Box Stock

Box Stock Predator

bullerman said:
I wonder if I have mine adjusted on the stand to turn 5400 rpm and I have the gearing to where I am 4900 at the end of the straightaway will it float the valves on the track? Just wondering.
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All depends on the engine it may or may not, if it does just target less RPMs
 
Ok I’m running a stock predator what’s the best rpm’s to run my class says 5000 rpm’s max 350 class at checkerflag track in Athens
 
I have ran everything from a 16-61,65, 68 to a 15-61, 64, 68 and 4600 on track has been my max rpm with 5350 on the stand. Hillard Flame clutch with white springs. My best lap was with the 16-60.
 
Theres a difference between hitting the governor and hitting valve float. I try to aim for 4900 on track rpm with 10.8 springs but it will hit 6100 rpm without floating if I let it. What I run into is we race at a track that gets faster as the night goes on. In practice I hit 5400 on track so I add a driver tooth. In the heat I hit 5400 again. Drop 2 axle teeth in the main and still hit 4900-5000 with 300 rpm drop. Ran ok but not great. Now looking at higher air pressures in tires maybe Im locked down. Every lap the throttle was WFO,
 
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This is Box Stock, 5500 rpm on stand. Like I said I was at 5300 on the stand when track checked it before race but none if the gear choices I ran got close to 4900 on the track.
Racing Promoter what does gear bound mean exatcly? Do you mena i should be on a 17 instead of a sixteen or a smaller rear gear. Seems with the 16-60 on the track I am in the 4200 rpm range. Could it be possible that's where it needs to be?
 
you want the engine to pull your from the apex of the corner to the entry of the next corner. if your engine can't climb to the desired max RPM your gear bound AKA kart is slow due to gear choice same deal if you are over revving. if you have an unaltered stock cam you need to look for 46-4800 on the tach
 
Well between a tie wrap on a few of the governor spring coils, the spring on the closest hole to the shaft on the governor and the throttle stop screw the motor is surging at about 5325. Will the butterfly fully open on the track while racing?
I know DNQ says theirs has to surge at 5500 or less. Going to give it a try this weekend. I assume their throttle is opening all the way up.
 
I finally have mine surging at like 5375 and on the track at 4800. Lap times are about the best I have made. I think I have the gearing figured out also.
Going to leave that alone and work on handling. Kart was twitchy the other night. It was suggested I go up on castor.
 
bullerman said:
I finally have mine surging at like 5375 and on the track at 4800. Lap times are about the best I have made. I think I have the gearing figured out also.
Going to leave that alone and work on handling. Kart was twitchy the other night. It was suggested I go up on castor.
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I forgot. I was on a 14/61.
 
bullerman said:
I wonder if I have mine adjusted on the stand to turn 5400 rpm and I have the gearing to where I am 4900 at the end of the straightaway will it float the valves on the track? Just wondering.
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It shouldn’t. I usually go with a weak clone spring. Like something you would run in a red plate. 10.2 or so @.850.
 
bullerman said:
I finally have mine surging at like 5375 and on the track at 4800. Lap times are about the best I have made. I think I have the gearing figured out also.
Going to leave that alone and work on handling. Kart was twitchy the other night. It was suggested I go up on castor.
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Wow 5,375 awesome, awesome 4,800, is yours governed how did you that, usually I've heard it cab turn 4,000 RPM max with a few adjustments from the 3,600 RPM max
 
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Raced last night. Heat race i was on a 14/60. High rpm was a little over 4700 on the track. I qent to a 61 and actually dropped a few rpm.
I have a few of the coils wired together on the governor spring. It is in the hole it cam from from the factory. Throttle stop screw is backed off qhere butterfly will open fully. I adjust the rpm on the stand with the spring on the accelerator rod.
I am going to put new valve springs in before nest race. We ran a 50 lap race last night. This is the 4th race on this motor with factory springs. Never have floated the valves on the track.
 
bullerman said:
Raced last night. Heat race i was on a 14/60. High rpm was a little over 4700 on the track. I qent to a 61 and actually dropped a few rpm.
I have a few of the coils wired together on the governor spring. It is in the hole it cam from from the factory. Throttle stop screw is backed off qhere butterfly will open fully. I adjust the rpm on the stand with the spring on the accelerator rod.
I am going to put new valve springs in before nest race. We ran a 50 lap race last night. This is the 4th race on this motor with factory springs. Never have floated the valves on the track.
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Coils wired together?
 
The spring that goes from the carb to the governor arm. Wire a few of the coils together and the governor won't come in as soon. You have to experiment some. To me it is a combination between throttle stop and tension on the spring.
 
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