[s-cars] RE:Wastegate spring tightening

[Joe Pizzimenti]

>From the other side of the world...

I've found in tooning my own car, even though the Evo has a lower
compression ratio (8.8:1 vs. 9.3:1), on pump gas the limit seems to be
22psi before timing starts to get pulled back due to detonation.  Ask
around and most other tuners will tell you the same thing.  Unless the
timing advance is really, well, retarded, running high boost on pump
gas is a great way to remove your cylinder head without lifting a
wrench.

Personally, I think there's more to be gained with moderate boost
levels and good timing advance rather than the other way around.

FWIW, YMMV, etc.

Joe, I'm not a real tooner, but I play one on the Internet, Pizzo




On Fri, 15 Oct 2004 14:16:31 +0200, Mihnea Cotet
<mihnea.cotet at easynet.be> wrote:
> Guys,
> 
> Just a little info here: 28 psi all the way to 6k RPM and 25 psi up to the
> redline are both "suicidal" boost levels for an RS2 turbo.
> 
> Apart from being bad on the turbo itself (overspinning at high RPMs), it's
> also totally unefficient and turns the turbo into a large heat pump.
> Efficiency must be close to 40% at these sort of boost levels and such high
> RPMs. Which means that your cars will be making lots of power at relatively
> low RPMs (4k to 4.5k) and then the power will simply tail off, because of
> the increase in heat on the intake side, and also because of the stupidly
> high backpressure levels in the exhaust, which in turn makes the engines
> ping a lot easier, so the ECUs will dial the timing advance back to keep
> the engines from knocking.
> 
> Together with my german tuner colleagues, we have a phrase to sum all this
> up: manchmal ist weniger mehr, or in english: sometimes less is more.
> 
> Just a thought...
> 
> HTH,
> 
> Mihnea
> 
> 
> 
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