BoostdR

I made 380rwkw with a 65mm restriction in my GTR exhaust. I run the std exhaust on my GTT, with a barrel cat and stainless dump pipe. You will find these are the main restrictions

Troy and I will catch up when i finish work. I have my 34 on the road now. Was up till 2am putting the intercooler in last night. made a restrictor up for the wastegate line at work today....13psi now...just need to put in some more timing give her a wash and I'll be there...about 8pm i think.

Is that the CarToys modded Grey 33? I saw it at the autosalon in Adelaide. That power is at all four wheels btw.

I've posted this before in my T618Z 10cm2 vrs HKS GTRS thread....search function isn't working for me though. We flow tested some Chinese stainless rb26 manifolds and the flowed twice as much as the std cast items. We then spent 6 hours porting the cast manifolds-taking the bumps clean off the head side, opening right up the turbo collector paying attention to the wall thickness with some pinches. The greatest increase was had from the short turn....huge amounts can be taken out. They were reflowed and came up within a few cfm of the stainless items. With the energy retaining benefits of cast over stainless, I know what I will be using. The runner diameter was not increased at all. Matt

Are you sure you mean the Spec 2 Profec? Thats the one with the digital display, I have had nothing but trouble with them. The Profec B with the 3 knobs I prefer.

My engine will be tuned on an engine dyno. The tunner is not from the commercial/retail circuit.

I have had very good results from my Profec B spec2 on twins. Nice and easy to use to.

I agree the nismo collector works very well, however is may not be as well suited to 800hp....how much average power difference I would like to know..... The Nismo intake collector is designed with form & function in mind, and is fully optimized for air flow in tuning the GT-R engine (400ps to 600ps). This intake collector is a standard item in the NISMO Z-tune GT_R34 Ver.2002. It is completely bolt-on installation, and no modifications on are necessary on the idling control, fuel piping, clutch piping & vacuum piping. (The only minor adjustments needed are on the throttle linkage & throttle sensor). Improved medium speed torque is achieved by improving airflow onto each cylinder, and this is done by refining the diameter & length of the inlet pipe & cross section of the intake collector. Normal Collector Based on factory item with respect to form factor, air is not evenly distributed to all 6 cylinders. As a result, the NISMO air collector tried to distribute air flow evenly & equally by redefining the intake form factor. There is a difference in turbine inlet exhaust gas temperature between the front & the rear. The overall temperature difference has been reduced drastically due to an improved & efficient intake quantity between the cylinders on both sides. (The exhaust gas temperatures at the front-rear turbine was reduced at an average of 18% at 2400 RPM to 7000 RPM) The fuel supply density is high in order to protect the turbocharger from high exhaust gas temperatures. With the NISMO air collector, temperatures are reduced and this resulted in improved fuel economy & improved output. Both cylinders & ignition timing could be optimized because exhaust gas temperature differences becomes small. (At 4800 RPM to 7600 RPM, output improved by an average of 1.8%, and fuel consumption improved by an average of 0.4%)

A GTS4 box is as strong as a GTR box, they do have shorter ratios aswell. I have run them in my GTR a few time's, they are much better on a tight track. I have been through 10 boxes so far so I can tell you: All Skyline 4WD boxes are just as strong, the GTS4 boxes have shorter ratio's and the series 3 boxes have better energiser syncro clips on 3rd and 4th but are no stronger. Third gear must be changed at a normal speed to increase box life.

That is very very impressive indeed! I think I'll hold onto my -5's and back to back them on the engine dyno =) I have a JUN plenum to go on...will see how that goes....also trying the new Tomei dump pipes over my current HKS ones. What are your thoughts on porting the head? We have been looking at some work in the intake bowl area and short turns but minimal oversizing of the exhaust to aid port velocity.

Mate haven't you got something better to do. I made 30 more rwkw with stainless manifolds and match ported turbine housings and no loss what so ever in the bottom end. If you think thats a waste thats fine. It's my engine. I'm sure others would have differing results...but I couldn't care less.

Sorry, i'll confirm for the sloower individuals. When I said "they make 350rwkw on the std cast manifolds"...I mean the two -5 turbo's on my car on my dyno....was pointing out that the stainless manifolds flow more and the cast ones can be made to be just as good if not better. Obviously others will make more and less power and have there output measured on many different dyno's with many different ramp rates with many different correction factors, with many different rolling diameters, etc Those guys who posted up lap times in there signature block are giving me a better indication on what works. There is a few corners at Mallala that I get caught low in the rpm range---so I can see why -5s on an Rb28 or Rb30 would be a wise setup for a tight track. Thanks for the constructive replies from those that gave them so far.

That is some very nice mid range indeed.... over taking the mid range of the 2530's in most ranges aswell. I recall your setup making minimal power increase intially after changing from the GT2530's? The GT-RS's are aboviously after a different setup engine...can you shed some light for us embarking on the initial voyage.? At this stage I will be just at Mallala. Then I'll venture out from there

Thanks for the info, what capacity engine was the dyno graph comlpeted on? So you are currently making 534rwhp with the -5s on a 2.8ltr?

Do you mean 600rwhp? I am currently using GT2860R-5's on my 87mm bore 2.6, .5mm larger valves and tomei 260 9.15 poncams. Response is 1bar @4050rpm in 4th and positive pressure at anything after 1600rpm. My main goal obviously is not to go backwards in response. They make 350rwkw on std manifolds, 380rwkw on stainless manifolds and more on jungle juice. Peak power isn't my main concern however a usable power range is. From what I can see anything bigger than the GT-RS's will give a hole in the mid range... Just not a whole lot of info on twin Greddy turbo's on GTR's out there. We are building the same planned GTRS setup for John Munro's Track car so we will see how that goes on the engine dyno and go from there. Matt PS. on the subject of manifolds, we flow tested a chinese stainless manifold and std cast manifold and the stainless flowed 50% more! Then we spent 6 hours porting the std cast manifolds paying particular attention to the short turns and they flowed 46% more(4% less than the ebay ones). With the relability and heat retension properties of cast I know what I'll be using

do you have a copy of your dyno graph?

I have the upright respect for my engine builder/tuner. So the "he said she said" is not and arguement I am interested to have. Suffice to say he has tried the combination of HKS GTRS's on std to 3ltr capacity and they have come up short of the compressor flow ability. The mismatch between the compressor and turbine.......proven by the signature compressor surge causes restriction of the topend capabilty but obviously gives stonking mid range. They are pushed hard to make over 420rwkw on pump fuel, to the point where the exhaust manifold pressure and associated gas temps are not a combo that I can reliably get more than a few laps out of. just to confirm again..capacity IS 3ltrs so is there anyone out there with experience on the Greddy 10cm GTR turbo's? Matt

Thanks for the reply, It's definately a 3ltr, It's already prepped to go. Do you have any power figures from your experience? What twin setup would you run for 450rwkw with optimal response?

I am currently building an RB26/30 to replace my RB26. My original plans were to use HKS GT-RS's(already purchased) which in theory should work reasonably well on a 3 ltr. I have just been advised not to follow this path due to the GT-RS's choking exhaust flow up top and restricting power to ~420rwkw @ 1.65bar. If a 0.7A/R turbine housing was available to bolt on, we would be set.... The Greddy t517Z and T618Z come in a 10.0cm2 turbine A/R which equates to 0.7A/R. I have seen these turbos make 40 odd kw more at the top end however they are 50 or so kw down in the mid range. I assume I won't have to much of a reasponse issue with the 3ltr but the GTRS will still be ahead in the mid range not matter what. I guess average power will end up similar.....I'm very undecided. The other options I have considered was looking into abrasive porting of the HKS GTRS turbine housings or/and running an external gate setup to reduce to onset of exhaust gas choking... Or if available running a 0.7A/R exhaust housing from another family and making custom dump pipes to suit. Any thoughts would be appreciated Matt PS Cams will most likely be JUN 272 or less

GTR http://cgi.ebay.com.au/ws/eBayISAPI.dll?Vi...em=310066056639 RB25DET http://cgi.ebay.com.au/ws/eBayISAPI.dll?Vi...em=310066056319 Look pretty damn good to me, these will sell like hot cakes!

I have this exact spec cooler, I went from a Trust item and the ARC is better in every single way. The difference was night and day. I am making over 400rwkw without an issue. Mine came with plugs to block the BOV's off with. I paid $1600 and it was in much more used condition. Just look at the open tubes on the inlet....every other cooler presents a 50% brick wall to the inlet air, ARC are knife edged and flare out on the inlet side of the cooler for much less restricted flow.

The GT2871R suffers from surge, the anti-surge cover is designed to suit. Haven't heard of surge issues with the GT3071R

">The boy got skills

Thanks for the kind words.....btw my GTR is Black, not purple...lol I lost everyone after GG, so headed to Gawler and came back via the Gorge. Matt

lol, what have I started. We could start an SAU car yard.