AndyStuttgart

Actually I don´t think it´s such a good idea of potentially having two different charge temps and boost levels for the front and rear cylinders...so no, I won´t jump the bandwagon saying twins are shit. For me both variants are cool and I´d leave it to personal preference for everone. While I live by "it came in twin form by factory so I´d stick to that" for most of my cars, I still choose a single on some of my projects to try it out as well. Hopefully this year I´ll be able to more or less compare an EFR9180 single vs. twin G25-550 on two similar built RB30s (forged bottom end, Poncams).

RB30 bottom end, RB26 head Forged rods / 86mm Wiseco RB26 pistons, CR about 8.7:1 HKS Step 1 cams 8.7 lift, 256in 264ex, exhaust mildly ported ID1000 RawBrokerage T4 twinscroll manifold with two Tial F44 WG (1 Bar spring presure) EFR8374 1.05AR twinscroll 3.5" exhaust 45mm screamer pipes Made over 600hp on wastegate pressure: 700 with manual bleed valve (unstable boost dropping to 1.45 bar at redline) 95 octane pump fuel (as setup will go to the states next year in a R32) Video:

*reminder*

I also used the anti surge housings with the GTX, with the stock cams Full boost was there around 4500, Same as the HKS GT2530s before. HKS GT-RS with their anti surge housings did take at least another 500rpm to spool. All on stock cams, with 100cpi cat and 3.5" exhaust. Didnt retune since the install of HKS 256 in 264ex cams but even with 2-3 degree less ignition now feels to push a lot harder.

Did you use the -5 before on the non-built engine? Or how do you come to the conclusion the GTX are laggier than the -5? I have used HKS GT2530, GT-RS and now GTX2860 (all in their genuine housings) on a RB30 with stock cams, and the GT-RS were the only one which were REALLY laggy. As they have been on the car inbetween I can´t really compare the 2530 to the GTX side-by-side, but my impression still is that the GTX are way better spooling etc. than the 2530...am I really that wrong? BTW all turbos were running with about 1.5 bar / 22psi.

What diameter is that? No middle or backbox? Surely no street car then

I have to measure again, I think I used 80mm pipes and bends, so 76mm inside diameter for each turbo until the cat converter, then 88.9x2mm to the back...as the cat is the biggest restriction anyways. That´s why I used two catalic converters on the GTR, and after the middle box there´s a 114.3x2mm pipe towards backbox + end, as this was the biggest possible diameter between rear axle and LSD

Are the tomei REAL 3 inch dumps? That´s the only one I could find where you can see the custom dump pipes...but it was before the GTX came in.

Instead of buying turbo elbows, just build your own - that way you can maximize size and still gain some space towards the rear turbo

It´s in the RB30 hybrid dyno thread ;-) 20 degree is not that much, taking into account that I use 102 octane pump fuel... If you compare that sheet to the last (disappointing) one I posted, you can clearly see how much later torque etc. is produced - as the dyno did not use it´s eddy-current brake. So I bet on the Superflow I´d see about 650hp and 550lbft...with 2 bar of boost (so fuel pump issue resolved), 700hp should be no problem! BTW the car drives absolutely fine on the road! Full throttle in 2nd gear, no traction issues using 265/35R18 Toyo R888 on the rear...in a GTR this would be a dream to drive from the starting line!

I was disappoint regarding absolute numbers, but not about the power delivery. Before the remap we / Steve from FC Tuning did now, there was no fair comparison possible between the HKS GT2530 we had before and the GTX2860R we use now - as the HKS´s were mapped "a bit", but the GTX were not. To be precisely: about 15 degree ignition timing at 1.35 bar got us more power with the HKS than with the GTX at 1.7 bar and 9 degree. But the GTX at about 21 degree ignition timing are a whole different story then ;-)

Can´t wait to see the graph when it´s done :-) We managed to get 604whp on a Mustang Dyno at 1.7 bar with more ignition timing (about 20 degree, last time on a Superflow we only managed to get around 415whp with 10 degree).

So, car finally got mapped but it looks like stock fuel lines give too much backpressure - so 1.7 bar was the save limit before mixture leaned out, which disappointed me a bit. We still could get much more power out of the car, by adding about 10 degree of ignition timing - no wonder we made such poor results the last time ;-)

It can be seen on the Dynosheets I posted above, although the boost pressure reading is wrong on the one with the GT2530´s it gives an indication when full boost was achieved (around 4800rpm), compared to around 4400 using the GTX.

The additional 50hp ain´t worth it - but 400rpm sooner RPM on a dyno and a much smoother power transition on the road are worth it. And your drivetrain won´t be f**ked as hard...

It´s got an initial tune but nothing final yet...so conservative ignition timing but with adjusted fuelling of course. I will run as much boost as necessary, same counts for the rev lmiter. But as doing high-speed runs in Germany is a totally different story than anywhere else in the world, I will definately not beat the shit out of it for longer terms. Because I do 300kmh+ runs for minutes it would definately kill my engine, no matter how well it´s set up. As said, totally different story than just to to some 0-200 pulls or 1/4 mile runs! Doing that I´ll produce about 2megawatts of heat that can´t really be absorbed that well...

As I´m not a native speaker I have to admit that I don´t really get the point what you are trying to say? The R34 is not really tuned yet, still just running a redline of 8500rpm and not more than about 1.5 bar of boost...

It´s my ex-GF´s car, so what should I say... But it´s fun to smoke a lot of other fast cars with a Hello Kitty airbrushed S15 Silvia ...although it doesn´t really runs that well on revs as my twin GTX3076R RB28 BNR34 ;-)

Nissan S15 Silvia RB30 stock bore size / milled to achieve 8.8:1cr Wiseco pistons Steel rods crank collar fitted/crank balanced Tomei head gasket ARP RB25 head studs stock head stock (machined) exhaust manifolds 1st round, about 1.2 bar, R34 elbows, greddy downpipe, R34 stock catalic converter, 3" Fujitsubo catback (60mm backbox inner diameter): 2nd run, about 1.3bar boost, exhaust changed to a 3.5" one that came off an MK4, but still with some 3" restrictions, downpipe modded to fit a 100cpi catalic converter (boost reading on printout is wrong, measured at wastegates): 3rd run, still on HKS GT2530´s, but now with about 1.35 bar boost and fully custom 3" elbows + downpipe: Now with different custom intake piping and GTX2860R´s on about 1.7-1.8 bar boost (and obviously a bit less ignition and not yet optimised A/F ratios) - we usually ran the car at 1.5 bar, just tried it once on the dyno with more boost (and were disappointed by all the results that day):

BTW this it what it looks like now:

I´d kick out that stock TT pipe, even with the plate modification it´s not so ideal flowwise. Just been on the rollers yesterday, but did not ran that good and now I´m a bit disappointed with the results. Been on the rollers three times with HKS GT2530, last run was about 530hp and 700nm of torque at 1.35 bar. Now (with the old tune being gone because of a computer crash) the GTX made much less, even on more boost. Here you can have a look, the runs being done on 1.5 and about 1.7-1.8 bar. Car popped off some hoses so I had no chance to alter A/F ratio or ignition, as it was on a dyno day and I was kind of stretching it anyways doing about 6 runs with fixing some pipe stuff/altering the boost... For comparison (same dyno type), run on 1.35 bar dropping to 0.7 bar (boost controller safety feature not switched off) with HKS GT2530s: And on 1.5 / 1.7-1.8 bar with GTX2860R´s:

Did anyone else put these onto an RB30 yet? Had it running the first time now, let´s see what they can do with stock head and forged bottom end...

Did you get the software in the end? Got the japanese version, would need a english one

Thanks mate When I got it, it was silver, stock and damaged...as it´s been hit by a tractor when the previous owner had it. But since it was the VERY FIRST street legal german R34 GTR and by the time I bought it still the only one with registration, I wanted to make it something special

Been a while since I put on my last pictures...hmm. Well, car is standing around with engine removed for almost one year now, since I didn´t find the time yet to complete anything. But pics from last years Tuning World Bodensee exhibition should be better than what I postet here in 2008 I think