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any ever seen or done a twin turbo setup on an m20
Eurospeed88: I would agree, that a standard M20 would not take that kind of power without being rebuilt with chosen parts and then balanced, which is what he has done. I have no doubt that the engine he built can cope with that power.
Actually, the stock engine holds together pretty good as it is. Compression on the cat-version is only 8.5:1 or something like that which gives you a strong NA engine to boot, but still low enough to take 1 bar / 14.5 psi FI. The combustion chambers need some work and the pistons need to be worked on if you're going for high hp because the M20 stock engine has a high tendency to detonate because of the physical shape of things in the combustion chamber. Things get much better with the M50 engine.
Still the thing that really kills, no matter the engine, is detonation, if you can run the enginge without detonation you can have the cake and eat it. But it requires proper tuning of fuel and ignition! Usually that means that the stock ECU has to go.
darien28: You forgot about the Intercooler (perhaps not intentionally). You need to cool the charge air unless you like detonation. High intake temperatures are bad.
But you have a good recipe there I'd say. You should ask Matt325is on this forum about his car, or at least read through some of his posts. He's got a killer M20 turbo in his E30!
one problem is the ct12b's sequential setup, which seems a bit difficult to adapt since I'm told it's run off a complex set of actuators controlled by the ecu..,.
so I'm thinking about running them parallel, but then I'm told that the lag is going to be a problem... anyone know the exact specs of these turbos? I've only heard they have a ~.45 a/r which i think is for the exhaust side, and ceramic fins.
does anyone know if i can run them parallel from separate cylynder banks? 1-2-3 and 4-5-6 or 1-3-5 and 2-4-6 to each turbo while having the front turbo continuously boosting with the rear turbo kicking in somewhere in the upper range?? or would that mess things up with boost spikes since there's only 1 wastegate?
I've talked to matt already and am going to run the same engine management he's running amongst other things.
darien28: As part of the expenditures of your project, consider investing some cash into a book by a fellow named: A. Graham Bell.
"Forced Induction Performance Tuning: A Practical Guide to Supercharging and Turbocharging"
It will probably save you a lot more money than it costs.
Edit: about your idea with twin turbos, I think that spells "double trouble" to me. :)
Be sure to keep exhaust back pressure, exhaust turbine size, pressure losses through the IC and other things under control. Doing things wrong might mean that you have to boost 1.4 bars instead of just 0.9 bars to get the same power!
i have corky bell's book, "maximum boost" as well as a book on engine blueprinting... and I have read them both.
I wanted to tdo a TT setup cuz it was unique.. but now am seriously rethinking cuz them turbos are damn heavy as #@$%...
now to start looking for suitable single turbos... need ~.48 compressor and ~.82 exhaust... or something along those lines.
prolly going to end up running 8.5 compression w/ 6-8lbs for street use and maybe a max of 1bar for track use after dumping 3 gallons of toulene in my tank.
contact Jay Stcok E3, he did the Bi-Turbo setup in his previous 325i, homemade, he told us when he get the chance he will turboed their actually 325is but with single turbo, two are much problem and will make the same power as single turbo
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