I have a clutch kit from the Outdoor Shop. Last weekend I was racing 600-700 feet, reaching speeds of about 90 mph. Max recall on the digital tach was 7900 RPM. I am adding the Speedwerx Air Intake and will be racing in the same field again this weekend. Will let you know the results.
Mine was somewhat different! When I brought it home it would only pull 74 to 76 hun. After a couple hours on the stand she would run to 78 hun. Tests done on the sled on grass, not on the stand. I got about 6 or 7 hours on it when it kicked into hyperspace.
I took it for a nice ride, through the country, sun shining, on the trailer to some local grass drags. I ran in the 700 Stock, 700 Mod and the 800 Stock classes.
The sled had been through two or three warmup passes plus the first Stock 700 and Mod 700 heats. The max rpm on these runs was less than 79 hun.
Then in the first heat of the stock 800 the bitch broke loose and pulled 8250.
Needless to say we did alright at the drags but the F7SP continued to inpress.
I pulled down the rpm through the primary and have not looked back since.
What you need to do is: get it pulling at the top of the torque band with the last of the power used to rev out to no more than 8000. At this point the torque and hp drop big time.
I just recieved the new heavy hitter clutch kit and am on my way to tapping the peak out of this beast. Of course based on gearing, length of race and the clutching.
I have to go and charge the radar gun now, so hang in there and wait, the beast will settle down sooner or later, just make sure you are holding on when it decides to twist if it has not already.
The peak rpm for top h.p. is 7800 to 8000.The highhest I've seen on mine is 8000. If you're going over 8000 it's probably not good. You can adjust by moving sping in secondary to one hole below center.Snowhunter
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