Box Stock

Light finally went off on rpm drop

Down on rpm last night. Been racing at 4800 to 4900 rpm. Last night I was at 4600. The track was slow and slick. It just felt different. Was .6 to .9 slower on lap times. I checked my self on the stand and I was at 5400. I guess it was just the track.
I was having some clutch trouble on the start but after I got rolling it felt OK. I run the Hillard Flame with Bully conversion. I never have been really satisfied with it and may try something different next year. I service if after every race. It just doesn't seem like it engages good to me. I have tried the shoes in both directions. Last night it felt like it was slipping. What's another good drum clutch people use?
 
bullerman said:
Down on rpm last night. Been racing at 4800 to 4900 rpm. Last night I was at 4600. The track was slow and slick. It just felt different. Was .6 to .9 slower on lap times. I checked my self on the stand and I was at 5400. I guess it was just the track.
I was having some clutch trouble on the start but after I got rolling it felt OK. I run the Hillard Flame with Bully conversion. I never have been really satisfied with it and may try something different next year. I service if after every race. It just doesn't seem like it engages good to me. I have tried the shoes in both directions. Last night it felt like it was slipping. What's another good drum clutch people use?
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It seems like you may still be a little confused with this RPM deal, what rpm it's set at on the stand has NOTHING to do with what you turn it on track, or slower lap times . A Stinger clutch would be another option .
 
I have it in my mind if I turn 5400 or so on the stand and not be over 5500 I will be good on the track I guess. This is not right? I know it is not going to turn the same thing on the track as on the stand. Or at least I think it won't. Last race I was in the 4800 to 4900 rpm range. Last night I wasn't. I did look at my tack today and I had some bad rpm drops. I may have lost those rpms on the corners.
I really haven't seen a good video on you tube of how to adjust the governor for a rpm rule. They have a bunch of how to remove it or tie it back. If there is a good video I would like to see it and make sure mine is right.
 
bullerman said:
I have it in my mind if I turn 5400 or so on the stand and not be over 5500 I will be good on the track I guess. This is not right? I know it is not going to turn the same thing on the track as on the stand. Or at least I think it won't. Last race I was in the 4800 to 4900 rpm range. Last night I wasn't. I did look at my tack today and I had some bad rpm drops. I may have lost those rpms on the corners.
I really haven't seen a good video on you tube of how to adjust the governor for a rpm rule. They have a bunch of how to remove it or tie it back. If there is a good video I would like to see it and make sure mine is right.
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Correct not right the fact that it's 5400 on stand doesn't enhance how well it runs on track, 5300 on stand would make no difference performance wise, the fact that you turned less rpm last run out sounds like your clutch might have had something to do with it, but I'd say mostly track conditions were different and tires weren't matching the track thus less forward drive result lower rpm with no prep rule not much you could do other than add 2 teeth to the rear .
 
You may be right. The clutch could have been slipping the whole time. They were definitely pulling me off the turns. I watched the race again today. Some of the karts I usually pull were pulling me.
 
bullerman said:
Finished second the other night. They checked our motors on the stand. We have the 5500 rpm rule. The kart had set probably 40 minutes or so before they checked us. I undid my tach so they could use the one the track has. It's a mychron 4. It wouldn't work so they used mine. I reved it up and held it for three or four seconds. I was at 5478rpm. I had checked on the stand here at the house. I was at 5377rpm and motor surging. I thought I had it set. The motor wasn't hot like after a race. The last couple of times I adjusted it I did it by adjusting the nut on the accelerator stop spring. I am turing 4800 to 4950 on the track. If I back it down to 5200rpm on the stand Wonder if it will hurt me that bad on the track. It may put me in the 4600rpm to 4700rpm on the track.
Don't want to get DQ.
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I turned ours down from 5500 to 5200 so we could go to a different track. I used the throttle stop spring. It did not effect anything, it ran just as good.
 
No expert on the clutch, or any part of racing, but we were getting clutch slippage from a Hilliard in the corners caused by too heavy of a spring set. The rpm drop was below the stall speed of the clutch. Which springs and what weights do you have in the clutch? Maybe you just need lighter springs or more weights to keep it engaged.
 
Went back at looked at the last race high rpm for the race was 4593. Maybe it slipped at the start of the race. Well I am sure it did, I could feel it on the start. Seems like if it did slip during the race the rpm would be higher like you said.
Like I said I run white springs and no weights. It has never engaged like I thought it should. The springs have 10 or so races on them. They feel ok.i may try the weights.
I did have at of rpm drop most of the race. I may have dropped so much I couldn't gain it back therefore only turing on the 4600 range instead of 4800.
Calispec. I adjust my rpm with the stop on the accelerator rod spring. I adjust the nut to the rpm I want. I tried adjusting it with the throttle stop on the motor but I was getting a lot of variance. I don't know what the correct way to do it is.
One more thing. One of the kids that races got a new predator. I am trying to help him with the rpm setting. If he puts the motor on the kart, backs all the way off on the throttle stop on the motor and revs it wide open and it hits the governor and turns close to 5500 on the stand should he just leave it alone. We have a 5500 rpm rule. Thanks for the help.
 
In my opinion adjusting with the throttle rod stop is incorrect .
As to the new driver ,
. Set it at 5400 rpm gives you some wiggle room when its checked .
 
Do you use the throttle stop screw on the motor itself then set the stop on the rod to that? I don't know what the correct way to do it is that's just what I did.
 
Redid it today Flattop. Set rpm to 5375 with the throttle stop screw then adjusted the accelerator spring and nut to it. Will give this a try.
 
SoCo Tire Treatments said:
Its one of the checks they do for stock Predator, its an RPM rule with some wanting the surge as well.
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So Co. If you ran in the Box Stock class would you run a governor if you don't have to. I do run mine but I am beginning to wonder if I should or not. I wasn't running it but I was having trouble with the rpm check on the stand. I basically had to use the throttle stop screw. I had to close the buttery to keep it under 5500. I would thin you want the butterfly wide open. Just wondering.
 
bullerman said:
So Co. If you ran in the Box Stock class would you run a governor if you don't have to. I do run mine but I am beginning to wonder if I should or not. I wasn't running it but I was having trouble with the rpm check on the stand. I basically had to use the throttle stop screw. I had to close the buttery to keep it under 5500. I would thin you want the butterfly wide open. Just wondering.
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This i dont understand, an RPM rule with no governor. Im in the SE, the OTB Predator guys all must have governor intact with RPM rule. And with that still they need to adjust the throttle stop depending on where the RPM rule hits at.
 
I agree. I think we should all have to run a governor but according to our track rules you don't have to. They checked us several times during the year. I know some had governors and some didn't. Nobody was over the 5500 on the stand limit. They checked me one time and I was dead on 5500. I started out without a governor but put mine back on.
 
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