Overdriven Paxton?

[Lud]

In reference to this discussion: http://www.nsxprime.com/forums/showthread.php?s=&threadid=24018&perpage=50&pagenumber=3 I would like to find out if there are any BBSC folks who have run an over-driven blower? If so what are the details, what else was done to the car and of course what was the result?

I had the impression it was either being tested or soon to be tested early this year from the discussion in this thread and had looked forward to hearing more: http://www.nsxprime.com/forums/showthread.php?s=&threadid=16648

So has anyone done it? If not, is this still being actively pursued?

 

[kpond]

Hi Lud,

With the exception of potentially MB testing himself, I don't think there are any out there on BBSC cars.

I talked to a few manufacturers at SEMA and I have a couple of leads but who knows if they will pan out.

There's a lot of bantering around of this topic with theories and formulas, etc.

I believe that a "base" BBSC kit with a 10psi pulley clipped at 6psi on the top end would provide a much improved low and mid-range torque improvement and without too much extra heat, etc. The trick is in bleeding off excess pressure without causing undulations that are above and below the clip level.

 

[WOODY]

i have a compressor map that paxton sent me for the novi 2000. I did the calculations and plotted the lines for both 6 and 11 lb boost based on 3.2 displacement. Both fell well within the 65% efficiency island. It would appear that the rpm/boost can be increased substantially with only marginal increases in heat. Certainly an aftercooler would do a good deal to facilitate the effectiveness of the higher boost with blowoff. I can try and post the compressor map if anyone cares. I couldnt get my hands on the novi 1000 for comparison...could be interesting if someone has one?

 

[TampaBayNSX-R]

I, for one, would be very interested in more information on this subject. I currently run the original NOVI1000 BBSC and will be upgrading to the AEM soon. The option of "upgrading" to the NOVI2000 has been made available but I'm not sure if that's the best way to go. I suspect that there must be a way to build more boost earlier in the rpm range and then clip any "excess" boost at a predetermined level. MB planned to make these upgrades available over a year ago but there has been no sign of smaller pulleys and new bypass valves. I welcome any comments that are offered. TIA

PS I ran a 12.49 et at 112.50 one pass only due to time constraints last fall in an original 6lb BBSC '94. (For the member who felt no data had been posted re 1/4 mile BBSC, this was discussed on Prime extensively) "Search is your friend"

 

[spdntckt]

Interesting - in hte compressor maps you have - does it mention how many ft-lb of torque it takes to spin the compressor at the required speeds to make that PSI?

wondering what the addt'l parasitic loss is...

 

[WOODY]

The book I have "supercharged" by Corky Bell, only states parasitic loss range at 5-15% for all types of superchargers. With centrifugal blowers being on the high efficiency end of the spectrum we might assume 5-10%, or <40 hp on a 400 hp application. My guess is that the higher rpm has nominal change in power requirements.