Which Turbos for GTR, street and circuit?

[Simmo]

I'm going to upgrade the standard turbos soon on my GTR, its a street car that does the odd circuit day, but will be going to the circuit more frequently in the future.

Its not over the top, Power FC, cam wheels etc. Internals are standard, and will remain this way for as long as possible. I realise with turbos I will need to upgrade fuel delivery, and possibly the intercooler.

Afaik there is basically 2 options, 2530's or N1's. Can someone explain the different characteristics of these turbos please?

Cheers

Simmo

[Sydneykid]

Hi Simmo, I have driven GTR's with both N1's and 2530's and there is not a lot of difference in maximum power (around 620 bhp) or its delivery. I'd give the 2530's a very slight advantage in response, but I would think you will be pretty happy with either. Be aware that split dumps make a big difference on both. For circuit work the N1 Turbos are homologated, so running in the "standard class" may be attractive.

If you are using an R32 VSPec or N1, R33 or R34 GTR standard intercooler it will be OK, if it's a standard R32 GTR interccooler you will need to upgrade.

A Bosch 044 in tank fuel pump will provide more than sufficient fuel for your stated purposes.

I didn't see a CAI on your list, it makes a big difference on a circuit GTR, plus an oil cooler and enlarged baffled sump are both ESSENTIALS (you have been warned).

Hope that is of some help

[vspec2]

hi Sydney kid its interesting to hear you say that a R32 Vspec intercooler is ok to use yet a standard R32 GTR is not. I pulled out my stock cooler from my R32 Vspec2 and its exactly the same as a stock R32 GTR in size, fins and end tanks are the same etc.. unless I'm missing something

cheers

[Amaru]

Simmo,

Im currently getting HKS 2530's fitted to my R32 GTR as im typing this (I managed to blow a stock one up).

Only mods to the car are Apexi Power FC, Apexi AVC-R, 300ZX afm's and upgraded injectors. Due to this (stock cooler, no oil cooler yet, sump baffles etc) it will be running a pretty modest 12psi of boost until I can invest in these things in the future.

Ill get back to you with how it goes, and im also in Canberra so we could meet up one day and go for a drive if youre interested.

[Sydneykid]

Hi vspec2, Nissan are notorious for this type of thing, when they run out they use what they have, i have seen all sorts of examples of this. The R32 Vspec is supposed to have the same intercooler as an R32 N1 and R33 GTR. I can only personally say I have checked 1 X R32 Vspec and the intercooler was the same as our N1, with 2 more rows than a standard R32 GTR intercooler.

The standard R32 GTR iintercooler has 24 rows with the top and bottom on the fins not having tubes (they are flat plates instead) connected to the end tanks. The Vspec and N1 intercoolers have 26 rows with the top and bottom tubes on the fins being connected to the end tanks. This effectively increases the coolingarea by 10%, one reason why we find the standard R32 GTR intercooler to be OK to 270 rwkw and the R33 GTR OK to 300 rwkw. There may also be internal differences, but I have never cut one up to find out.

If you measure the dimensions you find almost no difference, you do have to know exactly what you are looking for or have a sample one to compare next to it.

Hope that helps

[Amaru]

Hey well I just picked my car up with the 2530's and what can I say... damn

They are awesome on the street, you can just use a quarter throttle and cruise around nicely, and if you want put your foot down and they spool up very fast (and im only running 12psi).

[vspec2]

Sydney kid, I never checked how many rows so that might be it. I sold my cooler a long time ago so I guess the guy who bought it off me got a pretty good bargin then. I now have an ARC cooler which have huge fins.

btw you know the correct way to setup/install an AVCR on an GTR

cheers

[whytry]

simmo DDDUUUUUDE long time no see/hear. yep the 2530's are the way to go. apexi make similar spec turbo's to the 2530's if you want to be different.

there is a lot to be done on gtr if you willing to take it to circuit once in a while. since you mentioned you'll still be driving on road, most is what sydneykid mentioned and then some more.

properly baffled oil sump (and i'm not talking bout the trust sump extension)

oil cooler (a must)

trans cooler (unless you'r really serious bout racing)

diff cooler (same as above)

larger (aluminium radiator)

intercooler

proper brake pads (endless, pagid ect for circuit/street)

proper brake fluid+'legal' braided brake lines

brake rotors (since gtr has cross drilled and slotted rotors, you'll find that they'll crack once you do the above mentioned brake upgrades, once on circuit and hard driving, so you might want to check the condition their in)

cusco brake master cylinder support bracket (the cheapest and the best upgrade)

oil catch can (a must)

suspension (take to a specialist to set the camber for track + balance and alignment)

semi slicks tyres would help

tuning (you can never have enough tuning, just stick with ONE workshop to do it, and not 'just' on dyno but while driving i know it sounds silly but it makes a difference, preferably on circuit/track. go for maximum torque not kw)

i'm presuming you'll be racing it in goulbourne (wakefeild park) if so you won't need 'most' of the parts i mentioned as the track is small and tight and high revving/high speeds won't happen.(unless you're a real nutcase)

gearbox (depending how hard you 'jam' in between gears you might want to look at strenghthening the syncro's as you found out)

i hope i haven't put you off with owning a gtr, but if you want it to last, it'll help if you go about it the right way. that's my 2 cents anyway.

p.s. is she on the road?

sydneykid wrote "around 620bhp on n1's or 2530's maximum power" ??????? running what fuel?

[whytry]

another easy or cheaper alternative.

buy standard gtr turbo's change the ceramic wheels to steel, have it tuned low boost on normal pump fuel, extreme high boost on c16 or avgas. either way you'll need the sump + oil cooler. then enjoy specially when you tell people you're running factory turbos.

[Simmo]

Thanks guys

most of the things you guys mentioned are being installed or modified atm.

I thought I had brakes sorted, ie brembos braided lines and good fluid but 5 laps at wakefield and I'm all outa brakes! anyone want some brembos 2 piece rotors and race pads? Ap seams the best option, they'll be going on soon $$$$. Gearbox I'm not going to go overboard with, just a 98 spec with double syncros and a twin plate.

2530's seam to be the go, I think they'll get the nod.

Anyone want some whiteline bilsteins? only about 5k km on them.

Car is kinda on the road, just has a split intercooler hose at present. but its got to go here there and everywhere to get bits and pieces done.

Who do you guys use in canberra to play with your car?

Cheers

Simmo

[Sydneykid]

Hi Simmo, what tyres are you running? What lap times at Wakefield? What pads? What brake fluid? Have you removed the backing plates? The reason I ask is, I have never had a problem at Wakefield with the braking system as you have described, something is wrong.

As whytry posted, we use slotted rotors but never drilled, they crack very rapidly. Nothing exotic, DBA's (comp spec) work great.

We find Bilsteins hard to beat on Skylines, what seems to be the problem with them? What sort of spring rates are you running? Stabiliser bar rates? Did you have the Bilsteins revalved to suit these rates? Wheel alignment settings? Hicas still connected?

You will find that as you increase the corner speed, brakes become less of an issue. As an example, by adding just 10 kph to your corner speed on the right hander at the end of the straight at Wakefield you remove 25% of the required braking effort.

There is lots to be learnt here.

[Amaru]

Hey Simmo,

In Canberra id reccomend TEZ Automotive in Mawson, they did my turbos and did an excellent job, cant reccomend them highly enough. They also picked up a few other problems with my car that wouldve gone unnoticed until too late, and theyre a good bunch of guys.

If you speak to them, make sure you talk to Ed.

[Roy]

Yeh Brembos are crap, sounds like the two piece rotors are had it as well, ill give you $100 inc postage for them.

Worth a try isnt it... sounds like you have all the hardware, but for some reason they arent working in conjunction with one another. As others have mentioned try perhaps different fluid/pad as that setup should be fine at Wakefield where there isnt really any big stops. Whats turn 1, 180km/hr to 100km/hr?

Like many aftermarket mods, may need a tweak or two to get working properly.

[whytry]

k simmo the truth.

don't worry bout oil cooler,sump or turbo's.

just spend the cash on brakes and suspension and leave the factory power alone. and i guarantee you will lap anyone regardless how much power their putting out.

i've seen it happen to a guy who owns a subaru wrx stock engine,gearbox etc but he spent like 20+ grand on brakes and suspension and was lapping everyone (corners anyway). no one beleived him that he had no mods under the bonnet.

and since wakefield is a small 'tight' track, you'll be going quicker and out braking anyone around corners.

+ you'll find if motor is left stock and power is stock it won't be working as hard as say more power. thus the need for oil cooler,sump turbo's etc you won't need, as the brakes and suspension will do all the work.

another of my 2 cents anyway.

[Roy]

. and i guarantee you will lap anyone regardless how much power their putting out

Not pointing fingers or casting dispersions about ppl but the best modification to simply go fast at a cricuit is to put a good driver behind the wheel, that or learn to drive.

But that doesnt help someone enjoy their car at a track...so do whatever pleases you, and as far as the best turbos for the street/track i think you now know the answer.

And running suspension with a definite slant towards circuit work takes away more from the streetability of the car then turbos that are perhaps a little too big.

Whatever you do dont run too much boost, us GTSt owners lose heart quickly.

[DoughBoy]

Originally posted by Roy

Not pointing fingers or casting dispersions about ppl but the best modification to simply go fast at a cricuit is to put a good driver behind the wheel, that or learn to drive.    

And here I was thinking that by spearing off into the mud and cutting across half the track was the "fast" way around the track. Now I know what I am doing wrong.

[Roy]

Smile, your on DIY Race Cam

[Simmo]

OK

Feroda racing pads all round

dba 2 piece rotors up front, slotted but not drilled.

GP 600 racing fluid.

Nismo braided

falken 115's 2653518

I am not all that surprised that my brakes aren't quite up to the task, so many people told me that with roughly 400hp that would be the case.

complete whiteline works kit, bumping bump stops up front. I'm leaning towards a setup very similar to some of the targa gtr's. hicas operational.

wheel alignment settings not sure, but street not track.

First time in this car was down to 11's hand timed after 10 laps, was improving each lap but split an intercooler hose.

I think I was doing 200kph through the kink before turn one, I think.

Yep i know ED.

Keep the advise etc coming guys, invaluable!

Cheers

Simmo

[Simmo]

pic

[Roy]

Ive just switched from AP 5.1 to GP600 and i feel the brake pedal now requires more effort... just a gut feeling, and could be off base.

Hopefully getting my car to Eastern next week with an extra 100hp i found in the glovebox so if the GP600 isnt as good as the AP fluid then ill soon know.

I doubt i have the answers, but im curious to know what you mean by all outta brakes.