Clean shaved/tucked M20 turbo - TUNED 378hp/282kw

[potatomash]

Pretty happy with how my car's looking now. Hate to say it, but I think I'm actually finished modifying my car...for now haha.

[ForcedFirebird]

The pressure you need to reduce is between the turbo and head, not after the turbine unfortunately. You should be able to just bolt on a larger housing, just match the trim. Garret offers several, listed right on the product page for the gt35.

Your turbo ratio would be more suited to a high HP small displacement engine (ie, high intake flow, small exhaust in NA form, such as a Honda etc.).

The problem is you are running a larger turbo at minimum capacity. One 44mm gate is not big enough to bypass all the exhaust volume you need to barely work the turbo. You can add another wastegate, increase wastegate size, or run a boost pressure thats in the operating range of the turbo!

I said the same earlier int he thread.

I have the same manifold on a 3.1L stroker m20 and i have some boost creep also. good to hear I'm not the only one. I thought increasing boost pressure might help it. I have a 6 psi spring and creep up to 9 psi. turbo is a precision 5862, wastegate tial mvr 44 mm

Turbo specs?

Local is using the RSI manifold with a 6267 BB t4 .6 housing, and it was perfectly stable down to 6psi for street driving with a 44mm gate. Made 518+@19psi when it got the wick turned up. Granted a t3 .8 housing would have spooled earlier, its a good demonstration of the housing size vs pressure release.

[ForcedFirebird]

Pretty happy with how my car's looking now. Hate to say it, but I think I'm actually finished modifying my car...for now haha.

Looks great! What diff are you using? I have been popping in 3.1 and 3.2 diffs on the higher powered cars using a g260. 2.93 or 2.97 has been good for the zf turbo cars. A 3.73 with a turbo m20 is pretty useless. I put in a 3.15 from a z3m in the locals 500hp car, he called me giddy like a school girl about how his car pulls like a raped ape to 110mph in 3rd lol.

[potatomash]

Looks great! What diff are you using?

I just have what came with it, which is 3.91 LSD. It seemed good as far as I thought apart from 1st gear which is useless..but I've never been in any other turbo e30s so have nothing to compare to

What difference would I see with a lower one??

[MrBurgundy]

Your lower gears will be usable. great build btw

a 3.9 is really low for that power output.

[downforce22]

I said the same earlier int he thread.



Turbo specs?

Local is using the RSI manifold with a 6267 BB t4 .6 housing, and it was perfectly stable down to 6psi for street driving with a 44mm gate. Made 518+@19psi when it got the wick turned up. Granted a t3 .8 housing would have spooled earlier, its a good demonstration of the housing size vs pressure release.

interesting, here are my specs.

Precision PTE 5862
Compressor 58.00 76.20
Turbine 71.00 61.90
Journal Bearing
T3 0.82 AR, 3 inch V-band Exhaust
4 Inch inlet P-Trim Anti Surcge Compressor Housing, 3.5" outlet

My engine is a 3.1L M20 (86 x 89.6 mm) with 9.5:1 CR and stock 885 head, cams, valves with G&T manifold and 44 mm Tial MV-R gate dumping to atmospheric screamer pipe. I assumed it was the size of the engine turning a smaller compressor, but it looks like match bot shows a 38 mm wastegate to be adequate. you can see it clearly on my logs

Wastegate was opening at 2600 rpm and run stops at 4300 rpm in 4th or 5th gear.

I just have what came with it, which is 3.91 LSD. It seemed good as far as I thought apart from 1st gear which is useless..but I've never been in any other turbo e30s so have nothing to compare to

What difference would I see with a lower one??

If you found a 3.64 or 3.25 you would be able to stay in each gear longer and have lower rpm on the highway. Essentially you get to use the torque of the engines powerband more efficiently. Like you know how good acceleration in 4th feels since it takes a bit more time? Well you could feel that in 3rd gear and 'use the boost' to accelerate to a faster speed instead of just revving past the powerband of the engine and having to shift immediately. It makes it a more enjoyable driver and gives you a usable first gear. I wouldn't go shorter than about 3.64 from your 3.91, 3.25 would be ideal. a 2.93 would be getting too long of gearing.

Look at this video and compare the pull in second gear at 0:13 to the one in 3rd gear at 1:35

https://www.youtube.com/watch?v=SgW5p-OyVI8