Brief update on FJ spec motor proposal

[Scott Boito]

Well I was not privy to the initial discussions, but I know the idea has been floating around for probably years by now. The reasons I've seen mentioned are:

1. 2-strokes are loud and belch lots of blue smoke.
2. 2-strokes (usually) do not have on-board battery starters, so stalling on the line and/or on course causes event delays.
3. having so many engine options inevitably leads to some kids/karts being more competitive than others.
4. a spec motor puts all the kids on equal footing so that driving can be the only focus of the kids and parents.

There are probably more. I won't comment on any of them other than to say send in your letters on the proposal (published in the October Fasttrack, http://scca.cdn.racersites.com/prod/assets/11-fastrack-oct.pdf).

To address your comments on mounting the WF to the chassis, I share your concern, but have been told that there is a mount (or a few mounts) to help with it. It's important to note that there is a long sunset planned for the 2-strokes, but we need some letters to get an idea what folks think would be an appropriate timeline to phase out the 2-strokes (if, in fact, the proposal gets approved).

In short, write a letter with your concerns and ideas. We could use the ideas and suggestions.

Thanks, Scott
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KM #68 - Haase/Honda kart
BetterOffRacing
Member of the SCCA KAC

[Danny Kao]

Matt,

Scott is 100% correct and the reason he listed are the main reasons why. (Even though Scott is new to the KAC, I have a feeling that he is 100% up to speed now. )

We realize there is an engine mounting issue, especially with cadet chassis. The intention is also for parents to purchase one kart and it can last throughout JA and JB years; so for parents that are new to the class, they can perhaps get an adult chassis to begin with. But this doesn't resolved the problem if you already are running a cadet chassis.

This is where is sunset rule comes in. I can't speak for anyone else; but my opinion on the sunset rule is it has to be long enough so if you already have a non WF motor and you are starting in JA this year, you can run at the National with the same motor until you "retire" from JA. If you are entering JB and have a cadet chassis, the sunset rule will last long enough so you can run the same cadet chassis until you retire from JB. In order to do so, the sunset rule has to expire at 2016; which is what I am proposing in the rule set.

I realize this is a long sunset rule; and please remember that Junior rules can change at the moments notice by the decision of board of directors and SEB, so KAC really dont' have the final say on it and we can only propose it. I believe the longer sunset rule will protect the existing equipment investment by the parents. I really hate to see the parents "have to" buy a WF and I really rather see the parents "want to" buy a WF. By having the longer sunset rule it will make the transition better in many ways.

Also, the current proposal does not apply to local events and it's for National events only. I hope folks will follow suit if the program ran well Nationally; but there is no mandate to force this rule upon the local events. I do hope by 2016, 2 strokes are out of the local competition as well and the motor choices become WF, Raptor, and Clones; but that's just my wishful thinking. For now there is no spec motor proposal at the local level as far as I know.

I hope this answers some of your concerns. Basically, if the sunset rule stands, you are good regardless what you are running as long as it meets current rules. But we hope you would consider running the motor we proposed in the spec rule for the reason Scott listed above.

BTW, I am not the spokesperson for Briggs nor they pay me. I only get benefited if you purchase Microsoft products.

[Matt Miskoe]

OK, I'm learning some things here, which is always good.

I don't disagree that simplfying the options makes it easier to get into racing. I've done enough road racing in cars to understand that.

So more questions.

Why is the slide restrictor proposed? Why not a simple flat plate? The oval guys use these, (my son did a couple of years of this) they are color coded by size and you can walk around the paddock & see that it's installed. Both types have to be removed and measured to be verified for legality, but w/ the Animal/WF motor you are often taking the carb off to flush it out between events anyway. Having watched the video I think swapping a flat plate restrictor is no harder, possibly faster. I'm curious to the advantage of the slide restrictor. No re-jetting?

In my opinion, I would allow blue printing. This allows many more options for a motor to be repaired if damaged. It also can lower the costs for those chasing horsepower. Looking at what the Spec Miata and Showroom Stock classes do in road racing, they build 3 or 4 (or 5 or 6) motors, dyno them all, then pick the best one. I've heard of people weighing every pistion/rod in dealer's stock in all of North America to get a matched set. Besides, how would you enforce a no-blueprinting rule, all the parts would be within spec?



Does anyone have details on what motor mounts that allow a Briggs motor to fit on a Cadet chassis originally intented for a RH drive? I studied the chassis I have in the shop last night & it will be easier to move the axle (lengthen the track length) than modify the offending frame parts. It comes down to the sprocket being the limiting factor.

I now understand what you're doing and need to figure out what route to go. Thanks for your insights on this. I wish I'd known more about chassis when I bought this one, I would have done something different if I'd known the trouble of fitting 4 stroke motors on it.

Thanks
Matt

[Scott Boito]

Matt,
The plate restrictor has been the subject of much debate. Lots of folks have had lots of problems tuning with the intake restrictor. The slide is much preferable as it eliminates the tuning issues. The proposal will include Briggs supplying a tool to easily check compliance that will be made available to all junior kart-running regions. And for the JB kids, it will be pretty easy to tell if the restrictor is not present.

I agree on the blue-printing since it would be impossible or at least very difficult to tell anyway. But as Briggs has told us, it should also lead to very little since their tolerances on the motor are very tight already.

And don't worry too much about the chassis you have now versus one that might work better in the future. I found that my tiny junior driver (Kieran) actually fit better in a full-size chassis than he did in a cadet, so ditched that one after one season. Little is permanent in this game...
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KM #68 - Haase/Honda kart
BetterOffRacing
Member of the SCCA KAC

[Danny Kao]

I hate to agree with Scott every time, but he is right!

With the intake restrictor we currently allowed, the engine gets flooded at WOT. We even have parents limit the throttle opening to just over 1/2 by using cable stop to avoid carb flooding with the intake restrictor. With the throttle slide restrictor, the stumbling problem goes away entirely. We spoke with Brigg's Director of Racing and he pretty much stated that the best way to go is a slide restrictor. Also, Briggs racing is going to provide the entire throttle restrictor kit, including check tool and carb locking cap free of charge for JB racers. I am pretty they are doing so because they believe that's the best solution to limit HP for their product.

We have until June to ratify the rule for a 2013 implementation. We don't have that much time, but we certain have enough time to come up with a sample list of what chassis can accommodate WF and how to mount it. As soon as the rule is through the SEB we will have installation instruction of some sort ready. I know this might sound ambitious, but I think it can be done... So Scott, who should we put to work?

[Jason Vehige]

For Matt and any other FJ or potential FJ parents... read over the proposed changes on this matter and PLEASE PLEASE use the link below to share your thoughts..... Discussions on this board are great but only "letters" submitted through the link are official comments for the KAC and SEB.

http://www.sebscca.com/
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Jason Vehige

08 Gillard Charlotte / SGM sl204
05 Vanspeed Sirio / SGM sl204

[Joe Ricard]

I mounted a WF on a Birel C28 Cadet. Took a bit of fanagling to get 2 seat struts installed but it did work. Used a Burris 2 piece mount.
Gearing was 17/63 for bigger courses.
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Arrow AX-8/ Rotax Sr.

[Steve Ekstrand]

When I picked up Robert's Tony Kart Rocky Cadet it had a WF mounted. I'd have kept it if there had been a decent option to keep it running in FJB.

It mounted fine. The right side pod had to be cut. The seat uprights were bent slightly to the left and the seat was offset left. That did make a slightly awkward angle to the steering wheel.

I've been talking about this issue a lot with my local parents. Robert and I are having a great experience so far with our KT100. But we're still in learn to drive a faster kart with a high stall clutch (kidlet just turned . We haven't pushed for every last ounce of power out of it til the piston seizes.

Still, I support a quick move to the Briggs WF. Sure, leave the local option open for existing motors regionally, but for national events, pick the spec and bring it on. If the KT100 stays competitive at the national level then people are still going to buying them. And how do you really manipulate it so it isn't competitive? Adding a bunch of weight gets ridiculous and difficult. And heavy to lift!!!

I'd just as soon see National events entirely Briggs WF in 2013. Then I can buy my kidlet a new suit.... Four days running total on the brand new suit and its back is all covered in two stroke oil. I hate that stuff....

I've seen decent used WF's for $600. If you're running a Yamaha right now you can get money for the engine. Starters bring very good money. For National level families it doesn't have to be a huge layout. You can always spend more of course. At least with the WF as spec I don't see the risk of huge expenditures like we saw last year on the Yamaha's.

[Tom Reynolds]

A couple of things that may or may not have been mentioned (I didn't see them).

The SEB is pushing a 4 stroke agenda for the reasons listed above, we are advising them how to do this but again, we advise them on what their ultimate goals are. I happen to agree with them on this point but I can tell you the recent adult 4stroke stuff we published is higher on their list compared to ours (mine).

Briggs is against the flat plate restrictor (explained technically to us by them) which really ended that debate for us. Since they didn't create the slide restrictor but immediately jumped on it and offered to produce/provide them at no cost, it became more than obvious this was the best choice.

Keeping the SCCA aligned with karting orgs is the goal, but often it can't happen given some restrictions we can't control such as performance expectations for insurance purposes. We've cornered ourselves with the current KM "mod moto" to avoid tech issues, but makes one of the most competitive packages something that doesn't exist anywhere else and the genie is out of the bottle. With that fresh in our mind, we are moving forward on the WF design with caution.

A big thanks to Danny and several members not on the KAC providing a lot of their time and resources to weigh in on the topic both with opinions and data/dynos.

[Dale Seeley]

It's my hope that the sunset rule applies only to local/regional events, the National events will require the WF.

The sunset rule is a great band-aid to get the kids through the regional events, but for National events, where it gets nutty, do the right thing and rip the band-aid off quickly.

There's no way I'm subjecting myself and son to the BS that happened last year again for an autocross experience.

[Robbie Nelson]

[Robbie Nelson]

[Joe Ricard]

Agree with Dale once again.

If there is no requirement for WF only at any national event I will throw on my freshly rebuilt stock gas raptor @ 245 pounds and let it eat. I am confident the Raptor is going to whoop the restricted WF. We will be running both packages heads up this weekend. Probably throw in a drag race with video just for kicks.
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Arrow AX-8/ Rotax Sr.

[Danny Kao]

[Joe Ricard]

Got the throttle restrictor stop bushing (can't figure what to call it but that is what does). took about 3 minutes to install on one of our WF's

Fired on 1st pull on a cold motor. No biggy as the stop doesn't come into play at idle. Slight bog off idle when going to full throttle but that is sorta common with most WF's till you get the needle just right. But over all it ran OK

Then fired the Raptor on it's 1st go after rebuild. Litterally closed the side cover put oil in it and fired. Dang I love the sound of a Raptor with a nice header. Crisp cean instant throttle response.

I'll race them this weekend even if it's in the school parking lot.
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Arrow AX-8/ Rotax Sr.