V8KILR

I used stainless steel for the one I had built and I ran it for a year with no problems. Looked just the same as the day I built it after a year of drag racing. If you use the right stainless steels like I did, they are fine. Sound Performance have very few failures these days as they only sell their heavy duty version now.

The chance of damaging your turbo without a BOV is pretty low, but can occasionally happen The main reason I run one is for speed of boost recovery on gear changes. When drag racing, with the plain bearing turbos I run, it makes a huge difference to how fast the boost recovers. With ball bearing turbos it is probably needed less, but would still help. On the street you would be hard pressed to tell the difference.

Yes, they do work. I had one in my car for a while but sold it with my old setup. You usually get around 400rpm quicker spool from them. Sound Performance in the USA make a reliable QSV. Only one other company makes them and they are dearer and more suited to diesels.

Same. Works great.

You definitely feel much better acceleration in each gear with the 3.769 diff, but there are other things that offset that advantage. With the 3.769 diff, it required changing into 5th at the drags back when I had the stock rpm limit, so it was no quicker then the 3.266 diff was on the 1/4 mile due to the extra gear change. A higher rpm limit would probably fix that issue though. Also as you change from 1st to 2nd (and all other gear changes), it is at a lower mph, so the same time (say 0.5 sec for the gear change) not accelerating is worse for elapsed time. This is because you are going at a lower mph when you change gears so you cover less distance during the gear change time.

I also used to have the 3.769 diff in mine years ago and it made it much easier to drive on the street as well.

I recently ran the numbers with this calculator http://www.wallaceracing.com/drag-sim.htm and surprisingly, for drag racing it is slower to use an auto diff (3.769 or 3.538) vs a manual diff (3.266 or 3.133). The calculator assumes you can slip the clutch to a higher mph for the manual diff ratios, so it may not match what would occur in a real world test. I switched to the 3.538 diff a while back thinking it would give me quicker time on the 1/4 mile, so I'm hoping it actually does.

Lots of guys running this in the USA. Most power I've seen so far on this manifold is 1018whp with a Precision 6870 on a dynojet. http://www.supraforums.com/forum/showthread.php?913673-1018whp-on-a-cast-manifold& I have the SPA manifold and did my own port matching. It is fairly good quality and no problems or complaints so far. I'm only at 490rwkw as running a smaller turbo than previously, but have a Precision 6870 that will go on it after I upgrade the wrist pins.

Any update on how the run in went. Is it still smoking?

Volks 17x9.5, 17x8 with 275 rears and 255 fronts.

Fair enough, you need to follow your engine builders recommendations. Yes, I run my engines in a lot harder. First engine was up to 7000 rpm and up to 10 psi boost. All this within the first 20 miles to get rings to bed quickly. Second engine was not quite so hard due to tune not being 100%. Limited that one to 6000 rpm and 5 psi boost. Both times the engines made good power and never smoked or had any issues.

You have done everything the complete opposite of what the http://www.mototuneusa.com/break_in_secrets.htm suggests. It will be interesting to see who is right.

This is how I recommend to run an engine in: http://www.mototuneusa.com/break_in_secrets.htm

I can confirm that the new 50mm Turbosmart raceport BOV fixed the huge delay in boost recovery during gear changes. I tested this at the Powercruise #55 meet yesterday in Hampton Downs. It worked so well in fact, that I won the Off Street drags event.

A cast manifold is very strong and they are cheap as well. This SPA (aka FSR) manifold has made over 1000whp on a dynojet so far. Another alternative is a steam pipe (normal or stainless) manifold.

A BOV does reduce the slow down of the turbo during gear changes and does reduce turbo lag on gear changes. This is based on personal experience. A long time ago when I upgraded to USA spec turbos, I had to add a second JDM BOV (20mm) to improve how quickly the boost recovered on gear changes and that worked great. After I changed back to the Getrag a few months ago, I then raced at the drags (currently running a 65mm MasterPower turbo) and realized my twin 30mm HKS SSQV BOVs (probably fake ones) were no longer working. There was no noise on gear changes under boost and the boost was incredibly slow to recover when changing in to the next gear. I have removed both the HKS BOVs and added a 50mm Turbosmart raceport BOV (for more flow than both HKS BOVs combined), which I'm sure will fix the issue. I'm racing again in 2 weeks, so I will know for sure then. In a race car, you could set it up so you didn't lift on the gear change (flat shifting) or you could use anti-lag on the gear change to keep the boost up. Both these would be better than using a BOV, but it is hard on the car but for a race car that doesn't matter. I didn't need them when the Supra was auto of course as no lifting on gear changes. On a manual street car it's optional, but I did like the sound that the HKS SSQV made on gear changes.

Nope! The V160 sits a lot higher at the rear so you need to change the tunnel top piece to the manual one.

Many people use a BCC or FCD and run up to 18 psi on the factory turbos with factory fueling and factory ignition timing without any issues. This works because the factory ECU provided lots more fuel then is needed at 14 psi, allowing a safe A/F ratio even at 18 psi boost. Obviously you must run a high pump octane fuel to do this. So would this be any worse then running a small single (52-55mm) at 14 psi, just under boost cut? I'm pretty sure it wouldn't be any worse and it may actually be easier on the engine as the air from the single turbo at 14 psi would be way cooler then the factory twins would pump out at 18 psi. The only way to know for sure would be to check the A/F and knock sensor readings for both setups on a dyno (at all boost levels) and see who is correct. If the wife's TT Auto Supra turbos crap out, that's what I will be doing. A MasterPower MP-R544 or MP-R545 is what I would use with my spare Threadstone (aka Turbonetics) cast manifold. MP turbo options are: MP-R544 54/77mm compressor, 49/61mm turbine, T3 48, .63, .70, .94 MP-R545 54/77mm compressor, 59/70mm turbine, T3 48, .63, .70, .94, T4 .68, .81, .96, 1.00

Ditto. I drove my car for a few years with that same type of setup.

Yes, of course it can happen at higher rpm as well, as it is the extra fuel for when the #2 turbo comes online. E.g. If cruising at 5000 rpm and then flooring the accelerator, the #2 turbo comes online at say 5500-6000rpm. Around 4000rpm is where it occurs from a low rpm run.

Obviously it doesn't just always dump fuel in at 4000 rpm for no reason. My comments were for when the #2 turbo is coming online, which only happens if you are already at significant boost with the #1 turbo.

On a completely stock setup, max boost is 11 psi (not 1 bar) as fuel cut occurs at just over 1 bar. The fuel dumping you refer to is in relation to the second turbo coming online which usually happens at around 4000rpm. My comments are not assumptions, but are based on how the sequential system works: http://www.max-boost.co.uk/max-boost/supra/boosting_the_beast.htm http://www.max-boost.co.uk/max-boost/supra/turbo.htm

For those people just wanting a similar performance single (aka 52-55mm range) to replace old twins, then the stock fueling is fine up to 1 bar as the ECU learns very well using the O2 feedback loop for normal driving. E.g. I've run 550cc injectors with the stock JDM ECU and within 20km driving, it has compensated completely for the injector size difference for normal driving. As you go bigger in turbo size, then the differences in efficiencies at boost under 1 bar become greater and you would definitely want to run some form of fuel control adjustment.

The stock ECU will probably dump some extra fuel in around 4000rpm as it would think the second turbo is spooling then, but apart from that it should run a small single just fine. No different to people running true-twin with the stock turbos.