I tried to buy a clutch from McCloud today and asked about their Soft Lock. I was told it would burn up on one run. The tech told me that I wouldn't have drive train breakage on the salt with there Mag Force clutch that doesn't slip but has low inertia. He claimed the you never completely hook up on the salt and thus won't break drive train components with it. He further stated that they have hundreds of Bonneville racers using the Mag Force clutch. What is your experience and recommendation??? I want to use a clutch that wont break parts on the gear change in a car that weighs 4500 lbs. and has about 900 hp. Transmission is a Liberty. Thanks George
I never follow the crowd. 8-) I use a full-centrifugal CrowerGlide (8",3-disc) in my lakester. It's damn near impossible to hurt it. I took all the weights off so full lockup is about 4,300 RPM, which helps my small engine (F/BFL) get the car off the line on pavement (LTA). I knew it would survive, since I used it for years in pulling with a 900 HP engine.
George, what parts are you breaking now? I know you are pushing at the start.... give us more info about your issue.
I'm mainly trying to find out about the guys claim that 100s of his Mag Force clutches are being used at Bonneville. But my experience is with a 7.5 inch two disc Tilton. First time I shifted the Liberty into 3rd gear under power it broke my quick change. I know I can buy a fully adjustable slipper type clutch, but they are big money. My 3100 lbs. lakester made 22 runs over 270mph with my powerglide, so the immediate breakage was a big disappointment
My Liberty Story
When we changed to the Liberty transmission we tested at the LTA event in Maine prior to going to Speedweek in 2021. The transmission worked perfectly so when we got back home we now began the preparation for Speedweek which overall is simple just change the gears in the Halibrand 6 spline quick change. That's when I discovered I was not able to remove the lower change gear from the shaft in the rear. The splines on the shaft had twisted enough to
make a gear change impossible so i replaced the lower shaft and all was fine as far as changing gears was concerned. Since time was short before heading west to Speedweek and now knowing we have a problem with the rear our solution was bring three more lower shafts as well as spare ring and pinion just in case. We also came up with an ignition momentary kill circuit so on every upshift for a split second this would unload the drive train and also eliminate the problem but I never added the kill idea to the car. For our quick and simple solution for 2021 was on each upshift we simply lifted off the throttle shifted and then got back into it we never changed any parts the rear survived. Fast forward to 2022 I changed the rear to a Halibrand 10 spline now with the power level we are at the 10 spline is holding together fine. We don't use any type of soft hit clutch or multiple disks we also don't make 900HP. Our clutch is from Center Force its a single disk made for this application the steel flywheel come from them as well.
If it was me I would add a kill circuit to the shift system that would certainly work my thoughts were to add the ignition interruption for second and third gear by forth gear the RPM drop is so low I doubt there would be any reason to be worried and the same is true for fifth as well.
Ronnieroadster
Those are good insights and I appreciate that. But just FYI I had a new Center force clutch and was told not to use it by there tech department. For a high RPM application the nodular iron P.P. face is not suited for the kind of RPM my engine is capable of. I will definitely look into your suggestions. Thanks
Quote from: racergeo on November 16, 2024, 12:51:39 PM
Those are good insights and I appreciate that. But just FYI I had a new Center force clutch and was told not to use it by there tech department. For a high RPM application the nodular iron P.P. face is not suited for the kind of RPM my engine is capable of. I will definitely look into your suggestions. Thanks
The Center Force PP we use is their light weight aluminum version with a steel insert face not sure what the max RPM is for that we turn 6500 for the speeds up to 250 we are running with a 219 gear and 29 inch tall tire. Since the CF diaphragm design has weight's between the many fingers the centrifugal force is adding a lot of clamping pressure once its clamped there's been no slippage according to the data system were running. But I still like the split second ignition kill idea to help save parts breakage.
Ronnieroadster