Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

New Supercharged 1990 GT Results

Thread Tools
 
Search this Thread
 
Old 10-22-2004 | 05:56 PM
  #76  
John..'s Avatar
John..
Three Wheelin'
 
Joined: Nov 2001
Posts: 1,446
Likes: 0
From: Northern Kentucky
Default

Yes Tim, it should. Maybe we should all quit while ahead before one of us has "An Unfortunate Schmelting Accident"...sorry but my wife bought me the Goldmember DVD for Sweetest day (she got roses and a card). I think I have already picked the name for the TT 32 valver...any guesses? Now if UPS would deliver the pistons the conveniently lost on the last shipment I would be able to get something done this weekend...The Audi needs work anyway so I'll do that instead.

What say ye, 16-18 psig on that sweet 4 valve combustion chamber? Sounds like 5.0 liters of forced induced fury to me!
Old 10-22-2004 | 05:57 PM
  #77  
worf928's Avatar
worf928
Addict
Rennlist Member
 
Joined: Oct 2003
Posts: 16,607
Likes: 1,712
From: Gone. On the Open Road
Default

Originally Posted by Old & New
...""Squiggles" can be cause by a few things, such as timing, detonation, rear tire imbalance and even air flow issues.
No new information there.
With extreme jaggedness, you can perform a coast down/negative horsepower test to rule out any rear tire imbalance.
Well, at least we have one new way to gather more data.

However, he's confirmed for us that all the items I suspected can lead to the squigglies.
Old 10-26-2004 | 12:16 AM
  #78  
Carl Fausett's Avatar
Carl Fausett
Thread Starter
Developer
 
Joined: Dec 2001
Posts: 7,005
Likes: 60
From: Horicon, WI
Default

Old & New - yes - we did notice an out-of-balance condition that was quite obvious. The car really shook especially above 90 mph. We reported it to the owner. He hasd beautiful new aftermarket wheels and tires - but of course - had instructed the installers to only put the wheel weights on the inside so as not to ugly-up the alloys on the side we all see. You can rarely get a whell/tire combo in dynamic balance that way.
Old 10-26-2004 | 12:27 AM
  #79  
Old & New's Avatar
Old & New
Rennlist Member
 
Joined: Dec 2002
Posts: 1,975
Likes: 0
From: Southern New England
Default

It sounds like we may have the answer, then...!
Old 10-26-2004 | 12:33 AM
  #80  
worf928's Avatar
worf928
Addict
Rennlist Member
 
Joined: Oct 2003
Posts: 16,607
Likes: 1,712
From: Gone. On the Open Road
Default

Originally Posted by Old & New
It sounds like we may have the answer, then...!
One very probable means of producing a squiggly. RPM measurement noise is still high on my list of probables for things we cannot see,feel,and hear when we're watching a pull.

O&N? Any new news from the DJ folks? Carl?
Old 10-26-2004 | 03:38 AM
  #81  
Old & New's Avatar
Old & New
Rennlist Member
 
Joined: Dec 2002
Posts: 1,975
Likes: 0
From: Southern New England
Default

Just what I posted above. I'll pick the brain of the operator next dyno session.
Old 10-27-2004 | 07:58 PM
  #82  
Mattman928's Avatar
Mattman928
Racer
 
Joined: Mar 2003
Posts: 333
Likes: 7
From: Falls Church, VA
Default

I think the 4th gear pull will give more accurate profile of the power curve, since the increased sample per cycle will better define the curve.

The dip may simple be the exhaust harmonics. As the gas flow hits resonance there may be a little backpressure.
Old 10-27-2004 | 11:15 PM
  #83  
worf928's Avatar
worf928
Addict
Rennlist Member
 
Joined: Oct 2003
Posts: 16,607
Likes: 1,712
From: Gone. On the Open Road
Default

Carl, how did you determine that the knock sensors were not singing?



Quick Reply: New Supercharged 1990 GT Results



All times are GMT -3. The time now is 01:33 PM.