Re: TAP vs IA Chip/Boost mods

["Graydon D. Stuckey" <graydon@apollo.gmi.edu>]

On Tue, 20 May 1997, Sherry & Chuck Clark wrote:

> only problem that I've ever had with TAP box is that the car will 
> ping somewhere around 16-17 PSI boost as seen on the VDO guage 
> mounted separately in the center console. If you leave your right 
> foot planted as this Ping is happening, It will turn to a studder or 
> slight cutout.
Hmm, when I was running a pressure regulator to control boost, I was 
getting 16-17psi, adn no ping, or stutter at all.   Mind you, _I_ only 
use 93 octane or above.  :-)

>   Now with a helmet on cruising at 115 mph on the track, this ping is 
> tough to hear and i have to constantly lift off the throttle to keep 
> it out of the danger area. What this does is drops the boost 
> immediately to 10 psi and then it builds back up to 16-17 but only 
>  after you've lost some time feathering the throttle to accomplish 
> this. You can not simply drop the boost a single pound or two by 
> slightly lifting your right foot. It always dropped to around 10-11 
> psi first.

I've found with the QLCC chip, I can feather the throttle to control 
boost quite easily.   It's too bad Audi didn't use a real throttle 
position sensor on the car - they could have had boost as a function of 
throttle position, which would have allowed a much more linear throttle 
pedal.   My SuperCoupe does this - half throttle = half boost, full 
throttle = full boost.

>  After installing Neds IA Stage II box and running it hard for 5 
> laps, I found the following. The boost needle would immediatly jump 
> to 15 psi, back off to 14 psi and stick there no matter what rpm or 

That sounds much like the QLCC chip.  ALthough the QLCC chip doesn't 
usually overboost.

> than the TAP box, it was consistant at 14 psi which let me keep my 
> right foot planted at all times. Stock bar guage read 1.7 bar all the 

Shows the inaccuracy of the stock guage - mine reads 1.9 when the 
Autometer guage says 14psi.

Good report Chad.

Later,
Graydon D. Stuckey 

"Cool name man!" - Jay Graydon   :-)