[Jim Derrig]

Sam,  must have missed the MX reference in your bio.  Yes, MX is good training for karting.  A few people claim karting is a step down.  A lot of TaG and shifter guys seem to be MX guys who got tired of breaking bones.

Brandon, a “MY09” is just the designation for the most recent version of the Leopard (model year 2009).  The revisions are reliability oriented and performance between the years is the same.

[Jim Derrig]

[quote quote=15500] I’ve read several times that the shifter kart is a steep learning curve. I’m curious – what makes that such a steep curve? Focusing on shifting while focusing on line choice? Chassis set up?  [/quote]

Everything happens faster and there’s more “everything” to do.  My Skip Barber instructor said the next step up from a shifter is a full Indy Car.  If you think auto crossing a WRX has made you ready for the next step below an Indy car, then by all means get a shifter.  ;)  If, on the other hand,  you suspect that you possess a somewhat lower level of skill, start in a TaG or even a 4-stroke.

[Jim Derrig]

I run a Leopard but have driven both.  Have to agree that overall and on average the Rotax is more reliable.  The starters suck on both motors.

But it’s still racing and I’ve known Rotax owners who’ve broken down constantly and Leopard owners who never seem to have to do a thing.  Anyone who buys a used racing engine banking on it being low maintenance is deluding himself.   That being the case,  I’d just go with what is most popular at the track you are running at or with the used kart package that gives you the best overall deal.

I wouldn’t worry much about the chassis, so long as there is a current importer.  Look at the chassis running in the supernates.  Any of those will work and will be plenty competitive at the club level.

Serious advice:  Buy a ribtec or other quality rib vest.  Do NOT try and save money here by buying something on eBay or from K-1.

Some of the Leopard expenses can be offset with home rebuilds, unlike the sealed Rotax.   I’ve done  4 at this point and that motor is about as complex as box of corn flakes.  Also, 20 hours (rough Leopard rebuild cycle) is a lot of seat time.  Assuming you are not burning up practice miles and are just club racing, it will last you that entire 10 race season.

Tires?  My first racing season I ran about 9 races plus occasional practice days and, due to a promise to my wife, did it on two sets of tires.  Since I was slow anyway it didn’t make much difference.

[Jim Derrig]

Well, total dominance by Vettel once again.  Even more dominating than schuey in the early 2000’s, I think, because the field is deeper and Vettel doesn’t have the tire advantage  the “Ferraristones” gave to Schumacher.

[Jim Derrig]

The original question is a bit ambiguous, because he could be asking what the redline is or he could be asking what max rpm gives the fastest time.  I’ll assume he’s looking for a redline.  It’s about 17,000, though you definitely don’t want to spend much time there.

At some tracks I hit 16,000 and a little bit more.  If I’m bumping up near the redline that’s definitely an indication that I want to look at gearing down, as I’m likely not spending enough time in the fat part of the power band.

[Jim Derrig]

The friction between the links is greater with an o-ring chain, so it takes a little more power to bend the chain around the sprockets.  This power is not transferred to the rear wheels, so you can say the chain “robs some horsepower.”

[Jim Derrig]

Vettel

Webber

Rosberg

[Jim Derrig]

Vettel

Webber

Alonso

[Jim Derrig]

I competed in that race last year and the driver stopped at one of the worst possible spots on the track for a pile up.  Not only is it at the end of a straight, but the surface changes there to create some “interesting” braking issues.  I received a bent frame in one race as proof.

Really sad that both the driver and the competitor that stopped to congratulate him were DQ’d after so much effort and success, but the move could not be tolerated.  I wonder if the drivers could have been given the option of paying a fine, however.

[Jim Derrig]

Dalton, asking for “anything about karting” is a bit like asking for “anything about football.”  The question is so broad that a 10,000 word answer still wouldn’t be complete.  You might try going to amazon.com and looking for books on karting, like “Karting, everything you need to know” by memo gidley.

To answer your specific question, yes, a 6’1 245 pound person can fit in a kart, though you wouldn’t want to be any bigger than that.  And you can have plenty of fun.  I know people your size who race karts.  However, you will almost undoubtedly will not win races or even be particularly competitive, as the ideal kart racer is about 5’6″ 145 lbs, much like a Formula One racer.  In fact, F1 racers use karts to train and practice in the off season.  I tell all the big guys, “remember those little guys in high school that we used to push around on the football field?  Well, this sport is their revenge.”

 

 

[Jim Derrig]

<div class=”d4p-bbp-quote-title”>Dave Rutter wrote:</div>
My question to you fathers out there – is it reasonable to move right from Yamaha to Shifter with one season experience?

Without knowing the driver, this question cannot be answered with any degree of confidence.  And if it can’t be answered with any degree of confidence, then it is irresponsible to answer it “yes.”

But we’re racers so its part of our make up :)

I’ve raced shifters against 15 year olds who I trust on the track more than most 40 year olds.  I’ve raced shifters against 15 year olds who were fast as heck but were totally out of their element in terms of race craft and handling traffic.  Medical science says that until our early 20’s the part of our brain associated with making rational judgments is not fully developed.  That’s an average and there are many exceptions.  But playing the averages and considering only one year of experience, I’d say the question should be answered “no.”  Besides, TJ is dead on about developing technique slowly and with patience.

[Jim Derrig]

Vettel

Raikonnen

Alonso

[Jim Derrig]

Vettel

Alonso

Hamilton

[Jim Derrig]

Okay Juan, you got me.  My Leopards that originally came with push-button boxes must be interim models that can accept both stators.

[Jim Derrig]

I’m usually on the road about 6:00 a.m., so its classical music for the first hour or so.

Then a wide variety of thumping guitar stuff.  Hendrix, Cream, Foo Fighters, Soundgarden, etc.

Sorry, no 1980’s hair bands.

[Jim Derrig]

Juan and Tim are not correct.  The part number for all digital ignition selectra systems is the same.  As long as you have a key start ignition (which you do), it will fit either model of motor.

The 09 uses the same key start ignition as the 08.  It isn’t the 09/08 difference that’s the problem, it is that the analog (box) and digital (key start) systems are not the same.   If you have the key start ignition, it will fit an 08 and an  09 and either motor will run fine with it.

These two ignition systems will fit either engine model just fine with no modifications.  You just can’t swap parts between the two ignition systems.  For example, I recently forgot that little fact and bolted my key-start Selectra onto an older engine without swapping out the old-style stator.  Didn’t run so good.  Three minutes later–2 to swap out the stator and 1 to kick myself in the rear–it ran like a charm.

[Jim Derrig]

I lost a lot of respect for Vettel after that crap he pulled on Weber this year.  I’m not a great fan of team orders, but to manipulate team orders so as to take a win from a teammate?  That was really low.  In my mind he became just another prima donna,  egotistical athlete no better than those NBA jerks who scream and pound their chests when they score.

Have to disagree that Vettel only wins because of the car.  While having a Newey-designed car certainly is a significant advantage, let’s not forget that he won the Italian GP in a Toro Rosso.  Major, Schuey-Senna level talent.  And a jerk.

[Jim Derrig]

I give a triple thumbs up to floating sprocket hubs.  I was busting chains right and left until I switched to one.  Haven’t suffered a broken chain in 2 years.  A floating hub with o-ring chain is the way to go.  The carrier itself is just as reliable as a fixed one.

[Jim Derrig]

Yep, comcast.  I clearly recorded NBCSN, as their logo was regularly displayed on the recording.  the DVR retained the settings and I had the right times programed.  My wild guess is that there is some sort of local provider option to select alternate programing and comcast either is consciously exercising it or is clueless and isn’t hitting the right buttons.

[Jim Derrig]

Don’t know if anybody else had this problem with Spa, but NBCSN repeatedly said it would air at 7:30 am eastern and this also was published in the local paper but instead we got Lucas oil off road and then hunting.  No F1 all day.

[Jim Derrig]

vettel

Raikonnen

Hamilton

[Jim Derrig]

[quote quote=6635] I have driven my friends kt125 eagle kart. Not the same I know, but I love to race so I should be ok. (and it was too slow, especially down low) Can a shifter power-slide on MG reds in a hairpin or slow sweeper? How fast are these things? Motor is a cr125 ’95 head stock porting, ’99 ignition, RLV 4 exhaust, Wisco piston. [/quote]

How fast is a 125 shifter?  Well, my Skip Barber instructor said he thought the next step up from a shifter is an Indy car.  Regardless of whether he was exaggerating, it’s several levels of performance ahead of that E30 you’ve been auto crossing.

If a KT100 (there’s no such thing as a KT125) seemed slow “down low” that probably was because you were not carrying enough speed into the corner.  A competition kart, and really any open wheeler, will have a much higher entry speed than that tin top you’ve been driving.  For example, a 2.5 g mid corner transient is common in a kart and all but unachievable in a modified street car.   It’s a 2-stroke so you are not going to power your way out of a corner with low end torque.  Rather, you’ll carry way more speed into the turn and get on the throttle much earlier because the grip is so much higher and because you need to keep the revs up.

Can you “power slide” it?  Oh yea.  But be careful.  The polar moment of yaw inertia in these things is almost zero, so it will spin almost on a thought.

[Jim Derrig]

[quote quote=4988]The Simpson & Hans devices are made to prevent the head from going forward during impact (Earnhardt)which is the issue in an auto frontal type crash since the body is restrained by the seat belts. . . . [/quote]

I agree.  The primary reason for a HANS device is to prevent a basal skull fracture, where the skull snaps at the point it connects to the spine.  This caused by hyperextension, which in turn occurs because the seat belts stop the torso from moving, but the head/skull in not similarly restrained and thus continues to move forward.  The HANS device ties everything together so that the entire upper body now is restrained.

[Jim Derrig]

Aaron,  whatever the cause of your rib injury, I doubt it was from the seat being “too tight” as you state.  The rib injury likely is from the g-force of cornering.  You will experience exactly the same g-force no matter how tight the seat is.  In fact, if your seat is too loose you will be thrown back and forth between the seat sides, increasing the stress on your ribs.

The Tillet seat you have is very good.  I switched from one to a Ribtec for reasons unrelated to rib stress and the Ribtec was not a big improvement in that regard.  To the extent there was an improvement, it was because the Ribtec was a special “tall” model and at 6’2″ the extra seat hight has been helpful to me.  I doubt switching seats will help so long as the one you have is snug.

In my limited experience rib bruising and cracking is the result of pressure points, where the cornering stress is focused on too small an area of the ribs rather than being distributed over the entire side of the rib cage.  In my case, an off-brand rib vest created a pressure point because it was too short.  Switching to a ribtec vest made the problem go away.

[Jim Derrig]

The “trucks” were so slow on that track and there was so much slop in the driving that it reminded me of the Long Beach Gran Prix celebrity race.

[Author]

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