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Old 04-07-2010, 01:26 AM   #18901
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Originally Posted by cosmo1974 View Post
Hi,

When NARROWING the rear track width (thin hexes), the Hudy setup book indicates following:
· Increases grip at corner exit (* I'm assuming this means rear grip *)
· Increases high-speed understeer.
· Increases front grip in hairpin turns.

I think Korey mentioned the same thing about Hara's RROC 2008 setup (ie: thin rear hexes, 72044, for more rear end grip).
REF: Hot Bodies Cyclone

If D2 gets less (and nothing else is changed), Wheel Rate gets larger:
---- Wheel rate = spring rate * (D1/D2)˛ * sin (a)
Not sure about roll centre change.

Why does narrowing the rear track width INCREASE grip at corner exit ??

Thanks in advance
Track width is interesting. In my experience, narrower track widths usually give more traction. The problem is when you exceed the limit of traction, the car is really unstable. With a wider car, I typically find there is less overall grip. BUT when you go beyond the limits of the tires, the car just slides progressively. It's not an abrupt snap. It's a give and take type of situation. It's something you just have to try. Luckily its easy to change.

I sometimes go up to the driver stand, make a few laps, pull in and make a small change. I usually carry a few tools in my pocket just in case I just want to make a small change.

-Korey
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Old 04-10-2010, 10:32 AM   #18902
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i have a painted body for sale for a cyclone tc if anyone is interested thanks
cyclone tc painted body
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Old 04-10-2010, 07:32 PM   #18903
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Default Question about FDR

I just spent the last half hour looking for a good FDR for a low-med traction outdoor parking lot track, medium size, using a SPX (for now) and an Ion 13.5 motor. I was unsuccessful. Please help!
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Old 04-10-2010, 08:42 PM   #18904
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I just spent the last half hour looking for a good FDR for a low-med traction outdoor parking lot track, medium size, using a SPX (for now) and an Ion 13.5 motor. I was unsuccessful. Please help!
Predating the Tekin era, 13.5's were geared between a 4.0 to 4.7.
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Old 04-10-2010, 09:08 PM   #18905
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As soon as I can get one, I plan on getting the Speed Passion 2.1 so what would the FDR be? Thank you very much!

Mark
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Old 04-10-2010, 10:01 PM   #18906
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When narrowing the track width,the car will have more lateral weight transfer in either direction, so with more weight being transferred to one side, that side will have more normal load on the tire, which means more traction. But as Korey stated, the car is easier to exceed the limit and then has prompt slide

Quote:
Originally Posted by cosmo1974 View Post
Hi,
Why does narrowing the rear track width INCREASE grip at corner exit ??

Thanks in advance
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Old 04-11-2010, 12:15 AM   #18907
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As soon as I can get one, I plan on getting the Speed Passion 2.1 so what would the FDR be? Thank you very much!

Mark
With the SP stuff, according to your track, 6.9- 7.6. This will also depend on the many combos you can run with the 2.1.
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Old 04-11-2010, 12:55 AM   #18908
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Thanks guys! I appreciate the help especially considering the outdoor season is upon us!
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Old 04-12-2010, 07:14 AM   #18909
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Hey Guys, Just raced @ our local club yesterday and still working out some bugs. Car pulls right under hard acceleration and I cant really find any problems in set up or chassis tweak. Could the steering servo be the problem? I will admit I am running a cheap hk metal gear unit. Is the torque of the brushless motor creating torque steer?
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Old 04-12-2010, 07:48 AM   #18910
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Hey Guys, Just raced @ our local club yesterday and still working out some bugs. Car pulls right under hard acceleration and I cant really find any problems in set up or chassis tweak. Could the steering servo be the problem? I will admit I am running a cheap hk metal gear unit. Is the torque of the brushless motor creating torque steer?
Sounds like a droop or maybe even a spring tension issue. Check both and see whether they are even from left to right.
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Old 04-12-2010, 08:08 AM   #18911
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Originally Posted by 05forfun View Post
When narrowing the track width,the car will have more lateral weight transfer in either direction,
...
But why is there more lateral weight transfer
This is the thing I am having trouble visualising

As mentioned before:
If D2 gets less (and nothing else is changed), Wheel Rate gets larger:
---- Wheel rate = spring rate * (D1/D2)˛ * sin (a)
This seems to indicate the opposite, so there are other "forces" at work here which I need some educating on

For example, is the Roll Centre getting LOWER, and the resultant force (increased leverage) outweighing the INCREASED Wheel Rate (I just dont know)
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Old 04-12-2010, 08:54 AM   #18912
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Originally Posted by Touring Jr. View Post
Is the torque of the brushless motor creating torque steer?

You don’t really get torque steered on a belt driven cars. First thing you want to check is a set screw on your pulley and spur adapter. Makes sure they are tight.

Are you running diff front and rear or rear diff and spool up front? Check the diff makes it doesn’t slip under heavy acceleration. If you are running one-way makes sure it’s still a “One-Way” not two-way.

Normally when one of those above happened to me the car generally pulled to the left though. I have had a front belt flipped on me one time and it pulled to the left. Not sure what would caused it to pull to the right.
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Old 04-12-2010, 09:22 AM   #18913
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Thanks Komkit,

I am running front spool and rear diff. Rear seams to be smooth and tight I think? When I hold the tires and push It with my thumb I cant turn it. But if a loose rear diff causes a pull( or push per say ) to the left I guess that doesnt apply here anyway?
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Old 04-12-2010, 10:13 AM   #18914
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Quote:
Originally Posted by cosmo1974 View Post
But why is there more lateral weight transfer
This is the thing I am having trouble visualising

As mentioned before:
If D2 gets less (and nothing else is changed), Wheel Rate gets larger:
---- Wheel rate = spring rate * (D1/D2)˛ * sin (a)
This seems to indicate the opposite, so there are other "forces" at work here which I need some educating on

For example, is the Roll Centre getting LOWER, and the resultant force (increased leverage) outweighing the INCREASED Wheel Rate (I just dont know)
wheel rate has nothing to do with weight transfer.
wheel rate is like a spring rate but transfered to the wheel center.
so if it tells you the force per wheel travel.

the total weight transfer is calculated as
weight*lateral acceleration*cg height / track width

so reducing the track width increases weight transfer
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Old 04-12-2010, 11:58 AM   #18915
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Exclamation LIPO Fit????

Huge Question, I just got the TC, my Lipo battery does not fit the chassis because its hitting the purple aluminum piece on the other side of the motor mount (sorry i forgot the name). do i just shave it to where it wont fit or will this mess the chassis up because it connects to the upper deck. THanks and i cannot wait to run it! I am running the 40C SMC lipo
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