RE: Blow OFF!!!

["Hussey, Dan" <husseyd@rayovac.com>]

Ross,

Yes, you are correct.  It is better to just dump the boost back-pressure
straight out into the atmosphere!  But, only in race and rally car
set-ups.  For street cars it is much more beneficial to use a surge
valve (like on the '91 200TQ 20V and the 944 turbos) which re-routes the
air back into the turbocharger and keeps it spinning during gear
changes, etc.  This will minimize turbo lag as well.  It will also give
you a smoother, more powerful powerband.

In race and rally cars, they produce soooo much boost that they need to
get rid of it as soon as possible, so they just dump it out into the
atmosphere, hence the blow-off valve.  The turbos also have very light
impellars and they will not loose as much boost, and what is lost can be
regained easily.  Most street cars don't produce enough boost to where
this would be beneficial.  Why wouldn't you want to use that back
pressure, rather than dump it?

Think about it.  BTW, I am currently looking for a surge valve from a
'91 200TQ or an S4 for my 5ktq.  Anyone know where I can find one?

Ross, wasn't YOUR car supposed to be in this months issue of Turbo
Magazine?  Maybee I didn't look hard enough, but I didn't see it in
there.  What's up with that?  Next month?

Later,
Dan Hussey
Rayovac Corp.
Madison, WI


>----------
>From: 	Ross[SMTP:rippmods@rapidramp.net]
>Sent: 	Tuesday, June 17, 1997 7:19 AM
>To: 	quattro@coimbra.ans.net
>Subject: 	Fw: Blow OFF!!!
>
>Ross Esposito              rippmods@rapidramp.net               
>  
>Ripp Modifications        718-442-4723 voice.
>
>  Performance Spoken Fluently!!!
>
>
>
>
>----------
>> From: Ross <rippmods@rapidramp.net>
>> To: quattro@coimbra.ans.net
>> Subject: Blow OFF!!!
>> Date: Tuesday, June 17, 1997 12:26 AM
>> 
>> Ross Esposito              rippmods@rapidramp.net             
> 
>>   
>> 
>> 
>> Wow,you guys really look into stuff!
>> 
>> From my expeirence with the Blowoff valve,
>> My car spools alot faster than not.
>> 
>> Now, Dave Busher,who happens to have one 
>> of the FASTEST Mitsu.cars on earth runs
>> an open blow of valve and Vincent Ten,
>> who was crowned THE FASTEST SUPRA IN
>> THE WORLD by Turbo mag. 10.68-138.7 this past
> weekend,also uses an open blowoff valve....................
>but your  right I guess we're all doing it wrong!
>> 
>> Hey,Bob.......Hey Vinny,guess what, thiers a
>> guy named Mike,and he did our homework,
>> and guess what........................
>> 
>> Ok now, Thanks to all 11 of you for the info on
>> Center force.The reason I didn't go that way 
>> myself is,I go to a yearly show called SEMA.
>> All the major performance guys go to it.
>> I spoke to the Center force guys and they said 
>> they can't help me. but I'll they giving them a 
>> call.
>> 
>> I guess no one has the 4.11 diffs for a 5ktq huh?
>> 
>> Man,oh man I think I wan't to try this EFI thing!
>> Yes Gradon I agree and I even asked those Audi 
>> 12sec guys about your set up they just looked at 
>> each other then me!
>> The Audi with the 2.8twin turbo I spoke about is 
>in Readers rides in European Car Mag.
>>        
>>        
>