I think they're all using 5 discs. I've never heard of a 6 and I don't think anybody is trying to use the old 4 disc setup.

I seem to remember the buzz around the pit’s a few years ago when Tony Schumacher’s crew started to back the dragster into their pit space instead of pulling it in forward like everyone else. The rumor was….. They didn’t want anyone to see the experimental 6 disk clutch they were trying.

The HP produced is calculated based on the fuel flow during the run.

Most fuelers make more than enough power. Geting it to the track is the key.

Not a lot of R&D $$ spent on making more ponies. Making them more effeciently or easier on parts maybe.

Pretty easy to measure the nitro percent before it actually goes into the car though. LOL

The clutch is pretty interesting. The floaters are toast during 1 lap. You see them carried off regularly by fans. Most use 4 floaters 5 clutch discs. the flywheel and pressure plate have an equivalent floater built on that is resurfaced after every lap. The actual clutch disc is generally used twice. 3 new and 2 with 1 lap in the clutch pack.

Lesser sponsored teams will use them a bit more.

As I stated a long time ago - a friend who participated in the SWIFT (Spinning Wheel Integrated Force Transducer) tests on Kalitta car stated that there were some "surprising" horsepower results. As in over 9000 hp. Kalitta Team, Weld Wheels and S.W.I.F.T. put a lot of effort into these tests. To my knowledge, this is the only test using multiple sensors and a very sophisticated data gathering system to gather scientific results. Each run produced gigabytes of data. NHRA displayed absolutely no interest in the results - perhaps because they didn't want to know.
IMHO - Attempts to back into horsepower numbers via fuel flow or a single strain transducer are simply SWAGs.

__________________
"The Counterfeiter"

Reminds me of the saying:

Go first class, just not very often...

__________________
Eric
1956 Modified / Outlaw
Nitrous Master