Turbo M20 owners attention

[OrangeFiero]

OK so Ive gathered a ton of info in all kinds of turbo m20 builds. Only problem is half of it is speculation, people claiming it will work with no proof. I would like to see examples of real setups to compare them to sort out some things and have working proof of systems actually performing. So i would like to see these things...

1 Pistons used
2 Crank
3 Rods
4 Head work (including valvetrain mods)
5 Cam
6 How much boost, and with what turbo
7 Tranny
8 Any block work done
9 RWHP
10 Bore, Stroke, Displacement
Other

If this kind of thing has already been done, please let me know with a link, thank you for your time

[MR 325]

1 Super Eta pistons
2 Eta crankshaft
3 Eta rods
4 Port/polished 885 head w/IE HD rockers
5 274 turbo spec'd cam
6 9psi / T3/T4 turbo Exh .57ar/Comp .50
7 Stock 260 trans
8 Stock rebuild w/ARP hardware
9 267whp / 276wtq

[darvo]

You must have a really low C/R!! :D

[codrum]

1 Stock*
2 Stock*
3 Stock*
4 OEM Goetz headgasket with ARP studs
5 Stock*
6 15psi, Holset H1C with 18cm2 exhaust
7 Getrag 260, stock
8 None
9 Have not dyno'd, Ran 13.4 at 108mph in the 1/4 (195 shit tires, 5800' elevation, open diff..)
10 Stock*
11 MS II/e - 42lb injectors, stock fuel pump

* = 1989 325i m20b25

Fuel/ignition management is the most important part and should be added to the list. I've been running this way for almost a year with no problems.

[OrangeFiero]

How much do you think you have in your setup codrum?

[MR 325]

You must have a really low C/R!! :D

Well that combo is originally 8.5:1 since it's basically a factory setup. Not sure how much the thick HG lowers it though.

[reelizmpro]

Stock rebuilt M20B25 with Cometic MLS headgasket, Metric Blues, Garrett T3/T4, Ebay manifold, intercooled, 30lb injectors, MS1v3, dyno tuned 265rwhp at 11PSI on dynapak chassis dyno.

[Kershaw]

9 Have not dyno'd, Ran 13.4 at 108mph in the 1/4 (195 shit tires, 5800' elevation, open diff..)

elevation does not affect turbo cars the way it does to n/a cars. the 195s and open diff are probably a bigger draw back.

[codrum]

How much do you think you have in your setup codrum?

I have almost exactly $3000 into the turbo setup including the wideband and MSII/e, if you're interested I've kept up a spreadsheet of every little part I pieced together.

elevation does not affect turbo cars the way it does to n/a cars. the 195s and open diff are probably a bigger draw back.

I'd disagree saying that elevation doesn't effect turbo cars. Sea level atmospheric pressure is 1 bar or 14.7psi, at 5800' of elevation the atmospheric pressure is roughly .85 bar or 12.5psi. That means naturally aspirated I start at a disadvantage of a few psi compared to sea level racing. I can overcome that difference by turning up the boost but the thinner air causes more work and forces the turbo to be less efficient. When I say I'm running 15psi that's relative to atmospheric conditions, relative to sea level that's only 13psi or so.

Here's a nifty calculator I found: http://www.modulardepot.com/density.php

The 195s and the open diff made it pretty tough to get off the line though, my 60' times were awful.