hypergear

Yes it does. Stock manifold has better down low response and torque using the same turbocharger. Reference: http://www.skylinesaustralia.com/forums/topic/261613-hypergear-hiflow-service-continued/page-298

I don't see shifting shaft speed or what ever happens between the two turbos would be a problem. The only reason I would considering compound system is gain response while make heaps of power which means reaching the maximum flow capacity of turbo B. By enlarging turbine end of turbo A so to suit turbo B's flow I will lose response. I'm not going to argue the effects of compound system on Petrol engines to a dead end as I've not trailed it my self, but point out areas that could be considered problematic. On the same manner, the sequential twins are much more manageable, and theory in practice suits petrol engines better. Which It will be the last project to be trailed on my Skyline.

Just my opinion that Compound didn't work on paper. Mainly because of the exhaust side as small turbo's rear need to satisfy the flow of larger turbo's compressor. I can think A way for this to work, that is making the smaller turbo's rear to have identical flow as the big turbocharger. For example if the larger turbo is a 3582 then the smaller turbo has to be a 3571 sort of thing. But if we use above method to cool down the exhaust end, then the compressor end will have issues as the smaller 71mm compressor wheel can not flow as much as the 82mm compressor feeds, its probably going to cause Turbo B to surge. For 3082's power and stock turbo's response, A sequential system will do. So before 14psi engine pumps gas into a small 2860 lets say, and after 14psi, the 2860 goes to sleep and 3582 wakes up. The 3582 during the time before 14psi needs to be always in a "half sleep" state or its going to create a dip in power curve if its coming from stand still. Just needs to put abit of smart thinking into manifold, dump and discharge pipe. I think this will work in a much better manner.

I looked at compound system few years ago. The original compound Diesel system for a truck which is by turbocharging a smaller turbo with a large turbo, Not sure if it would work on a high performance petrol system. There are two things doesn't look right for petrol. 1. Exhaust side Exhaust manifold mounts to the exhaust housing of the smaller turbocharger. The outlet of the smaller turbocharger's turbine housing goes to the inlet of the large turbocharger. 2. Induction side Outlet of the large turbocharger force feed smaller turbocharger's inlet, out let of the smaller turbocharger goes to the intercooler. Put them together we have: Big compressor of turbocharger two, with small turbine end of turbocharger one. Unless there is a way which turbocharger one can increase its flow capacity to suit turbocharger two's compressor when needed. I think its going to make the engine pin. Also if photo above is based on a RB25det using a Compound turbo system, then I think the SS2 Alpha have made better power band. Other alternative for huge power with stock response is by using a welly tuned sequential twin system. I do have drawings to make that work and is probably the next thing on the trail list. Its going to get very expansive how ever, and I'm not sure how things might be fitted under the bonnet.

Looking back to my result, actually this external gate setup managed to match my Brae high mount manifold's result in exception of slightly lower in upper range torque. G3's result which share the same compressor as the OP6 high flow. http://www.skylinesaustralia.com/forums/topic/261613-hypergear-hiflow-service-continued/page-355 So this setup is enough to max out your 2535's compressor flow. Scotty is coming over this weekend and we will be looking to get all the plumbings properly made and jigged, before offered as a cheap and effective service.

Stock induction pipe will suck shut. You can make a hard induction pipe out of couple of silicon joiners like: http://www.skylinesaustralia.com/forums/topic/261613-hypergear-hiflow-service-continued/page-89 or you can pm M35scotty for his induction pipe which allow factory bov and breather plumbings. http://www.skylinesaustralia.com/forums/topic/261613-hypergear-hiflow-service-continued/page-288

Means I do the engineering work, and supply the gate. You are doing the welding. Which is why I've been talking to you about making external gate running out of stock exhaust manifold, and I don't think there is more then $200 of welding involved. Well, if that is a GTX3582 then that is a tinny amount of power. I still want to see the dyno paper.

I'm not in the business of doing welding related fabrication work, all arguments are purely technical referring to topic. I'm only in the process of finding the most cost effective way of creating the highest possible out put. And if my ideas have resulted in better output then it is far more effective then what had been done. I only believe what I see based on solid results. So if some one claims Rb25det factory exhaust manifold on a stock spec engine is capable of flowing 400rwkws+ on E85 then I don't believe it till I see it. VQ25 results does not count. The cold side has some to do with flow, The hot side has more to do with pressure. Assume the amount of volume that is in side the turbine housing does not change, then pressure at any point of exist remains constant, which is why the shape of the housing based on identical volume has no affect in velocity of pressure discharge, As result, by high flowing a T3x turbocharger out of a R34 Neo makes no difference to, as if the same turbocharger was inside a .63 turbine housing made by whom ever.

Well, my claims are so far are supported by evaluation results. Cold side might be flow related, how ever the turbine end has every thing to do with pressure. I'm not going to get a 31kws gain from 5kws regardless of how smooth my screamer pipe is or how differently shaped of turbine housing might be, based on the same size. Beside exhaust manifold restrictions from RB has already been proved. Details of the evaluation on exhaust manifold is at: http://www.skylinesaustralia.com/forums/topic/261613-hypergear-hiflow-service-continued/page-298 Its is obviously much cheaper using factory exhaust manifold, If people can make big power from it externally gated off turbine housing then no one would be bothered going for high mounts. And we would be seeing plenty of results supporting it. Scotty: If you are well to weld one for me free of charge, then I'll be happy to trail it and give you dyno feed backs. Johnny: Unfortunately I'm not be able to trail your exhaust housing as the dump pipe of mine won't line up to your current (already been cut). Since you've got an external gate this exercise isn't very costly.

The manifold of a Rb25det could be significantly different to a M35 Stagea which should be more modernised. There is a 15 KWs gain just by swapping stock exhaust manifold to some thing properly made. The restriction on it is before the entry of the turbine housing, of where three collectors merges into one. By adding an additional collector at that point reduce excess heat, and pressure as what we can see in the change in upper power and torque curve. The overall gain of this modification have made a difference of 31kws, with a final result of 376rwkws that is some thing that no one have ever made using turbine housing mounted external gate setups on standard Rb25det exhaust manifold. This is also my first attempt, there are few things that could be done improving upper rev range torque. Scotty: it is probably worth while making a jig and properly fabricate stock RB exhaust manifold in similar manner to what I've done. With proper external gating setups, the factory exhaust manifold could be performing at same level as some of the popular aftermarket high mount setups.

Rb25det Neo OP6 high flowed factory turbocharger 93 model R33 GTST Forgied CP pistons, valve springs Stock Cams 1200cc injectors 600x300x75mm Front mounted cool Stock exhaust manifold HPVA 50mm external gate Teed from factory exhaust manifold HPVA 18psi Internal gate actuator Xforce 3inch Cat back exhaust 100 Cell Cat Profect B electric boost controller 4inch intake pipe Adaptronic Plugin E85 Fuel Max Power externally gated from stock exhaust manifold: 376rwkws @ 24psi Max Power internally gated using stock exhaust manifold: 345rwkws @ 22psi

Apart from the turbocharger and gate. I have: 450L/H Fuel pump 1200 cc injectors Adaptronic plug in ECU 3inch turbo back exhaust 600x300x75mm cooler kit My engine is forged with CP 1:9 pistons, Super tech valve springs and valve sets. Your stock engine is fine for up to 20psi mark which is about 350rwkws on paper. To build this turbocharger I will need a donor turbo from a R34 with a OP6 rear housing. Back to the high flowing topic. The current profiled OP6 turbocharger should be pretty close reaching 300rwkws on a internally gated setup with pump 98 Fuel. And good enough for 350rwkws working with a proper high mount externally gated setup running E85.

Video:

Ok. Some feed backs with results: OP6 Standard high flow profile. + Stock exhaust manifold Internal and externally gated result with wastegate fitted to factory exhaust manifold: Gain of 25kws based on same boost level. ATR43SS2 stock exhaust manifold, internal and external gate. With external gate fitted on rear housing: Solid red = internal gate Dotted red = external gate Overall gain of 5kws. So in summary based on using factory exhaust manifold. The gain over internal gate by fitting external gate on factory exhaust manifold in this case is: 7.24% While the gain over internal gate by fitting external gate on turbine housing is: 1.5% In conclusion. If you are considering fitting an external gate to a factory setup, Then fit it to stock exhaust manifold.

I'm using a 3 inch metal induction pipe that is clamped onto the factory air box. OP6 high flowed turbocharger. Standard turbo profile: Here are all the results labeled: I was unable to run any more boost beyond 22psi with internal gate. How ever had no issues doing 24psi external. Power wise compare internal v external was 25kws. note the back to back run on 19psi. I'm very confident that this high flowed turbocharger will do 385rwkws on the Brae high mount manifold externally gated. Even tho this is a remarkable gain from modifying a factory exhaust manifold. How ever, running the same turbocharger with a proper high mount will gain bit more power and much better top end torque. The gain over internal gate by fitting external gate on factory exhaust manifold in this case is: 7.24% While the gain over internal gate by fitting external gate on turbine housing is: 1.5% Reference of Internal gate V external gate on turbine housing: Solid red = internal gate Dotted red = external gate off turbine housing And if any one wants their manifold to be done. The cost for doing so is $300 and our 50mm HPVA gates are $350 in additional.

^^ Standard high flow will be fine. ^^^ Trailed the new OP6 R34 high flow profile today. With factory manifold + external gate assembly above, it maxed at 376rwkws on 24psi. That is very decent amount of power considering a $850 high flow service, $350 gate and couple of hours of marking around. I guess no real need of a high mount kit any more. I've also done a back to back test of having the same turbocharger running on both internal and external. Above external gate setup have made an extra 21rwkws with more torque based on the same boost. Uploading videos now, Will post up results when I get a working scanner tomorrow. And Happy new year every one.

I have the same fuel pump. It needs an extra earth to work properly. Connect it to the factory + / - wiring inside the fuel tank Out side thank, Tee an earth wire into the factory earth wiring that is connected to the fuel pump. It will then work fine.

No, it can never have too much oil that forces out of your rear seal from your RB25det pump. Because the tolerances between the bearings, bearing housing bore and shaft, limits the amount of oil flow. If the turbocharger is flooded as in if there is a oil drain problem in which stops the oil from getting out, both compressor and turbine end seal would be leaking oil (unless it is and you've only noticed the smoking end). In your case, because the compressor side has a collar that spins that throws away excess oil directed towards it, so the compressor end is dry. Means the bearing housing is not flooding there for you don't have a oil drain issue. If there isn't enough oil and oil pressure going to the bearings which I definitely know the Stock oil feeding line and benjos don't. Then the shaft has no centripetal support, the rear end (heavy end) would be vibrating it self in an orbit starting with chewing out rear seal splattering oil. ^^^ Above opinion is only suited for a proper Holset turbo, if what ever installed is a knock off copy then the matter could be at a newer level of complication.

You will need a oil restriction free feeding line for this turbo. Factory oil line has a oil restrictor in it, might have damaged the bearings already. Get a proper dash 4 hose with speed flow connectors for the feed. Make sure the oil drain pipe is not capable of storing any engine oil any where. Make sure engine breather can breath freely (photo have shown that it is), crank case pressure can also cause oil flooding issues to the turbocharger. If above don't help then this turbocharger do needs to be looked at.

The problem mentioned is not very related to a ECU, Such as the back firing, the down revving under throttle and etc. Those are more related to the differences in the volume of air that the engine had to what the AFM might have sensed. If aftermarket ecu is on the list, I recommend Adaptronic Plug in R33 ECUs. Plenty of functions and cheaper then most of other options around.

Get some forged pistons and valve springs then build it properly. Plus they aren't that expansive to buy. RB25dets really pays for doing them properly.

GTX3071 is different, that is equivalent to a 3076 turbo. Which will make more power. Here is some photo of the 3071 that came out of mine: ^^ Definitely the proper GT3071. I've done few extra drawings for a couple of different compressor and turbine wheels. Will be getting them made after the new year holidays.

Pre-load the actuator rod first and see if that makes any changes before switching boost controllers. I'm currently using a Prefect B EBC and seems to be fine at current stage.

Mainly its out of the same jig as mine and it worked ok on my car. Can be modified with no problems. Water is in m18x1.5 Oil is in m10x1.25 Do NOT use oil restrictor on the normal versions of the ss turbos. Merry xmas every one.

No this is a full 60mm 10 blade GT30 turbine wheel. Not the 56mm cropped 9 blade version you have in mind. That was the first thing I looked at when I pulled this turbocharger out. And that was all it could do on this S14, which as I've mentioned about the variances between SRs . I will use its power curve as a base line to compare with.