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01-14-2013, 04:25 AM | #1 |
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Stick car, too much clutch?
I have 2 stick cars, my 85 Mustang Stocker, and a 78 Fairmont with a FE Ford engine, back halved ladder bar bracket car. Both have Jerico 4 speeds and McLeod Soft Lok clutches (10" on the Mustang, 10 1/2" in the Fairmont). I`ve been running both cars ( as sticks)for over 10 years each, and thought that I had a fairly decent handle on the clutch setup, as I normally get 2 years out of a disc, and have minimal breakage. Neither car is high RPM, and the clutch is set low enough that a drive up the return road in 3rd gear, at about 25 MPH, will result in considerable slippage if I lean into the throttle much.
However, a local track photographer recently made a DVD of a few of my runs in the Fairmont, and I gotta admit I was suprised to hear the tires barking on the gear changes. It is quite noticable in the recording. I had always assumed that with this style of clutch, there would have been enough "cushion" to prevent the clutch from hitting so hard. Is this normal, or am I way off on my clutch setup? I know that Mr Gullett and Mr. Lee will be saying to get a Youngblood clutch, but a pair of dual 7"ers are not in the budget anytime soon.
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NHRA 6390 STK M/S 85 Mustang |
01-14-2013, 09:28 AM | #2 |
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Re: Stick car, too much clutch?
Red@ Mcleod told me years ago to keep backing pressure plate down until it slips in high gear have to make 1/4 mi passes,my car always starts bouncing front end like you are letting off and on throttle when I get to point where it is slipping in high gear,then raise press back up 1/2-1 turn.
I say if you are chirping tires you are too agressive or have too much air gap .050'' max too much air gap will cause to hit tires too hard Mike Taylor 3601 |
01-14-2013, 10:54 AM | #3 |
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Re: Stick car, too much clutch?
Hi Rory,
What do you have for levers, and CW? I had a heck of a time with my original Ram 10.5" Hyatt setup. No CW levers, and then I switched to his billet CW levers. It should not be hitting that hard on gear changes. With the original setup, I had to adjust base to be a compromise between the launch and high gear. Sean
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Sean Marconette 84 Mustang 5060 SS/N |
01-14-2013, 11:17 AM | #4 |
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Re: Stick car, too much clutch?
You really have not provided any info that anybody could comment on other than you are chirping your tires.
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Jeff Lee 7494 D/S '70 AMX |
01-14-2013, 11:35 AM | #5 |
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Re: Stick car, too much clutch?
Where do you leave and shift at? Are you running counterweight? If I had to guess if your running to much counter weight and its locked up tight at your shift points. That is just a shot in the dark.
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Todd Hoven 1035 Stock |
01-14-2013, 01:12 PM | #6 |
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Re: Stick car, too much clutch?
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01-14-2013, 01:21 PM | #7 |
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Re: Stick car, too much clutch?
You have too much clamp load at your shift point, whether base or counterweight induced. Peak torque is at lower rpm where counterweights are less effective. If the base is quite low and you make up for it with counterweight to get enough clamp load at peak torque, it is easy to then have too much at the higher shift rpm.
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01-14-2013, 01:58 PM | #8 |
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Re: Stick car, too much clutch?
For the last time you don't need a Youngblood clutch to go fast. PM me and I will direct you to some very fast cars in ND in the records section not running that clutch.
As others have stated give your base,cw if any and rpm shift points. That will help. Good luck.
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Ed Carpenter 2005 Chevy Cobalt A/SM Race Engine Development |
01-14-2013, 02:05 PM | #9 |
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Re: Stick car, too much clutch?
The pressure plate has a 280 lb base, I started at 5 turns out, and backed it down until it flared on the 3-4 shift, and added 1/2 turn. I normally leave it like that until it flares again, however many runs that takes. I don`t really play with counterweight, as I can not remove the bellhousing in the car, engine has to come out. For counterweight, I have the short steel bolt and nut, I believe that is about 6 grams per lever. I launch at 6000-6200, and shift about the same.
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NHRA 6390 STK M/S 85 Mustang |
01-14-2013, 03:36 PM | #10 | |
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Re: Stick car, too much clutch?
Quote:
Now if you have a problem with Advanced Clutches, whether you can't afford one or you think they don't work, take it elsewhere.
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Jeff Lee 7494 D/S '70 AMX |
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