PaulW

So to get 400 HP with a 85% efficent intercooler, I would need 5.88 lbs of boost.

This does not include any pressure drop from the blower to the manifold, so that will probably be approximately 1 PSI. So a total of just under 7 lbs.

To get 450 HP, I would need a boost of 7.29 PSI plus pressure drop across the components.....so just about 8.29 PSI.

The intercooler outlet charge temperature will go from 9.2 degress F over ambient at 400 HP to 13.2 degress F over ambient at 450 HP. Probably will still be okay in terms of detonation.....but I have to learn more about that.

So why don't I just make sure I get a blower that works in this range, worse comes to worse, just change the pulley.

I've ordered a few more books on ECU reprogramming and one on the Bosch Motronic fuel injection system.

I have been looking at compressor maps and found at least one that looks like it would work from Rotrex. They are very small, high speed superchargers.

Now I have to figure out the fuel and ignition....oh, and how to mount and drive it.....but I've got the compressor sized!

Heck, why not do the 450 HP design???

:-)

PaulW

Yea, buy me the blower and other stuff, and teach me how to reprogram an ECU at home!

skiracer

I would be thrilled with a net 6 psi of boost at redline- 3 psi to make it back to sea level and 3 psi for fun! Actual HP at altitude around 360 or so?!?

PaulW

I have done so much research and came across a dyno plot for before/after using a rotrex compressor.....the torque curve was nice! I think it went up 30%?

1st gear will really be the only concern.....the torque produced by gearing usually far outweighs the torque produced by the supercharger....i.e. a normally aspirated version has more torque on the driveline in first gear versus a supercharged unit in second gear and on up.....the clutches could slip, but other than that, it appears that it won't snap anything.

I will have to do more research on altitude. You could pulley it to make more boost....but almost no supercharger system has a waste gate valve, which would limit boost on the top end. You design the system to only make so much boost.

pw

KaMaKaZieP -ALUMIN8-

Hopefully we can get a prototype and make this work. If you need any help researching let me know what topic and ill do what i can.

airbil

I am only capable of plug n play tuning methods myself, but courtesy of the S-Car list: "Uncle Bob" Pastore does tuning programming of eproms but I dont know about surface mounts. Bob is in NJ.
rpastore@animalfeeds.com
I run his software in my S car and it is extremely smooth.
Probably or the seemingly most knowledgeable is Mihnea Cotet in europe.
mihnea.cotet@easynet.be
He has been over here a couple of times and tunes cars real time and may at least provide you with an approach to supercharging an A8.
Also, FWIW there is Feico VanDerMeir (sp?)
FvAMI@aol.com
Feico is an electric genius from LA who basically invented the vmap pressure transducer for the I5 Audi.
This will be no easy task, but if anyone can do it, it be you HTH<ul><li><a href="http://members.***.net/urs6/index.home.htm">vmap homepage</a></li></ul>

ohbw

How much is the blower?

Bauer

You perfect it, I'll buy it

tozoM8

over stock. My tranny guy installs SC and he said 7 psi is the safe limit. His experience is that people who go crazy, will pay in the end.

KaMaKaZieP -ALUMIN8-

Between 1250-1500 i believe..