2.5l 5cyl via diesel crank and smaller bore

[Mihnea Cotet]

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.

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.

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.

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.

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

Mihnea

At 12:54 17/09/2003 -0400, JShadzi at aol.com wrote:
>Well, granted, my experience tuning the Motronic system is limited, but
>Hap over in Colorado is running Motronic, and with reasonable mods he's
>pushing some 400 wheel hp on a very reasonable K26/TO4 54 trim turbo.
>
>If the Motronic is ad tuneable as you say Mineha, then tuning for bigger
>injectors to supply enough fuel shouldn't be a problem either.  Of course,
>if the Motronic can't keep up with the power, then a better alternative
>should be considered ;)
>
>Javad
>
> >Javad, Todd, Pantelis,
> >
> >500 HP, even on an RS2 engine, with real long term reliability is *not that
> >easy* to achieve. First off because the Motronic can't calculate a long
> >enough injector opening time of 16ms at 6k and 14ms at 7k. It need serious
> >tuning with not that much error margin and freaking big injectors too.
> >Plus, the cold side it would need would have to be something like a T04
> >60-1 trim combined with a turbonetics #8 K26 hot side (which is about as
> >big as a standard Sport quattro K27 #7 hot side) as well as ideally an MTM
> >S1 EM or a tubular one.
> >
> >Everything is possible, but the main issue remains the budget, 440 safe and
> >reliable HP can be done for pretty little money compared to what it would
> >take in order to make 500 or 500+....
> >
> >Just my 0.02 Euros,
> >
> >
> >Mihnea
> >
> >At 12:15 17/09/2003 -0400, JShadzi at aol.com wrote:
> >>If you build that motor up right, no reason you can't have 5-600hp out of
> >>it if you wanted, heck, I'm getting close to 400 out of a distributor
> >>ignition'ed 10v, a direct fire RS2 motor with rods, the right turbo, and
> >>of course the proper management can make 500 crank easy.
> >>
> >>The difference between an "alleged 360" and 400hp is small to say the
> >>least, I completely agree with Todd, I'd make 500 your goal for this
> project.
> >>
> >>Javad
> >>
> >> >Right,
> >> >  But if he is gonna spend the time and money to say, Extrude
> >> >HOne and P&P the head and EM, put a Ceramic Ball bearing T3/T4
> >> >Turbo on there, and who knows what else, why not shoot for a
> >> >little more than 400.  I guess thats what I'm saying.  With a
> >> >similar setup, simply moving to the T3/T4 and then doing some
> >> >serious chip tuning Alex and Ned ended up with a 4ktq that was
> >> >WAY more powerful than it was before.  We did not Dyno the car,
> >> >but it was around 380hp before the mods and was maxed out.
> >> >After the changes I'm guessing the car jumped to at least 450hp
> >> >as it was MUCH MUCH faster.
> >> >  I hear everything your saying, I just feel that if one is
> >> >going to spend lots of dough on upgrades and custome rods they
> >> >may as well aim a little higher.
> >> >l8r
> >> >  Todd
> >> >
> >> >--- Mihnea Cotet <mik at info.fundp.ac.be> wrote:
> >> >> At 00:26 17/09/2003 -0700, Todd Phenneger wrote:
> >> >>
> >> >> >   Anyhow, my Point was why shoot for 400hp when he is so
> >> >> close.
> >> >> >Might as well go for more and see a noticable improvement.
> >> >>
> >> >> Because the difference between 380 HP at the
> >> >> reliability/efficiency limits
> >> >> of a turbo is sooooo big when you compare it to 400 HP with a
> >> >> turbo that is
> >> >> at 80%+ efficiency and no reliability issues. 380 safe and
> >> >> reliable HP in
> >> >> the long run is almost impossible for an RS2 turbo, except if
> >> >> there's a big
> >> >> IC, very good exhaust with no cats and possibly some head work
> >> >> done, BTDT
> >> >> on the dyno.
> >> >>
> >> >>
> >> >> HTH,
> >> >>
> >> >> Mihnea
> >
> >