Viability of a multi-manufacturer, 100cc TaG Class?

At my local club’s first race a month ago, we had two KAs run with us KT100s. I run the direct drive pipe (DD87) at 360 pounds and I believe the KAs also were at 360. I was the front running KT and was about 7 tenths off the KA all day. The lightest weight I could make would be about 330 but I don’t know if that would get me those 7 tenths to directly compete against the KAs. Do the KAs run a restrictive for the junior classes? I feel like that would really be the only way to make them equal to the KT but then I feel that defeats the purpose of the KA and makes it less attractive.

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There is a restricted exhaust manifold for the juniors, it’s 19MM as opposed to 39MM for seniors. From what I understand it would be fairly easy to bore out the junior manifold to be somewhere in between those two. I know the club I run at (Thompson Kart Raceway) plans on doing some testing of different sizes. They run a pretty unique 2 cycle class where basically any 100cc 2 cycle engine is eligible, and weights are based on the engine/exhaust combo. It’s worked alright so far, but I’m concerned about getting anywhere close to parity with the KA/VLR. At the moment before these were brought in Yamaha Can was 325#, Yamaha SRY 365#, and Yamaha Open Pipe 415#. I also agree restricting the KA takes away from the appeal of the engine.

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My thought, for what it’s worth up here buried under snow…

Take the approach that the KT100 is simply a cheap and cheerful way to get into 100cc racing. Trying to get total parity with a (pretty prehistoric) piston port against reed is going to be difficult, leave it as “best effort” and go from there. Keep the KT as a super cheap way to just get out there and learn the ropes in a decent sized grid.

Parity with the VLR and KA100. I guess we’ll have to see. Certainly more feasible than trying to get the KT on par with those reeds though.


One thing that could be cool would be to figure out a formula (Call it 100 Sport or something) with specific engine packages that could be applied on a broader scale with specific engine packages that more folks can enjoy 100cc racing.
Of course alarm bells of what happened with TaG go off immediately, but I think given what we’ve (hopefully) learned from that experience, maybe something could work well. Something along the lines of an annual regional event.

Anyone know the HP and Torque of the VLR Engine?

That’s kind of what the SoCal F100 series tried doing. You could run a KT, KPV, or HPV engine with a variety of exhausts and the BoP was weight. Their rules even allowed for TaG engines to run in the same class with a restrictor and a heavy weight. We modeled our rules after that but just for piston port. I think down south they have been finding some success with KA/KPV/KT but I don’t know specifics. We ran with the KAs at our first club race because there were only 2 KAs.

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Thanks Daniel. I know somebody here mentioned a 100cc format in Cali somewhere, but I couldn’t remember where or who.

[quote=“KartingIsLife, post:4, topic:1875, full:true”] My biggest concern here is for the local tracks that have adopted the KA and now will have racers asking for Rok VLR. Can they be raced together?


Tri-C Karting has their 100cc TaG Classes already listed as combined with the IAME KA-100 and the new ROK 100.


Do you think the KT100, Rok, and KA would be more equal on a high speed, more full throttle track? I feel like the KA has more torque, right? So faster on a tight track?

The KA and VLR have more everything, everywhere compared to your typical piped KT. I don’t think a higher doeee track will help.

Makes sense. This weekend there is a race that’s part of a mini travel series between my local club and two other nearby tracks, but I don’t think very many, if any, other KT guys will be out there. Wondering how equal it would be against the KAs if I took all my weight off (since it wouldn’t matter if no one else was in my class). Probably will end up just skipping for now.

Can you add a little nitro within the rules. That would pep it up. Proceed with caution of course, it generates a lot of heat.

The stories from the '70s and '80s about hot fuel are pretty wild. Can you imagine guys rebuilding the carb every time they came off the track now?

The problem is there is no association to set rules that issues driver licenses like FIA /CIK. That is where the power comes from. Want to race and progress from a club license to a National license to an International license, then you have to participate in sanctioned events that comply with official rules. I actually don’t recall there being “outlaw” races when I lived in Germany. In the USA, since any Tom, Dick or Harry can license, sanction, and run a series they can make their rules.

Not sure how all these series get their insurance, but if they had to comply with a set of rules and a set homologation, requiring an official driver’s license to participate to get their insurance, there would not be an issue.

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I see motor grouping/classes as separate to driver licensing. To give my perspectives on Europe vs USA on having a single body like the CIK…

You have to remember in Europe you can travel only a couple of hundred miles to need an international license. In the US… it’s thousands in most cases.

Really only about 400-500 racers out of 20,000 would need a national license. With maybe 50 of them needing an international one. So it doesn’t matter in the US. It’s not worth the effort of enforcement for so few drivers. There’s really no incentive.

Things have changed a lot. (@Alan_Dove can give better details than I can). Until the late 90’s in Europe, CIK sanctioned the majority (practically all) of “competition” Karting.

Then two things happened.

Anti-competition ruling in the EU court allowed FIA drivers to run in non FIA competition without risking their license.

Rotax Max came along and turned the karting demographic upside down.

When it came to product/market fit…the CIK’s response (KF) was tragically off base but was still forced on ASNs

One problem… most kart racers didn’t want it.

Racers, teams spoke with their wallets, the CIK became out of touch with karting beyond their “ladder” bubble. “Independent” karting became a thing and since then I’d wager a significant number of racers are no longer running under an ASN.

It’s not really insurance’s place to enforce that though.

I’m open to correction, but my understanding is that most Karting insurance in the US is underwritten by a Lloyd’s of London… Then brokered by a handful of groups. WKA, NKA, IRA and AKTPA/TAG (from memory).

In short, the effort required to enforce or even incentivize a system like that in the US is not worth it and insurance companies have their own standards
in place for safety based on their assessment of risk.

That said, SKUSA do have a licensing system in place.

Problem is that there’s little incentive for them to do so. They each have their own small markets which are generally married with local karting businesses. They rely on each other to survive, so they do what’s best for them.

In WA… you know how that goes :joy:
Now don’t get me wrong, I’m not saying it doesn’t suck.

The only way you can get close to uniformity is to offer an incentive of some sort to racers and tracks. This is why the Briggs 206 has done so well.

  • The simplicity appeals to new and existing racers, especially with how people value their time these days.

  • It’s not super fast so you can have newcomers drive it and have fun right away.

  • The parity (always relative of course) is pretty good.

  • It has marketing and a brand behind it, including prizes and benefits for racers and tracks. Also the prizes

  • go beyond just awarding the winners of racers.

  • The rulebook and tech make it easy for tracks to implement.

You need all of these for widespread adoption.

It’s a natural consequence of the high demand for single-make racing. Manufacturers aren’t going to stop building engines, they have to react to market demand. Instead of 6 manufacturers racing in one class we now have 6 different classes or concepts. Complexity is just transferred from one place to the other. Even the cure ‘TaG’ just made everything even more complicated.

The nature of racing makes it very difficult to manufacturers to sustain a monopoly as well which can reduce some of the inherent complexity single-make racing brings for new people to karting. Single-make customers only really allow a certain amount of development, so even if a manufacturers grabs a big chunk of the market with a product which is miles better than everything else (like Rotax did, for all my 100cc I can recognise why the MAX was popular) over time it can’t out-innovate the competition without destroying its customer base. The rivals eventually catch up and everything splinters again. Rotax couldn’t innovate within the MAX market share so tried RM1 and it didn’t work. They’ve tried the electric thing, but that seems to have been invisible this year.

There’s not real solution to this. The suggestion of emulating the CIK, in my view, doesn’t represent something realistic. Europe isn’t a bastion of simplicity. It’s just as complicated and sporadic as the states. Europe isn’t a homogeneous market and there is just as much diversity in classes and products. In the UK tracks are actually de-affiliating with the MSA and embracing the IKR concept. So they get their own insurance and write their own rules.

But back to the point. To me it seems perfectly logical a manufacturer has to build and sell engines. If they don’t they go out of business.

Curious - do you the karting consuming collective out there think if they took the KA design and said this is the standard/blueprint or whatever you call the exact technical spec for an engine and said to manufacturers build your engines to this standard (homologation), this standard would be in place for 10 years, it would work?

Basically same as ICA, KF, OK homologation but for a simpler engine and it remains in place for 10 years.

I think that’s a decent idea, but that could make it difficult for anyone who already bought a KA100. Since that’s the benchmark, I see all the other manufacturers creating better motors. Suddenly all the drivers who got into KA when it first came out are screwed in terms of competitiveness.

I think if we were to make a formula for 100cc air cooled engines, we would have to define these parameters before any motors come out.

For these specifically, if it happens that the Vortex, IAME, IM, and whoever else are all competitive with each other, I would see no problem with running them in the same class. However, since there are no current guidelines on specs of the motors, this could turn into what used to be the TaG days when there were 4 different motors that each run better at different tracks, and then you end up with 4 motors per driver and costs going way up, at least from what I’ve heard that’s what it was like.

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This absolutely would work and it’s how every true multi-engine class SHOULD be implemented.

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