Big Single or Twin for GTR???

HIRISK · #1 12-09-2001, 06:21 PM

Hi Guys,

I am unsure of wether this has been discussed in detail on this forum but here goes......

I have a 1992 R32 GTR. My goal is to acheive 550 to 600hp.

I am slowly working on the motor and adding all the things that can be done before the turbo's......like intercooler, exhaust etc.

What I would like to know is how the hell am I supposed to make an educated decission on wether to go SINGLE or TWIN!!!

As an example.....if you had two IDENTICAL (appart from turbo's) RB26's, one had a Trust T76 and the other had two GT2540's.....both are tuned to 600hp......which would be the better engine???

I know that there is a lot of things that will change the outcome but I would just like to get peoples opinion on this.

So what is better for 600hp - TWIN or SINGLE????

Gtr2.7L · #2 12-09-2001, 08:35 PM

Everyone that I've spoken to about it has said pretty much this. If you plan to go more than
750 HP...go with a single BAT (that's Big Ass Turbine

). If you're planning on staying under
that number, go with Twins....you have better spool up with the Twins (which I'm sure you know
will give you better kick at lower RPMs). If they could make
twins that put out the same volume as a BAT and still fit in the engine bay, that's probably
what they would do. (it's that whole cylindrical volume increases exponentially with radius
thing) As for the 2540's....Although that's what I'm running, I've heard the 2530's put out
almost the same power and give you better spool up (they're just a smite smaller).
Over 600, most people out here use the HKS 3037's for twin turbos....
Single is cheaper (don't forget you have to buy a new exhaust setup though),
Twin gives you more boost at lower RPM's (You really should buy the HKS Induction Piping kit
anyway...about 1000 bucks, otherwise you could be faced with piping collapse in that rubber
piping they use!)

R33 · #3 12-11-2001, 02:38 AM

Well, that about sums it up GTR2.7L. Could not put it any better. I am running twin 2540 and the car churns 605 hp. Lag is not that bad but to I have to mention that the head and manifolds are ported and polished to improve flow (that helps to reduce lag). Also the cc is increased by using oversized 87mm pistons.
A friend of mind is running about 600hp in his 33 and he is using a single HKS T04R married to 264/264 cam kit. On the track our respective car seem to be the same in performance but my car has the edge after about 7500 rpm (I am using 264/272 cam set up). I have heard that drag GTR always use single - I am not too sure whether that's true. But if you do choose twin, I suppose 2530 would spool up a bit faster than the 2540 though I think the 2540's lag will be cancelled out at about 6000rpm when it really is on song.

Suprascene · #4 12-11-2001, 12:26 PM

I posted a thread asking a question like I'm about to ask which can be found here. Basically if you guys can help meo ut on that thread, I'm looking for info and perspectives on the smaller HKS twins. Thanks!

Sorry about being off-topic. Goodluck in any event HIRISK!

NIGHTMARE · #5 12-20-2001, 12:09 AM

I have a single coming:licker:

Shooter Boy · #6 12-20-2001, 08:53 AM

Quote:

Originally posted by NIGHTMARE
I have a single coming:licker:

Its just a little guy though.....

j/k

We are running the HKS T51 and will know more about potential and HP number when we finish the engine....

We should be able to make some pretty amazing HP numbers though.

R33 · #7 12-21-2001, 03:43 AM

I feel THREATENED! :silly2:

RazorGTR · #8 01-02-2002, 05:07 PM

Most of your top GTR drag cars in Japan run a twin setup. The HKS car uses a twin set up and is the quickest ever.

skylinegtr · #9 01-04-2002, 08:51 PM

I say big single. but at the end of the day mate it is upto u

PVL-747 · #10 01-07-2002, 04:16 AM

although i drive a VL turbo, i have a RB26dett head with a RB30 block, my car is being setup for 1/4 mile racing. i have gone for a Y2K turbo. very large!!

1000+hp turbo.

http://www.geocities.com/pvl747/pvl747.html

Gtr2.7L · #11 01-07-2002, 05:49 AM

RB30DETT! VERY NICE! I've got all the instructions on building one to put in the "R". I'm looking around for an RB26 head now.....
How much did you pay for yours...with or without turbines?

PVL-747 · #12 01-07-2002, 05:54 AM

Gtr2.7l, the complete motor not including turbos cost me $2800. its a R33 GTR 1996. it had one crack piston. i'm only using the head, i've got all the goodies for the motor. can't wait!!

http://www.geocities.com/pvl747/pvl747.html

R33 · #13 01-07-2002, 11:56 PM

RB30 block....that's awesome! Where did you get it from and how much?
BTW, GTr2.7L, could you tell me how much is the OS Giken 3 litre stroker kit for the GTR? Is there any second hand unit available? Can you source it for me? I would also like to know whether there is any HKS seq.6 set second hand in Japan. Your help is very much appreciated.

PVL-747 · #14 01-08-2002, 03:25 AM

it cost me $100 for the 3 litre block. it's out of a Aussie VL Turbo Commodore (which is a Nissan RB30det).

http://www.geocities.com/pvl747/pvl747.html

Gtr2.7L · #15 01-08-2002, 04:09 AM

DEFINATELY GO PV's way! OS Giken wants 1.4 million yen (11,000USD) for their kit.....You're WAY better off getting the block from Australia, an RB26 Head with all the goodies, reinforced rods, pistons and shaft ....all for a "measly" 7G's....and it would be just as strong!

Also...whoever asked me about the Hollinger 6 spd....I'll look....but I doubt it will be much less than list.....I'll keep a close eye for a used one...those things are gold though!

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