RS500

fyi, a friend of mine ran the N1s on his RB26 with the standard and everything was fine, although he only ran 12psi, and it went quite hard. i believe he is selling these turbos atm, so if you're interested PM me and i'll pass his details onto you.

nv033, could you tell me the CHRA number of your turbo please? this can be found on the id plate on the centre core.

nv033, just an idea, is the exhaust housing an original garrett GT30 A/R .63 unit? the reason i ask is that when i bought my turbo, it came with a non-garrett A/R .82 (split-pulse) exhaust housing and we experienced the same problem, later finding that we had a huge back pressure problem in the exhaust side which was restricting gas flow and obviously robbing power. given this, we went back to the guys which we bought the turbo from and got them to send us the original garrett GT30 housing which made a huge difference giving us the results we have now. before making any other decisions about the turbo, etc, it's probably worth tapping into the exhaust manifold/housing and measuring the back pressure. this should give u an indication of how the turbine is flowing the exhaust gasses.

nv033, fyi, my 2L cossie has a Garrett GT3040 (A/R .63 exhaust housing) and was only making around 185rwkw on 17-18psi, which was really pissing me off as we were expecting more like ~220-230rwkw on that boost and ~250rwkw on 20psi given the specs & size of the turbo, but it wasn't the case. So just as i had decided i had had enough and was about to pull the turbo off the car, my mate/mechanic got in touch with Geoff Watson (Garrett, NSW) and after telling him the story (i.e., specs of the engine, boost & power we were making, etc), his recommendation was that we would need about 25psi to get the power level we were after. So under his instruction, firstly we slowly wound the boost up to 22psi first and wouldn't u know it, power jumped straight up to 247rwkw very viciously before wheel spinning on the dyno. after some more fine tuning and a little more boost, my 2L cossie engine chalked up 265rwkw @ 4500rpm on 24psi before wheel spin problems again on the dyno. so, maybe you need to push it a little more given that your engine is smaller than mine. also, the GT3040 definitely has the minerals to make ~300rwkw with the .63.

i seriously don't think u need a larger exhaust housing, they just want to make some money off you in your time of desperation. how are you hoses connected to the wastegate, also which wastegate are u using? have u tried to see if it opens (with a compressor) while off the car?

hi there, fyi, i had the same issue with my Garrett GT3040 on my 2L where it wouldn't make any decent power at about ~17-18 psi, but anything over about 21-22psi and it really woke up scaring the pants off me. This was quite disappointing as i was intending on running lower boost to get my required power given the large compressor size. in your case, first of all, i believe this turbo might be a little on the large side for your 1600cc engine, so you'd be better off going for something smaller, but if u prefer to stick with this coombo, then you'll need to try winding the boost up closer to 25psi as to see some decent power, as the turbo still isn't working in it's high efficiency zone (which is where it produces the air-flow for the required power level)

which external wastegate are u using?

u looking to buy one dude? i have one which was on my sierra cosworth for only 1.5 months before i shit the engine.

dude, is the GT35R still available?

so, another one with an RB31DET, nice. dude, i think you should be fine with the GT35R (A/R .82) if it will a street driven car, and with the specs of the engine (if the same as bl4ck32) and turbo, i would be looking more along the line of a low 11 if the car is setup right and has good traction.

nice specs dude. what's the application of the car? the reason i ask is that for a 3.1L engine with twin-cam head, you'd probably be better off going for something a little bigger (eg, GT35R with A/R .82) as you'll be able to reach your power target easily & efficiently and yet still have heaps more headroom to be able to make more power again. Although, again, it all depends on what the purpose/application of the car is.

Dave, first of all, what engine is it going on and what are the specs of the engine and support systems? fyi, 500rwhp is ~373rwkw, so it's a bit of power, but i believe this power is able to be achieved with the GT35R (A/R .82), although it will need to be pushed on the higher side of 25psi. i have seen a few of these Garrett GT35Rs on RB30ETs and they've had no problem making ~320-330rwkw on ~20psi. Of course, there were other engine mods to help make this power. with the A/R 1.06, the power will be made easier and more efficiently as there will less backpressure in the turbine side, but i guess this will depend on what your application is. if the car is for street/strip use, go the A/R .82 even 1.06 (as they're not all that laggy compared to the .82), or if it's for drag/dyno comps, then definitely go the A/R 1.06. give this link a go, it'll help u with your decision. http://www.turbofast.com.au/TFmatch.html good luck.

dude, i'm glad i could be of help. what engine is it going on? fyi, did u know that garrett make an equivalent turbo in their GT30 range? wastegate; most people with large turbos are running larger sized wastegates, so i'd recommend the turbosmart 45mm external gate. works a charm.

to all, fwiw, the BA XR6 turbo doesn't have any problems producing 250+ rwkw with an internally gated Garrett GT35. if it's lower boost you're looking at running, i think it should do fine. Bl4ck32, what's your power target? this should help u make your decision. the HKS 30307S (A/R .87) will help you make up to 330-340rwkw on anywhere up to 25psi, but the Garrett GT35R will allow u to make closer to 380rwkw with the same boost, although bare in mind, the garrett GT35R has larger wheels so the response would be worse when compared to the HKS GT3037S. but then again, it all depends on how much power u want, and how u want it.

GTR-Ben, this core number is not listed as a standard Garrett core. It must a variant from HKS. does the plate say anything else on it apart from the CHRA Part No.?

for that kind of power, turbo wise you'll need a HKS GT2835 or the Garrett GT30 equivalent

as you said it dude, with the bb R34 ceramic turbos, you are limited to you 15-16psi, whereas the R32 steel wheel turbos will allow more boost/power and hence last you longer. If you're interested, a friend of mine is selling a pair of R32 Nismo (steel wheel) GTR turbos from his R32 GTR. send me a PM and i'll pass his details onto you.

search my friend, search and u will find.

amosite, thanks for your reply. btw, are the exhasut housings the genuine garrett items or HKS? the reason i ask is that the A/Rs u listed are the A/Rs which are available only in HKS housings.

first of all, if you're looking to build a car for drag racing, why are looking at retaining the crappy 4 spd Jatco? depending on what times you're after, you'd ideally be better off going for a Trimatic or even a 2spd Powerglide :kick: secondly, if you're really dead set on the idea of the Jatco, i believe Yarrey Valley Autos are the guys to talk to.

what's with the exhaust housing options? has the turbo been bought yet?

wrong compressor map dude, that's the compressor map for the GT35 wheel, you have an 82mm GT40 wheel in your GT35 turbo. also, y are u selling the turbo??

R31NIsmoid, a GT35 is too big for a RB25? i don't think so. i have a 600hp GT30 (A/R .63 exhaust) on my 2L cossie and it's great to drive with heaps of mid range punch, and not too mention great top end. i guess it depends on what u want from the car. if u want to push 300rwkw + comfortably and don't mind a little lagginess down low, then the GT35 is the go, otherwise if u want a very punchy street car with about 250-280rwkw, then the 600hp GT30 with an A/R .82 is the go for you.

nice power curve dude, it looks like it's got the minerals up top. good results for 20psi. mine goes on the dyno tomorrow, to do a power run as it is, and then boost's going up ;-)

fyi, 2540's are found to be very laggy in twin form for a GTR. they are more suited for single use on a RB20 or RB25. i'll send u a PM with more details.