Anyone using a single turbo GT-R as daily driver?

[medici78]

I'm looking to place an order at Motorex for an R32 GT-R (I'm in the US) in the next couple of months and I figured I'd start stocking up on parts while it was in transit. I have seen excellent results for single turbos on Supras, and while the GT-R may not generate the same absolute numbers that a Single supra can (assuming the same turbo kit, etc.) I would like to try this out on a GT-R. I was just wondering if anyone here used a single turbo GT-R or had experience with them. I would like to get at least 500hp to the ground, maybe more, but I don't want to open up the engine aside from installing a metal head gasket.

[R33]

Hi Medici..glad your GTR is forthcoming! Join the club....and enjoy!
A friend of mine over here is running a single HKS TO4R turbo on his 33. Has about 535 rwhp with no problem. I'd driven it before and the performance is comparable, if not better, than mine. But there are a lot more mods in the engine, for eg, 24 cams, oversized forged pistons, carbon fibre prop shaft, metal head gasket etc etc. For best result and reliability, IMHO, u need to change at least the pistons, cams, pulley kit and gasket with the kind of power u are looking at. Fuel pump and injectors are also mandatory to ensre adequate mixture. It also means that ECU has to be remaped.

[medici78]

Yeah, business is picking up again and I want to enjoy the $$$ while I can. Anyway, I did have several of the other mods in mind. I know for a fact, the fuel system would need an upgrade. The cams were also a possibility as well as the obligatory metal head gasket. Basically, I would like to do everything you mentioned, minus the bottom end.(pistons, crank, etc.) In fact HKS T04R or Trust T78 are two kits I had in mind. I know the one of the guys from Motorex (Justin) was putting down over 500HP to the wheels with, I believe, 2535 HKS turbos(not sure of model, but if I recall, one step below yours). He had yet to open up the bottom end of his motor and they all feel it is capable of at least 600HP without replacing con-rods, pistons, etc (once again the head gasket is necessary, though). Of course, you're blessed with more knowledge of these cars than most (you lucky $%&!). Is the lag that much worse? I figured with the appropriate driving technique it could be tolerable. You mention a "prop shaft". Do you mean driveshaft(transmission to rear differential)?

BTW: It's been awhile, R33! God to see you're still around! I decided on the Skyline after deliberating between new M3 and '94-98 Toy Supra. Even though these other cars are relatively rare here(believe it or not, the Supra is pretty rare in US), I know NOBODY in my town will have a GT-R until the next generation comes around. Also, the Skyline (even with Motorex mark-up) far cheaper than the M3 and comparable to '98 Supra.

[R33]

Yeah...I think it's ok with the stock bottom end up to the big SIX! I changed the pistons to forged ones just in case and also they are lighter and that helps a lot revving up. My 2540 is not that much bigger than 2535. The lag is tolerable with boost coming in at about 2100rpm in 5th and going up to 1 bar at below 5000rpm. All in all I could live with that but the top end is something to be experienced! The lag is somewhat countered by the porting and polishing job. Added to that, I don't mind changing gears .
The carbon fibre propeller shaft (which connects the front drive with the rear) is expensive but it is a work of art in itself! Seven times stronger than steel and a lot lighter which goes a long way towards improving response. If I have the money (It's always IF isn't it?) I would put it in.
I thought there were a lot of Supras over there. It's a beautiful car and very comfortable and yes, very fast as well although the traction is shitty. The M3, well, I am not into yuppie cars!
Good luck mate and do fill me in on your GTR.

[Gtr2.7L]

Why go single? I would stay with the twins. Most tuners stay with twins until 750 or so. Less lag and the price is about the same...if not less. Where you planning on buying the turbos from....I can get you a pretty good deal on whatever you get if it's from Apexi or HKS.

[32godzilla]

R33 how much boost do you run in your turbos? What type of ecu/injectors/fuel pump? And what a/r are your turbos? What would you recommend as an all out low mount setup? 2540r's? i don't mind lag but would to know the best a/r for the turbos?

many thanks

[R33]

The boost is set at 1.5 bar though it sometimes peaks at 1.55 (boost cut is set at 1.58 bar though that never happen). ECU is Top Secret Competezione ROM. Injectors are NISMO 600cc with NISMO fuel pump and SARD fuel pressure regulator managing the supply. My AR is o.64.
I have driven my friend's TO4R equipped GTR and another's 2530s equipped GTR and I would say the 2530s offer a well balanced low mount street package. The 2540s' top end however is addictive, to put it mildly, and it completely eclipse whatever low end advantage the 2530s may have. Just wait till it hits 6000rpm and the rest, as they say, will become history in a very very short time .
There are ways to manage the 2540's inherent lag one of which is to port and polish the head and manifold which I did. If you go to the track often, I would say go for the 2540s. If you are a traffic light racer, you may want the 2530s.
That's my personal preference.

[32godzilla]

Thanks for that R33, I was just a bit worried spendind a lot of money on turbos and not having the desired power levels. These turbo's really sound like the ideal upgrade for a weekend drag racer/daily driver. Can i ask if you are still using the stock intercooler? Basically i'm looking at pretty much the same fuel setup/power fc and the hks stage 2 cams setup/twin plate clutch. Do i really need to worry about forged pistons? sounds expensive?

thanks heap!

[SkylineUSA]

I have always thought when it comes to engines. Your engine is only as strong as your weakest link. If you plan on running the same as R33, I behoove you to use forged pistons.

When you try to cut corners, it always will bite you in the ass, not to mention you end up paying more because of the damage it causes. My 2 cents.

[32godzilla]

SkylineUSA you make a good point. But i was just wondering whether the forged pistons are a critical upgrade as i have seen other setups using the stock internals. When it comes to rb26's i'm a newbie. I have been told that they are a true racing engine and can support over 600hp providing they are tuned correctly. Any ideas?

[Spoolin']

You are probaly right about the stock piston, but if I am running a 600hp engine I will not run the parts that I am using at there limit. Meaning, I will build it for 750hp and then run it at 600hp. For the 600hp internals I would max out 450-500hp. You will have a longer lasting engine that way.

[R33]

The GTR is a living legend and like every other legend, it's full of myth! Unless we are privy to the GTR's design team, we would not know for sure the FACTS!
My point is that we will never know for sure about the strenght of the bootom end of the RB engine. Neither will we ever know the limit of the stock gearbox, oil pump etc etc. I have read of Mario's GTR for instance, which is churning more than the big six horses at the wheels with completely stock bottom end and it is running okay! On the other hand, there are people, like my local HKS tuners, who would not even touch your GTR if you are thinking of more than 500 horses without changing the pistons, oil pump etc. Is it a FACT that the stock engine would bottom out after 500 horses? We don't know! And we won't. These advices could very well be aggressive marketing by the tuners, to say the least.
So, when we want to mod the GTR, we are left with all sorts of questions and options. Since it is our money, we had to make a choice. And I am a sucker for reliability. So, when the tuners say "change the pistons", I had to agree. Because they are the proffessionals. I have to confess that I don't know whether it was necessary to do that in the first place!
As for the intercooler, ambient temperature is pretty high over here all year round (average temperature is 35 deg. C). So I changed to HKS GT intercooler which is damn expensive. I suppose the choice of intercoolers are far more varied in the US so it wouldn't be of any problem to you.
And yes, I have heard that the RB can be tuned up to six hundred if they are fed properly. Mario's car is a testament to that.

[Gtr2.7L]

Sort of what I did....I'm running 450 AWHP on a 750HP capable engine. GTR's run best in road events between 4-500 to the wheels. If you want to drag..obviously you need more. I'm pretty happy where I am....plus, I don't have that annoying idle that comes with the crazy cam profiles!

[R33]

Yeah...I think 450awhp is more than enough to smoke the opponents!
Erm...one more thing which I heard people said. It's not the boost which fries the pistons, it's the revving. Stock pistons are good for up to about 8000rpm, if you want 8500rpm, change the pistons, 9000rpm, change the rods and anything above you'd have to change the crank. Facts or myth, I do not know!

[Gonthrax]

Originally posted by R33
And yes, I have heard that the RB can be tuned up to six hundred if they are fed properly. Mario's car is a testament to that.

The RB can be tuned up to 1000+ hp if you want to spend the money But that cuts down on drivability if your using it as a street car or if you run races on road courses. Drag racing only I say, although I'd like to drive one once


32godzilla: It is a true racing engine, its name even says it RB26DETT = Racing Breed 2.6l Dual over head Cam Twin Turbo