 753 awhp with a tiny shot of nos to spool the turbo......

leeperryracing

Get the CR to about 7:1 and DUMP boost in if the motor is built that is. I just redid my 383 with some 7:5:1 ross pistons and running 16.5 psi, I made over 700hp from the motor itself. Read my thread in the power adder forum.

PhLaXuS

Thanks a lot everyone...I'm planning a 383 build and it would SUCK to have to rip the entire thing apart as soon as I finish just to run the turbos. On 93 pump gas, 800HP is roughly what I want to make, but more is always better.

If anyone else has more to add, it's welcome as well.

PhLaXuS

I just ordered copies of:

·"Maximum Boost" by Corky Bell
·"Turbochargers" by Hugh MacInnes

but they won't even ship until Aug 30 & Aug 27, respectively. I was going to expedite the shipment until I saw that. Argh...

1bdbrd

iTrader: (1)

another thing i would suggest that no one else has, dont go with a 383. the thing about turbos thats obvious is the ability to chang eboost levels. thats nothing new. its also not news that a smaller engine wont make as much torque as a bigger one. a turboed v8 will make a TON of torque as is. let alone a big v8. i would suggest sticking around a 355 or so that way you limit your torque and also help your traction on the street.

i would also reccomend something a little smaller than a t70 turbo. not having any exact engine details doesnt help with turbo selection. get your exact setup picked out and you can go from there.

also one last thing, i see you havent picked out your heads yet. you dont have to go really extreme with the head choice either. get something that flows well but it doesnt have to cost an arm and a leg like AFR heads. maybe some trickflows. or something in that range. you have to remember you are forcing air into the engine. the engine is no longer using its intake stroke to pull in air.

Syn

a firend and I are twin turboing a 383 in his 85 firebird. were using 2 to4b turbos

TurboedTPI

Thats what i was going to add too. Go with a 350. Shorter stroke=higher RPM=better powerband, just my .02