RE: More on overboost

["Kaklikian, Gary" <Gary.Kaklikian@Compaq.com>]

Scott J wrote:

>  A ride in Chad Clark's ex 5000tq (k24 with profec boost control) or 
> Gary Kalikians 4ktq (k26 with profec) sure has me convinced that the audi 
> feedback on the wgfv circuit could benefit from some hardware/feedback 
> improvement without "overshoots".  Watching a proper boost profile in
> first 
> and second gear alone makes me a believer.  
> 
> Scott Justusson
> 
Scott,

My 4ktq has never had a boost controller on it, but it is about to get a
Profec B. All it has ever had is a stiff wastegate spring, a custom
programmed MAC-14  (thanks to Steve E.) , and a great intercooler with
short, direct plumbing in/out.  It suffers from the stock WGFV and gets a
maximum boost of only 13psi, which drops to 11 psi if I stay on the
throttle. Good throttle response (especially for a K26), great mid-range
power, but it still falls off at the top end.

Dave Jones, who built both Chad's ex-5000's motor and mine,  has finally
convinced me to go with a boost controller. Chad was running as high as
18psi boost on his car in the winter, this with a K24 vs. my K26, less
efficient intercooler and only a single knock sensor, but with lower
compression. Chad and I are going to set up my 4ktq initially with a high
boost of 15psi (sustained in all gears!) and see what happens. I've been
warned that this will trigger the fuel pump cutoff, which will probably have
to be disabled. I've also been warned that the knock sensing system will no
longer be able to reduce boost if it needs to.  I'm not sure how the ECU
fuel and timing maps will work, but will know shortly.

Thanks and I'll keep you posted on the results. I think we can get another
30-40hp and similar torque increases. 

Gary Kaklikian
86 4kcstq
86 5kcstq