OK Classes in USA Slated for 2021

In Formula A, ICA and ICC we would have racks of engines at European races, when racing for a manufacturer. But at the British Championships it was usually 3-5 and you knew ahead of time which two you were going to race. Sure some people turned up with racks but it didn’t make them win.

Additionally most of the time, they were off the shelf units that were tuned (within the regulations). You could do that yourself or you could pay varying amounts of money to a tuner to tune. And i want to clarify, I mean a tuner, not someone who just pulls out a standard piston, hones a barrel and puts a standard piston back in. One of my major bugs in the first years of rotax and x30 was calling the rebuilders tuners when they aren’t legally allowed (or talented enough) to tune.

Like Alan said, the initial issue with rotax was the variance in the tolerance of different parts meant you could mix and match parts to make a super engine. IF you could afford to buy 20+ engines and a dyno to run through all the combinations. Its supposed to be better now with tighter manufacturing tolerances but it might just be that fewer people race rotax now.

Tag onto, that you weren’t tied to a manufacturer or parts. There was nothing stopping you using IAME parts in a vortex engine (if it fit).

So in summary engines were cheaper, parts where cheaper, and you could do the work yourself if you had the skill set. I baulk at how expensive parts are for the commercial classes. You’ll always have people turning up with tonnes of material (chassis, engines, carbs) because if people can afford it they will. The difference with the old classes is you didn’t need to, you COULD tune your way better then the people who did have tonnes of material. I know of a few British champions who won on a tenth of the budget of the biggest spender and that was a super competitive championship.

Can someone send me the link? And is this still gonna happen?

I haven’t heard anything since this PR was sent out. Then COVID happened.

Forgive my ignorance, but what is the big difference between OK and say TaG. They look to be the same basic design with a few obvious exceptions like no starter, no clutch/direct drive and the addition of a power valve. I can see how ditching the starter and clutch can save weight and reduce rotating mass. The addition of a power valve widens the power band. Is OK just a Maxed Out version of a TaG engine? I am guessing the biggest draw would be the added power from one of the engines. Is this class considered an Open Class with loose restrictions on components?

OK is the international standard, top-tier single-speed class in the world. It isn’t a TaG (touch-and-go) engine because it doesn’t have a starter.

in addition to what TJ said.

Senior OK is a class that is based upon a single set of technical specifications published by the FIA (its kart division was known as the CIK but now I think it’s just FIA Karting but it’s still part of the nomenclature ) that manufactirers build to and then compete against each other with in the major INternational karting events with the World Karting Championship being the pinnacle.

Essential it works like F1. The problem with karting is we’ve had multiple ‘name’ changes for the pinnacle class that represented significant changes to the technical regulations. It’s a ball ache to get your head around.

In the 80s the pinnacle class was known as Formula K (135cc a/c) then Formula Super A (100cc a/c with slide carb) to Formula A to KF (125cc with powervalve starter and clutch) and then OK (125cc,powervalve, no clutch). There’s also sub-divisions within this structure to add to the complexity hence why you might read about ICA and KF2. Senior OK however has no sub-divisions… it’s one single formula largely (junior has diff rev limit and no powervalve).

Because it’s multi-make racing manufacturers have no desire to be long-life and reliable so can develop with performance in mind. It’s why a Senior OK produces 40+ horsepower. They are heavily development based and thus you’ll see tuning and updates. It’s pretty awesome if you like racing.

TaG is kind of a weird term because it essentially describes any kart engine with a start motor and clutch (and KF for example includes starter motors and clutches in its technical regulations). But it also describes a set of engines that are produced by manufacturers for the ‘leisure market’ - X30, MAX, Leopard etc… and these engines are not designed to race against other manufacturers but within their own single-make grid, but they get lumped together because local market dynamics might force them to do so because there is not much else choice.

TaG is kind of a misnomer really.

Sorry for the use of TaG, I was thinking of the basic design of a Leopard or ROK. Just trying to wrap my head around the rule set. My comparison was not meant to be an insult. I do not have the foreknowledge of previous rules and regulations for the best comparison. Was curious more about their construction. Induction Type? Number of Ports? Rev limiter? Pipe design? Carb Selection? Are all of these relatively open? I assume displacement is fixed for a given Class?

Definitely sounds like the Constructor’s Cup in Formula 1. Also sounds like even among the Elite Drivers, only those with Factory backing would be able to Compete for any length of time as Cost would prohibit privateers.

[quote=“GregF, post:28, topic:5319, full:true”]Definitely sounds like the Constructor’s Cup in Formula 1. Also sounds like even among the Elite Drivers, only those with Factory backing would be able to Compete for any length of time as Cost would prohibit privateers.

That’s a long complex issue. I do not think single-make racing has been particularly good for privateers. I could buy and tune two ICA engines and go race out the back of a car at national level for less than one of the $20,000 Rotax MAX engines that did trhe rounds when it was the biggest class in the UK… Elite doesn’t mean expensive and ‘commercial’ class doesn’t mean cheap.

A Senior OK is

Reed Valve
24mm Carb
Direct Drive
Water cooled
16k rev limit (I think)

That’s exactly why these top-level classes never really take off here in the States. ICA used to do okay here with reasonable entries, I imagine because the engine itself was largely pretty simple so there wasn’t a bunch of ancillary stuff like starters and clutches and batteries tacked onto it. But once KF came in, no one really had any interest in running it. A few series tried it and I can remember maybe 10 entries at most. Which isn’t a lot of fun when you’re spending $4k+ on an engine.

The OK formula seems to be less of a pain in the ass and more friendly to the user, but still, these classes thrive mostly on factory supported teams, like you see at the world level in Europe. I drove an OK engine once and it was so much fun and ballistic fast compared to the X30 I was driving at the time. But the US market tends to hold grudges against failed efforts, and most people I talk to are perfectly happy to continue running X30 and the other established engine packages rather than bring in yet another new engine package and class structure. From a driver perspective, I talked to a lot of the top X30 guys in the country and I think a lot of us would enjoy driving OK more than X30, but lots of those top-tier drivers aren’t the ones footing the bill for engine rebuilds etc.

You’re good. It’s a confusing moniker sometimes even covers some shifter engines that have an electric starter.

TaG USA which uses an acronym of Touch and Go promoting a direct drive class. Confusing doesn’t describe ha


I guess without an American Based Manufacturer, there is not much in the way of Local Support. I think it would stand a better chance if Karting had a Haase of sorts.

I think it is also that the U.S. market is far more diversified than the European market. Here there are lots of ways to Go Fast. You don’t hear about Dirt, Drag and Enduro happening in Europe. Closest thing might be Midget. Seems like Sprint Karts are their predominant flavor so everyone falls in line with the latest and greatest products the manufacturers are marketing. I think the U.S. formula is more Driver Based than Product Based. That is why the most of the successful series here have frozen changes for x number of years.

My experience in Auto Racing has seen the same formula over and over from SCCA, to IMSA and even World Challenge. Different manufacturers can compete, but restrictions to keep the playing field level like weight or displacement. There is room for broader limitations. An example here might be the Petite LeMans or 24 Hr of Daytona among the Prototype Classes, but even in those races you have more Limited Classes too like GT.

I agree! Within the TaG USA guidelines they outline specs for various parts of the engine along with Weight restrictions for each. It seems the general TaG 125 is fading in favor of Engine Specific Series like X30, ROK Cup, KA100 and VLR100 or in some regions PRD.

Exactly. As stated earlier, there would be constant updates from the manufacturers and anyone wanting to stay competitive would be forced to change or be left behind. This kind of cost is only worth it if you can recoup it somewhere else. For the manufacturers it’s in product sales. For the Teams, it may be Services or Support. For the Privateer Racer, there is no recovery other than Prize Purse or Endorsement Deals. Bring on the Goodies & Pennzoil commercials…lol!

What happens if I buy 200 X30s, mix and match until I have the perfect engine? If the rules don’t change and there’s no updates how do you beat me?

Not saying people don’t do that and there aren’t differences, but to be fair, the X30 parity seems to be pretty good from the factory. I won a few fairly high-level races on a stock X30, on power-sensitive tracks.

Some things have moved on and builders are maybe finding key things here and there, but I have rented and raced engines from multiple builders and they are all comparable.

Parity is pretty good with the karting specific engines from Vortex and IAME now. The ROI on buying a ton of engines to mix and match is pretty low for those.

From my perspective, being a serious recreational kart racer, the engine performance differences between X30/KA100 motors seems like “noise” and there is more time to be gained by driving and getting the chassis right than piecing together a special motor.

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12 posts were split to a new topic: Discuss: Europe\US … Spec\Multi Manufacturer