rocket5979

iTrader: (1)

The backstory: I am planning on building the engine, amongst other things, in the G8 GTTT here soon. Still deciding whether I should end up going with a stock displacement forged shortblock or a forged 408 shortblock since the prices aren't terribly far from one another. I currently am running a pair of Garrett GT2871R's which spool very well on the 364ci stock engine and are tucked down beside the transmission in a similar design to what APS uses. This is ALL street car, with a little bit of weekend dragstrip racer mixed in which means I care more about spool and boost response than all out maximum peak power.

The Question: Since the GT2871R's are a bit on the small side, when it comes to flow, for a 408ci engine what turbos of similar physical size (to fit beside my transmission) would you recommend? I know of quite a few turbos that will flow what I would want with a 408ci engine but the issue is verifying their physical size so that they will actually fit into the space I have next to my transmission. And recommendations would be appreciated.

Thanks.

Ping King

iTrader: (20)

i cant offer any suggestions, but i wanted to know if you are running a scavenge pump. If so, what kind?

I saw that your turbos are mounted low by the trans

rocket5979

iTrader: (1)

Yes I am running a scavenge pump.

Ping King

iTrader: (20)

What pump are you running?

rocket5979

iTrader: (1)

To The Top

98Z28CobraKiller

iTrader: (17)

Are you currently maxing out the turbos?

HydroStream6

iTrader: (16)

35Rs and call it a day. Or T60s.

rocket5979

iTrader: (1)

If I were to run something in the 35R range then I would probably just bite the bullet and run Precision 6062 or 6057 series billet wheel turbos.

lordrazo

iTrader: (18)

get a good pair of true 67mm garretts we made almost 800rwhp whith these @ 15 lb boost didnt even sweat them at all if you go a single do a gt88 or 91 in my opinion

Shawn @ VA Speed

iTrader: (3)

we ran a pair of t3 flanged precision 58's on a 427 due to packaging constraints,made over 800 rwhp thru an auto with no issues.They would be more than enough

rocket5979

iTrader: (1)

I understand that you are trying to help by offering suggestions but please re-read the first post of this thread. I am not asking for general recommendations of turbos; especially not in single configuration. I am asking with specific regard to physical size (not just flow ability) of the turbos due to the location they would be going back into. Right now I am running twin Garrett GT2871R's down by the transmission and it is tight down there. I was looking for suggestions on turbos that would be physically small to allow proper fit down there but also flow well enough to support a little over 400 cubes too.

I am aware of the Precision 6062's already having been used in a similar build, but on stock cubes, on the G8 in here but I am looking at all options rather than just playing copycat.

I do appreciate your input but my question is very specific here.

Shawn @ VA Speed

iTrader: (3)

you should be able to make 1500hp with 67's.no need for such large turbos

rocket5979

iTrader: (1)

Thank you Shawn, this is the exact sort of information I am looking for.

Shawn @ VA Speed

iTrader: (3)

sorry-they were 59's.precision 5957's

HydroStream6

iTrader: (16)

Stock T60s (like you can find from an STS setup on here pretty cheap) are pretty small and under a grand for the pair if you look around. They would do 1k rwhp.

wilson34

iTrader: (7)

Shawn, did you use the T3 Vband inlet from precision? Also do you think if you stepped up to a 62mm or 67mm precision and ran the same compressor cover as the 58 would limit the turbo to much?

rocket5979

iTrader: (1)

Sorry didn't see this reply earlier in the thread. I am only running the stock 364ci bottom end right now so the GT2871R's aren't maxxed out as of now. However, when I do the 402 they will be. Great turbo's, just not quite large enough for where my car is going.

redss86

What kind of power are you making on your current setup? What is your new power goal?

rocket5979

iTrader: (1)

Last dyno I did I put down 500rwhp/570rwtq but I have played with a few things since then so that is not an accurate power estimate anymore. My new power goal is somewhere in the 800 range and very streetable.