Any GT-R owners running a single turbo?

[medici78]

Just wondering if anyone here has experiences with converting from twin to single turbos and pros and cons of doing so.

[R33]

Medici, I only know of one GTR R33 which is running a huge single HKS TO4R turbo kit. Doing about 525 bhp at 1.2 bar of boost. Cam setting is 264in 264 ex with oversized 87mm HKS forged pistons. Went to tha track with the owner last mth and it is damned fast. Whupped my GTR coming out of a corner in 2nd (I was in 3rd!). Managed to catch up later but too late to overtake. Lag seems to be less than my GT2540s but I heve more top end power after 6500 rpm with my 264 in and 272 ex set up. Haven't had the chance to drag race with him. The owner however had dragged with a GTR with GT2530 and he lost out in the quarter. I suppose it's a good set up and the TO4R kit is actually very very good value - came with manifolds, GT wastegate etc.

[medici78]

R33, we missed you, my friend! Well, it looks like my chance of getting the Skyline idea is getting better and better. Since the initial purchse of the car (at least here in the US) is gonna drain most of my available finances, I will want to upgrade on a budget. From seeing the example you speak of, would you recommend the single turbo?

[GTS-4 Ben]

There are a couple of Single Turbo GTR's here in New Zealand.

From what I have seen there is no difference either way. I have seen a R34 fitted with both. A T88 Single or 2 slightly smaller ones. Power was the same, just a few different characteristics.

The main reason for a single turbo setup is it is cheaper than modifying and buying 2 turbos to achieve the same thing. The GTR is ofcourse twin turbo from the factory, but when much larger turbo's arw used the exaust manifold has to be replaced.. therefore a larger one is recommended.

On a 6cyl car such as a GTR. They say for anything over 400HP single will work out the best.

[R33]

Medici, good to know that I was missed! I was off line for sometimes as I was busy moving office. I was also assisting my partner in a murder trial!
Single vs twin. That's a conundrum! I am advised by the HKS guy over here that the single has less lag than twin. (although that seems to defy logic! I mean, it takes a hell of a lot more to move a huge single than a pair of small turbos. But I suppose in a twin configuration, the exhaust gas would be divided to turn a pair of turbo while in a single set up the whole gas turn a single turbo - that balances it out I suppose).
I know however that many draggers use singles. Single also reduces weight as there is only one turbo and one everything else. I am also advised by this guy that a TT would be better around the track than a single as the TT top end is almost inevitably better . I tend to agree with that because on the track, after the TO4R guy overtook me in 2nd, I managed to catch up when my boost came on full (bearing in mind I was in 3rd when he overtook me). I however could not overtake him the lap after that because his suspensions is better set up (he uses 2 spring set up at the rear) and his AP caliper is far better than mind (full racing caliper compared to my road and track caliper). But on fast corners, I always caught up with him. I think my TT and cam set up is better than his on the track (anyway my car is optimised for track). The TO4R I think behaves more like the GT2530s (which I am advised is the best TT set up up to 550 hp).
So it boils down to preference and driving condition really. Having a GTR is half the fun ....the other half is getting to know the beast and setting it up to your own requirement. I am pleased to learn that you will be owning one soon. I tell ya....you won't regret it!

[R33]

Sorry, one more thing. GTS 4 Ben, I don't think a single turbo mod would be any cheaper than a TT mod. In fact it could be more expensive as in a single set up, you would have to change a lot more things (manifold, induction pipe etc). That's why a single turbo always come in a kit for the GTR. The TO4R kit comes with all the required bolt on things including a monster wastegate and really well built manifold. In Malaysia it cost about USD 5K while my 2540 just cost USD 2.5 K. The engine parts are the same anyway - cams, valve kit, pistons, oil pump, fuel pump etc.

[GTS-4 Ben]

R33 you are right, but when installing significintlly larger turbo's for a twin setup you also must replace the exaust manifold and new intake manifolds must be created because of the larger intake diameter.. even the old AFM's will be useless...
2 Large turbo's will never fit in the factory position, they have to be moved up.. hence a new exaust manifold, also with external wastegate fitted.

The single system becomes a hell of alot cheaper when you are going for HP upwards of 800HP. I think from what I have heard as much as 30% cheaper than a twin setup.. but even for 500 + HP a single system can prove cheaper.

As for performance difference, both systems seem to have reached max boost of around 1.3bar at almost identical RPM. Trust T8834D and Twin TD06. The twin setup may have a slight better responce..

So ofcourse if you keep the twin system with the stock manifolds the twin will be cheaper.. but when you are paying $4000 for a turbo.. and still have to buy the manifolds.. I think I would be buying one big one

[R33]

Well GTS 4 - you are correct to say that - if the TT you are putting are damn huge, you need to put them on top as there would be no space in the original position. That would entail new manifold/piping set up and would also be costly. The HKS GT series turbos are however fittable at the original position and like in my GTR, the manifolds don't have to be changed. In my case, the manifolds are ported and polished. I'd love to put in the HKS manifolds, really well built and much lighter but in my country's climate, they are proned to crack.
BTW, a set up of anything more than 600hp would be extremely expensive and driveability will become an issue (unless you are not going to drive it everyday). There are a lot more parts to change after 600hp - gear box/crank/rods for instance.
I'd seen a 800hp R34 in S'pore where I did my car. It's AWESOME! But the owner told me he has to drive in 3rd gear all the time if he is doing only 100-110kph! His clutch burns up every 3 mths or so! And if he drives more than 10 mins in heavy traffic at say 20-30kph or less, he's got to watch out for the oil and engine temp. On the other side of the coin is this guy called Mario in the Oz who I think have a 800 whp GTR without changing the internal! Dunno how he did it and whether it's driveable or not! He must be a genius!
IMHO, 600hp is the limit for road use with more than average performance on the track. Anything more, you would be driving a race car.

[GTS-4 Ben]

Yeah Mario has 600HP at the 4 wheels at the moment. He has spent alot of money on the Cams etc.. he would never tell you the exact setting for them..

I think his is also drivable with 600Hp at the 4 wheels.. but that costs the extra money.. I know people with 500HP, but they don't last long and are not drivable.

So good to see we get each others points. A twin setup will never be the good option for over 600hp.. but what fun it would be

[Shooter Boy]

Since the motor is currently out of the car, don't ask me to elaborate on what our times/BHP is at the moment, cuz there aren't any, but this is the setup:

HKS T51R Single Turbo
HKS 60mm GT wastegate
HKS 3" downpipe

that is the standard upgrade for the single, but along with that we are in the process of completely working the motor, with all new HKS goodies. The fuel system is being handled by HKS Fuel Mgmt system, with 1000 CC injectors, SS braided lines, 1500 HP extrenal pump w/ multi filter setup, huge Race Spec FMIC etc etc.

Now, I didn't read above - but what are you asking about the single?

[GTS-4 Ben]

I think we sorted it all out.. try reading it..

Just came to talking about advantages of Single or Twin etc..

[brendonm]

Nick Jenkins is running a single turbo in his R32 GTR over here in New Zealand, he is running consistant 10's on the 1/4. His GTR is supposedly well above 600hp. It's main problem is delivering to the ground as he has been through a number or gearboxs and clutches...

Brenhan has also just completed a twin to single conversion in his R32 GTR and has chosen to go from a LINK aftermarket ECU to Haltech. He is setting up for drag.

[GTS-4 Ben]

Awesome, the more the better

[Brenhan]

Mine is not quite complete , still waiting on Mr Rob to do his part . mine wont be much of a drag car , it should be more like "will be set up to scare passengers" .
Brenhan

[GTS-4 Ben]

I hope you are going to bring it down and scare me and Johno with his new Blue race GTR.