[urq] speaking of 28psi

[Ben Swann]

Mike,

No major problem with 3 Bar.  I am running the GTQ 3 Bar chipset in my avant and have
several other folks running the same or even more boost - VMAP is adjustable to 4 Bar
and tweaks can be made for fueling - details provided with the chipset.

That said here are some caveats:

1. I don't recommend pushing a stock engine with 3 Bar chipset.  You are ok with
occasional bursts and the 3 Bar chipset allows one to get 2.5 bar more consistantly.
Also, the k24 just does not cut it, and one should lose the K24 even when going to 2.5
bar.   I am presently running some turbo equivalent of Pratt and Whitney fanjet-   What
a sleeper!

2.  Hoses, fitting, seals start to be subject to higher pressures.  At 2.5 bar, my
experience is you will find a bunch of marginal hoses blowing off.  At 3 bar you will go
through the weak spots again, and I found the Samcos don't cut it - too slippery and
slip off the intercooler or turbo.  I had to make my own custom hoses - cheaper and
better in the end.

3. Ignition is OK as long as you maintain everything correctly and use the recommended
plugs or NKG substitutes.  Ignition problems will show up at higher boost levels.
Definitely make sure you are using the narrow tipped rotor and that there is no timing
belt slop and that the Hall is set dead middle of window.   I had a miss that came about
because the extra boost was blowing oil into the plug wells through the original cam
cover gasket - that needs replacement, but for now I just clean out the oil every so
often.

4.  If you need 3bar sustained, the stock internals probably won't last too long.  

5.  You need to watch fueling.  You will need to go with larger injectors - 38, 42, on
up depending upon how much boost and how fuel pressure is set.  I recommend tuning with
WBO2 and adjustable fuel pressure regulator.

So that is it - 3 bar is fine with stock motor as long as you don't push it. 

Ben
www.gtquattro.com

[Date: Mon, 17 May 2010 16:51:21 -0700
From: "Mike Sylvester" <mike at urq20v.com>
Subject: [urq] speaking of 28psi
To: "urq Audifans" <urq at audifans.com>
Message-ID:
	
<20100517165121.195365548da1c44eaf4974b0054c21d8.b96de415cd.wbe at email.secureserver.net>
	
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Can you safely run 28psi on a 3B?
Is anyone doing it and keeping the distributor?

I'm curious why MTM would make a 3B chipset that will boost to 28psi.

Mike

www.urq20v.com]