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Discussion Starter #1
Hey guys once again I need your help. After changing my setup from purple/r double purple/f to double pink/r purple/f I was running and a few other cars got on the track at the same time I did. well I was coming off the sweaper and onto the back straght and cliped the inside board causing the car to spin out on the straght. then one of the cars crusing around the track (a 1/12th scale) hit me. and then the car started to make a strange rumbling sound. so i brought it in for a pit, and to my amazement the impact had taken a rather lage chunk out of a brand new set of double pink jaco foams. so I was just wondering if this is a freak accident or if the double pinks are actualy realy easy to chunk. because I dont wana run these tires whith a bunch of touring cars wizing around just waiting to take a bite out of my tires. so any help would be much appreceated. Also I know todd hodge glues the outer sidewall of all 4 of his foams not only for traction roles but also to help reduce chunking. maby I should concider doing the same because the car has pelnty of rear traction and actualy needs help rotating at high speed. but I like the way it feels everywhere else on the track

THANKS
Sean Scott
 

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the softer the foam the easier it will rip, tear, or chunk and i know pinks are pretty soft. kind of expensive too. if there's wrecks, any compound tire will chunk. i would think purples would be the hardest to chunk, lots of rubber content plus they're pretty hard. i myself would'nt glue them, i would "TRY" to avoid the wrecks.
 

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There are a couple of things you can do to prevent chunking of new tires.

-Put them on a truer and make them smaller. Smaller tires have less flex and will help your car sit lower to the ground which equals better handling. I realize this isn't practical if there isn't a truer at the track with touring car arbors

-Bevel or round the outside edge of a new tire. Sharp edges on new tires like to grab the body. If the new tire doesn't have a beveled edge, put a 45 degree edge on it. Easiest way is to use a truer. If you don't have a truer you could place your car on a stand and put some forward roll into it and carefully use a file to bevel the edge. You could also hand sand the edges with sand paper. This might not achieve the prettiest results, but will help take that edge off. Some brands of tires come with beveled/rounded edges.

-Lightly super glue the entire outer edge of the tire. Put a drop of glue on the edge and take a q-tip/popsicle stick to move the glue around the tire. Repeat until you get desired result. On a really soft tire (pink/green) this will give the outside edge of the tire a little extra stiffness. It can also help against chunking as the outer edge may be glued better to the rim. However, many traction compounds will dissolve super glue - such as Paragon. You should always check to make sure the foam isn't separating from the rim as this can cause issues as well.

-Make sure the body is mounted properly (even front to back and side to side) and the wheel holes are big enough. I know it doesn't look cool, but I'd rather have my race body not rubbing the tires. Also, round off any sharp edges around the wheel openings. A dremel with a sanding drum works well for this.

-Don't throw away the chunk. Super glue it back to the tire. This may not look pretty, but at least you will have a tire that you can practice/bash with. Unless the rim is cracked off, you should be able to get more use out of that tire.

-Lastely, don't wreck. Remember in road course racing that slower can actually be faster.

Hope this info helps.
 

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Discussion Starter #4
lol i dont mean to be mean but I know most of that already. and I myself have a tire truer. but I dont like to true down new tires if I dont have to but Its looking more and more like I am going to have to start. and yes I do bevel the edges of the tires so that they are rounded.


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Sean Scott
 

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I wondered if you did. I wish I'd known more when I did get into touring cars. I was in shock when I first started racing and chunked a new tire on its first run. Which brand pink tire are you running?
 

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Where I run touring car pretty much all people cut the tires down pretty low for proper rollout and stability.

I know you do not want to cut them down but I would glue the foam back in and true them down more.

Getting the proper tire size will help the cars handling, motor efficiency and also somewhat save tires from chunking. May be hard to believe but less there to cut by something else.

Check your body lines out for possible areas that can buckle and cut the tire.

I was just like you when I started running tc and tossed a new pair set of tires the first night because the car handled funny do the the size and the body tore the hell out of them.

Just some thoughts and ideas.

mc
 

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I can tell you jaco tires are very easy to chunk if you hit or get hit.. When i use to run there 10th scale tires, they chunked the outer edge all the time.. didnt seem like it mattered if i wrecked or not.. Ive also been running there 2 stage foams in 12th scale a bit.. ive chunk 4 tires in 3 runs.. Nothing major as far as wrecks go either.. just seem to chunk very easily.. Im going to continue to run them, cause i have so many but after that its back to BSR, or TM..
 

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Discussion Starter #8
yea the tire i chunked was a jaco. and yes I think the double pinks are easy to chunk cuz the body got caught on the tire (even tho I try and trim out the boddy so that it wont) where it rubed the tire it made a little ripple like line donw the center of the tire. but I need to lock down a setup soon. because I was running purple double purple for a bit. and that made it so the car strugled to make every turn. then I tried purples all around and that worked if I realy watched my stering and throtle inputs then I put the double pinks in the rear with the purples up front and that worked fantasticly. the car only stugles to make this one realy sharp hair pin corner that has alot of speed dumped into it. and that will change as soon as I get double pink orange fronts.


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Sean Scott
 

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Sean:

Hi,

Burbs is right. Jaco's chunk very easy. if you have them at your LHS try Parma foams. either the Double Pink,Double Pink/Orange or the new Indigo's that just came out. they have the same amount of bite as the Double Pink/Orange but wear better.
cutting down your tires..... I know that some people don't like to do this but you need to. depending on how well you drive and how well your car is setup makes a differance. you could go as large as 2.300 and still have a good handling car. I cut our's down to 2.200. but my sedans like short tires (except my Tamiya's). and they last 4 to 6 weekends of racing. (if the setup is correct on the sedans).
 

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Discussion Starter #10
ok guys I have a question. about how big should I make the foams out of the box? because I was truing them down to 60mm. should I go further because this is still very tall and I wont mind truing them down as much now because we are starting into our racing season. so what should be a good starting point for a new foam? also with racing started shure its more money "waisted" up front but more money saved in the long run. also that tire i chunked. the chunk is pretty substantial but it did not seam to effect the car noticably. especaly since it is on the part of the car that is on the inside for moast of track. so do you think i should continue using these tires or should I just keep em in my pit box for practice?


THANKS
Sean Scott
 

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Discussion Starter #12
ive been using trc's and I like them alot but they arent avalable localy. the only thing I can get localy for 13 bucks is jaco's. then it goes up to 18 bucks for parmas and 22 for bsr's so I usualy try and make em last untill I can get a mail order out. so what do you guys think I should do? pay the extra for parmas or bsr's or should I just get a few different trc's? because I was running purple rear and double purple front and the car worked very well but it just seemed to push alot during acceleration. thats why I tried double pink, and purple. but also I am gona try a few other things that may help the setup of the car. because right now I am mimicing a drivers setup and it works well its just I need a bit more front traction. but he uses 0 deg front caster blocks and I was using 4 so I finaly got the 0 deg caster blocks and also he puts 2 little brass shims under the sterring rack ball studs. so Ill try that and see what happens because the car just needs a bit more front traction and it would be perfect.


THANKS
Sean Scott
 
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