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OK, i thought i decided what i want for my 383 build, but after looking at a few posts i am worried they will be MUCH too small. I thought i was going to use a pair of TO4E, 57 trim, .63A/R turbine .50 A/R compressor.
What do you'all think?
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uhm...
havent picked out a carb or cam...
forged 383 crank, rods, +.030 pistons, 8.3:1-8.5:1 compression, Weiand intake, 882 heads to get the lower compression. all ARP bolts.
wouldnt go past 6000K for sure! horsepower around 500 or so...
i was told if i put my other heads on, which would raise the sompression to around 9.5:1 and got a 150 shot of nitrouse and a good cam i would be pretty near 500HP, but i can get those two turbos dirt cheap and if i buy the rest of the turbo stuff i need (all i need is carb and cam, already have everything else from different project) it would be about the same price as the cam and nitrous if not less
I think the turbos should support the numbers your looking for.
__________________ Boosted and intercooled L98 with 749 ecm
10.78@128-1.5 60ft(new best time july/06)-570rwhp@13lbs on pump gas. Est. 600+rwhp@16lbs on 100 octane. Capable of 18lbs, but havent done it, ok maybe once.
Featured in GMHTP mag July 07
TWO..T04E-57 turbos and your wanting only 500ish HP...
The -57 turbos are 49lb/min air flow..that is good for about 550hp EACH!!
You should have enough airflow for 1100hp...
With your 383ci get the .82 exhaust A/R's. My little 305 with two T04E-57 and the .63 A/R is almost to small on the exhaust side....
Are those T3 .63A/R turbines or T4 .63 A/R turbines? What were you seeing for before turbine back pressures that made you think that they are too small?
Are those T3 .63A/R turbines or T4 .63 A/R turbines? What were you seeing for before turbine back pressures that made you think that they are too small?
Yes, those are T3 .63 A/R.. It's not a back pressure issue of peak power. It is the relationship of exhaust volume and turbine speed that is proportional to creating boost. These .63 A/R create boost very early with my TPI, at 1800rpm I have positive intake pressure, by 2200-2300rpm I am at 6psi. This type of power/boost ok, but remember this is a 305ci. " sLoW'n'StEaDy" has a 383ci engine. His motor would create boost earlier (all factors equal) than my 305...hence the a larger A/R may worth looking at.....
No doubt I would use larger than T3 .63 A/Rs on a street twin setup with T4 compressors. I was curious what you were seeing for exhaust backpressure. That is a quick spool time for T3 .63 A/Rs on a 305ci. Is that measured with a ECM or eyeballing guages? I think exhaust heat, cam selection, torque converter stall, and gears have the greatest affect on spool time. It sounds like your setup is pretty good.
I am data-logging my MAP, RPM, IPW. The 305ci does have ported heads, cam, and TPI work. I am planning to log the exhaust back pressure, I will do that when I start to turn the boost up. Single 3" exhaust....
If you’re really looking for 500hp out of a 383, you’ll be money and frustration ahead doing it NA or with some spray (this will all assume that the info that you gave so far is fairly accurate), swapping those 76cc heads for some 64’s will give you roughly a point more compression, swapping them for some 58cc heads will put you around 10:1. If you plan on running a 150hp shot of spray then you can practically get the 500 in your sleep. Just a straight rebuild/cleanup with 3 angle valve job and 2.02/1.60 valves will flow enough and you’d only need a big enough cam to make your HP peak around 4500 rpm. If you wanted to do it all or mostly NA, then you’d have to build the engine to turn about 6000rpm and find another 30-40cfm in the intake ports, which you could do with some pocket porting and some basic port work, or with a set of vortec heads and mostly just a clean up.
The fact is that you’ll be able to reuse most of your existing parts, and not have to fabricate anything to make this work, which in the long run will be cheaper no matter how cheap you get the turbos.
As far as doing it with turbos… well it won’t take much, a pair of 60 trim T3’s will do it easily, but will also come on like a freight train on a 383 and will stop breathing by somewhere in the 5xxxRPM range.
Who is the manufacturer of the T70's you have?
With two of them you should have enough flow for over 1000 HP or just keep one as a spare and do the 500+ HP thing.
OH yeah... i started a new thread but forgot to put it in here...
I bought another car a couple days ago and have decided to just "go to town" on the TA. moving into my new place this weekend, so wont be able to do too much for a couple weeks, but shouldt take too long to finish once i get everything situated!
turbos form ?Auto Power Enterprise? or something like that. i have run a few of them as well as a few other people i know with no problems what so ever. my buddy still has one on his DSM. Nearly a year now at about 20psi with no problems
Ebay...
I KNOW I KNOW... i have run them before, as well as a few friends, they hold up GREAT!! they are all cast unlike the SSAC turbos which are two pieces held together by adhesive!
Well, I won't give you a hard time about using the Ebay turbo(s). I think it is great that someone buys them and posts how they work and the reliability. Actually, I have seen quite a few Ebay turbos that look like they are built fairly well. It looks like there are different manufacturing plants and all of them get the name of SSAC because they are not marked with a manufacturer name.
What gets me about the Ebay turbos is all of the incorrect specs. Things like trim specs with mm (millimeter) on the end don't make sense. Sometimes they don't spec the inducer size and only give the trim which is useless. For example, they call that turbo you bought a T70 when in the normal turbo would it would be called a T-60 (60mm inducer wheel). That is, the old T series stuff and not the GTXXYY terms.
I clicked on the link. Does it really have a 60.5mm inducer compressor wheel (you measured it)? Is the trim really 64.5 trim? Is the .84 A/R housing a T4 size or T3 size? Is the inlet gasket a T3 or T4 flange. I have eyeballed the GT42 series to play around with on a stock 305ci 130K engine I use as a dummy fab engine. The engine is junk and nothing would be lost using the no-name GT42 except for time but the experience would be fun.
EDIT: Do you have a close-up picture of the TAG on it?
EDIT AGAIN: Where did you find the V-band clamp for the turbine outlet and the turbine inlet flange? Is it a standard T4 or T3 stainless steel gasket? Is the outlet 3"? What's you favorite color.....just kidding....lots of questions here.
