Loop the car, lose the starter?

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10.07.22, 9:47 AM
SpexRacer

Loop the car, lose the starter?

If anyone.can tell me why this happens and if it is preventable I'd be greatly appreciative.
Every now and then I am prone to losing the rear of my car (ex DSR, now P2, home built in 2001 with a solid rear axle, chain driven, K1/K2 GSXR 1000 power) and when it happens no matter how quickly I get the clutch in, my starter fries. Now I know the first obvious answer is Don't loop the car. I try not to but when it does go there's no saving it with this solid rear axle. It just snap over steers and that's it. Trust me, I'm working on it. But when I do have a spin, two feet in, All that good stuff, but the car is already stalled before I even come to a stop. I'll try to start it and click nothing. There's been times when I've been able to dump the clutch with it in gear while still rolling and get it to start and drive it back into the pits. But regardless the starter isn't doing me any good at that point anymore. It'll be too hot to even touch and once it's removed and cracked open, it's basically just a canful of crumbs at that point. I understand. It's possible that even during a 360 spin the engine was driven backwards for some very small amount of time between the start of the spin and the time I got the clutch in and I've been told that will do something to the starter, but I don't know what's actually happening.
Can anyone explain to me why this happens and also short of not spinning or getting the clutch in that much faster Is there anything that can be done to prevent it?
10.07.22, 10:12 AM
Adriancnh

Quote:

Originally Posted by SpexRacer

If anyone.can tell me why this happens and if it is preventable I'd be greatly appreciative.
Every now and then I am prone to losing the rear of my car (ex DSR, now P2, home built in 2001 with a solid rear axle, chain driven, K1/K2 GSXR 1000 power) and when it happens no matter how quickly I get the clutch in, my starter fries. Now I know the first obvious answer is Don't loop the car. I try not to but when it does go there's no saving it with this solid rear axle. It just snap over steers and that's it. Trust me, I'm working on it. But when I do have a spin, two feet in, All that good stuff, but the car is already stalled before I even come to a stop. I'll try to start it and click nothing. There's been times when I've been able to dump the clutch with it in gear while still rolling and get it to start and drive it back into the pits. But regardless the starter isn't doing me any good at that point anymore. It'll be too hot to even touch and once it's removed and cracked open, it's basically just a canful of crumbs at that point. I understand. It's possible that even during a 360 spin the engine was driven backwards for some very small amount of time between the start of the spin and the time I got the clutch in and I've been told that will do something to the starter, but I don't know what's actually happening.
Can anyone explain to me why this happens and also short of not spinning or getting the clutch in that much faster Is there anything that can be done to prevent it?

Make sure your clutch is bled properly, and use Castrol SRF for fluid so you know the clutches are fully apart when you go 2 feet in.
10.07.22, 10:21 AM
Marty Nygard

The starter is connected to the engine by a gear train the reduces the starter speed to that required by the engine. The train has an over run clutch to disengage the starter once the engine is running. During a spin, if the engine momentarily turns backwards, the gear train back to the starter runs the starter rotor backwards up to a gazillion RPM and the pile of debris results.
I have heard of, but never seen, "starter savers" that completely disengage the starter from the gear train once the engine is running. Perhaps you can find one for your engine?
Also, FWIW, you can clean out the broken starter can and try to plug the hole in the engine casing to allow you to push start for the next session. The can, however, is seldom oil tight and (dependent on where the exhaust header is located) you might end up with a giant plume of oil smoke. If your friend is driving the car and you are in the pits signaling without a radio, they will probably ignore the smoke. Don't ask me how I know this.
Marty
10.07.22, 11:11 AM
SpexRacer

Thank you Marty for that explanation.
Adriancnh, Castrol SRF for the clutch hydraulic fluid? Or are you talking about oil for the wet clutch itself? I have AP racing brake fluid in the clutch line/reservoir and use Amsoil racing oil for the engine/gearbox. Approved for wet clutch, sport bike all that appropriate stuff
10.07.22, 11:56 AM
Racerex1

starter saver

Quote:

Originally Posted by SpexRacer

Thank you Marty for that explanation.
Adriancnh, Castrol SRF for the clutch hydraulic fluid? Or are you talking about oil for the wet clutch itself? I have AP racing brake fluid in the clutch line/reservoir and use Amsoil racing oil for the engine/gearbox. Approved for wet clutch, sport bike all that appropriate stuff

Contact John Rounds at Kartracer@wave.cable. He may be able help you find a cable and slide device that pulls the starter out of engagement after you start it. I had purchased one but can't remember where I purchased it from, never got around to installing it.
10.07.22, 1:39 PM
J Leonard

Install a slipper clutch?
10.07.22, 1:41 PM
SpexRacer

Quote:

Originally Posted by J Leonard

Install a slipper clutch?

I have a yoyodyne slipper clutch installed.
10.07.22, 1:42 PM
SpexRacer

Quote:

Originally Posted by Racerex1

Contact John Rounds at Kartracer@wave.cable. He may be able help you find a cable and slide device that pulls the starter out of engagement after you start it. I had purchased one but can't remember
where I purchased it from, never got around to installing it.

Interesting, I wondered if something like that ever existed. I'll reach out. Thanks!
10.07.22, 4:26 PM
Lastminuteracin

Quote:

Originally Posted by Racerex1

Contact John Rounds at Kartracer@wave.cable. He may be able help you find a cable and slide device that pulls the starter out of engagement after you start it. I had purchased one but can't remember where I purchased it from, never got around to installing it.

Is this the same John Rounds that used to race Superkarts in the northwest?
10.07.22, 4:48 PM
Onebadbug

I can't find it right now, but there's a machine shop who sells this for dwarf cars. It sits on top of the starter allowing it to move back and forth. I had to modify mine quite a bit, and I used a ford window lock solenoid to activate it.
10.07.22, 4:56 PM
SpexRacer

Quote:

Originally Posted by Onebadbug

I can't find it right now, but there's a machine shop who sells this for dwarf cars. It sits on top of the starter allowing it to move back and forth. I had to modify mine quite a bit, and I used a ford window lock
solenoid to activate it.

What engine did you have that setup on?
10.07.22, 5:43 PM
Onebadbug

Quote:

Originally Posted by spexracer

what engine did you have that setup on?

gsxr 1000, 2006
10.07.22, 7:57 PM
Adriancnh

Quote:

Originally Posted by SpexRacer

Thank you Marty for that explanation.
Adriancnh, Castrol SRF for the clutch hydraulic fluid? Or are you talking about oil for the wet clutch itself? I have AP racing brake fluid in the clutch line/reservoir and use Amsoil racing oil for the engine/gearbox. Approved for wet clutch, sport bike all that appropriate stuff

im talking about for the hydraulic clutch system, I've found bike powered cars often get air in the clutch lines and need to be bled. the srf seems to hold off the heat the best. A poorly bled clutch can cause the plates to not disengage well enough in a spin
10.07.22, 8:15 PM
SpexRacer

Quote:

Originally Posted by Adriancnh

im talking about for the hydraulic clutch system, I've found bike powered cars often get air in the clutch lines and need to be bled. the srf seems to hold off the heat the best. A poorly bled clutch can cause the plates to not disengage well enough in a spin

Thank you for clarifying. Prior to this season I had a cable actuated clutch to the K1/K2 generation sprocket cover. The clutch was a hand lever just like on a bike, mounted on my gear shift lever. I removed that and installed a Wilwood pedal box with 3 pedals. Took some work to shorten the pedals 2 inches each to fit in my space constrained footwell area and a little modification to the frame but ultimately it worked out nicely and (I believe) stronger and as safe at least as before. Using a Wilwood master cylinder, a length of braided brake line, and a K5 (2008) sprocket cover (I think I have the gen and year right) with factory hydraulic slave mounted, as the K5 gen was designed to accept a hydraulic slave actuator. Bolts matched up pattern wise but needed different lengths and had to fab a clutch push rod to get an exact length that wasn't too long to not let clutch disengage or too short to bite at all. Took some trial and error and garagista engineering. I thought the AP racing brake fluid would be acceptable, but I'm happy to try your recommendation. I'll definitely bleed again. I find myself already bleeding brakes almost before every weekend event anyway. Might as well include clutch in that routine now that it's hydraulic.
10.07.22, 8:40 PM
Marty Nygard

I hate bleeding hydraulics so I always converted to mechanical (Cable) clutch actuation. Never seemed to help when spinning backwards.
M
10.08.22, 8:03 AM
924RACR

I did find my clutch was really bad with needing a bleed before every weekend, and being useless by the end of the weekend... until I revised the geometry at the pedal to get the pushrod properly horizontal, then the problem went away, and I maybe bleed it once a year. Using ATE Typ200 brake/clutch fluid, much cheaper than SRF etc and wet boiling point almost as high... never an issue.
10.13.22, 2:56 PM
AJWALKER

I rent Radical sports racers for HPDE events at VIR from Kaizen Autosport (www.kaizenautosport.com). Early on they warned about spinning out and rolling backwards would ruin the starter if you didn't get the clutch in quick enough.
Recently they installed Rekluse (https://rekluse.com/) auto clutches to eliminate the risk of starter damage. Once you shift into gear with the clutch in, you release the clutch, car doesn't move until you apply the gas. It works kind of like a mini bike clutch.
10.13.22, 9:17 PM
SpexRacer

Quote:

Originally Posted by AJWALKER

I rent Radical sports racers for HPDE events at VIR from Kaizen Autosport (www.kaizenautosport.com). Early on they warned about spinning out and rolling backwards would ruin the starter if you didn't get the clutch in quick enough.
Recently they installed Rekluse (https://rekluse.com/) auto clutches to eliminate the risk of starter damage. Once you shift into gear with the clutch in, you release the clutch, car doesn't move until you apply the gas. It works kind of like a mini bike clutch.

Thanks that's very interesting. Were the Radicals running 1300 busa? Seems there's no GSxR 1000 option...
10.14.22, 10:04 AM
AJWALKER

I am pretty sure that they run a Busa.
It does appear that Rekluse doesn't offer anything for the GSxR 1000
Sorry to be a tease.