Boost Controllers: Risks and returns: Returns (shortish)

["Geoff Jenkins" <jenkinsg@pilot.msu.edu>]

After the recent tome on risks, I'll keep this brief. A few people asked
about the effects of the EVC on performance. To reiterate from the first
post, the key qualitative benefits are:

- Much quicker response on-boost
- Better sustained power at the high end
- Controllability of boost and overboost

In more quantitative terms, Graydon and I have run a number of tests in the
car with a GTechPro, yielding the following data:

Note:

A) All of launches of my car were at 3000-3500 rpm, near sea level,
temperatures c. 40-45 F. What improvements/losses would occur with a
different technique/different environment are speculative.

B) I don't want to get into a bragging match, so if you disbelieve the data,
that's your prerogative. All of the post-EVC measurements were taken with a
second driver either at the wheel or in the car with me.

=====================

0-60:

S4 (Stock): 6.2 sec
My S4 (EVC, K&N, Scorpion exhaust): 5.2 sec

*** Notes:

1) prior to the EVC, my best 0-60s for this car with a TAP chip, WG spring,
K&N and exhaust were about 5.6 sec.
2) by comparison, in European Car (March 1998), a 360 HP Hoppen S6 claimed
0-60 in 4.9 sec.

=====================

1/4 Mile:

S4 (Stock): 14.9 @ 94
My S4: 14.09 @ 102.5

*** Note:

1) previous best runs with my car (pre-EVC) resulted in times in the high
14s or low 15s (blame poor technique on my part) and trap speeds of c. 99
mph.

=====================

Power:

Stock: 227 HP @ engine
Pre-EVC: c.250 HP @ wheels
w/. EVC: c.270 HP @ wheels w/. + 1.25 bar boost

*** Notes:

1) Later, I will test what HP figures I get if I dial back the boost
incrementally
2) If there's any interest, I may videotape the GTechPro and tach
simultaneously, to get a pseudo power curve.

=====================

Geoff
'94 S4