AdrianM

iTrader: (4)

If you run Jaco Wraps or CRC Pro Cuts start at 1.75 and 1.80. Wraps and Procut fronts are worn out at just under 1.65".

Also you will need special .060" cut down front lower suspension arms to get ride height with tire smaller than 1.68" on an Associated front end. You can get these from IRS and CRC.

Tek Nickal

I was wondering if anyone had information on how the Jaco 2 Stage tires work on the sedans. The website doesn't say too much about the tires.

AdrianM

iTrader: (4)

The wraps are almost mandatory in Stock and 19T sedan where they free up the car in the corners. This improves corner speed and help the cars flow better.

In Mod what you want depends on the traction and your car. Use wraps on high traction tracks and on darty cars as part of the setup to mellow it out.

Tek Nickal

"wraps"? I don't really know the terms used for these tires. Where would be a good place to start with these tires?

AdrianM

iTrader: (4)

If you have low traction 58mm. If the traction is high start out at ~57mm and they will be good for about 2 runs before they peel. Wraps are fast but they are expensive because they generally only last 2 runs. If you run them bigger you get no benefit from them and your car will be slow.

swopemike

iTrader: (6)

Adrian,

Thanks for your summary. I appreciate you starting on the ground floor with us!

I have John's BSR double pink and double pink orange. The rims are very stiff and seemed more prone to crack than the new RP-30's. I just assumed since they looked and cracked kind of like the old RP-30's, they were not nylon. But they must be glass reinforced nylon then because they are so stiff. The new RP-30 rims look to be made from unreinforced, unpigmented nylon which is more flexible.

Based on what you said, I think the lesser toughness of the foams is likely due to mold design differences - thinner rim walls and no bead to reinforce. Maybe the flex of the RP-30's and rubber on the tires also helps them distribute load better in a crash.

swopemike

iTrader: (6)

OK, some more questions.

What's the thought process behind choosing a foam tire compound ?

I check with the top guys and the LHS who supplies some of them. For instance they recommend double pink rear and double pink orange front, John's BSR, for club racing on carpet.

What happens if I get a lower or higher shore / color dot, and how do I know how much I can go one way or the other?

Is there a way to choose tires that aren't quite as fast, but close enough for club races, to reduce my costs?

Anyone else have any more great tips for eliminating the dreaded chunking ? I can't afford new tires every week. I am trying the CA glue with moderate success.

A little while back I saw a nice article with pictures on repairing foams. Anyone have the link? Maybe it was a magazine article.

Foam Tire repair links I found:

http://www.rctech.net/forum/showthre...oam+tire+chunk

http://www.rctech.net/forum/showthre...oam+tire+chunk

http://www.rctech.net/forum/showthre...oam+tire+chunk

http://www.rctech.net/forum/showthre...oam+tire+chunk

adamge

iTrader: (1)

swope, I'm new to this, but here's what I've learned.
-Chunking isn't an issue if there isn't enough foam there to chunk, so run them until you are driving on glue.
-Start the tires at 60mm, and ignore the chunks - just keep driving them.

rollover

Can anything be put on old tires that are dry to bring them back to life?

syndr0me

iTrader: (32)

Paragon? Seems like a traction compound that's designed to soften the foam should do the trick for dried out foams. I'm not positive, though, it's just a hunch.

Iceracer

iTrader: (1)

How tight are the tolerances for matching tire height front to back? I threw some Jacos on my car right out of the box and have seriously poor handling compared to the previously shaved down tires. I now see that the rears are 63 mm and the fronts 61mm. Oops. What's a good starting point for height of a stock sedan tire? I changed too many things at once and now am not sure what to blame, as I also swapped in some heavier carpet weight springs.

AChupp2

iTrader: (24)

I like to start my tires at 58mm. It seems to be a good blend of minimizing chunking while increasing the amount of runs on the tires. I recommend Parma Purple and Plaid tires. They last forever and I rarely chunk the tires and I do hit things. Also when you true the tires round the edges a bit. Hope that helps

Team Speedy

iTrader: (55)

Usually Jaco's come out of the box around 63mm. That's what I usually get when I pull them out of the box when I go to true them. First I would strongly recomend truing them to at least 59-60mm. If you tight on a budget, start them at 60mm. If you have some $$ to throw around, start them at 57mm. The taller the tire the more runs you can get out of them. However, it can throw your setup off and you are more prone to chunking the tires if you do not round your edges. Chunking is caused by a lot of things such as, your body, track barriers, driving line, ect.. I would not recommend pulling tires out of a box and running that way. The FK05 (as I see in your signature) should be really good on tire wear and increditable on carpet. Most top guys around me are starting there tires at 55-56mm and running to the rim. (Myself included) If you have to start your tires at box height, consider grabbing or "borrowing a friends" caliber. But please return his caliber! He'll be looking for it soon enough! Also if your car is not set up properly you may noticed one tire wears faster then another. Adjusting your camber will help even out a few things. If that becomes a problem in the future, consider buying (or borrowing your friends sharpy) a marker in white ink and running a few horizontal lines across the tire from one edge to another. (NOT VERTICALLY!) Run a few "hot laps" and return to your pit. You'll notice that marker has worn down a bit. Adjust accordingly to the marker and run a few more laps. Keep doing this until the tire wear is flat across.

There is some much information I can type on this. I'm sure someone else can add to what I have said (or correct what I said) in this topic. I hope this can help all of you.

pcar951

iTrader: (23)

It's probably no big secret but, we're using "Speed Sew" to repair chunked foam tires. Four bucks a tube from Walmart and it's saved me a ton of $$. I feel a little stupid scouring the track after a club qualie for that little piece of foam but the repair is very durable. I've even used repaired tires at big races, they rarely fail if allowed to dry long enough.

swopemike

iTrader: (6)

Where do you get the speed sew, in craft section ?

I tried both "superglue" type and "shoe goo" types. Both work remarkably well for repair, although for prevention, so far "superglue" type is superior adhesion (works for multiple runs).

I can see why reducing tire sidewall ht is important. Too much flex at 61mm, scrub too much speed in corners. Tried 59.5, still too high, but better... probably try 58 next time.

Per my previous questions a few posts back, anyone want to post a summary on "choosing color dot / shore for carpet foams" to give us some guidance? For instance, can we use 2-stage to reduce chunking (seems to work really really well on my fronts) on the rear without losing too much traction ? Or what are the "acceptable" ranges of color dot we can try (e.g. just slightly less perfomance with a little harder shore to save $$$ at club races for us weekend warriors?). Or is there too much sacrifice in performance to be worthwhile ?