What would you say is a better turbocharger - a GT3076 with T3 divided exh. housing or T4? So far I gathered that there us also a choice of A/R for the housings, 0.78, 0.82 or 1.06. What A/R would give a better powerband?

 

If I was going to fit a gt3076 again I would go with the T4 housing and the .63 for better spool and map on methanol if I wanted more power. Personally I have tried the gt3076 and I find the gt35 a better turbo and spools better as well

 

It depends on the engine's cc and the heads/cams/induction/exhuast mods fitted, therfore affecting the whole set-up's potential max flow rate (if ultimate max power is what you're after?).

If you post your engine spec up, then I reckon the specialists will be able to tell which exh. side and A/R would be the most appropriate for it....

 

well, lets say one was looking at the following set-up:

2.35litre, 14mm head studs, ported and polished 06 spec C heads, uprated valves and valve springs, wild cams, Fujitsubo headers + de-cat Milltek, injectors, billet fuel rails, braided hoses, Solaris ecu, intake etc.

looking for the fastest spooling twin-entry 500hp turbo )))

 

Fastest spooling at the moment appears to be the scoobyclinic billet gt30 and would easily pull you in on your power range even with the .63 housing.

 

Faster than an MD321V? looking at JGM's dyno plot the MD321V looks better, although he's using 10% meths I think. Fair enough it not a twin entry turbo, but does it matter if you can reach this performance without.

https://www.scoobynet.com/general-te...ml#post9238081

Anders

 

the smaller A/R of the housing means faster spool right, but from NASIOC I got the feeling that for twin entry turbos the larger A/R is better. What is really the case?

 

Anders,
I suspect the OP is specifically referring to rotated requirements though and is only interested in that type of turbo.

I have looked back at another car with a V running on the Zen dyno as mine did, and the lowdown curves suggest mine came on quicker than the V.

Both cars ran on the same dyno (different days though) and both ran in 4th gear (6sp box and both 2.5 engines). Mine on straight VPower and the other car on 20% BIO mix. Mine ran at 31degs ambient and other car 24degs ambient. Valvetrain is very different between the two cars.

3000rpm mine
150bhp
270lbft

3000rpm V
125bhp
230lbft

3500rpm mine
265bhp
385lbft

3500rpm V
225bhp
340lbft

4000rpm mine
363bhp
470lbft

4000rpm V
363bhp
465lbft

It is not just about turbo, but complete specification including the turbo imo.

The only true way to compare actual turbos, is to do complete back to back on the same car using the same mapper. I believe another tuner is already highlighting some of these other test results.

 

I think th OP is deluded if he thinks a bigger housing will spool much quicker purely cause it's on T4, judging by his post I pressume he has nothing of this spec built? So get ready for a huge spend. For how expensive the rotated twin srcoll pipes are and for the gains achieved I would rather go single and get a billet wheel turbo. The best choice has been made by shaun and anders and go for 321v as they are superb value and get the OP in on his power figures.