DVSF? next year - Page 2

750hp · #21 (**permalink**) 09-07-2002, 03:38 AM

Wilf - the motor didn't perform as I wanted it to. I tried to convince myself beforehand that I'd be happy with a genuine 800hp using a super conservative tune up. It turned out that we achieved that, but I still wasn't totally happy.

I stopped the spark jumping problems, but once we were able to comfortably rev the motor over 6000rpm it started stripping blower belts.... The belts are rated for a pulley speed of 8000rpm, and my blower pulley's spinning at near 20,000rpm

Nothing like trying to run a product above it's rated specs!!!

Anyway, running a rich air/fuel ratio of 11.8:1, only 18 degrees total timing and 6,000rpm - it made 805hp and 705 lb/ft. At 6,400rpm (just as the blower belt cried enough), it made 859hp and 704 lb/ft. There's more power in the timing for sure, but I'm planning on only running the 18 degrees timing with a 6,000rpm limit. At this rate, the motor should last for a long time and still make enough power to keep me occupied.

wilf leek · #22 (**permalink**) 09-07-2002, 07:24 AM

Excellent results, with obviously more to come if you want it. What can you do about the belt problem??

750hp · #23 (**permalink**) 09-08-2002, 05:45 AM

When I ordered my pulleys, the company sent out 30mm wide ones. Most guys with similar engines to mine in the US Mustang Drag Racing scene are using 50mm or wider belts. I'm using Gates HTD belts. About 30% stronger are Gates Powergrip belts. Then the big momma of belt technology - the Gates GT2 Polychain. These belts require only 20% of an HTD belt for the same torque rating - BUT they are a lot more expensive, and the belt pitch isn't quite the same. Both belts have an 8mm pitch, but the physical shape of the tooth is defferent. While the tech guy said that it should work well, he didn't rule out the fact that the belt might not even make it to 6500rpm without also failing. The difference in tooth shape, combined with both belts having the same recommended belt speed might make the Polychain go the same way as the HTDs.

Anyway, if I know that I'll break stuff over 6,000rpm, then I have a pretty good reason not to go over that. I think my valvetrain and rotating assembly will thank me for that!

So, how many Pommy Cobra nuts have you persuaded to come to DVSF3?

wilf leek · #24 (**permalink**) 09-08-2002, 06:04 AM

Pommy Cobra nuts?? Interesting turn of phrase but no matter. So far lots of folks have shown interest, but here in the Uk no-one plans anything for the New Year until after we have finished eating drinking and spending too much at Xmas.
I have finally gotten around to writing this years event up in our club magazine, we'll see what interest there is after that.

750hp · #25 (**permalink**) 09-08-2002, 06:29 AM

Sorry - distinguished English gentlemen showing a keen interest in automobiles that look not entirely unlike AC cars.

The newsletter..... That's what I was supposed to do months ago!!!

rdorman · #26 (**permalink**) 09-20-2002, 12:27 PM

From Phoenix to London is about 1850 miles! I drove it this past spring. LONG trip. There are a lot of Cobra people here in Ohio. You could some straight in.

859 horsepower! You are a mad man!

750hp · #27 (**permalink**) 09-20-2002, 07:01 PM

1850 miles IS a long drive, but it's certainly a memorable one! We stayed on an extra day in Sedalia, MO for the World of Outlaws Sprint Car race on the way home. After that Hersh, Scott and myself covered the next 1300 (or so) miles basically non-stop

Driving back towards Phoenix with the morning sun just starting to show itself over the Sedona mountain range was a beautiful sight...