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Robbie Nelson
Joined: 26 May 2008
Posts: 131
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 Posted: Mon Jan 16, 2012 5:16 pm Post subject: |
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Request Details
Title: Spec World Formula engine
Category: Kart
Class: FJB
Car: none
Request: My request is in regard to the proposed spec World Formula engine for FJA and FJB.
I have been running a F125 for about 3 years. I love it! My two kids have been running in FJC for the past two years. 2012 was time for a new class, chassis and engine for the kids. I have plans to attend Nationals in 2012, so I chose carefully.
I purchased a kart for my two kids just after Nationals. I bought a Birel cadet chassis (Jesse Seely's) with a KT100 mounted to it. I spent a fair bit of time deciding on that engine. Here are my main reasons for choosing the KT100.
1. There seems to be an issue running the World Formula in FJB with the restrictor. There may be a way to limit the carburetor slide's WOT position to help the issue. But none the less, it's an issue that I was not comfortable with.
2. The KT100 was the most popular engine in FJB at Nationals. There were NO World Formula engines in FJB at Nationals. This is second hand knowledge since I wasn't there.
3. I already have mixed 2 stroke gas for my F125. So, that's not an issue.
So, I went with the KT100. The kids haven't even race the kart yet and the SCCA is about the get rid of the engine.
Question:
How can the SCCA decide to spec an engine that was a no-show at Nationals? That's nuts if you ask me.
Now for my suggestion. Spec the slide in 2012 for the World Formula engine. If the slide fixes the issue and people are happy with the combo, plan to spec the engine in 2013. Then provide a sunset period of 3 year with no weight penalty.
Are you 100% sure the slide will fix the tuning/WOT issue? I'm not 100% sure of most things. I'm certianly not 100% sure of this fix. So, give it a year to make sure it works, then spec the engine. You can give full forewarning of the intention to spec the WF in 2013.
Why the long sunset period? My situation is the perfect example of why it's needed. I spent a significant amount of money to get a ready-to-go package for my children.
I understand the desire to go to a spec package 4-stroke. I like the concept. But I fear that you are going to run a bunch of folk off. Folks that already have signifigant money and time invested. If you spec the engine in 2012 with a weight penalty to the other engines, the kids (and maybe pissed off me) won't be coming to Nationals.
Thanks,
George "Robbie" Nelson
letter number #7136 |
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Tom Reynolds
Joined: 08 Jul 2008
Posts: 555
Location: United States, New Mexico, Albuquerque
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| Posted: Mon Jan 16, 2012 10:39 pm Post subject: |
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Where did you see the WF is the spec engine for any class any sooner than 2013?
The only other 4 stroke in FJB is the Raptor, which they haven't made a new one off the factory floor in a decade, it wasn't our first choice.
Yes we are sure about the new restrictor, Briggs is not only backing it, they are making it - I'm not sure we can get a much better endorsement than that (and they did not design it). |
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Joe Ricard
Joined: 23 Jun 2009
Posts: 869
Location: United States, Mississippi,
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| Posted: Tue Jan 17, 2012 6:13 am Post subject: |
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I really really hope that something is out in writing soon as it's time to put fuel in the tanks of JB karts geting ready for Dixie.
Weather here is perfect for dodging cones in parking lots. 
_________________
Arrow AX-8/ Rotax Sr. |
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Robbie Nelson
Joined: 26 May 2008
Posts: 131
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| Posted: Tue Jan 17, 2012 6:26 am Post subject: |
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| Tom Reynolds wrote: | | Yes we are sure about the new restrictor, Briggs is not only backing it, they are making it - I'm not sure we can get a much better endorsement than that (and they did not design it). |
Ok. But how can you make an engine spec when no one ran it the prior year because it wouldn't run right at WOT? Like I said, the grace/sunset period need so be there or you are going to run off and piss off a bunch of people. |
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Tom Reynolds
Joined: 08 Jul 2008
Posts: 555
Location: United States, New Mexico, Albuquerque
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| Posted: Tue Jan 17, 2012 7:07 am Post subject: |
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| Robbie Nelson wrote: | | Tom Reynolds wrote: | | Yes we are sure about the new restrictor, Briggs is not only backing it, they are making it - I'm not sure we can get a much better endorsement than that (and they did not design it). |
Ok. But how can you make an engine spec when no one ran it the prior year because it wouldn't run right at WOT? Like I said, the grace/sunset period need so be there or you are going to run off and piss off a bunch of people. |
Robbie, I did not see anyone running the new restrictor saying it doesn't run right at WOT or part throttle. This is because anyone complaining has not run it as it's new.
We put this out for comment, talked about it since June/July, so we could easily do this within the system based on the letters received in the system. Just keep a close eye on the fastracks to see what happens. At this point, nothing is changing for 2012 at all and the deadline for 2013 stuff is effectively June and by then we should have a lot more feedback on the setup. |
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Dale Seeley
Joined: 11 Nov 2005
Posts: 524
Location: United States, Georgia, Marietta
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| Posted: Tue Jan 17, 2012 7:50 am Post subject: |
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| Tom Reynolds wrote: |
the deadline for 2013 stuff is effectively June and by then we should have a lot more feedback on the setup. |
Actually, there is no deadline for the FJ classes, we've been told in the past that because they are not actual championship classes that the rules can be adjusted at any time the SEB feels it is appropriate. |
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Tom Reynolds
Joined: 08 Jul 2008
Posts: 555
Location: United States, New Mexico, Albuquerque
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| Posted: Tue Jan 17, 2012 7:59 am Post subject: |
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| Dale Seeley wrote: | | Actually, there is no deadline for the FJ classes, we've been told in the past that because they are not actual championship classes that the rules can be adjusted at any time the SEB feels it is appropriate. |
That's incorrect in this particular case. Competition adjustments for safety/equalization and tech bulletins can be at done at any time. Changes in the actual rule set such as this have the same process as the adult classes. Trust me, been there, done that. Obviously this is a delicate matter as it affect pocketbooks as much as it does competition. We all know we can't please everyone, but we are trying to get it as right as we can.
FWIW, you all are seeing most of the behind the scenes stuff, probably more so than any other AC provides on a public forum in the interest of providing better understanding to everyone how this works. I don't mind the objections, but statements like "how could you" really come off as offensive when the question should be "What is the reasoning behind this?" A lot of though goes into the planning, doesn't mean its perfect but its certainly not made without a lot of consideration from a lot of volunteers. The KAC is now made up of 7 members, all of the names you'd recognize if you ran nationals in F125 in the past few years. |
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Robbie Nelson
Joined: 26 May 2008
Posts: 131
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| Posted: Tue Jan 17, 2012 11:12 am Post subject: |
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| Tom Reynolds wrote: | | Robbie Nelson wrote: | | Tom Reynolds wrote: | | Yes we are sure about the new restrictor, Briggs is not only backing it, they are making it - I'm not sure we can get a much better endorsement than that (and they did not design it). |
Ok. But how can you make an engine spec when no one ran it the prior year because it wouldn't run right at WOT? Like I said, the grace/sunset period need so be there or you are going to run off and piss off a bunch of people. |
Robbie, I did not see anyone running the new restrictor saying it doesn't run right at WOT or part throttle. This is because anyone complaining has not run it as it's new. |
The restrictor that I'm referring to, is the intake restrictor that was require on FJB engines in 2011. IMO, this is why no one ran a WF in FJB at Nationals in 2011. The slide restrictor was not available or allowed in 2011.
BTW, on a completely other subject, IMO removing Fastrack from Sports Car was a dumb move. It was one of the few things I read in that magazine. Now I hardly crack the cover open. Yes, I know you can pay extra to get a copy. |
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Robbie Nelson
Joined: 26 May 2008
Posts: 131
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| Posted: Tue Jan 17, 2012 11:19 am Post subject: |
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| Tom Reynolds wrote: | | FWIW, you all are seeing most of the behind the scenes stuff, probably more so than any other AC provides on a public forum in the interest of providing better understanding to everyone how this works. I don't mind the objections, but statements like "how could you" really come off as offensive when the question should be "What is the reasoning behind this?" |
I mean no offence to the SEB or KAC. I didn't keep up with Fastrac and I know that's my fault. But this is a big change that I'm just now hearing about.
So, what was/is the reasoning in specing an engine package that up until now was not available? Are the slide restrictors even available to the public now? |
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Tom Reynolds
Joined: 08 Jul 2008
Posts: 555
Location: United States, New Mexico, Albuquerque
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| Posted: Tue Jan 17, 2012 11:24 am Post subject: |
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| Robbie Nelson wrote: | | So, what was/is the reasoning in specing an engine package that up until now was not available? Are the slide restrictors even available to the public now? |
The engine package originally proposed was the plate restrictor version. After reviewing that and thanks to 3rd party testing/R&D a slide restrictor option came available. Briggs offered to provide it, and should have some as early as next week I believe but that's strictly an estimate on my part. In the meantime you can (and many have) run the plate restrictor. |
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Robbie Nelson
Joined: 26 May 2008
Posts: 131
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| Posted: Tue Jan 17, 2012 12:41 pm Post subject: |
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| Tom Reynolds wrote: | | In the meantime you can (and many have) run the plate restrictor. |
If they know the secret of limiting the throttle slide opening, they might even be successful running the plate. I personally don't want to have to deal with knowing whether I have the throttle stop in the right spot or not.
Tom, why do you think no one ran the WF in FJB at nationals? I'm not being sarcastic here. I want to know your opinion.
BTW, I'm focusing on FJB because it will be my kids class. I'll leave FJA to those parents. I'll likely be able to switch to a WF before we get to FJA. |
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Tom Reynolds
Joined: 08 Jul 2008
Posts: 555
Location: United States, New Mexico, Albuquerque
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| Posted: Tue Jan 17, 2012 12:46 pm Post subject: |
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| Robbie Nelson wrote: | | Tom, why do you think no one ran the WF in FJB at nationals? I'm not being sarcastic here. I want to know your opinion. |
I can't say for sure but I would surely guess they thought the package they did run was more competitive, already available, etc. |
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Robbie Nelson
Joined: 26 May 2008
Posts: 131
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| Posted: Tue Jan 17, 2012 12:57 pm Post subject: |
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| Tom Reynolds wrote: | | I can't say for sure but I would surely guess they thought the package they did run was more competitive, already available, etc. |
Exactly. Which is why I recently purchased a KT100 with plans to start attending National level events.
This is the thread that scared me out of buying a WF: http://ekartingnews.com/viewtopic.php?t=99868
It was:
A. Buy a WF and do R&D to get the restrictor plate to work well.
B. Buy a KT100 and be competitive out of the box (driver talent excluded)
I did consider a WF. There's a couple of kids running one locally. |
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Danny Kao
Joined: 17 Nov 2008
Posts: 192
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| Posted: Tue Jan 17, 2012 1:25 pm Post subject: |
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Robbie, I am one the few people that actually saw the WF slide restrictor in action. I know now Joe Ricard also has and he can share some of his experience with you here if he likes to.
The air intake restrictor chokes the carb so under WOT, there is too much fuel and not enough air. The work around that I have seen is to put a throttle cable stop to allow the throttle to only open 1/2 way. Trey White ran that the first day at the Nationals but his kart broke (I don't remember why, I hope it's not because of the POS motor  ) Tom Regganie offered him the co-drive that's why you didn't see WF running in JB.
The throttle restrictor is a metal cylinder that you put inside the carb so it restricts the throttle opening by 0.590". It allows the venturi opening at a little over 50%. It's exactly like you go 1/2 throttle on your F125; except is running on a 4 stroke motor. Since the air intake is not messed with, the engine should run well at normal jetting. I have seen it run for about 2 hours, shut down and restarted multiple times. Never once the engine got cut off, or die under "heavy spins". The motor just kept idling and pull the way it's suppose to under 1/2 throttle.
Obviously we have to look for some "weak spots" of this setup. Since the restrictor is in place, you will never get the throttle to stuck in wide open; so the motor should be pretty save. The only other thing is the restrictor is metal, and your carb cap will constantly hit the top of the cap and if you don't set up your throttle stop on your right foot lever, eventually the top of the cap will receive wear. We have locking caps to allow some adjustment of the cap so cap wear is not going to that much of an issue as far as changing the venturi opening, which increases horsepower; but use your foot throttle stop and adjust properly can avoid this issue.
Other than that, I don't really see any big potential problem with this setup. Like Tom said, Briggs Racing endorses it! The restrictor was commissioned and paid for by a volunteer; it was designed by a top Briggs Racing motor builder at the recommendation of Briggs Racing. Briggs is making the restrictor, locking cap, and check tool and will provide a certain amount to all JB/WF owners for free as well as all the regions that have JB participants; and they are looking into contingency and rebates for the parents. I wouldn't think Briggs will spend the money and offer the incentives without some confidence that this solution works. (In facts, it has been working in their LO206 engine setup and they just haven't implement the same thing to the WF line yet; but now they are)
Hope this and Tom's replies help to answer some of your concerns. |
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Jason Vehige
Joined: 21 Apr 2006
Posts: 282
Location: United States, Tennessee, Nashville
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| Posted: Tue Jan 17, 2012 1:43 pm Post subject: |
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Thanks Robbie for submitting the letter to the SEB/KAC. Nice job on the Deep Freeze FTD 
_________________
Jason Vehige
08 Gillard Charlotte / SGM sl204
05 Vanspeed Sirio / SGM sl204 |
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