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Spridget race clutch questions

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BuggerAll

Jedi Hopeful
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ANyone have any suggestions on a spridget race clutch short of a Tilton? I toasted a WInner's Circle solid center disc, which had been clamped with a beefed-up (extra straps, replaced the rivets with 3/16" AN fasteners) at Summit last weekend. I think it would have been okay if I had not had to reuse the clutch disc, which was in the car when I blew an engine a month ago (car doing 100 mph, engine goes from 6800 rpm to zero in zero seconds = rather accelerated clutch wear). The WC disc was down to 6.6 mm, but having no alternative I put it back in. Made it through qualifying and the Saturday race okay, but in the Sunday main event it started slipping badly about 8 laps in. SInce I will be going to a lot of race weekends solo, and tow with a Subaru, there is no way I can add a pit cart to the collection to tow the car through the paddock. ANy suggestions appreciated. Flywheel I'm using is a Fidanza alloy, with replaceable friction surface. Engine is a fairly robust 1275 LP which has dynoed 115hp - thanks for tips!
 
Give Hap a PM.
 
You can drive a car in the paddacok with 7.25" tilton set up, it will set you back a easy $1000, when you add up all the parts, the flywheel, the pressure plate, the disc and the special roller bearing set up, Winner Circle has it all, but here's the deal, it could very well be the last clutch you ever buy, and with a 140 hp engine I could not even wear out the clutch disc. While an expensive set up in the beginning, this set up is cheaper in the long haul, and puts the power to the ground way better than any stock derived set up. Everyone I know messing with a stock dervide type clutch is always spending a 100 bucks here and there, and having failure, and in the end the Tilton becomes a cheaper route, and one that will finish the race weekend.
 
One of the interesting things here (to me) is the increased stress caused my added power.

I've been running the same, stock clutch in my 1500 car for 6 years. My pressure place is the original 1978 unit. I looked at them last time the enigine came out (Dec '09) and they were fine. I've done 50+ weekends (probably 70+ races) on them. So far, so good.

Of course, I have to jump through hoops to pull a 1:37 at Summit or a 1:10 at Lime Rock.
grin.gif


It's all relative, I guess.
 
That a good point Nial, it's relative to HP, the more you have the more you need a killer clutch. At the end of the day, you're probably having more fun than the rest of us :smile:
 
Thanks for the responses. Will try at Summit again this weekend with a return to the original setup, with a couple changes. Using a new WC solid center disc, and a modded cover (replaced rivets with AN fasteners, extra straps) and cross my fingers. Did notice that on examination the clutch cover friction surface has cracks. Also noted that the cover I used before (a Quinton Hazell?) had 3/16" rivets, while the new cover I modded had 1/4" rivets and a different strap length. Will try and make it through to the end of the season with this setup before popping the $$$ for the TIlton or Quartermaster. It dawns on me that not all of the clutch wear results from the engine torque, some of it comes from tire-transmitted torque too, as you apply force to the drivetrain from the sticky rubber in high-g cornering. Duhh. Also one more lesson learned: I tried a set of Hoosier 20 x 7.5 x 13 R45 formula car fronts on my car last time at SUmmit, figured they were about the same size as the standard 20 x 8's. And I got them very cheaply from the Hoosier dicontinued sale end of last season. Well, they did not work. Oh, they worked okay in terms of holding the car off the asphalt but did not hold up at all, Left rear chunked (first time I'd seen that on a spridget), casting off tread on the inside (where it bears the load of hard right hand corners) and at one point sent me into the gravel trap off 10 at Summit at pretty close to top speed. That was a ride, with the result being no worse that one ripped off muffler and a sandblasted paint job on the rocker panel and rear flare. At any rate, if anyone is at Summit for the 26-27 race weekend, come by the #0 Hprod BRG midget and say hi. There's only four H cars entered so far: two VWs, self and Randy Canfield.
 
Well, the modded stock clutch failed again. Took advantage of a performance bonus from work to go ahead and buy the complete setup from Rick Haynes - his custom flywheel and T/O bearing setup, with a Quartermaster cover and sintered bronze disc. It goes in this weekend. No, it's not cheap but when I figure in the entry fees for a clutch-related DNF and a slipping clutch which caused me to slip back through the field in a race where I should have finished higher, it'll be worth it. Guess I fit the definition of penny-wise, pound-foolish, both as concerns the clutch and those formula car tires I referred to above. From now on...and while on the subject of modding, I fit an additional oil cooler in series with the front-mounted 13 row which was just not enough capacity on its own. If i ever figure out how to get pix into these messages I'll send some. Back to Summit 7-8 Aug. Bugger
 
I race a 1098 mk 1 sprite here on the west coast with about 95 hp which I understand is not as much as the bigger engines but I have been running a stock clutch in my car for almost 3 years now and have had zero trouble. 115 hp is a fair amount of stress on the clutch but we have done a number of much higher hp cars with the same size clutch and they live for a long time. In my humble opinion it sounds like there is not enough freeplay at the slave cylinder.(I.E. the pushrod from the slave to the throwout arm is to long) Just a thought.
 
That was the first thing I checked - believe me. New clutch went on this past weekend (in 100 degree heat) and back into the car. Will test it on the test day before the 7-8 Aug MARRS race.
 
You made the right choice, going to the race clutch will save you money over time. Some of us are harder on certain things than others, I'm tough on gearboxes for example. The 7.25 cintered disc will last you in a Spridget a very long time, you'll probably get 2-3 full seasons or more out of the disc alone, the pressure plate for most part will last as long as you race, I've only ever replaced but one, and it was used to me when I got it, it probably 50= races on it when it crapped out. You'll notice right off the bat, it just pulls better, never slips. For most of us the race clutch is the less expensive alternative for the long run, because the race stuff just last and last, like that eveready bunny :smile:
 
well, the new clutch works like a charm. Played with it a little during test/practice day 6 Aug, qualified 2 1/2 second faster (in the 1:32s) than previous best time (after all, this is my first season back since quitting racing to go back to school in 1977, still learning how well these new Hoosiers stick) and won the 10 lap Saturday race (in class anyway, 7th of 14 overall with Ep, FP and the GT Pintos). Engine starting running funny when warming up for Sunday race, then quit - the electromotive trigger wheel parted company from the crank damper. Got it buzzed back on in the right position with a mig just before the call to gris, did not have time to dress the welds, however, they ate up the water pump drive belt and only finished one lap before it shredded and the temp gauge shot up. Frank Jones took the well-deserved win, missed not being able to get in a good racewith him - this was the MARRS at Summit. Every time I fix one thing, something else happens. At least no more clutch worries.
 
Hey Bugger, meant to come look you up this past week at Summit Point, #0 car right, I started to head out to look you up and saw you headed out of the paddock on the trailer Sunday or maybe it was Saturday evening. I was there crewing for the two vintage MGBs.
 
Hey Hap, missed you, couldn't find where you all were paddocked. I had to leave on Sunday, withdrew due to the fact that I trashed my SCCR gearbox in Saturday's race, that's how McConnell got past me, since all of a sudden I ihad nothing but 4th gear. Got the box apart, what a mess, everything broken up. will put in a stock trans for the final MARRS race while I ponder my options - tried to order a set of SCCR gears from Moss Europe, they're only 331 pounds from Engalnd, but they back-ordered. Other option include a Quaife box from England, about 2100 pounds, a used Taylor here if I can find one. Let me know if you have something lying around, Hap. I was heartned by the increasing speeds, qualified at 1:30.5 which was 2.3 secs a lap quicker than previous best, so I am getting back into it - was having a good race with Frank Jones when the gearbox broke, had an EProd BMW between him and me which was too wide for Frank -
 
We got that on incar video, you smoke the brakes pretty good going into one, and then move over to the outside and seem to be exit the corner slowly, it's on you tube, search Summit Point , you'll find it. Yep Fred and you were evenly match, he got down to 1:30.4 on Sunday. After Sunday race, we starting doing a engine pull, it was panned, nothing wrong , but ime for me to refresh and upgrade, we took off all the bolt on Sunday after the race, then used Meathead's shop to hoist it out the next morning, He never planned on racing Monday, so i could get the engine and get on the road early. Next year, We'll probaly only doing vitage races, those vintage tires in a SCCA prod race are a good 2-3 second a lap handicap. They did it this year so his dad, Green GT could get his SCCA license making it easier to get accepted at vintage races without going to expensive pro drving schools. We hope to be back at Summit Point for the Jefferson 500 vintage races next spring.
 
well, the SC gears did arrive surprisingly quickly from England, so that's the next project. Then more mods, including rear disk brakes. I had originally planned on running mixed schedule of SCCA and vintage, but I guess I will stick to the MARRS series only. Now too many mods for vintage -
 
Hi Fred, if you could email it to me (michael.macqueen@dhs.gov) that would be very much appreciated. I would have had to skip Monday's race regardless because of work commitments, so I withdrew Sunday morning before heading out. As you could see I am having brake balance problems, either too much front (lockup) or too much rear (ultra-twitch). For my first season back since 1976, I'm having fun. Kind of disappointed in the mechanical failures (wife asks why don't I race a Mazda!) but have thoroughly enjoyed meeting all of the prodracers - next year will be H prod Midget 2.0 -
 
Is anyone here interested in a complete Spridget SCCR transmission?
I picked it up from Paul Asgeirsson's Morrisservice when I bought his inventory a couple of months ago.
It looks brand-new and the insides look perfect. I am assuming that Paul rebuilt it and anyone who knows Paul knows that he did everything very well. It says on the outside (in pencil) "BMC SCCR" and appears to have a Jack knight gearset inside but it could be something else, I don't know too much about racing transmissions - just regular and Datsun ones.
BillM
 
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