440 Trail Twister Performance

929rog · Post by **929rog** » Mon Feb 26, 2007 10:28 am

What are you guys getting for speeds with your Twisters? We have two 76 Twister 440s that we have been playing with on the lake. We can only get about 70mph on radar with each no matter what we do. Funny thing is my 75 Rupp fan 440 ran 75mph in the same distance. I started mine set up like I read on here.. Brand new 102c, purple spring, A12 ramps, stock secondary. Over rev to 7600. Soften secondary, still not enough. Went to A1 ramps (about a gram and a half heavier) and went better 7100 RPM still about 70mph. Tried stock cat hex clutches, same result. Tried running new style cat secondary's with clutches set for a 1 3/8 belt (3 kinds all new) (welded nut on end of jackshaft) Actually a little slower. Tried a ton of helixes ended on a 50/34... 70 mph Both our sleds have the smaller drivers for picks, motors are aligned, belt deflection great, been down this road before. Mine has a one tooth larger 19 on the top gear and the other sled we tried a 21 and a 20 tooth. They run very close to each other. Is this it???? Three of us spent all day saturday with everything we could think of and thats it.. By the way, the Rupp also has a new 102c Purple spring (the stiffer one) 42.5 gram ramps ( a goofy cat ramp with little tip weight) and stock belt. It will actually run out of gear and over rev.
What are you guys gtting for top speeds in 1000 feet???

440 MERC T T · Post by **440 MERC T T** » Wed Feb 28, 2007 11:03 pm

Good question, I recently went to small drivers and only had a little testing on bean stubble before I raced it (snow drags) last weekend. With th 18 top gear which is stock and the largest I have I was concerned from testing results I would run out of gear on 660 ft since the belt was going right up on the driver. But the race track was snow covered and a little up and down and the clutching work great. Beat a 440 Nitro II on Sat. and 340 GPX on Sun. for 1st. I do want to test with a 19 T/G next. Is the drive belt riding out on your drivers, is timing set at stock spec's for max rpm. A stock '76 T/T can do around up to 85. But what effect do the small drivers have on the whole top end picture I wonder? Jeff

929rog · Post by **929rog** » Fri Mar 02, 2007 11:14 am

We are running new style cat clutches and have been running fiarly shallow helixes until the other day. With a 18 or 19 we are not running out of gear. The things just would not pull at all so we decided to try something totally different. We had been running basically what Comet calls for with a stock clutch 30 degree helix so we stuck with the shallow helix theory. Ran a 58/50 helix and changed weights to get it to turn 7000. Wow, what a difference pulls hard ran 79mph. I think what we are running into is that the combination of the stiff secondary spring (yellow) and a shallow helix is just holding the shift to much. I mean it does not have close to the power the sled I usually work with. Now we need to find a good balance between the two clutches. I'm going to try basically a stock Cat Z440 set up saturday to start and see what happens. So I guess 85mph is the number to look for. Thanks

929rog · Post by **929rog** » Fri Mar 02, 2007 11:17 am

Forgot... Brand new rebuilt motor. .080 timing Hewtech CDI, new stator, cut out the coiled mess in the can.

440 MERC T T · Post by **440 MERC T T** » Mon Mar 05, 2007 7:55 pm

79 mph that's great, let us know how you do with the 440Z set up, I have been running a Quick Shift Gold Magnum driver with a stock nos Arctic driven but putting together a rebuilt A/C hex to try with a green spring. Do you have to go to a longer drive chain for the 19 gear? Mine's rebuilt to with all nos electronics except for the FIREPLUG cdi which is pushing 6 yrs. old (say no more). Jeff

929rog · Post by **929rog** » Tue Mar 06, 2007 1:40 pm

A 19 will easily work with a stock chain, its huge. In fact a 21 will fit. It snowed like crazy and then got warm so we lost all our lake spots. I'm back to a 18 tooth and am going to try a 17/36 as soon as I get them. These are geared soooo tall. We did try more stuff. I have 64 gram weights in it now (with a much bigger spring) and it goes really well now. My buddy put about the same spring with heel clickers we had from another sled and it pulls harder than mine. Hopefully we can get to a place soon we can run these a good distance.

440 MERC T T · Post by **440 MERC T T** » Fri Mar 09, 2007 7:17 pm

Thanks for the info, please keep us updated. JM

929rog · Post by **929rog** » Sun Mar 11, 2007 10:26 am

Got to run yesterday more. Could not run 1000 feet but probably 800. Brought a roller secondary, a ton of helixes and weights. Ended up on a heel clicker spring 360 finish (big) 64 gram weights, 55 degree helix on a button clutch, yellow spring. We left the set up in the other sled that ran 79mph last week. It could run 73 in this distance. By the end of the day mine could run 77mph at the gun and he said it was still clicking numbers off at a good rate. Works really well does not have a "heavy weight" feeling to it. Comes in around 4500 and pulls hard. These have seemed to like pretty steep helixes and I did try a 57 and 59/53. 57 too much and turned about 6800-6900. 59/53 worked good. 45 degrees today so no place to play. I,m looking for a spot we can run a long distance. I think we can get mid 80's. Still have not tried the 17/36 gear.

98mach · Post by **98mach** » Tue Mar 13, 2007 9:37 am

Very interesting reading as I recently restored a 440 t/twister that I want to set up for 660' drags.

Mine has 17/34 gearing in it. What was the stock gearing on these sleds?

What type of fuel are you guys running?

Did you find much difference by removing the coils in the exhaust?

440 MERC T T · Post by **440 MERC T T** » Wed Mar 14, 2007 9:46 pm

Stock gearing for the '75 T/T is 17/34 & 18/34 for the '76. In my race T/T I run 92 octane and in my daily drivers '75 & '76 both with timing set to '76 spec's (.080 bdtc) I run 87 octane. Now the silencer in the exhaust, thats a good question I was wondering about myself.

929rog · Post by **929rog** » Thu Mar 15, 2007 2:40 pm

Did not seem to make any difference taking the coil out. Its not that loud but sounds really good. Those coils are junk. We had a sled we absolutely could not get to run, cut the end off the pipe and it had "uncoiled" plugging the exhaust. When I got mine we cut it open same thing so I took it out.

929rog · Post by **929rog** » Thu Mar 15, 2007 2:47 pm

If you have the smaller drivers these are geared way to tall in my opinion. We tried larger top gears and its just too much. I want to get the thing to run out of gear and overrev at just over 80mph for what I'm doing (if it will go over 80). I have talked with guys that are running a 15/36 on the grass. Also, if you plan on changing clutches over to new style like we have they may give you a hard time racing that and getting through tech. Not sure, I really don't care about that. It is supposed to get colder this weekend at night so we are planning to get up real early and run these a half mile and see what we can get. I'll let you know.

929rog · Post by **929rog** » Fri Mar 23, 2007 10:38 pm

Ran again the other day... No matter what we did ran the same MPH. Took off the comet and put the hex back on and kept the newer cat secondary with a 50/44. Changed belt back to a inch and a quarter. Gained 4 mph. What the hell... It feels waaaay better and launched waaay harder. Does not make any sense, the comet should be a better clutch. Now running 83mph. Its 50 degrees but maybe another shot this weekend.