'Turbo' in MiniMax

[Ihor Bilyy]

I'm sure all involved in MiniMax class already know what is turbo. For those who don't know it is an additional kick of performance after 12500 RPM in Rotax FR125 with both exhaust and intake restrictors. It is called Turbo because it is significant power boost for Mini and not everyone can get it in a race.
I don't know how people feel about it. I think Rotax should do something about it. Why?

1. It makes not all engines equal. Going against Rotax spirit of engine equality. Feels more like SuperKF, where a lot of money spent to find/develop better engine.

2. It is not safe when you have somebody getting boost to 14000 RPM passing others with 12500, especially if you have several karts getting different level of performance gain. Sometimes it surprises driver, sometimes you have to run over certain part of the track to get it (New Castle, old 103rd track).

3. It provokes driver to jump in a seat and it is allowed for some series and it is not for others (FKCS, FWT yes, some local series, Nationals no).

Here is great video posted by Carl Cottrell on FaceBook from last FKCS race in Jacksonville. Check it out. http://www.youtube.com/watch?v=MxGgNJAKlrI
I wish, we all have electronic restriction at 12000 and then it is all about driver and chassis.

[Dale Seeley]

It is about driver and chassis Ihor.

Put Michael in the seat every weekend between races, and he'll get better at coaxing it past the 12, 341 barrier.

Sort out the chassis a little bit better and the engine won't have to fight it on the approach to 12,341.

Then it's up to you to get the carb jetted correctly. If you were running the jet setup you claimed you were at the last CMP event, 160+ at 90.1 ADR, then you were far too rich.

I enjoy seeing 14K on the Mychron, it means that we're getting pretty close to getting it right. Since we don't get it every lap, I know that something isn't as consistant as it needs to be (driver), and we have something to work on.

We're getting "turbo" at barnseville now. Not every lap though....which means there is still room for improvement.

If you want to compete with drivers like the Sargeants, Perry, Hunt, Stroll, O'Ward, Kirkwood, you have to put in the time and effort they do. I know that even if we won the race in your (Carl's) video, it wouldn't have been much of an accomplishment. It would have been cool, but if RDD showed up with Minimax drivers, it would have been a completely different weekend.

[Ihor Bilyy]

If you see RPM sits at 12450 flat for 10 seconds (Race Studio) and you going straight, its not about driver and chassis.

Yes, I was too rich in CMP (155, not 160) both times, when Michael won without turbo and when he was coming back to finish 6th after 1 turn accident (also without turbo). After Nationals, with many days of practice, I started to understand jetting much better (stopped using Palm version of MaxJet), but we also saw flat rpm line on Race Studio very often. Yes, I tried different front end setup to eliminate front tires drag. Yes, we were reaching 12500 before half of the straight in New Castle and No turbo at all. What we got is 13000 one turn before after dropping right tire out of the track slightly. This trick was observed too late (Saturday morning) to be any help for us. People were getting 14000 regularly, some more often, some just a few times.

[Dale Seeley]

nm

[angus hunt]

'turbo' is why we are moving up early to juniors.
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[jim rogero]

Ihor, I agree with what you are saying, but like others have said, " more testing in that area will help". What we found was we had it on Friday (test day) and lost it on Sunday (until the final). After digging through the data I found the problem. Ashley's exit MPH out of the bowl on to the straight was 1.4 mph less than Friday. I worked on the chassis to improve the bowl exit speed , ie lossened the rear. It was too loose the first 2 laps but was perfect the rest of the race. She hit turbo every lap afterward and went from 17th or 18th (last) to 3rd with fast time by 6 or 7 tenths.
Kart racing or any racing will always have these challenges.
I also set the "red light" on the mycron to come on at 12,000 so she would hop at 12,200 to 12,400.

P.S. We only have 1 mini max race left...more new things to learn.

In 35+ years in karting the "claiming rule" has only ruined or eliminated the class that it was put in place.

[Ihor Bilyy]

I'm failing to understand how exit speed can play a key role in getting turbo in straight like in Jacksonville. Lets say the exit speed was lower, others will have higher RPM and will close on me (5 kart lengths closer). Now, both are at 12500, fixed gear, same speed, same distance between karts. There is only 1 difference - kart with good exit speed had 12500 RPM 2 seconds longer and it helped him to shorted the distance between karts.
Having exactly the same engines, both karts will reach whatever RPM they can and keep the same distance. Where am I wrong?

[jim rogero]

[Dale Seeley]

That's crazy talk Jim !

It's always easier to claim that hard work and seat time is an unfair advantage.

He's going to keep pumping you for information until you tell him what he's doing wrong.

[Ihor Bilyy]

Jim, can you achieve it without hopping in a seat? I was always telling my son he is not jumping good enough. Maybe its time to sign him for a gym.

The original point of this thread was to show there is a situation in class, which does not exists in any other classes. And there are "minimax" engines and the rest fr125.

[Ihor Bilyy]

[jim rogero]

[jim rogero]

[Dale Seeley]

[angus hunt]

i totally agree with ihor on this.

the 'turbo' is unique to minimax only. what it's doing is hurting national competition. this is supposed to be a spec class where engines are equal. in brazil, they hand out engines. i don't think you can get regular turbo from a stock motor. i bought 2 and pretty much topped out at 12300. i bought a 'minimax' motor and immediately was running 12500's and within a very little while of working through jetting was getting turbo and 13800-14100. then we were at a point of needing to re-set up kart for increased entry speed into a couple corners because of the boost at end of straights.

i'd much rather see minimax motors 'levelled'.

like i said, this is why we're moving up early. i don't want to spend my limited racing budget just trying to figure out turbo. i'd rather spend it on driving lessons, and look to the future. which is not minimax
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