I am wondering why so many racers have had broken cranks and or crankcases and we have never broken a crank or a case ever?
Printable View
I am wondering why so many racers have had broken cranks and or crankcases and we have never broken a crank or a case ever?
High Cycle Fatigue is based on statistics and one data point is NOT STATISTICALLY SIGNIFICANT!!!!Quote:
Originally Posted by Jnovak
To get an FI 2-Stroke approved in this class and on the track will take at least 2-3 years. IMO a FI 2-Stroke is currently not cost effective or practical, especially if this is a Regional Class in 2-3 years. So, an FI 2-Stroke would be a bad Investment of both my time and money at this current point in time.Quote:
Originally Posted by Dan McMahan
The other reason I submitted this external jetting device rule was the constant talk about FI 2-Strokes Engines and how the carbureted engines can only be adjusted with discrete jets. These external jetting devices are relatively low cost, easy to use, and don’t have any electronics. In fact, the rule may need to be changed to Any Automated adjustment of external jetting devices is prohibited.
As long as you are trying to get ahead of the game. . .might as well suggest the wording to read: "any automated adjustment of devices that effect air/fuel ratio is prohibited."Quote:
Originally Posted by sathorp
That hopefully keeps an argument over what jetting devices are internal/external from starting. As well as keeping folks from jetting really fat and then introducing an adjustable air intake leak downstream of the carb.
Thanks for the suggestion. I don't think adding an automated control system is the right thing to do! It's going add cost and complexity. It's a Cost Benefit Analysis! Does the Benefit justify the added Cost and Complexity? Are you going to spend $5000 to research and build a prototype automated control system and get a 0.001 second reduction in lap time that you can’t even measure?Quote:
Originally Posted by Daryl DeArman
Nope. I don't believe it's the right thing to do either. I believe the solution is to either make it really easy for everybody to do (cockpit adjustable :thumbsup:) or make certain you don't have to get stupid creative to do so.Quote:
Originally Posted by sathorp
As to the reduction in lap times, I know you're speaking in hyperbole to make your point. However, the difference in lap time from a perfectly-tuned A:F ratio and one that is close enough is more than many might think.
However, I don't believe that to be the biggest advantage. The biggest advantage is having the proper tune every time without losing a session. 99% of SCCA racers don't spend enough time in the seat much less at a specific track to become truly proficient at the craft. All we are trying to do is get more proficient than the next guy. When one session can represent 20% of your track time on a given weekend, optimizing how you utilize that limited time is often the biggest advantage.
I was exaggerating to make my point!! I agree with all your points. What the reduction in lap time would be by making the adjustment manually in the cockpit vs. an automated system is still open in mind in terms benefit vs. cost.Quote:
Originally Posted by Daryl DeArman
From the 2020 GCR
9.1.1. Formula 500 (F500) Specifications
14. Snowmobile Derived Engines
A. Carburetors: The induction system is restricted to two (2) 38mm Mikuni VM 38 round slide carburetors (except AMW). No modifications are permitted to the carburetor bodies. The use of any jets or jet needles is permitted. External carburetor jetting devices such as Mikuni Power Jet, Thunder PowerJet, Dial-A-Jet, IntelAJet, or other similar devices may be used, provided they are plumbed to the float bowl and body of the carburetor for which they are installed. Cockpit adjustment of external jetting devices is prohibited. Any automated adjustment of devices that effect air/fuel ratio is prohibited.
These are the suggested changes to the rule based on the discussion so far (strike the words in yellow, add the words in red). Any other input?
Scott as someone who does contracts for a living my thought is you should spell out whether or not cockpit adjustable is ok. The SCCA philosophy as always been if doesn't say you can then you can't. You may also want to spell out if cockpit adjustable will be by mechanical or electronic means.
The language about automated adjustments works for me.
From the 2020 GCRQuote:
Originally Posted by Tom Grossmann
9.1.1. Formula 500 (F500) Specifications
14. Snowmobile Derived Engines
A. Carburetors: The induction system is restricted to two (2) 38mm Mikuni VM 38 round slide carburetors (except AMW). No modifications are permitted to the carburetor bodies. The use of any jets or jet needles is permitted. External carburetor jetting devices such as Mikuni Power Jet, Thunder PowerJet, Dial-A-Jet, IntelAJet, or other similar devices may be used, provided they are plumbed to the float bowl and body of the carburetor for which they are installed. Manual Cockpit adjustment of external jetting devices is allowed. prohibited Any automated adjustment of devices that effect air/fuel ratio is prohibited.
Tom, Thanks for your input! I've also written technical SOW's for large contracts and your right it takes some time to get the language right. Here are the changes (strike what's in yellow, add what's in red) I think the wording Manual Cockpit adjustment should work along with the last sentence.
If your turning a mechanical needle valve or a pot that controls an electronic servo valve it shouldn't matter if it's Mechanical or Electronic as long as it's Manual and not Automated.
Thanks for posting! This will certainly help new guys that want a new motor as well as others currently in the class. I didn't expect the price to be that high , but at least there's the option to purchase new motors!Quote:
Originally Posted by Richard-6
Quote:
Originally Posted by sathorp
I do not agree! An outlier data point can be very important in itself!
Quote:
Originally Posted by Jnovak
I don't care!!!
Go talk to the Crickets!!!
10 Hours - Crickets Chirping and Forest Ambience
https://www.youtube.com/watch?v=NOfVUBLKYQE
Richard:Quote:
Originally Posted by sathorp
I think this is the final language for this rule change. So, if you could write the letter to the CRB and submit this rule change it would be greatly appreciated. I have other things I need to get done this week.
Scott
Scott,Quote:
Originally Posted by sathorp
I think that this last suggestion is good. However I am no longer a SCCA member so I will not be submitting a rule change even though it is a good idea.
Richard
P.S. I already had the basic concepts for the auto tune on paper.
Okay, thanks for starting this thread and your input! For me personally I don't think the cockpit adjustment is going benefit me after reading about karts tuning while driving. I'll write this up and submit it to the CRB when I get some time! They could accept it as written, change it, or reject it.Quote:
Originally Posted by Richard-6
Scott
PS, if someone really wants auto tune then they'll have to make a rigorous technical & cost case for it and change the rule.
Go here
WWW.crbscca
it will take about 10 minutes
Quote:
Originally Posted by sathorp
Does anyone know if the SCCA CRB agrees the change the wording as proposed, can the change be implemented this year?
I seem to recall that the Board Of Directors once said that they would not change the rules in mid-year.
Richard
If the change is implemented it will not be immediate!Quote:
Originally Posted by Richard-6
Of course you can become an SCCA member.
They may have, but I'm thinking they changed that stance mid-year. ;)Quote:
Originally Posted by Richard-6
FASTRACK NEWS MAY 2020
CLUB RACING BOARD MINUTES | March 31, 2020
What Do You Think
F5
1. #28359 (Scott Thorp) Request for Cockpit Adjustment of External Jetting Devices
Should the rules allow cockpit adjustment of external jetting devices on two cycle cars?
Please reply via the letter log system.
Send all comments & input to the CRB Log System website: https://www.crbscca.com/
Over $6800 unprepared. No clutches etc.Quote:
Originally Posted by Richard-6
Just wrote a letter in support of letter 28359
Quote:
Originally Posted by Richard-6
Isn't the 593 HO in the link above different than the 593 approved for F500?
Cory
The May 2020 SportsCar had a article from the CRB on BoP - Balance of Performance.
What level Balance of Performance is the CRB attempting to implement on F500 ??????
I am still asking a serious question!Quote:
Originally Posted by sathorp
Why have we (Brian and i) NEVER broken a crankshaft?)
I am pretty sure that i know the answer.
I don't own a Rotax 593 Engine and I have no intention of ever owning a Rotax 593 engine.Quote:
Originally Posted by Jnovak
I also never plan to overrev any Rotax 2-Cycle Engine by approximately 10%. So, you may
have a serious question in your mind! But I have no interest what so ever in discussing Rotax
593 crankshaft breakage or High Cycle Fatigue of Rotax 593 Crankshafts with anyone.
You need to go find someone who owns a Rotax 593 engine and wants to discuss this issue
with you. Because I don't care, I own 10 Rotax 494 engine and 2 Rotax 493 engines I don’t
have crankshaft breakage problem!
Scott.
Exactly what do you think they're doing with the restrictor and weight adjustments? What adjustments do you think should be done above and beyond what they've been doing?Quote:
Originally Posted by mmi16
Runoffs winners
2014-two-stroke
2015-four stroke
2016-two-stroke
2017-four-stroke
2018-two-stroke
2019-four-stroke
Restrictor and /or weight changes for a two-stroke:
2014-2020 =0
As a curious bystander and a lover of the smell of Blendzall. . . what breakage problem do you have that warrants the need for 12 engines? Or is it just a collection to ensure the future needs of the class participants are met?Quote:
Originally Posted by sathorp
How many folks are actively campaigning that engine package?
The metric used is acceleratiopn from 60 to 100 mph in a straight line for casrs with the scca data aq system on the car.Quote:
Originally Posted by mmi16
However they have been ignoring that metric in F500 for years.
Scott the only problem with your thoughts on this is that the 593 engine as used in the F500 class is the defacto performance target for F500. With the current min weights for the 494 and the 593, the 494 would need about 110 hp and imo that is not possible under the current rules.Quote:
Originally Posted by sathorp
How many times do we have to go through this? There is NO STANDARD in the F500 class DeFaco or otherwise!!! The only standard that exists is in someones head! People just don't get it!
SCCA is not the problem, quit blaming SCCA, and the CRB!!!Quote:
Originally Posted by Jnovak
I'm still writing a reply, I'll have a reply latter today!Quote:
Originally Posted by Daryl DeArman
2 questions.Quote:
Originally Posted by sathorp
What is the problem?
Then why can't the 494 engines compete?
Quote:
Originally Posted by jnovak
Please Don't Feed the F500 Forum Troll!!!