hypergear

I should start building evo turbos. That configuration stopped making power on a Rb25det at 383rwkws E85 proper manifold and externally gated. Take 15kws off for factory manifold and 30kws off for internal gate. Then I should have 338rwkws. Take the Evo's 4WD trans lose (assume identical to a GTR) is 12% then the 285awkws is 319rwkws out of a RB. There should still be another 18kws that you can squeeze out.

What was the original turbocharger used to make?

High flow stock turbo Nistune factory ecu Stock injectors and AFM should be just enough for 300rwhp.

Oil cooled or not doesn't make much differences in turbocharger's life time, except if it is a ball bearing CHRA. How ever running water cooling can significantly lower engine oil temp, and maintain the condition of engine oil. As If i run a oil cooled turbocharger for dyno tune, by the end of the day my freshly changed engine oil would be black with a burnt smell to it. While running water cooling my engine oil remains clean after many dyno days. With the 25G L2 based turbo failures, The problem is in the back pressure which explains why the 4cyc 8.5:1 SRs and smaller 20Gs combination never had issues. The thrust friction is explained in Ff = MFn which Fn is by P A. It appears Greedy has made a smaller shouldered racing collar set to reducing A resulting in less thrust friction, that is probably engineered to encounter with Garrett's BB CHRAs. I guess those are suppose to replaced after every race event. The ones in the Kando items are the larger shouldered Greedy collar copies. To effectively counter back pressure, ideally is by using a bigger turbine housing or more free flowing exhaust wheel, doing any of those results in unwanted lag. What I'm doing is by increase collar shoulders that results in larger friction area, using oil pump pressure to increases the resistance to turbine pressure. It is not the ideal way, as the compressor and turbine flow is not resulting in a balanced sense, example would be as if I've built a 2582 configuration. Our SS/GX turbochargers are matched with much bigger wheels and housing depending on compressor flow, in a sense that I will end up reaching maximum compressor efficiency instead of reaching maximum turbine capacity. That way I never encountered any reliability issues. About our reliable low friction thrust collar and bearing assembly that I did spent alot of time developing, I won't be posting up photos of its components. But end result is:

About Kando failures I have had many came in for repair. It also apply to Greddy, but there were very few of them due to popularity. It applies to T67 and some of the new large billet T67 alike L2 based turbos in 8/10cm turbines most of them were used on Rb25/26/30 engines running around 20psi of boost. Have not seen any SR based issues or to any 20Gs. Every single one had a cracked rear wheel and a rubbed compressor. They are not metal formulation issues, but all of them had a worn thrust and burnt collar. Once the thrust bearing is worn, back pressure forces the turbine wheel spinning against its heat shield. At that point the turbine wheel cracks. Which is all of our TD06L2 based turbochargers has had its bearing housing modified with a SS2 thrust and collar inserted. From that point there are no problems. For any one whom has a T67 or larger compressor based L2 TD06, that is going to a Rb25det or larger motor. It is probably worth getting our modified thrust assembly before installation of the turbocharger.

Nice. thats a very high number for a bolton turbo setup. Dyno sheet?

This engine did cost abit of money to build, its worth while taken it back to the engine builder making sure there is nothing going funny. But thanks for the input I will have a S15 tensioner installed. By the way is the ATR28SS15 installed in yours? How does it feel driving around on road?

That's ok, I need to know if there is a issues on the actual turbo and sus out any issues on that model. After the stud fouling against the gate removed was the turbocharger back on dyno again for check ups?

I think the timing chain tensioner in mine is loose, sounds like as if the Chain is rubbing against some thing. Its going back to the engine builder for a proper check up.

From a couple of GCG's high flows I have seen, They are a trimmed down GT35 turbine with a 76mm comp. That is closer to a 3576. Replacing the turbocharger made no differences in out come. Means it is still pining if more boost is added. While the G3 has fixed set of boost level. So it just ended up with less boost and more timing compare to more boost with less timing. With no overall gain. Regardless, both turbochargers has under performed. The turbocharger is not your problem.

Yes the SR's on the dyno 4 times and starting to make a rattle noise in the head. Tolling it back to forced motor worx for check up on Tuesday. The RB, did it 1800 times no problems. I think most of its KMs on the clock are Dyno KMs. imagine a buyer comes up and saying "Its a high Ks car." I will be like: "no no its all dyno Ks" I think Peter might have posted result below some where. I got a proper copy from Trent yesterday, It is a Rb25det Neo, with the ATR43SS2 turbocharger on pump 98.

About the new ATR43SS1PU, It has been trailed today internally gated on E85, one of the goals in this upgrade was steady boost which the previous SS1PU had a boost tapering behavior. I'm pretty happy with today's outcome. Power made maximum of 325rwkws on 22psi of boost. Boost holding flat with a 18psi RB bolton IWG assembly. Compare to the boost behavior on previous SS1PU turbocharger based on Brae side mount: Blue / Orange: Current ATR43SS1PU Red / Green: Retired version of ATR43SS1PU It appears that what I have done to the factory exhaust manifold (by drilling out the bottle neck) have let down a little in response. So it now have the same response pattern as an aftermarket exhaust manifold. Blue / Orange: Current ATR43SS1PU Rest: Retired ATR43SS1PU on Stock manifold with heaps of actuator preload. Add: By the way today's dyno run marked the 1800th times of dyno runs from my R33, since the start of the ATR43 project.

That is a compact paragraph of questions, I will be answering them in reference to my experiences in Q&A form: Stao I'm curious to hear what you think of compressor housing size and power levels , where you think the cut off points are for the 0.60 T04B , the 0.50 and 0.60 T04Es . The T04S is usually as big as most go and I'm curious to hear how much difference you think there is between it and the 0.60 T04E . Depending on the size of the wheel that is installed. Ie. machining a .60 T04B to suit a 82mm comp wheel, it will break through. Performance wise as explained earlier, I give high bell clearance on small housings with large wheels, and low for large housings with small wheels. The end results are usually very close. It's no secret that I don't like the S covers mainly because they look bigger even if it's not much over the T04E port shrouded one . I just can't get my head around using a supposedly 700 hp comp housing on a 4-500 hp compressor . Use large housing with low bell clearance to satisfy compressor wheel flow, that maintains discharging velocity as to if it is in a smaller comp housing. Compressor housings , I think Garrett has a size problem between the T04B and T04E because the B probably runs out of flow and the E is physically significantly larger . The ported shroud on the HKS style Garrett T04E is huge for what it has to do at 4" 100mm . You may have noticed that some of these housings on GT Pro S turbo have the cast sections machined off and they make their own turned section and bolt it on the front . Think they are 80 or 90mm inlets and that makes plumbing easier . Larger compressor housings has more materials working with bigger comp wheels. Shifting compressed air, discharging volume are pretty close assuming the housing has enough materials to suit the wheel. However discharging temperature is higher out of smaller comp housings. I'm not a fan of the anti-surge slots. How ever surging is a problem for larger engines. I only use them if I suspect/predict surging issues. With the machined removable shrouds, I believe those can be replaced by solid sleeves or add in larger shrouds rectifying surge problems. Cost aside I keep thinking surely they could get away with slightly more modestly sized comp housings than the T04S 70 AR at their power levels . Last OT bit , punters make respectable power with XR6 turbos and they don't have big comp housings on them for a 4L engine . Low hot side restriction and modest boost levels I suppose . I didn't find much affects in using different comp housings on same compressor wheel, assume they are machined accordingly. Ie stock T04b comp housing (r33 comp housing) makes 376rwkws with G3 comp wheel, .large T04S .70 comp housing also made 376rwkws with G3 comp wheel with exact same response.

There are couple of things to consider, One of them is the bell clearance. Since I machine all housings from raw castings, the physical size don't make that much of a difference, while Garrett housings are all fixed. If a larger wheel needs to be use in a small .60 T04B type of housings then I would be leaving the bell clearance higher to compensate flow. By lowering the clearance, discharge velocity is higher, which encourages better response and sharper throttle response, higher discharging temp is encouraged and flow restriction is created. In this case larger compressor housing is used in compensation for heat. Finding the perfect bell clearance in reference to individual wheels and housings, a dyno is very useful in doing that, which has been used often. Larger compressor housings in general would have more materials, which smaller comp housings might machining through fitting certain wheels. It also allow anti surge ports to be added if required. Yes I can supply 20mm spacers, it will cost you $40 each delivered. To purchase please message through your details. The SS1.5 trailed is in a .64 rear housing. VNT turbine is working in progress at current stage. Getting better response on the SR, it is more of a case of when the .64 rear end getting maxed out. SS1PU is still the largest wheel used, SS1.5 would definitely be more responsive, in theory it should not be making more power.

its a internally gated SS1.5 turbo identical to your except I'm running the 3inches inlet with 2 inches out let.

Never mind chatting about other turbos here. It encourages me of engineering better turbos. Here are the result for the SS1.5 from today, from my Sr20det S14 with No VCT controller. Maxed out at 270rwkws, 20psi by 3850RPMs. Pump 98 fuel VS the Garrett 3071 and SS1 in .86 rear housing: Pink light blue: GT3071 Red: ATR28SS1 in .86 Rear. Thick blue: ATR28SS1.5 in .64 rear I would say this turbocharger is probably good for 260rwkws internally gated. We added heaps more boost in last run how ever it didn't hold and only picked up 10kws.

Just dynoed the atr28ss15 on my sr. Made 270rwkws on pump with 22.5psi at 4000rpms. Will upload sheets and attend questions when I get back home.

Assume if no cold side leaks. Make sure the actuator is preloaded and tightly shut. Test if the VCT is working. Lastly the ECU would deduct timing depending on whats been programmed to reacting on how hot the air temp is. So on a 38+ degrees day, under the bonnet it would be very hot. See if there are any noticeably differences driving on a cold day.

Updating some results: SLSS2 as some have already seen. Final result of 356rwkws @ 23psi factory engine stock cams E85 fuel. Brae manifold, Externally gated. 21U high flow on a R34 Skyline, final result of 266rwkws @ 17psi Pump 98 fuel. Going with high pressure actuator for 20psi, hopefully be seeing close to 300rwkws soon. ATR43SS2 factory Bolton Turbocharger on a stock Rb25det powered R32 with No VCT. Final result of 328rwkws @ 21psi E85 fuel.

Well, the test cars wasn't built with budget in mind so it has reasonably good parts. There are many variances to consider depending on setup just like not all 3076s make 300rwkws. How ever our turbochargers are always been improved for better. Later models has better compressor / turbine efficiency, response, boost control and power to boost ratio. Many members using our turbocharger have archived expected results. Just noticed the expected level of performance for OP is 300/330AWKWs, in which by comparing results, 4WD skylines are 12% in power behind RWD skylines. That means some thing at 370rwkws on E85. That figure is very hard to archive using stock exhaust manifold internally gated. Unless its been externally gated from the factory manifold or using a high mount setup, regardless this figure is way out of what a 20G in either external or internal gated can deliver. If it has to be a TD based turbocharger I strongly recommend our SLSS2 in 10cm or a SS2 in .82 rear, both externally gated. In terms of our high flows, bolton turbos and other turbos might be, more specifically to Rb25det will out perform the kando items with much longer life span. Plus we don't charge $1600+ unless you are looking at SS Alpha series. Usual high flows starts from $850 and the bolt on SS2s are for $1450 all including braided oil line.

I guess it is up to the limitation of what factory exhaust manifold can flow. How ever I think I can match or beat your result of 336rwkws by high flowing a standard R33 turbocharger using factory housings internally gated with better response perhaps. Can't stop trying harder for new heights

lucky you've mentioned it, I didn't take a note that it is for a Rb20det. The current R33 profile would be able to support roughly 250rwkws while older profile would be more responsive maxing towards 230rwkws. So would you prefer power or response? Some updated photo of the SS2 M35 Stagea high flow with our latest SS2 compressor wheel, and latest SS2's turbine wheel which is 3.5mms larger in diameter to the older version with a 2 degrees difference in blade radius. Please note the internal gate is to be enlarged which didn't take place when this photos were taken. And of course never stop trying. Here is a newer version of a ATR43 prototype, aimed at high 300rwkws with optimum response. It is for Mr Hovic's drift car.

Well 3071 is very laggy on my SR. 180sx doesn't have VCT so it won't be much better then mine. Getting things to work on the SR is much harder then on the RB. The current VNT turbine system have only made the car hitting 1psi much quicker, at 5% light throttle I can hit 1 psi. from 1psi to 20psi still takes for ever, there for, no end result differences. Doing some evaluation on SS15 on .64 rear at moment and it drives nicely. So further evaluations to be conducted at this stage. One of my FiveO motor sports's 1200 injector gave up the ghost last week after 5 dyno runs, which is abit disappointing. getting replacement installed shortly for SS Alpha bolton series evaluations soon.

Nothing wrong with current turbo, it is big enough for 400rwkws+ on E85. The power tread seems to be very similar to my KIA sportage, it is a high comp 10:1 motor how ever. Didn't like timing but still took more then the OP's R34. Fitted a couple of turbochargers on it, and larger turbochargers do result in a slight power increase every time. The new turbocharger is for the XR6 BA engines, bigger in both larger compressor and turbine. I think it will do 530rwkws on my car. I don't have much time on it currently. But following the turbo size to power tread, it should be sitting at 350~370rwkws mark on OP's car. It is not the right way, how ever is a possibly solution on getting more HP.

Any one suggesting "Biggerrrrr" turbo?