MC tweaks

[JShadzi at aol.com]

Yes Mihnea, as I've said before, hard HP # cutoffs are difficult to assert, and it really depends on many variables.  IME, tunning a 10v here in California on 91 oct, I had a difficult time breaking 300whp with the dist. system, given these variables.  420ft/lbs of torque just tells me that you're making max power sooner, thus the RS2 turbo makes sense, going with a bigger turbo, and thus a later power peak, would definitely bring that tq # down. Granted, if it was a 20v I'm sure my power levels would have been relatively higher, but I believe at some point the same would have happened.  

The car w/the misfire, I wouldn't say that spark can be blown away by too much boost, its likely an issue with the ignition coil dwell time.  When a motor makes peak power down low, the coil can better handle the firing becuase its firing less (at a lower RPM) and thus has sufficient dwell time to recharge.  Naturally, a coils output energy will fall the higher RPM rise, at 6k rpm a coil is firing 2x as much as at 3krpm, this puts a large strain on the coil, and thus it can saturate and not provide sufficient spark at higher levels.  I've found the stock Audi coil starts maxxing out above 5krpm, and in these high power level environments of the comb. chamber, combined wtih the short falls of the ignition dist, create a pretty limiting situation.  DIS is a wonderful and refreshing solution to all this, as all manufactureres have found out =)

Higher octane fuel definitely helps the situation, more advance allows a given spark to light off tougher and tougher mixtures, if you're tuning with say even the equivalent of 93oct, then that would help the situation proportionately.

Javad -Building a 20vt motor, can't wait to tune it =)

>I too used to think it didn't have to go, remember our last conversation
>Javad? What did you find out?
>
>I for one have found out (on the 3B motor with stock motronic, bigger
>injectors, RS2 turbo, EM and intercooler) that it can do 365 HP at 5600
>RPMs and as much as 420 lb/ft of torque at 3540 RPM running 1.7 Bar
>(relative) peak boost and dropping to 1.1 at 7k. No ignition issues so far
>with this car, though on another 3B I've put my hands into, with the same
>stuff except for a K26/27 turbo, we've had some ignition misfires (sounds
>scary) around 5.5k RPM running 1.7 Bar at those RPMs. I guess the turbo was
>pushing a bit too much air into the cylinders and has possibly blown a
>spark away...???
>
>Mihnea, tuning happily in Belgium and around Europe (sig line à la Hap
>Maguire) :-)
>
>At 09:15 4/12/2003 -0500, Ben Swann wrote:
>>[..bigger turbo .. cam ..dual pass..Ignition timing..simple things you
>>could do w/o any
>>major fabrication..Header..right turbo   <- edited
>>:
>>  "in conjunction, and IME, once you want to get much past 350 crank the
>>ignition dist. has got to go. "  Javad]
>>
>>Why does the (stock?) distributor have to go, please explain?
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