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Post by Simon on Jun 11, 2009 0:51:02 GMT -5
Hi guys, I see that there may be a bunch of NFRA folks heading to Davis this Sunday. If I can I'll try and get me and my clone up there for a test. What gearing are you guys running that have run at Davis before ? I would like to have the gearing at least in the ballpark when I get there.
Who's planning on being there ?
(Sorry I didn't get to say hi to the folks that were at PC a couple of weeks ago, it turned into quite a busy race day, rebuilding after wrecks, with my son's HPV-1 so didn't have much socializing time)
Simon.
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Post by Brad Wunder on Jun 11, 2009 10:23:46 GMT -5
This is who I know are heading out there:
Dean
Scott (w/his clone, not his F200)
Duffy and sons
Brad 42
Brad 9
Scott Smith may also make it out there.
Not sure about Paul, PJ and Sammie (I think they are going)
Also not sure about what gearing the BSC are running. Scott and/or Duffy should be able to give you a heads up on that.
Look forward to meeting you this weekend.
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Post by speedrome on Jun 11, 2009 10:52:58 GMT -5
Simon, What modifications have you done to your clone?? If you have just removed the gov and have not done any other modifications for blueprinting the clone is good for about 5500 rpm(maybe more depending on track). With that in mind, i recommend downloading this free program www.gregorybraun.com/KartData.html Its very helpful putting together gear ratios for karts and also has a kart scaling calculator. This will help figure out a ball park on your gear ratio... I plugged in 5500 rpm and figuring a reasonable straight away speed of about low to mid 50's you get about a 3.41:1 overall ratio. This will get you about a 16-17 tooth front driver on the clutch and upper 50's on the rear sprocket (58 tooth will get ya 53 mph). That might be a good place to start. |
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Post by ron90 on Jun 11, 2009 17:33:53 GMT -5
I should be out there with KT, F200, and son;s Kid Kart.
Simon are you from Dixon? Do you have the gearing for that track? I don't have a clone and don't know the gearing, but my KT gears are 10:86/87 Davis, and 10:80 Dixon. I don't know if that translates over to a clone, but you might be able to figure out a bal park gear to start.
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Post by brad42 on Jun 11, 2009 17:47:23 GMT -5
I'll have an entire box of gears. Bring whatchya got, and we will tune from there.
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Post by paulskirocks on Jun 11, 2009 17:49:27 GMT -5
If I recall correctly, a couple of the clones at PC were pretty close to the the gearing I ran in my Animal, which was 13:57.
At Davis, I run 13:59, which is 4.54, so a 14:63 or 64, or 15:68 would be similar This may be a bit low for a clone, but it might be a good starting point...
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Post by Brad Wunder on Jun 11, 2009 17:54:55 GMT -5
It just occurred to me that considering none of the BSCs have a tach (that I am aware of) basing gear selection on what they are running may not get you to your target RPM as we really don't know if they are over or under that value nor by how much.
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Post by paulskirocks on Jun 11, 2009 18:39:11 GMT -5
It just occurred to me that considering none of the BSCs have a tach (that I am aware of) basing gear selection on what they are running may not get you to your target RPM as we really don't know if they are over or under that value nor by how much. True. When I tried Duffy's clone powered kart, it pretty much ran out of gas around the start finish line. I was afraid to keep it flat footed, but it seemed like it just stops revving at some point, unlike my Animal that just keeps going til it grenades. On the other hand, there was not much bottom end, so I get the feeling that the fastest way around the track in a clone may get you at max rpm well before the first turn. I think the valves start floating when the clones reach max rpm, thus acting like a rev limiter... |
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Post by norcalacr on Jun 12, 2009 9:19:35 GMT -5
I hope to have the tach working for the weekend. To be honest though it's at the bottom of the list.
When I set up the clone for the kids I purchased an 18T driver. I calculated that this would keep me in the 62T - 69T range of gears I already owned. I sent the kids out with a 18/65 combo.
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Post by speedrome on Jun 12, 2009 10:23:10 GMT -5
18/65 is 3.61:1.. about 50mph is what that works out to at 5500rpm. Does the kart sound like it is accelerating till the end of the straight or does it run out of steam 1/2 way down? A tach is pretty important especially in the stockers as they dont have very much margin for error. Even though the clones are cheap to replace im sure the local tracks are NOT gonna like multiple oil downs from over revving these things.
Also, Just something to think about, using the larger rear gears can sometimes be problematic for curb shots and kicking chains.. Smaller rear gear sets can help avoid this..
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Post by norcalacr on Jun 12, 2009 14:27:53 GMT -5
Float the valves? I was happy the kids ran fast enough to engage the clutch.  |
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Post by paulskirocks on Jun 12, 2009 14:30:15 GMT -5
Float the valves? I was happy the kids ran fast enough to engage the clutch. ;D LOLing out loud! |
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Post by speedrome on Jun 12, 2009 17:20:46 GMT -5
Float the valves? I was happy the kids ran fast enough to engage the clutch. I should have recognized that dry wit... Scott B I presume, its been awhile bud. So your saying the apple doesnt fall to far from the tree then.. ;D |
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Post by norcalacr on Jun 12, 2009 18:35:18 GMT -5
I think "nut" would be a better analogy...
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Post by Simon on Jun 13, 2009 9:57:26 GMT -5
Thanks for the numbers guys, I have 15/55 on there at the moment which is around 3.6, so I think I'm in the ball park. I might go and pick up a 57 today as I'm not the lightest guy, and the poor clone thing might need some help pulling me out the corners ;-)
I'll borrow the Mychron off Daniel's HPV-1, so at least I'll have some rev data to look at.
BTW - I have never run a kart on a track before, so tomorrow will be a learning experience ... hopefully I'll not provide too much entertainment for onlookers.
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