Rolls

you are meant to kill the VCT after 5000 rpm or it saps top end power like shown there, I cant figure that dyno sheet out but it looks like it is making almost 75hp more at low rpm?

Yeah there is a big difference, if its missing its probably plugs/coils going, flat spot sounds like massive fuel lean out (fuel pump etc) or poor tune.

put it on a dyno, the difference is massive.

No one here would be capable of changing that though, might use wrong angle and make it far worse.

get a real tune done, no way to know otherwise, almost certainly the tune isn't correct for your car.

VCT makes a huge difference, its like comparing an rb20 to an rb25

How much is a high pressure actuator for an rb20 turbo? It has been highflowed by gcg but I'd like to give one a shot, see if it can hold 18psi to redline. the stock rb20 actuators tend to open later than the rb25 ones, around what psi do they start opening in your experience? it holds about 13psi with no controller if that helps.

could have been just not quite enough causing slight bearing wear, worth checking imo even if its a low chance.

oil analysis, its like $50 and mainlube.com.au do them, highly recommended, will tell you if you have shagged the bearings or anything. this is something you want to find out now before catastrophic failure, it could be fine though.

looks decent to me, but simple solution is tune for E85 with new injectors.

What are the main reasons manufacturing wise to go H or I beam? pros and cons? edit: a quick google says tensile vs loading, so basically high rpm suits one design and high pressure lower rpm suits others.

it isn't though, we claim far more than everyone else and we are only a tiny part of the population, easier to just say no.

VCT is the f**king shit, my controller died the other day for a few hours till I could rewire it, felt like I was driving a 20 again.

http://forums.hybrid..._1 interesting results from someone who made his own http://www.supraforu...265#post7419265 some more here, with valve open, valve closed and valve moving looks like it kills top end quite a bit, probably better off just getting a smaller turbo

How do all the sequential factory turbo setups know which turbo is on and when? You can do it. The people who binned their turbos on mazda were series 6 onwards people cause the twin turbos had lots of issues, the older S4/S5 units are still used by a lot of people.

By blowing half the turbo you are effectively changing the a/r as there is less volume. If you jam it shut all the time (why?) it will be like running a smaller turbo as you are only utilising half the blade area, then when it opens it is like using a larger turbo. You use a standard manifold, no way in hell you use a twin scroll manifold, I imagine you'd cook 3 pistons if you tried doing that. The concept makes sense to me, it just depends how negative the effect of turbulence is.

may or may not be an issue, if is you'd something that takes into account rpm and boost pressure, I imagine most decent aftermarket computers could offer something like this, or if you run it with rpm only you would need a decent boost controller that can compensate for it, depends what is slower the wastegate actuator or the flap actuator, the fastest one should be doing the most control, I imagine the wastegate would be the fastest so unlikely it'd prove a huge issue. Just means you'd need a competent tuner who can test all possible scenarios and ensure stable boost and no detonation, couldn't be too difficult. I can't see backpressure being a huge issue, you'd just tune the gate to open slowly once full boost is it, cause if you did it too fast boost would drop/dip.

anymore results people? it looks like a ghetto variable vanye setup to me, worse backpressure than a normal vv turbo but it has to spool better there's no way about it, you are halving the usable area of the turbo, will probably pose some restriction in the top end but my thinking is it will be completely worth it. honestly I dont think it is that dodgy at all, surely the flow couldn't be much more turbulent than a normal dodgy log manifold or unequal length aftermarket one, and even if it is, it can't increase backpressure any more than just running a stock turbo.

Im dubious about the amount of turbulence and why it would last less than a normal setup. Seems like a solid idea to me. Do you know what A/R actually stands for? Not until it opens fully, but who cares we are trying to gain response with minimal top end loss. and I am sick of shit posts, I want to hear about new tech that could result in faster spooling turbos for the same power, this sounds like something that could do exactly that.

Yes that is exactly how they set it up. no shit but it might bring other benefits that make it worth while, it would have more of a restriction and limit the overall power made however if it makes it spool faster than a turbo that makes equivalent peak power levels surely that is something worth investigating?

What do people think of using a quick spool valve on twin scroll turbos? seem to have some very promising results over in the states. essentially it just blocks one of the scrolls off and slowly opens it as boost comes on, kind of like a ghetto variable vayne.

just car will bring your premium down if you increase the excess, personally I have my R32 insured for 13k with a $950 premium but a $3000 excess. I'm 23 with with no claims or disqualifications.

sounds like my gcg rb20 highflow job, ~240kw on 18psi and that is with it dropping back to 15psi, full boost is by 3000 in the lower gears and it spools at 2k with light throttle like a stock turbo, don't think I'd have it any other way.

Call them and ask them?

oops