GoRideSno

"The car is a 1990 GT 5 spd. All stock everywhere, including exhaust.

283 HP at RW before (325 HP at the crank) is now 405 HP RW (465 HP at crank)

275 FtLbs at RW before (316 FtLbs at crank) is now 386 FtLbs (444 FtLbs at crank)

...an increase of 140 HP and 128 Ft Lbs of torque.

Air/Fuel ratio was constant at 11.5:1 Idle 750 RPM steady.
Boost gauge showed about 7 psi at 6,000 RPM."

Z,
It appears that the 90GT was running fine before the SC was installed from the quote above.
Also, please explain the mechanical problems this car has so that everyone will know to look for them. I am sure the average person installing a system would overlook them if you and Carl didn't notice them.
Thanks,
Andy K

Tim Murphy

I will venture a guess that this car will gain 40+HP on the dyno when it is done.
Along the the throttle switch, it appears that this car was making about 6psi on the dyno based on the numbers. I talked to the owner after it was dyno'd and he said he was seeing about 5 psi on the gauge, so I know the belt was slipping even more as it was breaking in. As I mentioned in the past, I have updated the design of the tensioner to incorporate a self adjusting spring which eliminates the belt tension issue therefore eliminating belt slip. This car should see 8psi with the current configuration.

GoRideSno

If the GT were to make the same percentage gain as Don T's car then it would need to make 33rwhp more hp at 7 psi and 56rwhp more at the kit rated 8psi. And for Lags statements to be correct then the GT will need to make even more than that. So the owner should see a minimum of 60-70 rwhp gain if everything Lag, and Z are saying is correct.
So this means that if everything goes correctly with Jim R's system (if he runs 8psi) then he will get a minum of 470-480rwhp. AWSOME.

Andy K

mark kibort

dynojet or brake dyno (mustang dyno)??

mk

Tim Murphy

from Dyno-Pro's website:

"Dyno-Pro has been testing performance vehicles on a Dyno-Jet© 248c since January 1, 1997. In these 5+ years of dyno testing we have compiled an extensive list of dyno results from Colorado's fastest street legal vehicles."

mark kibort

whats the difference between a 248c and the usual 248e that we all run with out here?
even still, im sure the differences are only 10-15hp max.

Mk

Tim Murphy

Not positive on this but I believe they are both the same base unit, just a different configuration such as in-floor or ramp style. Z is pretty familiar with dyno's and might know the difference.

Z

Below is the "before" dyno chart of that car with the air/fuel measurement shown. It sure doesn't look fine to me. I wasn't at any of the dyno sessions, or hadn't ever even seen the car running when the "after" dyno charts were posted. Most of you guys probably saw them before I did. I'm very, very sure that the dyno operator where the car was dynoed at had never even seen a running later model 928 before, let alone known what one is like on the dyno. How do I know that? I asked him when I was recently there picking up the dyno data files. The owner of the car really doesn't know about the mechanics of the car either, which helps to explain why the car still has it's original, 14 year old, factory installed timing belt on it. As far as Carl not noticing any issues with the car, I couldn't really comment on what he may or may not have noticed. I'd guess that the car's owner asked for a supercharger installation, and not a complete diagnosis and repair of the whole vehicle and everything in it though.



I couldn't say for sure, but that could be part of it. I see that the model shown on their web site now is the 248x, and that it has a higher horsepower capacity. I know that they've had a couple of different versions of the software, so that may have been some of what distinguished some of the models. Newer software allowed for easier graphical use by the dyno operator, and can just be bought to replace the older softtware without any other changes to the dyno required. The oldest of the software I've seen was a much simpler DOS program.