bradsm87

T4 is only the flange size. The T4 .92 housing certainly is not big for an RB25. Sounds like the one for you would be an EFR 7670 with the .92 internal gate housing. of if you want better response, go the 7064.

Got my EFR 7064 .92. Modded for external gate so I can build a super quiet 2.5" exhaust for the turbine gas only. A 2.5" exhast would be too small to flow the turbine gas and wastegated gas. Divided all the way to the wastegate valve.

I won't have time for ages but it lookes exactly the same as the pics posted on that BMW forum. It's a 7064 .92.

I just got mine and mine is just as bad as the one in the pics including the far off-centre bolt holes. I've been waiting so long that I'm just going to fill in one side on the turbine entry to make it smaller and symmetrical because I'll be blocking the internal gate anyway so may as well block it using a couple of bits of stainless plate to better direct air into the housing.

I believe so because the .92 internal gate is the by far the hardest to cast and that's the one that's been pretty much completely unavailable until now.

Only the .92's have these housings. All the others are still investment cast.

The problem is that the EFR 6758 is quite inefficient compared to the others, especially at low boost. Also the only turbine housing option is the T2 .64 which is too restrictive for my engine. I'm building a high compression, high flowing engine to run a big turbo at low boost. I could whack a 6258 on it and run 22psi but that's not the type of setup I want to run. I plan to replace the 7064 with a 7163 with the divided 0.80 housing after a year or so.

Nice! I'm hoping for boost earlier than that but I only really want/need 250rwkw so hopefully my smaller turbine housing, smaller cams, 160cc more capacity and higher comp engine will give me my target boost threshold of about 3000rpm. Fingers crossed.

Bugger. I guess my 7064 is going to look much like that. As soon as I can get my hands on the EFR 7163 with the new 0.80 divided housing, I'll be switching to that anyway. I only chose the .92 because there were no smaller divided options. It's very frustrating waiting 2 years for a turbo then it arrives and there is another turbo that's pretty much better in every way already announced.

Here I was working backwards from page 43 in that build thread. That photo was posted in January. What makes you think it's current revision?

The one by infamous_t ???

That last pic is a 1.05 which is a different housing that's going to be a lot easier to cast.If BorgWarner come out and state that the manky housings are the only way they can reliably make the shape of the .92, I'd be happy enough with it and just tidy up the inside with a Dremel. Deep down inside, I'm really hoping mine doesn't arrive like that though.

Hopefully with the availability issues gone, we can start to see a lot more results and discussion again. The Boost Lab received one EFR 7064 .92 last week and I snavelled it up straight away. I should get it in about 2 weeks which is roughly when I should get my block back with the Darton sleeves fitted. If I get the turbo before the block, I'll fit a spare rooted SR20 into the car so I can make an exhaust manifold ASAP. I seriously am sooooo keen to get this thing going. 2.2L, 9.6:1 comp, W2A intercooler across the front of the engine, Poncams, E33 fuel mix and EFR 7064 .92 twin scroll should be a shitload of fun for a street car, even on only 15psi through midrange (will taper boost upwards as RPM increases to hold the torque curve dead flat to at least 6000).

I'm going to buy straight ethanol from Just Fuel (only 10c/l more than pump E85) and mix it 1 part ethanol to 2 parts BP Ultimate (33/67 mix). This will give me enough ethanol in the mix to make peak torque without detonation while keeping a majority of normal petrol so easier cold starts, less oil dilution and longer lasting engine IMO.

I didn't hook mine up. Another 2 ppl confirmed that they didn't either on nissansilvia.

I've set a time limit of end of November. If there are no 7064 .92's available, I'll get a GTX3067R with an ATP divided .82 housing or a Tial .63. Full Race should have T3 .82 7064's in stock now with T4 1.05's due in about a week and T4 .92's due about a week after that. I'll believe it when I see it.

The GTX2860R would be the one. U'd need to make sure you get the .64 "compact 5 bolt" turbine housings to suit the GTR twin setup. The biggest problem is making good intake pipes in the tight space but if a decent amount of time is spent, it'll be well worth it.

Gas isn't constantly flowing out of each exhaust port. Each exhaust pulse happens over a period of about 220 degrees of engine rotation. it takes 720 degrees for a full cycle through all of the cylinders. 3 cylinder engine has. 220 x 3 = 660 which is pretty close to 720 so there is no overlap of exhaust pulses and pretty much no gap between them either. 6 cylinders into 1 means that most of the time, there are 2 runners flowing into the merge collector at the same time.

If it was a 3 cylinder engine, that would be true but with 6, there are more than 1 runners trying to have access to the "shared flange" at the same time, regardless of how good the collector is.

Sounds like it's getting too hot. I'd richen the mixtures which will also allow you to advance the timing a bit which will further lower your EGT. Also make sure you have inconel studs on the exhaust manifold to turbo flange.

Not true (true if the aftermarket cat is a generic one like most). A new 200cpi cat with newer tech coatings that is suitable for new Euro 5 cars is going to have better emissions and way better flow than a 15 year old stock cat.

Nah I like it. I hadn't heard of them until this thread.

The turbo's here are R35 GTR turbo's, not R32-R34.

Not a race car Depends which state you're in . There's one state that's more "nanny" than WA and I can assure you, screamers and decats are the norm.

Nah the street ones at www.hjs-tuning.de