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Old 04-01-2014, 10:07 AM   #256
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Originally Posted by TurboT View Post
Thanks for all the replies, Martin! Awesome to continue to have your experience and expertise in setup for everyone to benefit from!
Thanks Tyler!

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Originally Posted by mtbboy View Post
Hey Martin.

My car starts neutral and balanced however during the course of the run the car slowly becomes loose to a point of indri ability.

Any ideas?
Hi

The most likely cause here is that although your setup is balanced to start the setup is putting too much and relatively more heat into the rear tires compared to the front tires. When tires get too hot they loose grip.

So you can either try get the front to slide more or get the rear to grip more to resolve the issue. It is hard to suggest anything without knowing your current setup, but here are some generic answers.

Some things to reduce the grip on the front

1) lower the front roll center
2) decrease the front camber
3) lengthen the upper link


Some things to increase grip in the rear (this is where I would start)
1) Raise rear roll center
2) stand-up rear shocks one hole.
5) increase rear toe-in. Note: this could easily add more rear tire heat and make things worse, but if you are already running a very low amount of rear toe (like 1.5 to 2 degrees) then going to 2.5 or 3 will likely help things. If however you are already at 3 degrees then I would not increase the rear toe-in as this will most likely add too much rear heat and make it even worse.
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Old 04-01-2014, 01:03 PM   #257
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That sounds like a problem of the tires loosing mechanical grip. That could be from the the eauce wearing off to soon or the tire picking up trash (we had this problem at my local track when carpet was new for a few weeks, and now for the first hour or so of practice after they do a layout change. Also if you are on a carpet track and you track allows any tire sauce to be used, it could be that. Differnt tire sauces dont usually work too well together and cause promblems for everyone.)

Or it could be coming from you tires heating up. That could come from a couple different things. Your using too low of a shore rating for the given weather, or your suspension set-up is making them work really hard causing them to over heat. I am not sure on how to adjust suspension to fix that though.
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Old 04-01-2014, 01:59 PM   #258
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Originally Posted by Martin Crisp View Post
Thanks Tyler!



Hi

The most likely cause here is that although your setup is balanced to start the setup is putting too much and relatively more heat into the rear tires compared to the front tires. When tires get too hot they loose grip.

So you can either try get the front to slide more or get the rear to grip more to resolve the issue. It is hard to suggest anything without knowing your current setup, but here are some generic answers.

Some things to reduce the grip on the front

1) lower the front roll center
2) decrease the front camber
3) lengthen the upper link


Some things to increase grip in the rear (this is where I would start)
1) Raise rear roll center
2) stand-up rear shocks one hole.
5) increase rear toe-in. Note: this could easily add more rear tire heat and make things worse, but if you are already running a very low amount of rear toe (like 1.5 to 2 degrees) then going to 2.5 or 3 will likely help things. If however you are already at 3 degrees then I would not increase the rear toe-in as this will most likely add too much rear heat and make it even worse.
I'm going to try a couple of these things, too. I was experiencing the same thing. Raising rear roll center is what I'm going to try first.
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Old 04-01-2014, 04:46 PM   #259
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Got a race this weekend. Thanks for the response. I will try that out.
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Old 04-01-2014, 09:18 PM   #260
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Would tire noise be an indicator that the tires are being abused or over heating as car starts off quiet and then gets noise.
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Old 04-02-2014, 11:25 AM   #261
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Originally Posted by Martin Crisp View Post
Thanks Tyler!



Hi

The most likely cause here is that although your setup is balanced to start the setup is putting too much and relatively more heat into the rear tires compared to the front tires. When tires get too hot they loose grip.

So you can either try get the front to slide more or get the rear to grip more to resolve the issue. It is hard to suggest anything without knowing your current setup, but here are some generic answers.

Some things to reduce the grip on the front

1) lower the front roll center
2) decrease the front camber
3) lengthen the upper link


Some things to increase grip in the rear (this is where I would start)
1) Raise rear roll center
2) stand-up rear shocks one hole.
5) increase rear toe-in. Note: this could easily add more rear tire heat and make things worse, but if you are already running a very low amount of rear toe (like 1.5 to 2 degrees) then going to 2.5 or 3 will likely help things. If however you are already at 3 degrees then I would not increase the rear toe-in as this will most likely add too much rear heat and make it even worse.
what would you do if through the run the gets pushy? I did end up temping the tires after run and they were about 95F and the rear about 90F.
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Old 04-02-2014, 08:31 PM   #262
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Would tire noise be an indicator that the tires are being abused or over heating as car starts off quiet and then gets noise.
Some tires just generate more noise than others. To be honest I am not sure if the noise would get louder if a tire is overheated. Only a guess, but if the tire is too hot and thus sliding more, perhaps that would generate more noise.

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what would you do if through the run the gets pushy? I did end up temping the tires after run and they were about 95F and the rear about 90F.
you are overworking your front tires. you need to free up the rear of the car.
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Old 04-02-2014, 09:55 PM   #263
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Slightly off topic question but how would you go about improving the driver.

What would you consider a good consistency figure?

I have heard the suggestion to practice with a poorly setup car. One option was to get a well setup car and removal all the droop from one corner or fit a noticeably different spring to one corner.

Any specific training, where to look, how to find fast lines, goals to set ie consistency.
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Old 04-02-2014, 10:47 PM   #264
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Ok, so been doing some onroad racing for a couple months. I keep hearing at the track about fdr, ratio, etc. Of course when ask what is optimal, I get various answers. Even here on the forums, I read that some are at 4.0 and others are closer to 3.2...for the same car/motor size. Drives me nuts trying to figure this out. So, in generic terms, can it be explained on how to find the optimal fdr for a tc6.1, both 17.5 and 21.5 non-boosted, medium sizes track. I'm willing to put the work in, but just trying to learn on how to find the so called "sweet spot". Thanks
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Old 04-03-2014, 09:13 AM   #265
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Ok, so been doing some onroad racing for a couple months. I keep hearing at the track about fdr, ratio, etc. Of course when ask what is optimal, I get various answers. Even here on the forums, I read that some are at 4.0 and others are closer to 3.2...for the same car/motor size. Drives me nuts trying to figure this out. So, in generic terms, can it be explained on how to find the optimal fdr for a tc6.1, both 17.5 and 21.5 non-boosted, medium sizes track. I'm willing to put the work in, but just trying to learn on how to find the so called "sweet spot". Thanks
Gearing can be tough to find that "sweet" spot. There are a few different variances involved here (brand of motor, timing, motor temp and your chassis).

Example: Those Awesomatix boys can take advantage of more gear compared to a belt drive simply because there drivetrain is "more free" allowing less resistance. This allows them to run more gear compared to a belt drive car and run similar motor temps.

Different brand motors like different things. Some like more gear with less timing, some motors like less gear with more timing and some like something in the middle of all this. Finding that sweet spot (per motor) can be little flustering but the easiest way to do so, I found is the following.

Start with a FDR in the 3.9's or even 3.8's with the motor timing in the middle setting of the end bell. This will get you in the ballpark "medium size track" making small adjustments at that point (finding that sweet spot).

Once settled in with the following above. Run for 2 minutes, pull the car off the track and immediately temp the motor. Your looking for a motor temp 120 - 140.... With the following settings/gear (running a fan) and the motor isn't hitting the above temps you know you can do the following (add 1 tooth on the pinion, or turn the timing up 5 degrees for little more RPM. Do one change at a time, not both, run the car and temp.

Personally to find that "sweet" spot your looking for, first you need to at least get in the ballpark (3.9 -3.8 FDR, Mid Timing) should put you in there running on a medium size track 17.5. Then make small adjustments from there, your looking for consistent motor temps not exceeding 140 and a hard pulling car at the "3/4 Mark" of the straight (kind of looks like boost kicks in 3/4ths down the straight).

Make certain your running a fan on the motor. This is very important in finding that sweet spot your looking for.

My Setup:

I'm running a Team Powers 17.5 (fan on the motor) with a 3.76 FDR, timing maxed and motor is coming off in the 120's. I turned the timing down 5 degrees with the same gearing and the motor ran hot (150 - 160). The Team Powers I'm running likes a slightly taller gear and a lot of timing, pulls hard with no fading.

I'm sure Martin or someone else may be able to explain this little better, but hope this helps. Not very familiar with 21.5
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Old 04-03-2014, 10:50 AM   #266
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Originally Posted by NEED-MORE-SPEED View Post

Personally to find that "sweet" spot your looking for, first you need to at least get in the ballpark (3.9 -3.8 FDR, Mid Timing) should put you in there running on a medium size track 17.5. Then make small adjustments from there, your looking for consistent motor temps not exceeding 140 and a hard pulling car at the "3/4 Mark" of the straight (kind of looks like boost kicks in 3/4ths down the straight).

Make certain your running a fan on the motor. This is very important in finding that sweet spot your looking for.

My Setup:

I'm running a Team Powers 17.5 (fan on the motor) with a 3.76 FDR, timing maxed and motor is coming off in the 120's. I turned the timing down 5 degrees with the same gearing and the motor ran hot (150 - 160). The Team Powers I'm running likes a slightly taller gear and a lot of timing, pulls hard with no fading.

I'm sure Martin or someone else may be able to explain this little better, but hope this helps. Not very familiar with 21.5
I find it hard to believe ur motor begins to overheat with only a -5deg change . If this is the case and u start out at 0deg timing . How would one ever get over the "hump" in the timing/temp curv u just shined light on...?
im saying its really hard for the avg joe to find their sweet spot . I hardly ever stray from the gearing recomendations for the 3 fast guys at our track... lucky for me Ea is one of those guys
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Old 04-03-2014, 11:46 AM   #267
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I find it hard to believe ur motor begins to overheat with only a -5deg change . If this is the case and u start out at 0deg timing . How would one ever get over the "hump" in the timing/temp curv u just shined light on...?
im saying its really hard for the avg joe to find their sweet spot . I hardly ever stray from the gearing recomendations for the 3 fast guys at our track... lucky for me Ea is one of those guys
I agree with you, its hard for the average Joe to find the sweet spot. And you are lucky to have EA for reference, I had the privilege racing side by side with that guy, he seems to always have it nailed.

I found it hard to believe myself reducing the end bell timing by 5 degrees making such a spike in motor temp, but that was the case?

Getting over the hump isn't easy, I still feel as if I'm not over the hump as you call it, but I do the best I can. I never claimed to start at "zero" timing but to start at the mid timing on the end bell as all motors are different. All I'm claiming is, I found that is a good starting point to start tuning with

Personally I do agree with you based on your comments. However was simply trying to show a simple method I found that worked for me, getting one individual at a good starting point. Then making "one" adjustments from there instead of throwing anything and everything at the car in "hopes" of everything magically coming together.
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Old 04-03-2014, 12:14 PM   #268
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Originally Posted by NEED-MORE-SPEED View Post
Gearing can be tough to find that "sweet" spot. There are a few different variances involved here (brand of motor, timing, motor temp and your chassis).

Example: Those Awesomatix boys can take advantage of more gear compared to a belt drive simply because there drivetrain is "more free" allowing less resistance. This allows them to run more gear compared to a belt drive car and run similar motor temps.

Different brand motors like different things. Some like more gear with less timing, some motors like less gear with more timing and some like something in the middle of all this. Finding that sweet spot (per motor) can be little flustering but the easiest way to do so, I found is the following.

Start with a FDR in the 3.9's or even 3.8's with the motor timing in the middle setting of the end bell. This will get you in the ballpark "medium size track" making small adjustments at that point (finding that sweet spot).

Once settled in with the following above. Run for 2 minutes, pull the car off the track and immediately temp the motor. Your looking for a motor temp 120 - 140.... With the following settings/gear (running a fan) and the motor isn't hitting the above temps you know you can do the following (add 1 tooth on the pinion, or turn the timing up 5 degrees for little more RPM. Do one change at a time, not both, run the car and temp.

Personally to find that "sweet" spot your looking for, first you need to at least get in the ballpark (3.9 -3.8 FDR, Mid Timing) should put you in there running on a medium size track 17.5. Then make small adjustments from there, your looking for consistent motor temps not exceeding 140 and a hard pulling car at the "3/4 Mark" of the straight (kind of looks like boost kicks in 3/4ths down the straight).

Make certain your running a fan on the motor. This is very important in finding that sweet spot your looking for.

My Setup:

I'm running a Team Powers 17.5 (fan on the motor) with a 3.76 FDR, timing maxed and motor is coming off in the 120's. I turned the timing down 5 degrees with the same gearing and the motor ran hot (150 - 160). The Team Powers I'm running likes a slightly taller gear and a lot of timing, pulls hard with no fading.

I'm sure Martin or someone else may be able to explain this little better, but hope this helps. Not very familiar with 21.5
Now this is the explanation I was not getting at the track. Completely makes sense to me on what I need to do to get me where I want to be. Thank you very much for taking the time to explain. Now to put in some work and have more fun.
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Old 04-03-2014, 01:09 PM   #269
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Now this is the explanation I was not getting at the track. Completely makes sense to me on what I need to do to get me where I want to be. Thank you very much for taking the time to explain. Now to put in some work and have more fun.
Your Welcome. Glad it makes sense and hope you find what your looking for. Important you make single adjustments at a time from your staring point, run for two minutes then temp. If you make changes with gearing and timing all together it will be harder to find the small window of "fine tuning" your calling the sweet spot when it comes to motor, gear and timing.
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Old 04-03-2014, 04:02 PM   #270
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Originally Posted by NEED-MORE-SPEED View Post
I agree with you, its hard for the average Joe to find the sweet spot. And you are lucky to have EA for reference, I had the privilege racing side by side with that guy, he seems to always have it nailed.

I found it hard to believe myself reducing the end bell timing by 5 degrees making such a spike in motor temp, but that was the case?

Getting over the hump isn't easy, I still feel as if I'm not over the hump as you call it, but I do the best I can. I never claimed to start at "zero" timing but to start at the mid timing on the end bell as all motors are different. All I'm claiming is, I found that is a good starting point to start tuning with

Personally I do agree with you based on your comments. However was simply trying to show a simple method I found that worked for me, getting one individual at a good starting point. Then making "one" adjustments from there instead of throwing anything and everything at the car in "hopes" of everything magically coming together.
yea making one motor change at a time is the only way to find a gearing .. no chassis setup changes tire changes . When ur looking at the clock for ur improvement make sure ur change is the gearing/timing .
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