[s-cars] Ball bearing turbo

[djdawson2@aol.com]

 The GT30R works well in Denver.  I was running a .63 A/R turbine housing, but that led to some undesireable surge in the higher gears.  I have since changed back to a .82 turbine housing, and have changed to an RS2 exhaust cam.  I also incorporated the stock intake horn (with the internal flow dividers) into my intake setup.  This combo has eliminated the surge problem.  You can still "make" it happen by loading the engine excessively in a high gear (5th or 6th), but in normal driving, it never happens.
 
Dyno numbers... well, it has not been to the dyno in awhile.  Last trip was 442hp/430ft-lbs at the wheels.  This is a corrected figure.  However, I tried to end the correction factor arguement by going to the dragstrip.  A lot of folks said they thought the only true way to determine hp was via the 1/4 mile trap speed, using a 1/4 mile calculator and vehicle weight.  So I did this too.  The best results were 12.400 @ 113.35mph.  The hp calculator says this mean 455hp at the wheels.  So you can draw your own conclusions.
 
As a side note... the clutch won't take the power.  Javad (034efi) is setting me up with a stronger unit, and this should result in some 1/4 mile improvements.
 
Sounds like you've got a fun engine planned.  However, I'll eat my hat if you get to 450whp "uncorrected" in Denver.  I think it has been shown that some correction is required to deal with our altitude.  I'm currently working in Boise, Idaho... and the S4 is here.  Boise is at 2200ft, and the dragstrip is at 2700ft.  From a butt dyno perspective (and I'm not a butt dyno fan) I can tell you that it feels like something is wrong with the car when I return to Denver.  However, 450 corrected wheel hp isn't a difficult task... no special tricks required.  I'll try and get mine back to the dyno soon, and see what it's doing with the cam and turbine changes.
HTH,
Dave
 
-----Original Message-----
From: Jim Green <jim.green at gmail.com>
To: djdawson2 at aol.com <djdawson2 at aol.com>
Cc: s-car-list at audifans.com
Sent: Tue, 18 Oct 2005 21:02:50 -0600
Subject: Re: [s-cars] Ball bearing turbo





 
Dave, good info. Sorry if you've already posted this, but how's the GT30R act at Denver's altitude?  I searched and found your post about the dyno, but it looks like you may have had some ECU issues at the time.  Have you or anyone else ran a GT30R uncorked up here?   If so do you have the uncorrected dyno #'s?  I thought Hap was going to run one, but I haven't heard anything lately.  Stuff like when does it hit full boost, how bad does it surge, or does it when you step on the gas in 4th at lower rpms, 
 
I'm looking at going 20vt with a fully built block, mildly ported head, and the full 034 manifold treatment.  Basically Javad's motor, my 034EFI IIC ECU and a GT30R with very little wastegate :)
 
I'm looking to get a solid 450 uncorrected WHP hopefully on 91 octane and water injection.  500 would be nice on race gas.
 
Thanks!

-- 
Jim Green
'89 90tq
'89 80q
http://www.mswanson.com/~jgreen/car_home.html