[s-cars] Re: fuzzy logic et. al.

Mihnea Cotet mik at info.fundp.ac.be
Sat Jan 24 08:47:23 EST 2004

Dwayne, just one question regarding your boost controller and boost levels: 
what boost levels (gauge) are you running at WOT at 3k, 5k, 6k and 7k RPM? 
This is assuming you floor the car at 1000 RPM in 3rd gear or 1500 in 4th...



At 08:42 24/01/2004 -0500, QSHIPQ at aol.com wrote:
>Let's make sure we differentiate between software and hardware.  What you
>present below is a hardware problem (IMO), hence my urging for a better 
>valve to
>control boost.  The biggest issue with the stock WGFV is it's slow and 
>weak at
>the low and high ends of it's function.  To verify this, try adding a stiffer
>wastegate spring to the WG.  You will notice a significant increase in low
>end torque BTDT.  Why would this be on a bottom feeder that should be able to
>interrupt boost to the wastegate?  Confirming my point that certainly the 
>WGFV have a usuable and ramping range that is far from ideal.  In this case a
>boost controller with a better solenoid or a stepper motor will show faster
>low end response and high end trim.  That's not at all to say the motronic
>computer/software isn't asking for ideal, it just has a less than ideal rover
>attached to the other end of the wire.
>Scott Justusson
>QSHIPQ Performance Tuning
>In a message dated 1/23/2004 11:01:18 AM Central Standard Time,
>dccosby at hotmail.com writes:
>Not that I want to throw myself into this discussion...
>I do agree that you are giving up ECU control of boost and that could
>present a safety hazard. (I would hope that ECU will kill the timing if
>anything really messes up - that nasty bump would surely be enough for me to
>jog my foot off the loud pedal.)
>That said I run the same Apexi controller as Hap on my IA stage 3 chipped 94
>S4. About 1 year after the install, the Apexi pressure sensor failed so I
>switched back to the stock MAP/WGFV setup while waiting for the replacement
>part. Now running only the IA chip with the EXACT same peak boost (and very
>similar boost boost drop off curve) as the chip, the car felt so slow that I
>thought something else was broken. I'm sure the peak power was likely the
>same in both scenarios, but with the chip alone, the car was extremely
>unresponsive (in comparison) and boost came on later. Understood that Ned's
>chip isn't as aggressive as MTM's but I've driven MTM chipped cars and they
>still feel a lot slower than my IA + Apexi car. Before anyone chaulks this
>up to a particular of my car (i.e. wastegate issues, etc.), I helped with 2
>other installs after mine and we all felt the same way.
>I'm having a local tuner do a custom dyno tuned chip for my RS2 goodies, big
>TO4e/50, and custom mapped chip in about a month when I get all the parts
>together. I'll do some back to back comparisons with and without the
>controller (takes 15-20 minutes to change) - but I'd be suprised if my
>feelings change.
>94 S4
>p.s. I also run water injection (at the track) and I know how controversal
>that is too...
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