Legionnaire

I see what you mean, however I was talking about slightly different thing - a ENR model, i.e. 4WD. Let's classify this, too bad forum engine does not support table view. In model name - first letter refers to engine displacement, H - 2 litre, E - 2.5 litre (both turbo and non-turbo fall into this category), B - 2.6 litre Then optional N, which indicates 4WD. R34 - chassis designation. possible combinations: HR34, ER34, ENR34, BNR34 HR34 - long front shock, eye lower mount on rear shock ER34 non-turbo - long front shock, eye lower rear shock mount ER34 turbo - long front shock, fork lower rear shock mount ENR34 4WD non-turbo - short front shock, eye lower rear shock mount BNR34 (GTR) - short front shock, fork lower rear mount ECR33 has a shock combo identical to HR34 and ER34 non-turbo - long front and eye-mounted rear. The guy was asking about HR/HNR and if n/a R34 have the same coilovers as ECR33, I answered that there was no HNR34 and accurately speaking not all n/a R34's have same mounting - 4WD ENR34's are different on the front.

Not entirely true. HR34 has the same mounting, shock characteristics are probably different. There is no such thing as HNR34, 4wd skylines in R34 chassis were equipped with RB25, hence their code - ENR34. These have front suspension identical to that of a GTR, so its front coilovers are different to ECR33. Rear coilovers will fit.

Also nismo speclist here states Nismo fuel pump, flowing 4.6 l/min at 3 bar pressure, has 25% more flow than factory pump. This gives us a figure of 4.6/1.25 = 3.68 l/min, or 220.8 l/hour.

76mm compressor in the factory comp cover intended for stock 67mm wheel must have nearly no duffuser left so it looses thermodynamic efficiency big time. Try comp housing and backing plate designed for 76mm wheel and see if makes a difference (it should).

True. There was a scan of nismo afm speclist on here somewhere that plotted factory GTR afm, Z32 afm and nismo rr580 afm on voltage vs. mass flow axis. Z32 and nismo graph went only up to 1000kg/hour. I've taken a VQ table off a Z32 ECU and first extrapolated mass flow vs. VQ values at voltages up to 5.12V, then extended the graph, see attach. Based on factory VQ table Z32 AFM can measure flow all the way to 1740kg/hr, ~ 64lb/min. Assuming BSFC of 0.55 lb/hp*hr and 12:1 AFR this equals to 582 crank hp.

Out of curiosity - what mods are required to make NEO head run safely at 9000 rpm? Springs? anything else? Is there a possibility for clearence adjusting shims to jump off their positions at revs this high?

Worth mentioning though is the fact that nissan lists exactly same shock p/n's for R34 coupe and sedan. They also have the same wheelbase, so unless you drive with loaded boot, weight distribution is very close to sedan's.

Nah, sorry man, IDK for sure, but I _think_ it may be bolt on, as AFAIK A31 chassis is pretty close to R32, so line routing should be similar. If you post a pic of your BMC I'm sure people here can say if it's bolt on or not by the looks of it. Make sure you get yourself correct BMC though, i.e. the one suitable for ABS if you have anti-locking brakes (with two outlets), and non-ABS otherwise.

More likely it's BM38 - standard 7/8" BMC. R33 gtst uses BM44, which has 15/16" bore. Changing BMC is unlikely to fix spongy pedal, as it is usually something else that causes that spongy feeling, but it will reduce pedal travel and increase force required to be applied by your foot. If that is what you're after, then by all means do it.

24U20 means it's intended for R33 GTR. Bias is possibly different, but I don't think by too much, at least not enough to cause serious problems, as caliper piston and disk sizes are same for R32 and R33 brembos. Proper BM57 for R32 would be 46010-05U02. You can just buy a connector for your current reservoir though, the plug is same for a load of cars - from B13 100NX to late Altimas.

You should also be aware of the fact that BMC off a turbo R34 is not a BM44. Turbo non-GTR 34 skylines came with 1" BMC, marked either BM50 or just '1' on the BMC body. If yours is BM44, it is probably n/a R34 BMC, or an R33 item. It may still work, however brake balance front to rear may be slightly different to yours.

This may help you

Maybe you should try to induce some wheelspin using tallspeed of your auto box? press both pedals, it should rev up to ~2000 or 2500, then release brake pedal. If that does not help, then either you'll have to live with no wheelspin or put on some narrow tires or add ridiculous amount of camber to the back. Note that stallstart heats up ATF pretty fast, so don't hold both pedals for a long time and don't repeat this exercise very often. Added: according to factory manual, stall speed for RB25DE is 2350-2550 rpm. FSM does not recommend holding throttle pedal for longer than 5 seconds and also says to press throttle gradually. It also says to release throttle as soon as stall speed is reached, but you should release brake pedal instead and floor your throttle

Well, pressures may not be similar with a GT42 and GT30 because of different RPM at which those hp are generated. Actually, I'd even say that hp is irrelevant, torque gives more idea about chamber pressures. In-chamber pressure dynamics is a complex subject and OT here, but note how, say, HKS GT2835 usually produce higher peak torque than GT3076, although the latter makes more power. I'm looking for the smallest turbo that gives 500hp, and provides high torque over broad range of RPM, and this is usually achieved with the smallest housing rather than larger ones. And boost pressure definitely affects chamber pressures - it is one of the reasons why higher boost pressures result in higher torque figures and why low CR-high boost is a better combo than high CR-low boost. Pre-combustion chamber pressure roughly equals to pressure at the beginning of a compression stroke times effective CR^1.4. Since compression precess in not adiabatic, the exponent is lower. You can clearly see that even pre-combustion pressure is affected by boost pressure, peak and mean chamber pressure of course is a function of VE and a pack of other parameters, but pre-combusion pressure is one of them. EFR wastegates, as per above manual, are engineered to be enough for bypassing up to 40% of turbine flow for T2-flanged "A" housings (55 and 58mm turbine wheels) and up to 45% of turbine flow for T3-flanged "B" housing (64, 70 and 74mm wheels). "B" housing has 36mm WG port diameter and is inclined at an optimal angle for flow - so there is plenty of wastegating, I hope they allow even lower than 2:1 TIP/IMP ratios.

BM44 15/16" on all R33s except RB20e - 7/8" BMC - and GTR - 17/16 BM57. If you need P/N, let me know.

On R34s traction control is organized by modulating secondary throttle plate inside the throttle body. Look at your engine. Locate throttle body. There is no secondary plate actuator in there - none of N/A R34 have them from factory. Hence there is no traction control.

Hmm, actually I'm just trying to pick a turbo with a particular set of input parameters, of which decent spoolup for a given power level and sane boost pressures have highest priority. For a given power requirement, in the above case 500bhp or ~320wkw was chosen because 200hp/litre seem to be quite a common goal these days, I have to choose from EFR7064, EFR7670, and X3071/X3076 (as well as holset HX/HY35, some airwerks, mitsu TD06-25G, etc. but they all have worse response than garrett and EFR turbos), and of those 4 the X3071 seems to be the best, but no test data to confirm/diprove this yet. Sure, for different set of input parameters different turbo would be the pick - that's standard turbo matching, isn't it? Impressive for the turbo that big. Was it with a TS or SS housing? If 8374 provides response in between GT30 and GT35 but flows like T04Z I may reconsider my turbo plans, amazing turbo! Full boost at 5500 is funny though. Excellent, thanks for info. UPDATE: I thought somebody should post it: EFR Turbo Technical brief.pdf

Is R34 GTR intercooler considered shit? Ok, I know it isn't, but is it sufficient for 320rwkw goal? That's the one I use now. I'm somewhat worried about high chamber pressures as I'm not ready to reduce CR and put in forged pistons just yet. I believe too high chamber pressure is what breaks ring lands on factory pistons. True, knock can do nasty things to chambers, as can preignition, both knock and preignition can be eliminated by proper tune and can be monitored with rather simple and affordable sensors, however chamber pressure data can not be acquired without special and ultra expensive equipment, but can wreck bearings and pistons just as easily as the former two.

I agree with the above post. I don't see myself pushung more than 20-22 psi down the factory engine's throat. This boost equals to 2.4-2.5 pressure ratios, at which EFR compressors look pretty ordinary even compared to vanilla garrett GTs, let alone new GTX. E.g. take a EFR7064, which is advertised to be a 550hp capable turbo with unrivalled compressor size vs. flow characteristics and is regarded as a direct GT/GTX3071's competitor: True, it flows ~54 lb/min, but at what efficiencies (do I see two 60% lines on the map?) and, more important, at what PRs? Unless I want to run some 40 psi, there is no 54 lb/min flow, and since RB25 is no diesel engine, I am pushing 40 psi in. At my intended PRs, around 2.5, it flows only 48-49 lbs with ~60% efficiency. On the other hand, G's GTX 71mm compressor delivers 50lb/min at as low as 1.9 PR, and at desired 2.5 PR flows up to 56lb/min and delivers 50lb/min with 70+% efficiency, so for my particular application (factory bottomed RB25 Neo, possible poncams, 500 crank HP on 98RON, boost pressure no higher than 22 psi) turbo with a GTX 71mm compressor is better than 70mm BW one. Garret 60mm turbine is also known to be supporting this power figue, so no worries with the choked top end either. Sure, you may ask "why use 7064, go for 7670 instead". Good question, and the answer, as I see it, is following: I will happily go get me a 7670 but only if it proves to outspool GTX3071. BW 76mm compressor also doesn't show any impressive flow figures at 2.5 PR: - this is 51lb/min at 65% efficiency, not as bad as 70mm, but still worse than GTX 71mm. Also its flow at lower PRs is pathetic - at 1.95 PR it flows only 42 lb! All in all, although I do not deny huge effort invested in EFR development, and drool over lightweight TiAl turbine wheels and shafts, for the crowd that likes to achieve as much as they can with bolt-ons and without upgrading internals, EFR turbos currently seem to be less than optimal choice. I also don't think GT/GTX3582 vs EF 8374 is a fair comparison, as those turbos were designed around different concepts and with different power goals. The more fair comparison would be EFR 8374 vs. T04Z - 83.5mm vs. 84mm compressor and 74mm vs. 74mm turbine.

Well, just like GTX Garretts, EFRs still have to prove they are as good as BW advertises them to be. I wodner if 7670 can be bolted to the factory RB25 manifold. Good prices though - GTX3076 costs 1400 + IW housing 350 bucks , so it's 1750. EFR7670 can be bought for ~1850-1900 with 0.83 T3 flanged hsg, and this price includes boost control solenoid and antisurge valve. Bit it really should have T4 twinscroll IW housing, so 1950 for turbo + 1000 for suitable manifold. I need to allocate some money on this...

As with anything new, real info is scarce. For the new GTX35, turbine is limiting it. In the same housing there is very little, if any, power gain, but cost difference is significant compared to GT35. It seems to love 1.06 A/R housing, but i think 1.06 A/R is not user friendly even for a 3 litre engine. In smaller housings GTX35's power potential is similar to GTX30 with a one step larger A/R, e.g. 0.63 GTX35 is similar to 0.82 GTX30, but 35 spools slower. If for desired power level 1.06 is required, I'd prefer T04Z or GT37R because of its larger frame and more housing options. by the way, I'd really like GTX3582 to become GTX3782! The new 82mm compressor makes a good match for GT37 turbine imo. That result is indeed impressive. Even more impressive is the fact that the engine has 13:1 CR and takes 30 psi of boost.

Yeah, that graph is unusually wavy in the spoolup and high torque zone, so it's quite possible that something went wrong. I have a theory, but that'd be completely off-topic here... The results for med-frame GTX are currently disappointing, some of them predictably so, some are yet to be seen. Looks like so far we know that - GTX3582 is shit, we're better off using either GT3582 or T04Z - GTX3076 is utter shit, and TBH it was expected to be, as it conceptually recreates GT3082 which is not a particularly good turbo to begin with. IMO it should have been introduced as a GTX3276 instead - with a slightly larger, preferrably reworked 64mm turbine wheel in smallish 73 trim and some new large turbine housings... - GTX3071 is yet to be confirmed if it's shit or good. But seeing results for the above two, expectations are rather pessimistic Dunno what you mean by 'twinspool', if it's twinscroll then such housing does exist: http://www.atpturbo....tegory_Code=GTH

Lithium, Also pondering out loud, just as you are, but I wonder if track 997 porsche turbos use VGT turbines. Just as this "quick spool" valve I don't think VGTs are suitable for a track car, unless of course it uses water cooled exhaust housings. As for extremely high backpressures in certain circumstances - just to make sure I understand - 26psi in intake due to boost overshoot because of wastegate delay and gazillion exhaust psi due to spool valve operating lag, so both wastegate and spool valve are clorsed, but throttle is fully open and rpms are high? Is this correct? Timing may not be extremely advanced as when MAP-based ECU sees 26 psi when it expects only 20, it either shifts timing right back or cuts it off temporarily, but either way reacts before backpressure rises, on AFM-controlled ECUs... hm, I have to think about this... Dunno how PFC accesses its ignition tables, in factory ECU maximum load is seen when engine torque peaks... so 26 psi is irrelevant, is flow high in these conditions you described? Anyway, that's exaclty why I wrote about importance of choosing a proper pressure source. I think we should use exhaust manifold pressure as a reference for the swing valve instead of intake manifold pressure. The problem is that some ECUs may be unable to tell the difference between normal and dangerous operating window beacuse of the way they access load points.

Well, I'm sorry for the link above, I've just found out that after forum engine update I don't understand post edit feature for shit! Can't see simple tags, hence broken link. Corrected it now. It doesn't demonstrate boost curve, it is comparison of torque curve for factory turbo vs. 3071 that draws my attention. There is also a graph of the same setup after tomei poncam type B installation and tuning - I'm amaized at the torque increase. I also apologize for not making it clear in the above post - I'm not trying to compare 0.82 GT3076 and 0.63 GT3071. I was just expressing a hope that with the same housing GTX3071 will be slightly more responsive than GT3076 without any power deficiency because of possibly better weight distribution and lower moment of inertia of the smaller compressor wheel. On the other hand it still has to move some 50+ lbs of air per minute, so its power requirement still has to be similar to that of the 76mm wheel and power for the compressor is still provided by the same turbine stage.

Ditto. However backpressure changes suddenly only if you suddenly switch it from fully closed to fully open. With a proper pressure source this setup should stabilize the back pressure for some engine rev range, while the valve opens gradually, and when it's fully open, backpressure rises again. Actually if intake manifold pressure is used as a source, gradually opening valve does not stabilize back pressure, but rather reduces its rate of rise, as you have to maintain expantion ratio in order to keep level of boost. So many variables