Legionnaire

I don't think they would fit. R32 GTR calipers use 296mm rotors, Z32 and R32 GTSt use 280mm, caliper mounting "legs" are 8mm longer on BNR32, so you would have to find 324 + 8*2 = 340mm rotors with those dogbones.

Haha, nice, we really were trying to make roughly the same point in different words. Likewise, I hate unspecific statements about boost pressures when no other parameters aren't being specified. Truth is they both matter, but in different ways. There are basically two stages of pressure rise in cylinder - first starts at intake valve closing and lasts till ignition point (actual compression stroke). Pressure levels at the end of this stage are not significantly affected by the airmass, but seriously depend on initial boost, or absolute pressure before valve closing. Second starts with spark and reaches its peak at approximatly 15 degrees ATDC, but this is obviously affected by spark advance. Peak pressure, among other things, depends on initial (pre-ignition) pressure and mixture energy release rate (which in itself is affected by plenty of parameters). Denser mixtures with more mass of air/fuel per unit of volume certainly release energy faster, resulting in higher peak pressures for a given ign advance and initial pressure - it's actually what you said. So we're both correct. Now if that peak happens too early, say near TDC, or is too high and piston isn't moving down fast enough to relieve it, all that pressure has nowhere to go (yet) and starts to break things - like ring lands.

You're confusing airflow vs. boost for power production talk with peak chamber pressures that have broken rings in the above engine. Airflow, or you should really use more correct term airmass, of course affects power output, more air mass mixed in proper amounts with fuel, releases more heat and increases chamber pressure. To produce power you take average pressure per cycle, not peak pressure, read BMEP, iMEP, so not really relevant here. It's really boost pressure that affects chamber pressures, because chamber pressures are reached (calculated/measured) with all valves shut, so there is obviously no flow present. Of all parameters that directly affect pressures, boost takes part only in initial pressure conditions prior to valve closing. After that only majorly important things are DCR, gas characteristics, amount of heat loss and gas leak and ign advance, as well as chamber geometry, cylinder bore and stroke, fuel used and proportion of its mixture with air. Sarumatix, You have to take absolute pressure so it's more like (12 + 14.7) psi. Otherwise almost correct.

Absolutely. Chamber pressures are indeed affected by boost pressures, but boost is not the only, and not the major factor in resulting chamber pressures. Overadvanced ignition timing and preignition (mixture ignited by hot combustion chamber parts prior to spark) can cause very high pressures without any audible pinging. What was the compression ratio in this engine?

1)Yes, you can use R34 gtt pads in your R32 caliper. No, they have exactly same area as your pads. Yes, gtt uses 310mm rotors 2)Yes, you can use bigger pads in your current caliper, see attached pix, pads with same as factory mounting holes but with larger area do exist, but why would you want to do that?

Yep, GT3076R with internal gate seems to be the go, in 0.82 a/r housing Or GTX3071 in the same housing. Or better yet, you can wait for EFR7670 or 7064 to make it to mass production. Based on their comp maps, they seem to be killer turbo for an RB25, particularly the latter. And comes with a nice big internal wg and with T3 flange too!

I always wondered if internal gates, say, on GT30 series, have no problems holding boost and no boost creep problems, and usually have a flapper equal or even smaller than 38mm and located at a bad angle to gas flow, why would external wg have any problems?

I'd add to that if it's a fullsize GT30, with 60mm turbo that bolts up to stock dump it's no good. Won't make power.

Well, I don't know what numbers you're after, but by the sound of it you'd be satisfied with 260-280 kw. Maybe you should consider putting something from the GT2871 range put inside bolt-on housing instead of GT30 family?

Thought so. Apparently those "bolt-on" housings are not very good for power. Native garrett housings are better at making numbers. X3071 is a 300-320kw turbo, in a 0.7 bolt-on housing it'll make something in the region of 260-270kw. At this power level you're better off with HKS 2835. They are .63, .82 and 1.06 a/r mate.

What's that 0.70 housing you're talking about?

You sure should have it serviced before doing any power-ups on it. When you have that done, I'd recommend the following, depending on how far you want to go, what's your ultimate goal and how much money will you have left after servicing: - FMIC, - Nistune, this is fully compatible with auto tranny, - fuel pump, - zorst, +tuning for all the above at slightly higher than factory boost. roughly in that order. Your next iteration of spendings on the car should involve something like AT shift kit (or upgraded valvebody, whatever it's called these days), tranny fluid cooler, then injectors+afm and a bigger or highflowed turbo, again roughly in that order. That's what I'd do to an AT 34 GTT as a basic upgrade plan.

I would say it spools nicely on an RB25 with 0.64 a/r housing. Felt good at least. But it does surge a bit.

Does that GT crank have anything to do with Reimax crank, p/n 12200-RRR4A? Reimax one also has 77.7mm stroke

Does it matter if it's good or not if you already got one? It may not be the best out there, but it will make numbers like 370 flywheel hp. Been in a car with this combo. Nice torque in the midrange, pretty ordinary top end though, rally car style. Compared to factory turbo it's certainly an improvement. Boost was at 1.5 Bar.

Very true. Even having successfully bought 3 used ones that were perfectly normal to date, I would say go for a new one. There is no guarantee that a unit that was previously working fine will continue to do so for long. AFM's a very fine and precise piece of electronic equipment, it wears over time, dies from vibration and if it fails under load, ECU has no idea about actual engine load and returns wrong fuelling and spark data, so engine is at high risk of fatal leanout or ignition overadvance, which costs hell of a lot more than a coulple of saved $, so it's a false economy.

I don't know what awf is, but N/A and TT Z32 AFMs are identical - p/n 22680-30P00, red sticker

Keep the info and tuning tips coming guys! Some mighty interesting info here! STATUS, hey Trent, how does one determine if timing is overly advanced? Is there a way to do it without dyno?

Had both heads for direct comparo half a year back, so I may forget something, but basically it's like this: Ports on DE neo head are smaller than on DET head Valves are different Rods are same as R33 DET rods. Pistons are different to any other RB motor I've seen, nothing special though. I've also done chamber volume measurement on a DET Neo head, they were 62cc chambers in my case.

It is integrated in that the BMC body is cast with provision for the integrated prop valve. But the valve internals themselves are then screwed in. Attached are pics of disassembled BM44 prop valve. BMCs with no integrated valve, like on Patrol and Pathfinder have no valve body cast with them, as seen on the third attached pic. Actually, I would suppose that other than piston diameter and bias-controlling spring GTR BMC is identical to GTST and GTS BMC. Since on tandem master cylinders like ours both pistons are attached to the same rod and has same travel for a given pedal input, I'd say it is only piston size that may be different

You can see it in the pic in one of earlier posts it this thread. I've highlighted the valve part on BMC body.

It doesn't. But I think he meant proportioning valve that is built into master cyliner on GTRs, has wrong bias for weight distibution of a RWD skyline. Patrol has no integrated bias adjuster in its BMC, so external adjuster is necessary. I found this "vacuum can" in FAST. It's called "tank-assembly vacuum" in there and has a partnumber 47110-24U01. Must be inexpensive, so if it really improves pedal feel, it may be worth spending a couple of $ on.

It'd be interesting to see the result of your work. Post some pics when you're done with this "mod" as I'm still not sure whether calipers look better with or without logo. Are you gonna paint/coat them afterwards?

So BMC is equal in size to GTR's - 17/16". Thanks for info!

Luke, what does this thing do? You said it's a separator, so it separates vacuum? air? from what? And I don't think it would feel any less spongy with this thing on. Boz22n, what diameter BMC did you end up using? What bias adjuster? Ever had any troubles with adjustment range being insufficient, i.e. too much/not enough front/rear bias?