2.5l 5cyl via diesel crank and smaller bore

[JShadzi at aol.com]

Mihnea, see inserted..

>Javad,
>
>I won't argue with you about Hap's car because I don't know exactly what
>it's running nor who did the chips for it, but granted too, 400 wHP or
>about 500 crank HP on an RS2 exhaust manifold (be it extrude honed, ported
>and polished or whatever) with a "54" cold side trim isn't possible. Just
>use Mike Gough's rule of thumb of 10lb/min per 100 HP and see the 54 trim
>compressor map for yourself, the map ends at about 45 lb/min, way off the
>advised efficiency range, at about 65% efficiency.

You say not possible, well, obviously it is, Hap just did it, and he drives the car on the street, and its not unreliable.  I do know he uses much bigger injectors, and a bigger MAF, but the programming is the key to making this work in a Motronic equipped car - HAP, ANY INPUT?

Mihnea, you throw out very discrete hp limits all the time, I just don't buy that 1) there are any hard HP limits in the tuning world, all restrictions cause a %age decrease in output, and an increase in the rate of diminishing returns AND 2), you just don't have the evidence to back it up...sorry, but its moslty hearsay what you propose.

>Re: RS2 EM, go ask MTM, Dahlback, Lehmann or whomever you consider
>knowledgeable in this domain and they will all tell you the same thing:
>more than 440 HP on an RS2 EM could be possible but in the long run it
>leads to self-destruction of the engine. I know of a guy in Switzerland
>who's had his S2 with standalone management tuned on a dyno at 480 crank HP
>with an RS2 EM and a huge turbo, guess what happened 2 days after that and
>running only 455 HP? He just melted an exhaust valve, and he was running
>HUGE injectors: 530cc at 4 Bar fuel pressure and had a Bosch Motorsport
>fuel pump. The most likely issue? Too much heat in the combustion chambers
>from a too restrictive EM. The problem is that the guy who's tuned it only
>tuned it with a WB O2 sensor, no EGT, and that was his biggest mistake I guess.

I just don't buy it, there is no such thing as a HP limit for an exhaust manifold, there is a range in which it becomes excessively inefficient and restrictive, but there is not a discrete limit.  A burnt exh valve could be caused by a dozen things, a restrictive exh. manifold toward the latter IMO/E.

>The Motronic is very tuneable, but in terms of fuel supply, the ECU has
>more to say than the one who's programming it and really, without real
>"tricking" of the ECU (different methods are possible) it can't provide
>with 14ms injector opening time at 7000 RPM, it will only "give" 11 or so
>ms, I've "been there calculated that" based on some documentation I've
>already spoken to you about.

Not sure about the specifics, per se, but with the right injector 11MS will be enough for 1k hp..but 11MS is like 60-70% duty cycle at 7krpm, seems very low for a maxxed out injector driver.

>Now, that said, I haven't yet had a chance to try and tune a Motronic for
>500 HP myself, but this should happen in the following weeks and I'll keep
>you posted about that with hard data of course. This will be on 2 track
>S2s, with tubular headers, S1 style IMs, twin fuel pumps, huge enough
>injectors, ported and polised as well as flowbenched heads and Garrett
>turbos that make 600 HP on a few 2.0 liter rally cross cars at 2 Bar
>relative boost. So the turbos and the ancillaries shouldn't be an issue
>here, but the Motronic itself might be.

I'll be interested to see the results, the hard results.

>Let's please not turn this into a "tuner's war" :-)

No, not at all, my only disagreement is when people start throwing around arbitrary HP limits, we've had this conversation before, you told me that the 3B is only good to 340 crank HP with a distributor, well I nailed almost 400 crank with my distributor 10v, so I'm not buying the HP limits people throw around, its just not feasible.  Motronic has its place, and so does 034EFI, no disagreements there.

Javad