R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 08-09-2010, 05:48 AM   #1
Tech Adept
 
Join Date: Aug 2009
Posts: 226
Default How to cool down electric touring car rubber tires on carpet?

Hi, I race indoors in the UK on a low/medium grip carpet track. My car is an Xray 009 with Sorex 28R tires.

Its summer here and i'm having strange handling issues and i've come to the conclusion that the heat is causing the problem and has been for some time. My car also has a lot of power, even with a 13.5 because of having a SP esc with the latest firmware which also exagerates the problem.

When I take out the front screws from the top deck (which you're not really supposed to do as per Xray manual on carpet) the car has horrendous snap oversteer on entry and mid corner, which is why i'm also sure tire temps have hit the roof, because it's no where near as bad in the winter. Even with all screws in barring the front post, the car is better but the problem is less. General setup changes to the car don't solve it, unless I stick on new tires that last 2 runs and then the snap returns!

My tire temps are - FrLeft 83F - FrRight 86F --- RrLeft 83F - RrRight 83F.
To me this seems too high for Sorex 28R tires. I want to stick with this tire, as a lot use it at my club and at the big events its the tire of choice. What setup changes would drastically cool the tires down, other than changing the tire to a higher temp version like 32Rs?
maxg123456 is offline   Reply With Quote
Old 08-09-2010, 06:13 AM   #2
Tech Elite
 
sosidge's Avatar
 
Join Date: Dec 2001
Location: Bristol, UK
Posts: 3,865
Default

I don't think 80-90 Fahrenheit is at all hot for tyres.

What is your pre-race tyre prep routine? How does the handling develop during the race?

If tyre temperatures were the problem, I would expect the handling to get worse once the tyres get to racing temperature (ie a couple of minutes into the run), and be accompanied with squealing noises.

Your problem sounds more like a fundamental handling fault, probably an excessively soft front end. There is very little you can do with car setup to take temperature off the tyres, it has a lot more to do with the track conditions and the load you are putting through them from your fingers and thumbs.

Also, if you can't get 28R's to work, there is no point avoiding 32Rs. A tyre that works FOR YOU is always going to be faster than a tyre that doesn't work FOR YOU.
sosidge is offline   Reply With Quote
Old 08-09-2010, 06:22 AM   #3
Tech Adept
 
L@gger's Avatar
 
Join Date: Jul 2010
Location: Slovakia
Posts: 163
Default

I think four things have the most effect on tyre temps. 1. Driving style 2. track conditions 3. Car balance 4. Cambers, but overal tyre temp should be the same

Anyway I also think that 86F tyres dont have nothing to do with your problems.
L@gger is offline   Reply With Quote
Old 08-09-2010, 07:53 AM   #4
Tech Adept
 
Join Date: Apr 2006
Location: Croatia
Posts: 109
Default

Softer springs=hotter tires
Harder springs=cooler tires

Try to use harder springs on all four corners.
tomislav is offline   Reply With Quote
Old 08-09-2010, 08:00 AM   #5
Tech Adept
 
Join Date: Aug 2009
Posts: 226
Default

Quote:
Originally Posted by tomislav View Post
Softer springs=hotter tires
Harder springs=cooler tires

Try to use harder springs on all four corners.
I think youve made an error there. Its the other way round surely?
maxg123456 is offline   Reply With Quote
Old 08-09-2010, 08:06 AM   #6
Tech Elite
 
L.Fairtrace's Avatar
 
Join Date: Apr 2004
Location: Beyond the Wall
Posts: 3,774
Trader Rating: 23 (100%+)
Send a message via AIM to L.Fairtrace
Default

Lol 85 degrees is not hot for tires on any surface.

I think you have to look at your setup or the track for reasons why your car is ill handling.

Plus I think sorex 28s are good for up to about 110 degrees or something around that.
__________________
Awesomatix USA - EaMotorsports - RocheUSA - MonTech - Sanwa - BSR Racing Tires - TQ Wire - Solaris Racing Tires - Side Piece Racing

180 and 360 Raceway. Best on the East Coast. Take your pick
L.Fairtrace is offline   Reply With Quote
Old 08-09-2010, 08:08 AM   #7
Tech Adept
 
L@gger's Avatar
 
Join Date: Jul 2010
Location: Slovakia
Posts: 163
Default

With softer springs you get more weight transfer. With harder you get more slip. I think overal effect should be the same or hotter with harder suspension.
L@gger is offline   Reply With Quote
Old 08-09-2010, 08:09 AM   #8
Tech Adept
 
Join Date: Aug 2009
Posts: 226
Default

Quote:
Originally Posted by sosidge View Post
I don't think 80-90 Fahrenheit is at all hot for tyres.

What is your pre-race tyre prep routine? How does the handling develop during the race?

If tyre temperatures were the problem, I would expect the handling to get worse once the tyres get to racing temperature (ie a couple of minutes into the run), and be accompanied with squealing noises.

Your problem sounds more like a fundamental handling fault, probably an excessively soft front end. There is very little you can do with car setup to take temperature off the tyres, it has a lot more to do with the track conditions and the load you are putting through them from your fingers and thumbs.

Also, if you can't get 28R's to work, there is no point avoiding 32Rs. A tyre that works FOR YOU is always going to be faster than a tyre that doesn't work FOR YOU.
It does get worse during the run, thats for sure. As i've stated already, the setup is changed back and fourth and there is next to no difference. The front end is as per stock xray setup for carpet. 2.8fr/2.6r. I've tried 3.0 front springs and it seems worse. Probably even more nervous.

The things that I have found that does help are angling the rear camber links and standing up the shocks at the rear 1, as it stabilises the rear on entry, but no where near enough throughout the corner. I run 2 deg camber all over. I don't want to make myself seem arrogant, but I am a regular A finalist in a field of 60-80 drivers in the winter, so I know how to drive smoothly. I have been driving rc cars for almost 20 years on and off. The problem is that I could run 32R but there are events that state I have to run 28R and I really need to get the car dialled on the tire of choice.
maxg123456 is offline   Reply With Quote
Old 08-09-2010, 08:10 AM   #9
Tech Adept
 
Join Date: Aug 2009
Posts: 226
Default

Quote:
Originally Posted by [email protected] View Post
With softer springs you get more weight transfer. With harder you get more slip. I think overal effect should be the same or hotter with harder suspension.
I agree entirely. I tried 2.6/2.4, instead of 2.8/2.6 and the overall handling was the same.
maxg123456 is offline   Reply With Quote
Old 08-09-2010, 08:15 AM   #10
Tech Adept
 
Join Date: Aug 2009
Posts: 226
Default

Quote:
Originally Posted by L.Fairtrace View Post
Lol 85 degrees is not hot for tires on any surface.

I think you have to look at your setup or the track for reasons why your car is ill handling.

Plus I think sorex 28s are good for up to about 110 degrees or something around that.
Ok, so tire temp is not the issue then


I asked the question, thinking temp could be the issue, but it looks like i'll have to reconsider wtf is going on. I can drive it as it is, but I just want the rear end to stay planted, so I can drive with another 50% confidence the car will go exactly where I need it to go. I actually like a slight oversteer handling car, but my problem is not general oversteer, its that dreaded snap that looses a lot of corner speed.
maxg123456 is offline   Reply With Quote
Old 08-09-2010, 08:39 AM   #11
Tech Addict
 
Robert_K's Avatar
 
Join Date: Jun 2008
Location: Netherlands, Sweet Lake City
Posts: 500
Trader Rating: 2 (100%+)
Default

Are you using any additve?

When yes, It could be that there's a sticky mess on your tires, or the tires are getting sticky, and pick-up a lot of dust/hears/etc... Try a different one, and try not to let your tires dry up. Keep the tires wet all the time, untill you make them "dry" with a towel to go on the track.

When no... I think something is wrong with the set-up. 85 Deg's voor 28's is not hot, like all others say. It looks to me that you have to much steering. When you start at cold tires the car is "ok" and after a few laps the tires get warmed up, and you get more steering.... But that would not explain te flex setting you made...

Best Regards

Robert
__________________
Sponsored by: Schumacher Racing and Dualsky
Supported by: Shepherd Benelux and Thunder Tiger.
Robert_K is offline   Reply With Quote
Old 08-09-2010, 08:40 AM   #12
Tech Elite
 
sosidge's Avatar
 
Join Date: Dec 2001
Location: Bristol, UK
Posts: 3,865
Default

Quote:
Originally Posted by maxg123456 View Post
It does get worse during the run, thats for sure. As i've stated already, the setup is changed back and fourth and there is next to no difference. The front end is as per stock xray setup for carpet. 2.8fr/2.6r. I've tried 3.0 front springs and it seems worse. Probably even more nervous.

The things that I have found that does help are angling the rear camber links and standing up the shocks at the rear 1, as it stabilises the rear on entry, but no where near enough throughout the corner. I run 2 deg camber all over. I don't want to make myself seem arrogant, but I am a regular A finalist in a field of 60-80 drivers in the winter, so I know how to drive smoothly. I have been driving rc cars for almost 20 years on and off. The problem is that I could run 32R but there are events that state I have to run 28R and I really need to get the car dialled on the tire of choice.
But what are you doing with the tyres pre-race?

As for the snap oversteer, it's a common problem I have seen in the past with XRAYs. I'm going back to early T2s and 007s, when I used to race with a few people that chose them. Back then the cars components were too stiff and didn't generate any rear traction. I don't know if they've resolved that with the cars now.
sosidge is offline   Reply With Quote
Old 08-09-2010, 08:54 AM   #13
Tech Adept
 
Join Date: Apr 2006
Location: Croatia
Posts: 109
Default

Quote:
Originally Posted by maxg123456 View Post
I think youve made an error there. Its the other way round surely?
You are correct, i'v made mistake, softer spring coller tire, harder spring hotter tire, so advice is to go on softer spring, not harder,
thanks for notice my mistake
tomislav is offline   Reply With Quote
Old 08-09-2010, 09:00 AM   #14
Tech Champion
 
MikeXray's Avatar
 
Join Date: Oct 2006
Location: New York
Posts: 5,749
Trader Rating: 73 (100%+)
Default

Quote:
Originally Posted by maxg123456 View Post
Ok, so tire temp is not the issue then


I asked the question, thinking temp could be the issue, but it looks like i'll have to reconsider wtf is going on. I can drive it as it is, but I just want the rear end to stay planted, so I can drive with another 50% confidence the car will go exactly where I need it to go. I actually like a slight oversteer handling car, but my problem is not general oversteer, its that dreaded snap that looses a lot of corner speed.
If you can't find a fix in the chassis, you can glue the front sidewalls with CA, it works, but you will need to reglue it every couple of runs. Many think it's a "hack" but it does work if you can't find another solution. You could also try a less aggressive body.
__________________
Mike L. Awesomatixusa.com | TQWire.com | Islandraceway.com |JacksonRCracing.com | Horsham RC | Sweepracingusa.com
MikeXray is offline   Reply With Quote
Old 08-09-2010, 09:09 AM   #15
Tech Adept
 
Join Date: Aug 2009
Posts: 226
Default

Quote:
Originally Posted by Robert_K View Post
Are you using any additve?

When yes, It could be that there's a sticky mess on your tires, or the tires are getting sticky, and pick-up a lot of dust/hears/etc... Try a different one, and try not to let your tires dry up. Keep the tires wet all the time, untill you make them "dry" with a towel to go on the track.

When no... I think something is wrong with the set-up. 85 Deg's voor 28's is not hot, like all others say. It looks to me that you have to much steering. When you start at cold tires the car is "ok" and after a few laps the tires get warmed up, and you get more steering.... But that would not explain te flex setting you made...

Best Regards

Robert
Hi,
thanks for the response. I use LRP carpet additive. I apply 15 mins before the race all round. I've also tried 20 mins rear, 5/10 front before the heat started and car was better but I find the cars handling issue is still there. 10% better, rather than a near cure.

The reason I mentioned the flex at the front, is because a few weeks ago, I thought I had the problem cured because before the final I decided to put all the front flex screws back in the front and the car was 10 times better. It had mild understeer believe it or not, instead of snap oversteer it had one heat earlier. This is also why I thought the front tires overheating was causing the strange handling. It seems I was wrong.
maxg123456 is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
SS Raceway in Tampa Rojna Florida Racing 5042 07-15-2014 01:03 AM
Mugen MTX-3 university_dave Nitro On-Road 17237 12-30-2012 01:16 PM
Strictly RC Norridge IL Basher1957 Wisconsin & Illinois Racing 1058 10-11-2010 07:02 PM
N.C. State On Road Challenge Timmie Racing Forum 278 06-04-2010 04:16 AM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:28 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net