Steve

Good to hear its all going well. Thanks for the offer, when (if) I get to the stage of doing the emissions test, you can expect a pm:D

3037:) Why not go the twin setup? cheaper than going single and getting new manifold, dump, intercooler-turbo, turbo- afm pipes, wastegate etc.

What do you mean by offset design? Does that mean its not straight through?

It will be interesting to hear how it all goes:) Good luck

thanks PSI-VL, Mike, did they do stainless or Ali?

Not sure exactly, maybe around $350?

Hope you dont mind if I put in 2 c worth here Max. For use with pineapples, you only need, or use 4. I have this and it works quite well - as pineapples change geometry of rear cradle, but the hardmounts are used to remove the rubber parts that allow the cradle to move. Ride harshness increase isnt really very noticeable, but the car does feel tighter when throwing it around, and traction is a bit better too.

Have a friend who just fitted an AX53B60 to his GTiR, is very, very impressed by the spoolup and midrange, but said top end seems to be a little lacking, when compared with the stock turbo. He is still running stock injectors, ecu and cooler, with only an old model apex AFC, boost (1.2bar) and fuel pump. Sorry, not really quantifyable results, he has e-manage, injectors z32afm waiting to go in, so hopefully in the not too distant future will have something a little more tangible.

Eat the wagonwheel, eat the wagon wheel! Err, sorry, I meant, get an Apex flap:) If you go down to D1, James and Rob both have them fitted so you can hear how much difference they make.

I think I have already spoken to him:)

I see what you are saying WRT gas velocity. I was originally told (by an exhaust 'expert') - that longer runners will bring boost on gentler than short runners, as the gasses slow the further they move from the engine. This isnt the total reason for my post, here is another example of what I meant by flowing well and gas velocity - most jap manifilds (I have seen) run a short pipe after the gasses have been collected and before the turbine housing - OK I am a layman, but it appears to me that this pipe will do a similar job as the turbine scroll, in that it channels all the gasses together. If you have a 6 to 1 collector, without a pipe coming off it, surely the gasses would still be suffering from turbulance to a greater extent than if the gasses were directed toward the turbine for a short way prior to entering the housing. Am I so far out of left field its not funny, or would this have the effect of accelerating the gasses prior to entering the turbine housing, not as they hit the turbine housing - my guess is this will reduce turbulance, which would increase flow. Sydneykid, how did the ID of the GTSR extractors compare to the highmount? Also, did all the exhaust gasses meet as they entered the scroll, or before 'jap style':)

Thanks for all the replies:) The Yokies sound interesting, anybody know what they retail for? Cheers

Well to give you an idea, I went from a 0.61 (1bar at approx 3000rpm) to 0.87 (1 bar at over 5000rpm) on a single HKS 3037. Having twin turbo, I would think the smaller the housing the better, as you have twice the volume of flow as a single - this would undoubtedly improve resonse. When I fitted the 0.87 housing, tuning went a little way to improving response, but still no where near the 0.61 housing. If you are using 2 with large housings, it would be my guess that this is (a large) part of the problem, and perhaps look at getting a pair of the smallest housings you can find. Another thing that doesnt seem right though is the peak power figure. At 1.3 bar, a 2530 will flow enough air to deliver 230rwkw on an RB20 or 25, grepins 2835 (of which the GTRS has the turbine specs) flow 275rwkw at 1.3 bar with a 0.68? (not sure, but it was the smallest one made for this turbo) turbine housing. In tandem, I would have thought the combined flow of the GTRS would be much higher than 301rwkw, as it uses the 2835 compressor wheel. I cant remeber specific examples (anybody help out here?) but I was under the impression that even equiped with 2540s, a GTR would make better power than you currently have, with more response once the turbos finally (laggy) started making good boost. The exhaust side, unfortuneately JASMA by itself doesnt tell too much of the story. I had a nismo jasma approved exhaust, dual resonator, and street legal. Unfortuneately, sound and power production go hand in hand. My car was choking, by going to a better flowing, straight through design, with smaller resonators, (and still JASMA approved) I also picked up boost around 300rpm earlier and the car feels alot more crisp off boost and on. It would be very simple to try unbolting the exhaust (from the cat, only 2 bolts) and running the car on the dyno again. Minimal cost, but it will also tell you alot about the performance of the exhaust sytem. My current exhaust is the 3rd I have tried, the first one I had on was an N1 type, very straight, and a pretend resonator on the end - very loud, but the response and power were excellent. Just a tad loud for a daily driver:) Stick with it, its pretty frustrating doing R&D on your own car (and expensive), but by the looks you have a couple of wrinkles to iron out and you should have a killer combination. Good luck EDIT, couldnt see the markings on the turbine cover in you picture unfortuneately.

What size turbine housings are fitted? what type of exhaust? The reason I ask is it appears from your dyno that you arent getting the gas velocity needed to spin the turbos up. the boost response is very gradual, which is very uncharacteristic for HKS GT series turbos, that tend to hit pretty hard when they come on boost. Few things come to mind, either turbine housings are too big, exhaust is generating too much back pressure, manifold poorly designed, or all three - assuming the tune is OK.

What size turbine housings are fitted? What sort of exhaust system?

If you have plumbed the vacuum from the turbo oulet to the wastegate actuator, the boost you get is what the wastegate is rated at. You will need a new wastegate actuator to go down in boost. A stock one and a bleed valve should work fine.

Roy, when I did my injectors, a mechanic mate who was helping me at the time said just make sure I connected the power to one contact, and the signal to the other - I was told at the time it didnt matter which way, but do them all the same way, ie, power to A and signal to Z or vice versa. Seems to be working so far:)

Hi geraldjohn - I am sure you wont have many hassells finding a power fc here, but you may have more luck by posting in the Wanted to Buy section. Also, check the for sale section - see them quite often.

The minimum boost cannot be altered without altering the wastegate - as this is set by the spring in the gate - a bleed valve will only allow the boost to be raised, not lowered. The wastegate actuator spring resists boost pressure, and when the boost pressure exceeds the spring rating, it will allow the gate to open. Bleeds and restrictors reduce the amount of boost pressure going to the wastegate, thus raising boost. Wastegates are pretty easy to swap, if you put an add in wanted to buy section, or even in swap section - I dont think you would have to wait long to find one. I gotta know, why are you trying to lower boost? Most people want more.

First thing I would be looking for is a vacuum leak - check all your pipes thoroughly. It may not be on the cooler though (but this is most likely as those pipe joins have been messed with), so make sure you check every line/pipe/join/etc from the turbo outlet to the plenum, including AAC air line, BOV, boost guage etc.

Tilbrooks are an authorised skyline service centre arent they? J/K - sort of seems that way sometimes though. I agree with Dean, tilbrooks. D1 can fit sus, and if you wanted to improve handling James at D1 is your man, but if you want a full 100K service go to Tilbrooks.

Nightcrawler, thanks, they are similar priced - and I am in tightarse mode since it is redoing something that has already been done. Evan (PSI Fabrication) said a while back he could redo the pipework for me for around $150-200 (as I have spend $$$$ with him) - but he has fallen off the face of the planet! PSI-VL, I live near tilbrooks(hampstead gardens), about 10 minute walk Yes please to your mates, mates name:) that would be great. 350 in a TE/TG? holy fark! Does that live queenstown way? Think I saw a TG down that way with a candy yellow paint job, looked very nice (for a gemi:p)

Thanks Cheeky, seems there is a few people working on this now - getting there slowly, but surely:) Dean- bugger:(

Dean, how do you think the police presance will be on a public holiday long weekend? double demerits too isnt it? I am scared:) Could always put it off till the next weekend then cheeky and munro could come too:D and I wouldnt be so scared:p

TIMMMAYYY, from the vic forums from Vic Roads website zero tolerance.