Ignition retard knock sensor.

[Daniel Houlton]

Gary Derian wrote:
>
> How did it drive before the turbo?  If it takes 5 psi steady state now,
> before the turbo it should not have been able to maintain speed.  It sounds
> like the turbo addition has not improved power so much as it has increased
> detonation.

The turbo has improved power considerably.

I made the same trip last year.  Across the flats with the turbo
was 5th and about 4 - 5 psi at around 65 - 70 mph.  Last year, cruise   
control was just to hold the pedal to the floor.  No joke.  I could
only maintain 55 - 60 mph at WOT and most of the time was spent in
4th instead of 5th because it would just bog down.  Hills took forever
and even a slight headwind was horrendous.  3rd gear and 40 mph for
the big hills pre-turbo.  With the turbo I could make them in 4th at
7 - 8 psi boost and 65 mph.  Last year the one way travel time averaged
10 hrs.  This year it was 8.5 hrs.

I do have dyno charts showing the power increases as well.  The post turbo
charts are all with HomeDyno, but it was calibrated doing pre-turbo runs
against a chassis dyno run and was within a couple percent of that so
it's pretty accurate.  I won't be doing another chassis dyno run until
my fueling and detonation limitations are worked out.


> What is the exhaust pressure while you are cruising at 5 psi
> boost, both before and after the turbo?

I have no idea.  I haven't seen pressure gauges for exhaust.  Can you
just use standard boost gauges with a good bit of metal tubing (like
maybe several feet) tapped to the manifold and down pipe to allow the
gas to cool before reaching the gauges?

 
> Maybe the exhaust is plugged up, or
> just plain restrictive.

Doubtful.  While the down pipe from the turbine is on the smallish size
(stock one from the turbo car) the cat and muffler are both new free-
flowing types.  The down pipe is the bottleneck, but doubtfully enough to
cause any problems.  This is still a relatively low hp 4 cylinder engine.


--Dan
houlster at inficad.com
http://www.inficad.com/~houlster/amigo.htm