Not A Skyline But Maybe Some Of You Guys Could Help Me Out?

[BLN215]

Hey guys im new here hows it going?

Anyways im about to start progress on turboing my VS GTS (355ci forged bottom end/heads/custom roller cam etc) and i was looking into running a single GT42R or a slightly smaller Precision PT74 but im almost thinking twins could be a good option.

Would you guys think a pair of gt3082r's with a .68rear and the T3 style 2.5inch exhaust would be a good choice on a 5.8ltr V8??

Im looking at around 600rwhp on about 14psi with spooling starting around 2000rpm and full boost hopefully by around the 3-3500rpm mark,will these babies do the job??

Thanks in advance Nick

[Duncan]

how big is a "ci"? didn't we go metric in the 60s?

[mesmerized]

not trying to be rude, but wouldn't it make more sense to ask the guys on the ls1 forum??????????

http://www.ls1.com.au/

[BLN215]

how big is a "ci"? didn't we go metric in the 60s?

Thanks mate real helpfull

[R31Nismoid]

355 is a stroker to 5.7ltr i believe

383 is 6.3ltr?

correct me if im wrong, been MANY years since my v8 days died off

either way, VERY hard questions to answer when not many would have any experience, i certainly have no idea

[BLN215]

not trying to be rude, but wouldn't it make more sense to ask the guys on the ls1 forum??????????

http://www.ls1.com.au/

Yeah thats an LS1 forum i have a Holden 5.7ltr stroker,besides i thought you guys would have more of an idea on Turbo's being a skyline forum and all

[BLN215]

355 is a stroker to 5.7ltr i believe

383 is 6.3ltr?

correct me if im wrong, been MANY years since my v8 days died off

either way, VERY hard questions to answer when not many would have any experience, i certainly have no idea

Nah its definately a 5.8ltr it was a 5.7ltr or (349.8ci) when it was a virgin bore but after the 30thou bore during the rebuild the cubic capacity increased to 355ci and 5.8ltrs

[sh@un]

355 is a stroker to 5.7ltr i believe

383 is 6.3ltr?

correct me if im wrong, been MANY years since my v8 days died off

multiply by 16.38 to get the capacity in cc's (i.e 5814cc)- so 5.8 is right

The twin setup would be the best option- saves having to run a set of exhaust pipes all the way from the other side of the engine, with the backpressure differences, heat, and associated headaches that that causes. The 0.68 ones should work well. It will need to be intercooled to achieve that rwkw figure, obviously

[funkymonkey]

try this reading some info on this thread:

http://www.skylinesaustralia.com/forums/Ga...al-t134033.html

and this:

http://www.skylinesaustralia.com/forums/Gt...et-t169915.html

thing is most of us use a single 3082R on our engines, usually an RB20 or RB25 (2.0L and 2.5L respectively). What you're suggesting is using two of them on an engine with a displacement more than twice that. Now, turbo's are spooled by exhaust gasses, so assuming your engine burns twice the amount of fuel as ours, it'd make twice the amount of exhaust, which means it should spool two of those about the same as one of those turbo's on a skyline. Its only my guesstimation though. You'd really have to ask someone who works with turbo V8's for a definitive answer. I'd look towards forums in the US, specifically turbo corvette forums.

[BLN215]

multiply by 16.38 to get the capacity in cc's (i.e 5814cc)- so 5.8 is right

the twin setup would be the best option- saves having to run a set of pipes all the way from the other side of the engine, with the backpressure differences that that causes. the .63 ones should work well. is it going to be intercooled?

Yeah mate its got a 600x300x75 front mount already from my Vortech blower set up i sold off,would the .63's be o.k or a little restrictive on the 5.8ltr? Maybe a .82 or similar rear?

[sh@un]

thing is most of us use a single 3082R on our engines, usually an RB20 or RB25 (2.0L and 2.5L respectively). What you're suggesting is using two of them on an engine with a displacement more than twice that. Now, turbo's are spooled by exhaust gasses, so assuming your engine burns twice the amount of fuel as ours, it'd make twice the amount of exhaust, which means it should spool two of those about the same as one of those turbo's on a skyline. Its only my guesstimation though.

it's not quite that simple- essentially having 4 cylinders of "2.9L" worth of displacement per turbo would spool them quicker than a 2.9L RB feeding into the one of the same turbos used as a single- the reason for this is that turbos spool quicker when supplied with low frequency pulses from large cylinders

Yeah mate its got a 600x300x75 front mount already from my Vortech blower set up i sold off,would the .63's be o.k or a little restrictive on the 5.8ltr? Maybe a .82 or similar rear?

depends on the trim specs of the compressor and exhaust turbines, and the A/R of the compressor housing

i'd be looking to get turbos that can flow enough air in a twinned application to make at least 850 or-so-hp at the boost you want to run to ensure you can get the 600rwhp ur after

edit: you'll prolly want turbos that can make about 450hp each

[R31Nismoid]

ye the whole thing of 4 cylinders feeding as opposed to 6 in split pulse, or 3 in twin form

it makes for a massive dynamic difference

[funkymonkey]

but the net volume flowed through the turbine should be more, which should make up for the lower frequency of pulses.

[sh@un]

at high revs, yeah- but that's not going to help transient response low in the rev range

[funkymonkey]

hmm and given that he wants them spooling at 2000RPM that might not be too easy. Sequential turbo setup might fix that?

[sh@un]

complete waste of time

full boost by 3500 is doable on an engine that size

[Jdfnq]

complete waste of time

full boost by 3500 is doable on an engine that size

Yep agree with that

There are few lads up here and in Townsville that have the twin turbo set-ups on their V8's... There is also a wee Lexus IS200 with a twin turbo V8 in it

Try checking out qldstreetscene.com

[N I B]

Those Turbos will do what you want.The big problem you will face is head gaskets as the Old plastics only have 4 head studs per cylinder and need all the help you can give them,1/2 head studs,Good gaskets etc etc. If its not to l;ate maybe look at a Chev as they have many more studs and dont try lift the heads of.The other problem has been finding drivelines that can live with the torque.

[paulr33]

speak to capa or apss (air power systems) and get a twin turbo kit

its the easiest way to turbo a v8 with re-doing bucketloads of crap

a twin gt28ish would be plently enough for a good chunk of 500rhwp id expect

[wrxhoon]

If you can't make 600hp with almost 6 lts without a turbo there is something wrong .

Most stock engines make 100 hp per lt these days without a turbo and I can think of a few that make close to 100 kw per lt .

Get rid of the old pushrod donk and buy a proper engine, with the aid of a turbo you only need half the displacement to make your 600 hp.