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SO i am stripping my 33 Gtst with a built 26/30 down for racing and am considering converting from a single GT3582r with a 1.06 housing to twins.

What twins to drop in is the million dollar question. Previously had good fun with a 3076r - is there a chance to do two of these. Aiming for good boost response say upwards of 3000 rpm. Currently have 310 KW so around this mark will be perfect.

Thanks in advance

Mike

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https://www.sau.com.au/forums/topic/363127-twin-turbo-reccomendations/
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Save your dollar and change the turbo to suit your application, the 35R with 1.06 housing is more like your aiming for 400rwkw. You could simply swap out your rear housing to a .82 item and shoot for 350rwkw, response will be great and power will be thick and plentiful.

If your aim is honestly 300rwkw, the above mentioned 3076 with .82 rear will be an all out animal. I would recommend this over the said twins (-9s), not to undercut the stripey horse but redeveloping your entire setup to achieve 300rwkw is not necessary.

Consider the twins will cost you over 2k to buy, plus redoing your exhaust and intercooler, obtaining all the factory piping etc etc etc and making your car THAT much harder to work on.

You could buy a 3076R that uses the same rear housing arrangements and dimensions as the 35R, it will also have the same 4" intake and your intake pipes will even easily accomodate the change. The 3076 would set you back a maximum of something like $1800 from GCG and you would have near the ultimate 300rwkw turbo for a 3L motor.

Youtube amuse supra, its got a 3076R on it and has BULLSHIT levels of power/response.

Save your dollar and change the turbo to suit your application, the 35R with 1.06 housing is more like your aiming for 400rwkw. You could simply swap out your rear housing to a .82 item and shoot for 350rwkw, response will be great and power will be thick and plentiful.

If your aim is honestly 300rwkw, the above mentioned 3076 with .82 rear will be an all out animal. I would recommend this over the said twins (-9s), not to undercut the stripey horse but redeveloping your entire setup to achieve 300rwkw is not necessary.

Consider the twins will cost you over 2k to buy, plus redoing your exhaust and intercooler, obtaining all the factory piping etc etc etc and making your car THAT much harder to work on.

You could buy a 3076R that uses the same rear housing arrangements and dimensions as the 35R, it will also have the same 4" intake and your intake pipes will even easily accomodate the change. The 3076 would set you back a maximum of something like $1800 from GCG and you would have near the ultimate 300rwkw turbo for a 3L motor.

Youtube amuse supra, its got a 3076R on it and has BULLSHIT levels of power/response.

You are absolutley correct - when i built the motor , I was originally planning for 400RWKW plus - but we hit the limit of the fuel system - and without moving to a surge tank and additional pumps, I was stuck at 310 - hence the original turbo choice.

This year I have decided that my new project will be to race the car, and as such she is being stripped ready for a full cage and re-spray. I always knew that he current set-up would not be optimal and hence the question.

Cost whilst a consideration is not prohibitive, and i have no requirement for factory piping, unless it fits, as I have no need to remain RTA legal.

Back when she was an RB25 - the 3076 was a great piece of gear - but will it still stand now its 26/30 and is going to be raced. I reckon given teh cage, sprayjob, new wheels and tires, big brake upgrade, new ECU, electronic dash and all of teh other goodies - I am unlikely to see much change out of $30-35K. The engine is already built, so only the head will need work, besides a strip down and check/balance.

So the question still stands - single or twins, which will be thebest for a 970 - 1000kg RWD track car????

I am running 383 kw at the rear treads (dyno'd in RWD so as not to detonate front diff) with twin HKS 2530's on an rb26/30 setup. Still running (ported) OEM cast iron manifolds. Very responsive.

With tubular manifolds (expremes or similar) i reckon could be even more responsive.

What boost?

What other mods?

http://www.skylinesaustralia.com/forums/topic/275548-andrews-r32-gtr-bolt-on-build-thread-phase-i-of-my-mods/page__st__60

22psi. Anyhow, the main point is, the turbos are now the major bottleneck in the system, but the HKS2530's are capable of making that kind of power on a 3.0, even with stock cast iron manis.

2530's are bigger than -5s right.

So - if most people get 380rwkw on 20psi with -5s on 2.6ltr... running more boost, on bigger turbos, bigger motor... I think you've got issues somewhere.

You should be well over the 400rwkw marker.

no, 2530s and -5s are basically the same. few small differences in the HKS ones but nothing major. 350kw @20-22psi is more like the norm for a good set-up so 380rwkw on a 3.0L is about right. it's a good result.

most people get 380rwkw on -5's at 20psi? bit high wouldn't you say? - i had a dig through the rb26 dyno thread for 2530 results and from what i could tell, around the low 20 psi mark, 21,22,23 people were making 350-360aw/rwkw - which i thought was about spot on for the 2530's?

on 3 different dynos i've had 358, 353 and 357 around 21psi

High how? Look @ people like Aaron34, Tangomatt etc making 400-415rwkw with 2.8ltr's on 20-22psi with -5s

Im @ 365rwkw on 19psi with timing pulled out. Jack & Snowy both made 370-380 (-5, 2.6ltr). I've posted the graphs up before.

i had a dig through the rb26 dyno thread for 2530 results and from what i could tell, around the low 20 psi mark, 21,22,23 people were making 350-360aw/rwkw

Don't forget we aren't talking stock motor results. They do indeed sit around the 350rwkw marker on stock motors (hence i think -5s are a bad choice) - so no argument there from me at all, totally agree.

Built motors with some porting and so on make more in almost every case.

-9s and GT-SS are identical - 2530 and -5 are not.

2530s are bigger, and will make more power. A 3ltr, running more boost again (when you factor things in), evidence would suggest it should be higher.

Could be exhaust restrictions, or perhaps just a conservative tune or something else entirely.

It'll be good to see when Paul & Steve get their -5s tuned on 3ltr and 2.8ltr respectively. That'll hopefully provide some more results.

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