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I didn't intend to get involved in the usual FIP section pissing contest.....just to make the point that if your tuner says they "tuned for response" without changing anything mechanically you better find a tuner who isn't talking shit.

Jimmy, I was listing mechanical factors that affect response; once the mods have started most people forget how early the standard setup gets on boost. I built the stagea deliberately for response which is why it has standard zorst manifold, standard cams, standard head, small turbo and 3 litre bottom end. And it makes 18psi by 3200 rpm

stagea_dyno_2012.jpg

If I wanted more response I would add cam gear (as I have on the race car), it can bring on boost a few hundred revs sooner at the cost of top end power. But frankly it comes on hard enough early enough to empty the fuel tank quickly.

For a race car I would say it is a very different concern. Full boost at 5 or even 5.5 is adequate especially if you have short gears and a standard or raised rev limit.

I want this for my stagea... working on the 3lt currently but what turbo did you go with? my goal is the curve to be climbing through 120 odd kw at 3k (torquie is locked up by then) with a fat load of torque.

I remember Cubes saying years ago that a std GT3076R 0.82 AR woke up quite early on his RB2530 though that was with an R32 RB25 NA head on it - no VCT .

I'm trying to think along the lines of what Ford did on early XR6Ts when they wanted low boost with low restriction torque at lowish revs . Their GT3582R had the big turbine housing size with a smaller than usual sized compressor housing (T04E 0.50 from memory) and low boost pressure possibly 6-8 psi .

I know people reckon I harped on about GT3076R 52T turbos over the years but think about this . Results with GT3071Rs were inconsistent and the 52T is the smallest of the 76mm GT compressor options . The smaller 0.50 AR (vs 0.60 AR) T04E compressor housing would put the air speed a bit higher at lower turbo speeds which is what you want to make low speed torque IMO .

I think the critical thing is having low exhaust restriction at low revs but enough compressor speed to make boost in that engine speed range . Autos make life easier here because the engine revs can be a little higher at the point where the torque converter does exactly that .

20% more engine capacity will make a big difference in the standing to suburbing speed ranges so heaps of low down boost probably isn't necessary .

Other than a GT3076R the only other thing I can think of is maybe a 2835 Pro S with the larger 0.87AR turbine housing on it if you can find that kit . Expensive new but falls in and the 0.87 possibly better suits the RB30 .

I also agree with std cams and manifolds .

A .

Yeah 180kw at 3500 is pretty fun, I'd be surprised if there were many RB setups making that sort of power :)

I'm actually not sure of the exact turbo specs; I originally had an ebay "T3/4" bush bearing turbo on there and put a garret ball bearing core in when it failed. If it helps the turbo anorak wearers the core tag says "PC 0105J 7-6451-5005".

But whatever it was, it was spot on what I was after :)

  • 4 weeks later...

I went back to stock airbox from ARC airbox, Tomei Poncams 270 ex 9.15, tomei cam gears, arp headstuds, tomei valve springs. Will eventually change out AFM's to Z32's and get a hard piping kit to replace all the rubber pipes :)

ok so i have been told to build a reliable 600hp rb26 on e85 I will need a nismo (n1 block) that -5 turbos will not flow at that power. i was told that the stock rb26 block will crack for sure at some stage if its pushed past 450hp . my block is the r33 gtr block . What is your view on this guys .ps sorry if i hi jacked this thread

ok so i have been told to build a reliable 600hp rb26 on e85 I will need a nismo (n1 block) that -5 turbos will not flow at that power. i was told that the stock rb26 block will crack for sure at some stage if its pushed past 450hp . my block is the r33 gtr block . What is your view on this guys .ps sorry if i hi jacked this thread

Don't go back there again. They don't know what they are talking about LOL

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