TwinTurboM3

Attention to detail at highest level, excellent, excellent.

I would like to see photos of R32-33 transfer case internals, such as the cluch pack, chain, gears.

Would it be possible to control the clutch discs inside the transfer case with an aftetmarket ecu? I would like to put the 4 wd system of GTR33-34 without the atessa ecu and electronics into my bmw turbo. With an aftermarket ecu I can alter the PWM (pulse width) and change the oil pressure according to TPS, RPM, ROAD SPEED, BOOST. Alternatively, I can pulse the transfer case pump according to front and rear wheel speeds. Is this doable? How does the transfer case's oil pump work? Is there a table showing pulse width PWM and lock? I.e % 33 PWM = 40 % Front-60 % Rear?__________________

Planning on going from a GT3076 ball bearing to a GTX3076. Have you tested this? How does the GTX3076 spool compared to a GT3076?

Does a GTX3076 spool slower compared to a Gt3076? Was the Gt3076 ball bearing?

nice project. any dynamics runs in shoot out mode? very nice car.

Latest measurements 2.0 bar at the exit of each turbocharger 2.5 bar at the entrance of intercooler 2.45 bar at the exit of intercooler 2.2 bar at the intake manifold. A fitting is welded to the intake plenum. 1.2 bar AFTER the SIX individual throttle bodies. Am I flowing 2.2 bar into the engine according to the Intake Plenum readings or flowing 1.2 bar according to After 6 Throttle Bodies readings? The `after throttle bodies` measurement is made, where there are 6 runners after the throttle bodies, and each runner has a pipe which is connected to a main TUBE. I take the readings at the end of this TUBE, which gets air from all six runners. AM I feeding 2,2 bar or 1,2 bar into my engine? I checked the Drive By Wire and it opens 6 throttle bodies 100 %. So the throttle bodies work properly. Ambient temps were 30 deg celcius and intake manifold temps were 32 degrees. So the turbochargers are not being overrevved. At 2,2 bar, the intake manifold temps should be higher than 32 degrees. I cant solve this pressure difference across the 6 throttle bodies. One way would be to remove drive by wire, put a single throttle body. But the VANOS, cam control does not work without the drive by wire.

the main problem can be the 6 individual throttle bodies. drive by wire system operates the 6 throttle bodies and under 100 % TPS the 6 throttle bodies may not be opening. Thus restricting air flow into the cylinder head. i will check if the drive by wire opens 100%.

Thanks a lot, but we dont have the smoke machine here. With GT3076 i went maximum to 18-19 psi and then w/o maxing them out, i installed the GT4088.

yes twin Gt40s. i have a dyno dynamics in my garden, and have 21 psi @ 5400 rpm if i load the dynamics. during a power run, in Shoot out mode, 21 psi comes @ 8800 rpm. as i have a 1 bar leakage, the boost should come on earlier when fixed. i switched back to less overlap cams and back pressure is now 1,8:1. so i am happier with the back pressure. but the boost loss of 1 bar is making me sad. idle valve or throttle body shaft or some leak?

First of all, thank you for your comments. Back pressure dropped after decreasing the cam overlap. I have made the following PRESSURE measurements: Measurement 1: Pressure at the discharge of each turbo is the same. I have put 2 fittings to the pipes,these pipes connect the turbos with the intercooler. Both turbochargers flow at the same pressure. Identical pressure ratios. Measurement 2: Pressure before and after intercooler Before intercooler, measured @ intercooler entrance end tank 2,5 bar After intercooler, measured @ intercooler exit end tank 2,45 bar. Pressure drop accross the cooler is not much. Measurement 3: Boost pressure after the 6 individual throttle bodies is 1,4 bar. The engine has 6 individual throttle bodies. This means there is a 1 Bar Boost Loss between the intercooler and cylinder head. The 1.4 bar boost pressure is measured AFTER the throttle bodies, boost is measured between the 6 throttle bodies and the cylinder head. Tomorrow I will weld a fitting to the pipe which connects the intercooler with the intake manifold. and see if the loss is due to this pipe. Moreover, I will weld a fitting to the intake manifold and see if the pressure is being lost because of the intake manifold. I suspect the 2 following points: Idle valve may leak under boost. Or the throttle bodies may leak. As there is a shaft which moved the throttle plates, we may be leaking through the holes of this shaft. Would you please comment? Many thanks

on my 3.2L inline six BMW engine, back pressure on the exhaust manifold is very high. twin turbocharged. GT40 x 2 76 mm x 2 downpipes. no muffler, no midpipe. straight to road discharging. back pressure is taken between the turbo and cylinder head. 3:1 exhaust pressure to intake manifold pressure ratio i have changed to bigger A/R turbine housings and the ratio dropeed to 2,6: 1. still at the high side. power does not go up when i add boost. same power @ 16 psi. same power @ 21 psi. intake manifold temperatures are close to ambient temps, so the temps dont increase, stay close to ambient. Cams are high overlap, a total of 162 degree cam overlap. Would you please comment on the high back pressures?

Thanks mate:) german beauty + garreetts hmmm..

Thanks mate. I drove the 2.8L twin 2871 for 10 kilometers, then we decided to change the ex manifolds, and i fabricated tubular manifolds. as it is a hobby, it took some time. And a bigger intercooler is in place. first minutes engine did not pass over 5000 rpm. I was shocked. Boost was 3 psi. Then i realized the ECU had a safety rpm cut at 5000 rpm. Removed the limiter. During that 10 kilometers test drive, it was like sex driving twin 2871 2.8L Now, with the 3,2L and 3,9L capacity, the feeling (power) may be amazing, assuming all go well. Dynapackk, more time involved for wheels etc. But you guys should be proud of Dynamics, what a consistency and quality.

Precision has a range of 91 - 94 - 98 - 101 mm compressor wheels but i want to stick to Garrett. A 98 mm falls between a Gt55 and Gt60, but i insist on Garrettt.

answer is on the previous page

Zebra. Thank you for your interest. I own a M3, which you saw above, equipped with twin GT3076s. This M3, may have full boost @ 5000 rpm. And rev 9000 rpm. (stock limiter is set @ 8ooo rpm) . On the M3 i have a drivable and acceptable power band. Other than the M3, i also have a 2,8L BMW inline with twin GT2871s. This 2.8L is making full boost at 4700 rpm and revving 8ooo rpm. Still acceptable. When i was building the M3 3.2L with twin GT3076s and my 2,8L with twin GT2871, i was reading this forum and also gtr.co.uk and was trying to find out how Gt3037s of HKS responded on RB26 and RB30s. Thanks to members of these 2 forums, I have great feedback. SO far i did test the 2.8L twin Gt2871 on the road, was spooling @ 4700 rpm, A/Rs 0,64 on the hot side. When the M3 twin GT3076 will be done i will post dyno dynamics graphs here as well. Why did i tell you this story? M3 twin GT3076 and 2.8L twin Gt2871 are drivable on road. 100 octane pump fuel of Shell is used. So still daily. On the other side, the new project with 3.9L and GT??? will be used just for: RACING BIG BOYS. There are some 900 whp supras in the sphincter of the universe, one of them made 830 whp on my dynamics. And there are some 7.0L corvettes with 350-500 hp nitroussss. So with the 3.9L, just pure racing goal, C16 used all time, exhaust discharged straight to the pavement, no silencer, no interior, JUSTA BOMB to test with big boys on highway rolls. For highway rolls between 100 km/h to 280 km/h this latest project will respond and compete with big boys. What do you say? mert

Yes left hand drive. I am from the sphincter of the universe, not from US. Budget is the last restriction, in these projects, if one tends to follow the economy root, results are disaster. May I ask what you mean by LINE BORE BILLET? is this torque honing with the plate? I am not a professional, do it as a hobby, and got a dynamics twin retarder dyno. www.da-motorsport.com is my page, not professional, but as a hobby. GT55 with 91 mm comp wheel and 1.0 A/R spools at 6000-6300 rpm on a 3.4L supra with lots of head modification, with full race exhaust manifold. So, on a 3.9L, full spool should be around 5300 - 5500 rpm. Assuming all variables are well matched and done.

thank you very much. RB family has been helpful and also was a source of inspiration. i will test different A/R s on the exhaust side, different cams and try to find the best combo on my Dynamics. BTW you Aussie people have a wonderful Dyno, and i am also a lucky owner of dynamics dyno as well.

intake manifold during constructionn

this is when the TOP MOUNT GT30 was under construction

down pipe of LOW MOUNT GT30

what you see over is the TOP Mount GT30 now the LOW MOUNT GT3076 is

M3 has 3200 cc M88 engine has 3.5 to 3.8L capacity. add to that a stroker kit, we end up 3.9L Apart from the 3.9L project, below is my Twin Gt3076 E46 M3. photo is low resolution...