Track Tac

just a question

jcm900 said:
About 5 to 600 off on rpm
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not that I'm all that good at this stuff but; you're telling me you're losing 5 to 600 RPM with the same gear ratio? I certainly don't understand that!!

13/65 versus 14/70, those are the same gear ratio!! Even the most ardent believers in changing gear sets with the same ratio wouldn't claim that!
 
alvin l nunley said:
not that I'm all that good at this stuff but; you're telling me you're losing 5 to 600 RPM with the same gear ratio? I certainly don't understand that!!

13/65 versus 14/70, those are the same gear ratio!! Even the most ardent believers in changing gear sets with the same ratio wouldn't claim that!
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The thing is Al, most of us do understand that lol
 
gearing, ratio's, loosing or gaining rpm....it might not make sense on paper, but it does work Al. it's all in what the track can stand and what the driver is willing to commit to. while the 13/65 and 14/70 seem like the same ratio, and on paper they are....it's a big difference is how and when the engine spins up to speed and delivers the power to the rear wheels. at least that's my take on it. I've gone from a 18 to an 17 and found power available that I didn't have with the 18. of course this is seat of the pants math and you could probably prove me wrong with pen and paper.....but generally, we ain't got time at the track to think things out for too long. sometimes you just have to trust what your butt feels, what you know and more importantly....what works.
 
well I think we're going to throw the 13 on run hot laps in a heat race and just see where it fallsjust wanted to say thanks for everybody's input and I will let you know how it goes
 
Edit up front: It's tough to give advice with limited info. I read through only stuff you wrote above and used only what you said about gearing to write what I did.

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Reading what you wrote you only have a 65 and 70 to choose from.

I see the cheapest thing you can do to try something different is to buy a 67 and put it on with the 13 driver. Seems like anything below a 5.0 gear ratio is too much gear from what your saying. The 67 with the 13 will give you 5.154 making it possible for you to go faster then with the almost good, 14/70.

The net of it is if your almost good with the 14/70 and a pig with more gear, chances are making it possible to go a little faster when your skill increases or you fix some other on track problem, will have a better chance of happening and helping.

> Maybe someone else will say yeah, maybe I'm right about what to try.

What gear to change to most often nets out to, hey if ya want to go faster you HAVE to take gear off, meaning putting more teeth on either the back or the front.

Putting gear on generally is only needed(assuming your already close to what is needed) when you figure because of conditions or what ever, your going to be going slower out on the track.

Hide this in the back of yer head forever> Slower, more gear; faster less gear.

It's just like your car, first gear is more gear and high gear is less gearing. The only purpose of more gear is to help you get going. If you want to go faster, get rid of gear. ... the track dictates how fast is fast and you'll never know how fast is possible without >taking gear off.

You take gear off until you hit a wall(not the wall) and then you fix on track problems and push beyond the wall. ... :) If it was otherwise there would not be track records to be broken, there would just be a set number for how fast you can go.

Go fast young man go fast, throw out that gear which is holding you back. ... >unless the track slows down, then ya gota put more gear on. period.
 
First we have to read the entire thread. He has not ran the 13/65. He was running a 14/65. He was not achieving his desired target rpm range. He went to the 14/70. This has allowed him to reach a more desirable rpm target range but, he is still lacking something. I could be wrong but, I'd bet he's looking for a little something extra on starts, restarts and exiting the corner. He has a question about the use of the 13 tooth driver.

If he had changed from the 14/65 combination where he was short of his target rpm range, to a 13/65 combination, he would have picked up the extra rpm he was looking for. At least a large portion of it anyways.

As he describes it, the track appears to be one where it's a requirement to get out of the throttle for a substantial amount of time. IIF it is that type of track (they do exist), he has to be able to recover from the large rpm drop.

This is where that stored energy we always talk about comes into play. Because he is losing a very large portion of that energy with such a large rpm drop, he has to be able to recover it quickly. He isn't able to do that with the 14/65 combination. I'd venture to say he was losing right out of the gate on comer exit with that gear, just from his discription of things. And it's only multiplied as he got further down the straights.

With the 14/65 He wasn't hitting his target rpm because of that inability to recover quickly enough through acceleration. The result of that struggle is clearly seen by the engine not teaching the target rpm. This is why Brian suggested trying the 13 driver.

If the straights where longer, the engine would have more time, by way of a longer distance to travel, to accelerate into the desired rpm range. That's....IF. However, this is not the case. So you have to provide the engine with the ability it needs to recover from the rpm drop on the length of track it has.

This can be achieved with the use of the 13 driver as Brian suggested. Personally I believe you will find it to more advantageous to your situation. Like Brian said, "You won't know uuntil you try".
 
jcm900 said:
well I think we're going to throw the 13 on run hot laps in a heat race and just see where it fallsjust wanted to say thanks for everybody's input and I will let you know how it goes
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That's when it will show up best anyway, the better the track gets that when you start looking towards the bigger front driver. And if you stick with the 13 because it's better always pay attention to track conditions if a few weeks later the track has more grip come feature time then the 14 might be best.
 
feel the same way...don't really pay attention to the gear chart and get hung up on ratio's....I change a gear based on what the track is doing and what I'm willing to commit to (meaning how hard am I going to push it). clutches also play a big part in the gearing scheme of things too. set your lock up too low and it's a dog on the starts and seems to take forever to wind up....set it too high and you get passed like by a blue haired old lady with a walker because the motor was screaming and not moving you anywhere....it's a do and don't situation. like others on here, we can suggest based on our experiences and what we know, but until you actually try it, you'll never know.
 
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