[Rob Kozakowski]

One correction to Aaron’s post – it’s not a certified engine builder who builds and seals the LO206 – it’s the Briggs factory that does it, and does it only once before the engine goes out the door.  There’s no “re-sealing”.

Back to the question…

Reality #1 – as EXCELLENT a job as Briggs does in providing a level playing field, with GREAT rules, and tight manufacturing tolerances and specifications for every LO206 that goes out the door, there is always some possibility (however small) that some engines will be ever so slightly better or worse performers than others.  If you can acknowledge that fact, there is at least in theory, the possibility that there are some engines today that are faster than some engines built 5 years ago.

Reality #2 – even if you acknowledge Reality #1, unless you are paranoid or into conspiracies, there is no empirical evidence to suggest that any production batch has resulted in a better or worse engine than any other production batch, going back to the first engine produced.  The only people I hear suggest otherwise are those who are not winning – and while I hate to judge, I’d say they’re making excuses.  The guys who are winning have proven over and over with consistency that any (properly maintained) engine you stick on is capable of winning.

The LO206 is the best engine program ever introduced for kart racing.

[Rob Kozakowski]

Marty, what about a LO206, with a 6100 rpm (or thereabouts) rev limiter?  There is no “more” than 6100 rpm, so “more revs” doesn’t necessarily mean faster.

The answer Walt wants to know is whether you are better hitting the rev limiter and keeping your foot planted when you do (staying on the limiter) or backing off slightly and staying below the limiter?

I think the question comes from some rev-limited racing classes, where the electronics have an almost punitive effect if you hit the rev-limiter, where it might drop the revs several (hundred) rpm’s below the “limit”, slowing you down, before they climb to the “limit” again.

In the Briggs, the limiter just holds you at about 6100 rpm – there is no drop in engine or rolling speed.  Everyone I know (including some seriously fast LO206 racers) keeps their right foot planted.

[Rob Kozakowski]

My thoughts…

$3,000 for a “newer” shifter to go racing with would be tough to find.

But for autocross, you can probably get away with an older kart… which “can” save you money and allow you to find what you’re looking for if you’re patient.  I say “can” save you money because while some older karts have been well maintained (what you want), many haven’t, and by the time you get them prepped, you’re often better off with a newer kart from a cost perspective.

I don’t know much about autocrossing with karts, but several reasons why I would suggest an older kart are that I don’t think they require updated bodyworks and bumpers, and you might be able to get away with engines, and engine accessories (pipes, silencers, airboxes, carb, etc) that aren’t legal anymore in some of the karting orgs, etc.

As long as the brakes and the engine are solid and nothing on the kart is bent, you should be ok to autocross.

[Rob Kozakowski]

If it’s a LO206, keep your foot planted.

[Rob Kozakowski]

I’m no expert.  But there is some very recent advice out there from some of the best that I’ve shared below, where you’ll find one very important and consistent talking point – minimizing the steering inputs…

From David Cole’s latest On-Track article:

“One piece of input that Boswell had for me was to slow my hands down and provide less input into the wheel. He compared me to driving a dirt car, turning the wheel multiple times through a corner rather than a consistent, smooth process from entry to apex to exit.”

From David Sera’s latest Deadly Kart newsletter:

“To be a smooth driver, you need to be aware of the steering inputs you are making and ensure it’s minimal on flowing corners. This will enable the kart to grip to its full potential and your mistakes will be minimal.

When holding the steering wheel, a 9-3 hand placement is the safest option. Also straighter arms when sitting in the kart will minimise the inputs placed on the wheel.”

 

I’d suggest it’s easiest to understand how this applies on a real fast (no lift) corner, where most of us at some point have added too much steering input and caused the kart to suddenly transfer weight, turn violently, and scrub huge speed, etc.

Where it’s harder to really understand for the less experienced guys (and even seasoned guys like me have a hard time applying it) is probably on the slow, tight corners.  In order to get around these corners, you need to get the correct amount of steering input combined with good timing thereof, especially on initial turn-in, to get the kart to jack and unload the inside rear tire properly, or else the kart won’t handle properly, often leading to chasing chassis setup, when the handling issues are actually due to bad driving.  Too much input, and you get loose… too little, you push.  Beyond that point, you want to remove steering input very smoothly.  Basically, it’s a fast, but smooth initial turn-in (get the kart to jack), followed by a very smooth and consistent removal of steering input (allowing the kart to roll around the corner and to settle the rear back down smoothly without robbing horsepower), while also being mindful of when you get back on the throttle (if it’s too early and with too much steering input still applied, you’ll scrub speed).   For a slower corner, minimizing input doesn’t necessarily mean that the steering input is the same throughout the entire corner (feeling like a perfect semi-circle might not really be best), rather that the process is very smooth right from the transition from straight to initial turn-in, on to the removal of steering input.

The reality is that without any visual of what you’re experiencing and not knowing the profile of the corner(s) you’re talking about, it’s nearly impossible to say whether your traction issues are driver-induced (poor steering, braking, throttle inputs, or line selection), or chassis-induced, or some combo thereof.

However, in my experience, as well as based on the advice above, I would disagree completely with your idea that you want to be constantly counter-steering.

[Rob Kozakowski]

This is one time where Canada’s karting scene has had an influence on the US market.

The Eastern Canadian 4-cycle scene has been very competitive for a long time.  The big Canadian Birel, CRG and Tony (and some other) dealers recognized the ability to sell more karts by offering a “made for 4-cycle” product years ago, and worked with the factories to provide a product that worked well with a 4-cycle engine (first Honda, then Briggs).

This isn’t as much a case of Birel, CRG and Tony putting their “factory” efforts into the products as it the dealers putting in the effort to get the factories to build a kart for their markets, and making refinements when necessary.

For example, the CRG “Tork” or RS-4 and RS-5, was also called the PSL RS-4 or RS-5 because CRG built those karts for PSL when PSL was a huge CRG dealer.  When these karts first arrived in Western Canada in the hands of some drivers who brought them from the East, the biggest Western Canadian CRG dealer didn’t even know what they were because the Western Canadian market was focused on 2-cycle at the time.

These chassis have been refined over the years, and other brands have made chassis to suit the market as well (most notably of late, K&K, which is 100% focused on 4-cycle chassis).

These chassis are specifically designed to work with the ASN Canada 4-cycle rules, which mandate a 50″ max width and 180mm rear wheel.

When the rules are opened up to 55″ width and 210mm rear wheels and wider tires, it seems that either a 4-cycle specific chassis or a 2-cycle (TAG) chassis are pretty much on par with each other… the 4-cycle chassis are built for 4-cycle power, while the 2-cycle chassis are designed to be run at the wider track widths.

If you are buying a brand new kart for LO206, I would go with a 4-cycle chassis because of the lower cost.  The big differences are they generally use lower-spec brakes, less “beefy” 17mm (instead of 25mm) front spindles, 8mm (instead of 10mm kingpins), only have 2 (instead of 3) rear axle bearings, use 40mm (instead of 50mm) axles, and generally use more aluminum than magnesium components, cheaper steering wheels (i.e. is a $275 steering wheel – about 10% of the cost of some complete 4-cycle karts – really necessary?), etc. to keep the cost down.  Some chassis go down to 28mm tubing (or some combo of 28/30), but others are all 30mm.

[Rob Kozakowski]

If you are at all nostalgic, it’s hard to argue against the Top 8 from that 2006 list:

1. Lynn Haddock

2. Kyle Adkins

3. Lake Speed

4. Scott Pruett

5. Mark Dismore

6. Ron Emmick

7. Kathy Hartman

8. Duffy Livingstone

I’d almost argue that North American (sprint) karting needs to be broken up into 2 “eras”.  The first extends from the beginnings to the early 90’s, when most of the karts were American-made.  The names above absolutely define that era.

To me, the “modern” era began when the Euro-made karts really took over. I’m biased because I used to race a bit with the Italian Motors guys, but from the “modern” era, my pick as the best goes to Michael Valiante.  I think the greatest 3-way battle we’ve experienced in this era was the Formula A days between him and 2 other greats whom I’d rank right behind him – Phil Giebler and Patrick Long.  What separates MV from the other 2 for me was his success in Shifters in addition to the direct drive stuff.

[Rob Kozakowski]

Yep, Wine Country Motorsports is great for “better quality / higher end” helmets in that area.

You can probably use your Shoei as long as it meets the minimum Snell rating (not sure of the age of your helmet).

As for the helmet “debate”… Price isn’t everything when it comes to the relative safety of a helmet.  Snell / SFI / FIA rating isn’t everything when it comes to the relative safety of a helmet either.

The Snell rating is simply a bare minimum test that has to be passed.  Nobody knows by how much any helmet exceeds that rating.

Once you get past that hurdle, fit is the next most important.  A helmet that will pop off your head when you go tumbling is useless.  I’ve had a cheaper G-Force helmet that fit great when I bought it, but the foam padding inside was of such low quality that after 2 days in it, the foam had been compressed so much that the helmet wobbled around on my head.  It went in the garbage.

After that, I’d say it’s a bit of a crap-shoot… a more expensive helmet might be safer (see my example above for what you can get with cheaper helmets), but it might not.

A more expensive helmet will generally be lighter (which I factor into safety, especially so for kids), it will probably have more “bells and whistles” (probably not much to do with safety), and it will probably be better assembled with better quality materials (which may or may not impact on safety – again, refer to my example of a cheap helmet above).

I’d guess about 80-90% of the more serious karters are wearing Arai or Bell which will fall in the $500-700+ price range (there are a few other higher-end brands out there too), depending on which one fits the shape of their heads.  Yes, they’re a little pricier than some, but I think most of us would absolutely argue that we are getting great value for our money based on the fit and overall quality, and we wouldn’t buy anything less.  Once you’ve gone with a better quality helmet, there is really no turning back.

 

[Rob Kozakowski]

At this point, you’ll probably “like” the one with the most comfortable seat…

As the others said, find a chassis that is supported by a local shop and learn to drive it.  Then learn to tune it a bit.

Once you’ve made it that far, then worry about which chassis you want as your next kart.

[Rob Kozakowski]

The 2 most important things are the stopwatch and how your gear selection might affect race strategy… sometimes the gear that gives you the fastest lap time on your own will allow someone else to make an easier pass down a straight or with the draft and block you in the corners, making it harder to gain the position back from them.

Apart from that, “highest RPM at the end of the longest straight” may or may not apply – it is generally a good starting point, but where you go from there depends on the engine and the track.  And it depends on how you define “highest RPM”… point being that you’ll always hit your highest RPM at the end of the longest straight, even if you have the “wrong” gear.  The key here is knowing your engine’s “maximum potential RPM”.

As for my observations with the engines I’m most familiar with…

With the traditional 100cc 2-cycles, without any form of rev-limiter, more often than not, if you hit the engine’s max potential RPM just before the end of the longest straight, you were in the ballpark.

With a Briggs LO206 and it’s 6100 RPM “hard” rev-limiter, it can be all over the map.  There are some tracks where you will want to hit the rev-limiter in the middle of the straight, some where you will want to hit it almost immediately upon getting onto the straight, and others where you will want to barely hit it at all.

With a Rotax Max, which is rev-limited as much with ignition timing as anything, it’s again more like the Briggs.  There are some tracks where you’ll be fastest only pulling 12,500 RPM, even though the engine can hit 14,500+.

It all goes back to starting somewhere and testing to see what gets you the best results.  Daryle’s advice is great.  As he says, drop a couple teeth, and see what the stop watch says.  If it was the wrong way, add a couple teeth.

The only other comment I’ll add is that if your carb isn’t properly tuned, you may never hit your max potential RPM, so you could end up chasing gearing when your real problem lies somewhere else.

[Rob Kozakowski]

Maybe battery?  Bad / loose connection between the terminals and wiring harness?  Or enough juice to start it and run without any load on the stand, but not on the track under load?  Are you charging it before and between sessions?

[Rob Kozakowski]

I’d definitely want the H2O sensor in there… I’ve seen a few Rotax Max engines suffer major (expensive) damage from overheating that could be avoided, mostly due to lack of water or circulation (forgetting to put water in; a leak in the system – either hole in the rad or poorly connected hoses; or a bad internal water pump – maybe from leaving water in when it freezes). Running with less that ideal cooling (too much tape on the rad) generally won’t cause major damage, but will cause a decrease in performance.

I could live without a tach – let the stopwatch be your guide on that… however the tach wire is the cheapest part of a mychron, so I don’t see why you wouldn’t hook that up.

[Rob Kozakowski]

Lou – Check this out for some info…

http://eknclassic.com/viewtopic.php?t=16486&sid=68510323a9ecca02774885e14c87dc6b

[Rob Kozakowski]

Early PTK’s may have been the Zartarian-designed “Tracker” chassis (later KRT), built by MW, then PTK went to CRG, then OTK, if I’m not mistaken.  This looks like an older one.

[Rob Kozakowski]

I would try to add an additional crank sensor gasket (Rotax part# 431 500<span style=”color: #000000; font-family: ‘Open Sans’, Arial, Helvetica, san-serif;”><span style=”font-size: 13px; line-height: normal;”>)</span></span>

It was a common “fix” for a lot of people in our area

[Rob Kozakowski]

Gary is 100% correct.  Mychron for lap times.  Gear for best lap times (and/or raceability – you might need to consider drafting and strategy of where it’s easiest to make a pass or how to defend against a pass) regardless of where or when you’re on the rev limiter.  GPS is nice to have, but you have to be able to understand what it’s telling you to really make use of it (another thing to learn and an additional level of commitment, but useful for those who are in it to be the best – like Gary).

[Rob Kozakowski]

Yep, many Intrepid parts are interchangeable with Italkart and Praga, for example.

[Rob Kozakowski]

You can also check out kartdavid.com

They definitely do newer Intrepid kits and have templates for all bodywork styles

[Rob Kozakowski]

If you were running Rotax on Mojo tires, OTK is literally hard to beat… but still beatable.

For other classes, pick a newish chassis of any make and color, and it seems you’ve got a shot… if you can drive and tune.

[Rob Kozakowski]

Here’s the link to the FP7…

https://dl.dropboxusercontent.com/u/61580731/Templates/FP7%20Template.pdf

[Rob Kozakowski]

Check out http://www.kartdavid.com/templates

They have templates for all types of kart bodywork if you want to design your own graphics, and from what I’ve seen first-hand, the quality of their end product is excellent

[Rob Kozakowski]

They’re bigger, and definitely not as “pretty” or form-fitting (which can be a benefit because you don’t have to align things perfectly, etc), but you can find small atv covers (the bigger ones are “too” loose) at places like Walmart for a lot less money than kart covers.

They have enough elastic that they won’t fall off (shove some of the “excess” under the tires for better cover, and less slop/bulkiness), and unlike a tarp (which I’ve used before and is a pain), you don’t have to devise other ways to secure things so it doesn’t fall off.

[Rob Kozakowski]

Why set a target for max rpm?  It might be different at every track.

Instead, target minimum lap time – that is always the goal no matter what track.

[Rob Kozakowski]

Wider wheel will reduce sidewall flex.  With the tire rolling over on the sidewall less, you’ll reduce grip and free up the rear.  I think there may also be a 214 mm option.

It’s a very small adjustment… most people probably won’t even notice.

[Rob Kozakowski]

One approach that COULD work with hard tires (especially if they’re hard enough that you can slide the kart, without getting excess side bite that causes you to hop, etc) and a difficulty in rotating the kart enough is to “toss” the kart into the corner and use the brakes to rotate the kart…

Hard to describe the mechanics of how to do it, but you basically want to brake real late and lock the rear end up just as you’re turning in… almost like you’re starting to put the kart into a spin, or almost like drifting… instead of letting the front end lead with the back following, you want the back end to do the rotating, by letting it slide… you may need to modulate the brake and throttle, with a little counter-steering, to get the weight transfer you need and getting on the throttle as early as you can on exit with a late apex.

[Author]

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