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 Post subject: Re: Rear axle location
PostPosted: Sat Nov 23, 2019 7:42 pm 
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Joined: Thu Oct 03, 2002 10:34 am
Posts: 2925
Location: Wauwatosa, WI
The TANGENT continues, the movie was worth the watch. Mike, did the Kart racing thing with both sons.

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Have Fun ; )

David Dewhurst
CenDiv Milwaukee Region
F Prod #14


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 Post subject: Re: Rear axle location
PostPosted: Sun Nov 24, 2019 9:50 am 
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Joined: Fri Dec 23, 2011 6:59 am
Posts: 1310
Location: Spring Hill, FL.
Good choice . Cant buy that time back.

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Mike Ogren/Protech Racing, http://www.FWDracingguide.com http://www.ogren-engineering.com/ 352.428-8983 mogren@tampabay.rr.com


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 Post subject: Re: Rear axle location
PostPosted: Sun Nov 24, 2019 11:58 am 
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Joined: Sun Oct 08, 2017 2:58 pm
Posts: 37
Location: Dousman, WI
Given the money I'm spending on racing includes infrastructure spending (I'm working on an engine dyno installation) I'm aghast at the idea of karts taking more money. ;)

But hey, if the kid wants to go racing, I get to dip into the "kid activities" budget rather than solely my "dad fun stuff" budget. :D


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 Post subject: Re: Rear axle location
PostPosted: Mon Nov 25, 2019 6:31 am 
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Joined: Sun Jan 23, 2011 4:54 am
Posts: 1962
Protech Racing wrote:
If you guys think you're spending money on your cars, wait until the karts bite.
Whatever it takes .

That's why we're sticking with 4 strokes. It's the SRF/ FM of karting. $550 engine w/ a sealed bottom end. blueprinted head rebuild is $125, do it every ~40hrs or so.
tires are $220/set and last 2-3 weekends, depending on the track and event profile. old tires get pulled and used for practice, and last ~300 laps before they're trash.
4 strokes and the cadet classes use hard tires, so grip is relatively low- only 2.5Gs in the corners or so. a quality chassis will last 5+ years with a 4 stroke engine. the softer the better here since tire grip is low and they need a soft chassis to grip it up in the turns.


Want to go fast and blow money? then stick a 2 stroke on it. tires last a day- but still only $240/ set. you go through $50 of fuel in a day and $20 in oil, fluids, etc. Engine is $3500 new and a $750 rebuild every 10 hours of runtime- basically 3 races. Win a regional (or bigger race), and you roll out of tech with your engine in pieces. podium finish will cost you an engine rebuild. the poor guys put a new head gasket on it and race again. The rich guys swap engines and send the old engine back to their builder in a box with a $750 check enclosed.
A chassis will last 1-2 seasons before they start losing time, depending on the roughness of the tracks and chassis fatigue.

Really want to go fast? buy a shifter kart. have 10 weekends on the chassis? It's done, buy a new one. $3000 and transfer your old parts, or throw the whole thing away for $7000.

Want to win a national championship and work a real job? better have a support crew to haul your crap across the country while you fly in, race, and fly home. The support, coaching, and parts required to be competitive at a national tour will run $100,000/ year.. These are the kids that go to F4/ F3 when they turn 16.
My kids will still be running Briggs at the local tracks.

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Matt Blehm
Houston Region
EP 1st Gen RX7
STU Nissan 240SX


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 Post subject: Re: Rear axle location
PostPosted: Mon Nov 25, 2019 7:59 am 
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Joined: Fri Dec 23, 2011 6:59 am
Posts: 1310
Location: Spring Hill, FL.
We started with the "Kid karts" . The only rule was the power train parameters. So I used an old Coyote RR kart and installed the legal engine , gear ,tires etc.
Aluminum axle, removed all the seals from the bearings /total loss mobil one bearing holes drilled in the bearing carriers etc. Set the alignment by rolling it . The Kid flew in it.
He pulled into the pits and was giving his Mom a tour of his kart. He said this pedal stays full down and this one you use when coming into the pits.
When he spun a couple of times on old tires ( set to about 25# ) Mon asked why he spun. Old tires. I said .
"Get some new tires now "
The club eventually demanded that we bring a short whee base kart , that looked like the rest. I cut 9 in out of the Coyote and it went even faster . I had to cut the rear cross tube to soften it up and used a stack of steak knives for
adjustment , clamped to the cut .
I thought the tech guy's head was gunna explode . So after that the engine went home in a box every week .
Good times ..
WE cut the tires to size on a lathe adding a narrow straight line section in the middle with cornering areas that the tire would lean on. Trimmed the fronts the same to lighten them up. Totally out of control .
I would totally do it again .

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Mike Ogren/Protech Racing, http://www.FWDracingguide.com http://www.ogren-engineering.com/ 352.428-8983 mogren@tampabay.rr.com


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 Post subject: Re: Rear axle location
PostPosted: Mon Nov 25, 2019 9:00 am 
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Joined: Sun Jan 23, 2011 4:54 am
Posts: 1962
Protech Racing wrote:
We started with the "Kid karts" . The only rule was the power train parameters. So I used an old Coyote RR kart and installed the legal engine , gear ,tires etc.
Aluminum axle, removed all the seals from the bearings /total loss mobil one bearing holes drilled in the bearing carriers etc. Set the alignment by rolling it . The Kid flew in it.
He pulled into the pits and was giving his Mom a tour of his kart. He said this pedal stays full down and this one you use when coming into the pits.
When he spun a couple of times on old tires ( set to about 25# ) Mon asked why he spun. Old tires. I said .
"Get some new tires now "
The club eventually demanded that we bring a short whee base kart , that looked like the rest. I cut 9 in out of the Coyote and it went even faster . I had to cut the rear cross tube to soften it up and used a stack of steak knives for
adjustment , clamped to the cut .
I thought the tech guy's head was gunna explode . So after that the engine went home in a box every week .
Good times ..
WE cut the tires to size on a lathe adding a narrow straight line section in the middle with cornering areas that the tire would lean on. Trimmed the fronts the same to lighten them up. Totally out of control .
I would totally do it again .

yeah, further digression........

Most of that isn't allowed now. :)
Kart chassis (even the kids) have to be CIK/ FIA homologated, and there are max/min wheelbase and track width requirements. all karts must run homologated bodywork as well since they are considered impact structures and the saftey zealots now own the rulebook. for national tour races and many others, the front bumpers are mounted with pushback brackets, so if you bump into someone on track you have a tattletale. any time you roll into tech after a session with the bumper pushed back, it's a 5 sec overall time penalty applied at end of the race, regardless of how it happened.
No tire modification or prep allowed on the road racing karts- at least not in my area. If tire tech is in question at a big race, they put a sniffer on the tires. for regional races, some series require you to buy tires at the beginning of the event and they record serial numbers. no cutting or grooving is legal. pressures are 20psi max for the kid classes.

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Matt Blehm
Houston Region
EP 1st Gen RX7
STU Nissan 240SX


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