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This is a place to share knowledge related to 1/12th scale racing. It is not to be used for conversations.

KITS:
Click links to go to manufacturer product page. If any are missing please add them!

TIRES:
Pre-mounted tires readily available in the US:
Pre-mounted tires readily available in the Europe:
  • Hot Race ??

Gluing your own donuts:
https://www.youtube.com/watch?v=hm7z1rz-74s - Special thanks to Edward Pickering!
Truing tires:
https://www.youtube.com/watch?v=8wqHOLWq6Uc - Special thanks to Edward Pickering!

The following information came from HERE, with some editing and information added. Thanks Christian!

THIS MAY NEED UPDATING FOR THE NEW BLACK CRC CARPET

Brands:
BSR, CRC, Jaco:
Pro One is no longer selling to the public, but it and the brands above are all mounted by BSR and use the same foam. The nomenclature of the BSR vs Jaco/CRC is a little different in a few instances but is otherwise the same. The BSR foam consists of three families, and can be identifed as synthetics, naturals, and blends.

Synthetics - The old school, light weight, easy to true "dry feeling" tires. These include tires like CRC/Jaco Yellow (BSR White), Black, Gray, etc. These tires offer the highest wear rate and lowest grip. Many racers continue to use these nder high bite conditions.

Naturals - These tires are usually the best alternative for low bite and asphalt. They include Pink, Magenta, Double Pink, Lilac (BSR Team Purple), Purple, and other tires. These tires provide a ton of grip, but tend to get sticky in high bite conditions. This rubber does not wear as easily, and the cars will pick up gunk and fibers from the carpet under most high bite conditions. This is especially bad if the humidity is high.

Blends - These are the tires most people run today. They were initially called "JFT foam" by some, as it was believed that the tires were the same as the JFT tires. We can divide the blends further into two groups: high rubber and low rubber content. The high rubber would be the new rear Orange and Red from the BSR family, and the low rubber would be the Green and Blue varieties. When, asked about the difference, John Foister from BSR Tires said they came from the same "family" of foam, but they offered different grip. According to John, the Green/Blue has more bite than Orange/Red, but from track testing Oranges offer more bite than Green (being equivalent to in hardness) when the grip is high and absolutely no grip when it is lower. The Orange foam has a denser pore structure and the tire is not as prone to chunking. It is also important to note is that BSR Blue rears are not the same as the BSR Blue fronts!

JFT:
JFT stands for Japan Foam Tire. They started the new wave of foam tires we are all using now (Blue/Blu, Green/Greene, Dbl Blue, etc). These tires are a little different than the BSR tire family, but work in very similar conditions. They offers four varieties A (asphalt), C (carpet), S (???), and R (???). This does not mean that those types only work on that surface, but this is what they recommend.

JFT uses the same foam for fronts and rears if the color is the same.

A: Used on asphalt, considered close to the natural rubber variety and are named consistently with other natural tires.
C: Used on carpet, considered a blend.
S: Used on carpet?, tires are ???
R: Used on carpet?, tires are ???

For setup, the JFT foam seem to generate more bite than the BSR, therefore the car tends to be a little more aggressive.

Ulti:
Ulti is another Japanese brand that offers an array of compounds. They have their own way of rating tires, and are difficult to equate to other brands. They have 4 different varieties, each in varying degrees of hardness.

J: High rubber content tire, similar to Pink/ Magenta. Soft would be close to a pink. These offer the most bite and are great for asphalt/carpet front tire. (J hard being very popular)
X: "Balanced" blend, similar to JFT Blue/ Green. Soft is equivalent to Green, medium to Blue in hardness. Great for carpet!
Y: High synthetic blend with lower grip, and is not a very popular variety.
Z: A very expensive "special" foam that is supposed to be magic on asphalt. Only make it in soft shore.
European tires:
There are many great European foam tire brands that use their own types of foam, as well as traditional foams. SOmeone with more knowledge about them will need to fill this in!

Tire Diameter:
If you are racing on carpet, you have to evaluate how much grip your track has. If your track is low to medium grip, you can run bigger tires. If you are on higher bite you have to cut them smaller, there is simply no way around it. Bigger tires are needed for asphalt, especially in the rear. The larger tires provide much needed lateral bite.

Carpet (mm):
Low - Medium Bite
Front: 42.0 - 42.5
Rear: 42.5 - 43.00
Medium - High Bite
Front: 40.5 - 41.0
Rear: 41.5 - 42.0
Big Race
Front: 39.5 - 40.0
Rear: 40.5 - 41.0
Asphalt (mm):
Parking Lot
Front: 43.0 - 44.0
Rear: 44.0 - 45.0
Prepped High Bite
Front: 42.0 - 43.0
Rear: 43.0 - 44.0

Tire Saucing:
Most facilities have moved towards odorless traction additives such as SXT. Some of additives evaporate very quickly and some do not. This seems to be something that is also dependent on tire compound and ambient temperature. For example, saucing a Green compound seems like it never dries, especially when tjhe temperature is lower. We have found that wiping the tires off 15 minutes before we go run allows the sauce to cure, which makes the car come in much quicker with Green rears. Blue compounds on the other hand, do fine when wiped off right before hitting the track.

Saucing half front and full rear is a good initial starting point. If the front of the car is too agressive you can sauce les than half, or for a shorter amount of time.
Tire Fuzzing:
In conditions of increasing grip, foam tires will somewtimes get sticky and pick up fuzz and debris from the track. This is highly dependent on the rubber sedan tire that is being run at your local track and the compound/ type of foam you are running on you car. The softer the sedan tire and the harder/higher rubber content in your foam tire, trouble with fuzzing seems more likely to occur.

There are ways to get around fuzzing under most conditions, and usually involves the selection of the correct foam compound. The more fuzz you get, the softer/lower rubber content you want to run.

Examples:
Problem: Car fuzzes with Lilac/Team Purple fronts and car starts pushing.
Solution: Use a softer front tire and or different family of foam. Replace it with Blue or Double Blue front.

Problem: Car loses rear bite 6 minutes into the run. Blue rear tires look almost clean but have small carpet hairs.
Solution: Use Green rear tires. The softer compound wears instead of getting sticky, minimizing fuzz.

Tire Selection:
Starting out, pick 2 tire compounds for the front and rear. The following should have you covered 99% of the time.

Front - Green and Blue (BSR) or Green and Light Blue (JFT)
Rear - Blue and Double Blue (BSR) or Blue and Dark Blue (JFT)

You may wonder about other compounds out there and if they might be better, trust me, they probably won't be. Even if there are other tires that can be as fast, the synthetic family wears out really fast and the high natural rubber will probably fuzz on you over an 8 minute run. The blends family seems to be the most versatile foam type available today. They last awhile, and sticking to them will make your process of tire selection simpler.
Tire Charts:
BSR/CRC/Jaco



Contact



Corally



JFT (Japan Foam Tire)



Ulti



Enneti (Xceed)



ELECTRONICS:
ESC:
As of now, ROAR is staying 1S (3.7V nominal; 4.2V fully charged) for 1/12. There are many 1S ESC's with a built in BEC so nothing else is required to power the receiver and servo.

If you don't want to lock yourself into a 1S specific ESC, you do have other options! It is possible to use your 2S ESC without a booster or receiver pack, and the ESC simply supplies the lower voltage. If that does not appeal to you, you will need to use an Rx pack or booster. The Rx pack and booster will both supply the receiver with a higher voltage than the 1S pack.

If you decide to use an Rx pack, MAKE SURE TO REMOVE THE RED WIRE FROM THE ESC PLUG THAT GOES INTO THE RECEIVER!!!

If you choose to use a voltage booster, it works exactly how it sounds. Instead of plugging the ESC into the receiver, it plugs into the booster, and the booster plug goes to the ESC, supplying the higher voltage.

1S ESC:
If there are any missing please add them!!

If anyone would like a need for a chart comparing the ESC's specs PM fenton06 and I'll get one made and put in here!
Voltage Boosters:
If there are any missing please add them!
Servos:
BODIES:
Black Art (CRC - US Dist):
  • Audi R8C - BA002 - .020 Thick



  • Black Market (Mohawk 12) - BA005 - .020



  • Lola B10 - BA006 - .020 thick
  • Toyota TS030 - BA008 - .020 thick

    Lola - black/red, TS030 - green/pink


PROTOForm:

Reflex Racing/RSD:

SUSPENSION ADJUSTMENTS:

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Old 12-08-2008, 10:19 PM   #29851
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Steve...how sure are you of the above? I'm certainly open to correction but I believe you get more camber gain with a shorter upper arm, less with a longer (seems the opposite of what you've indicated). This is one of the reasons "real" race cars use very long suspension arms compared to what was true in the past.

I believe roll center only changes if you change the angle of your upper arms from parallel with the ground (or at the rear, as with the Low Roll kit on Carpet Knives, by raising or lowering the pivot ball). You can also affect roll center by raising or lowering the center of mass. It's been a LONG time since I looked at this but it strikes me that pointed more down at the inside ends effectively lowers the roll center while bringing the upper arms up closer to parallel with the ground would raise the roll center. I believe you want to raise roll center if traction is low, lower it if traction is high (ie. traction rolling, "tripping" over the front, etc).

Again, MOST open to correction...so have at ye knowlegeable mass!!
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Old 12-08-2008, 10:32 PM   #29852
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A more parallel upper arm will yield a lower roll center. A more angled arm is a higher roll center.

Shorter arm more reaction/intial cut
Longer arm more overall steering, not as reactive.
Parallel arm will reduce traction roll, take some side bite out
Angled arm will increase side bite, camber gain
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Old 12-08-2008, 10:48 PM   #29853
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Quote:
Originally Posted by Scottrik View Post
Steve...how sure are you of the above? I'm certainly open to correction but I believe you get more camber gain with a shorter upper arm, less with a longer (seems the opposite of what you've indicated). This is one of the reasons "real" race cars use very long suspension arms compared to what was true in the past.

I believe roll center only changes if you change the angle of your upper arms from parallel with the ground (or at the rear, as with the Low Roll kit on Carpet Knives, by raising or lowering the pivot ball). You can also affect roll center by raising or lowering the center of mass. It's been a LONG time since I looked at this but it strikes me that pointed more down at the inside ends effectively lowers the roll center while bringing the upper arms up closer to parallel with the ground would raise the roll center. I believe you want to raise roll center if traction is low, lower it if traction is high (ie. traction rolling, "tripping" over the front, etc).

Again, MOST open to correction...so have at ye knowlegeable mass!!
Not sure at all, that's why I'm asking. Ay my age, I've forgotten a lot. Just trying to figure out what the changes will be if I move the pivot points around. I don't get enough track time to just try them all and hope what happens is right.
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Old 12-08-2008, 10:58 PM   #29854
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The end of a longer arm travels in a wider arc then the arc of a shorter arm. Because of this the amount the top of the king pin moves in toward the center of the chassis is less then the amount the top of the king pin moves on a shorter arm. Thus a shorter arm will have more change in camber as the suspension compresses.
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Old 12-08-2008, 11:00 PM   #29855
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Quote:
Originally Posted by robk View Post
A more parallel upper arm will yield a lower roll center. A more angled arm is a higher roll center.
This is correct. I just looked it up in Fred Puhn's EXCELLENT "How To Make Your Car Handle". It had been too long. So "what he said".

Since our lower arms are fixed parallel to the ground the higher you raise the inboard pivot of the upper arm the closer to the car the instantaneous center becomes. The lower line passes from the instantaneous center through the center of the tread contact to the point of intersection with the same line from the other side which will put the roll center below ground.

With the upper arms parallel your instantaneous center is at infinity (lines described by the upper and lower arms are parallel thus never intersect) which puts the roll center AT ground level.

Lowering the inner pivot shifts causes the instananeous center to come back from infinity (albeit described from the opposite side of the car) and move ever closer to the car. The difference being that instead of taking angles from arms and to tread centers on the same side of the car we're now measuring from the opposite sides of the car so the roll center rises the closer to the car we find the instantaneous center.

Ay yi yi. More stuff to ponder.
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Old 12-08-2008, 11:16 PM   #29856
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Well I held out as long as I could. I've been running brushless in my TC for a while, but I wanted to stay with brushed motors in my 1/12 car for as long as I could because the sight of all that wiring in a 1/12 car just didn't look right to me. After this last weekend I couldn't hold out any longer. Having the only brushed 1/12 car at the regional (Region 1) didn't bother me, but the power fade after only a few laps really did... I saw a post by Carl Giordano in the Speedmerchant Rev5 thread with some pics of a car that odpurple built for him, and it was clear that it IS possible to get all that wiring hidden away. I'm nowhere near the perfectionist that odpurple is, but I at least have a brushless 1/12 car that doesn't hurt me to look at. Here's my newly converted Flexi '07, the Tekin RS makes it pretty easy to get a nice tidy job... Can't wait to run it this weekend at the Toys For Tots race at 360 Speedway in Babylon, NY
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Old 12-08-2008, 11:26 PM   #29857
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Looks great Trips! Those FF cars sure are nice looking...If I didn't have such an aversion to saddle packs I'd be looking at one myself
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Old 12-08-2008, 11:34 PM   #29858
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Quote:
Originally Posted by jdeadman View Post
WOW!!!!!!! So totally true. I raced on Sunday and started to be more consistant. Going slower is totally the way to go. And Looking more forward really helps. I'm still going slower then the top 5 guys but I made it to the A-Main this week which was cool and came in 4th.

Just a couple of questions about setup.

How (with out a setup board) do I set camber and Toe or the CRC 3.2R. I Think I may be having basic setup issues. On power up THe car tends to pull to the left.

Thanks Again
I use an RPM camber gauge to set camber, for toe I just eyeball it. They also make a toe gauge, but I've never tried one. Here's the RPM web page with their gauges... the second item on the paage is the toe gauge, the third item is the camber gauge I use for 1/12 and touring cars.

Niftech makes a tool to measure toe, camber, and to center the rear axle in the car correctly, but I've never had one.


Pulling to one side under power is usually a sign that the car is tweaked. If you don't already own a tweak station, consider the Unity Tool tweak station... it not only does tweak, but it also can measure toe and camber. Pricey, but VERY NICE. I use a MIP tweak station, which does a great job, but doesn't have the camber and toe measuring capabilities of the Unity, but if I ever manage to break it, I'm buying the Unity one for sure.
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Last edited by Trips; 12-08-2008 at 11:59 PM.
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Old 12-08-2008, 11:48 PM   #29859
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Quote:
Originally Posted by SteveL View Post
One of the best writen descriptions of this that I've ever seen! Well done, and I would have never thought of telling this as a driving tip before but should. After reading your post, I realized that this is exactly what's going on when you're the fastest and why I have a tendancy to hit stuff when it isn't. I started racing again yesterday after a 5 year lay off and found that I was not doing a very good job of this at all. I was focusing too much on the car and over shooting corners a lot. This will make next weekend a lot easier I think. Great stuff and thanks for posting!
You know, I almost didn't post that, because it can sound pretty weird, but I'm glad I decided to go ahead and do it.

I never gave as much thought to the mental aspects of racing until I started trying to figure out why I haven't been able to do as well lately as I did a few years ago. I read a GREAT book on the subject, titled "Speed Secrets 3 - Inner Speed Secrets: Mental Strategies to Maximize Your Racing Performance" by Ross Bentley, a professional race driver and race driving instructor. He wrote a whole series of books, you can see them HERE. The third book on the page is the one I'm referring to. While it's really aimed at people driving full size race cars, a LOT of it is helpful to us as well. I've also read the first book on that page, a lot of it also is interesting and helpful to us, but again, really aimed at racers who drive from inside their race cars...

Most any good bookstore can get any of these titles, I just ordered my copies from Amazon...
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Old 12-09-2008, 12:09 AM   #29860
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Originally Posted by InspGadgt View Post
Looks great Trips! Those FF cars sure are nice looking...If I didn't have such an aversion to saddle packs I'd be looking at one myself
I hear you... I haven't raced a t-bar chassis since back in '94... but the FF is so sweet looking I just HAD to try it... and with Stormer selling the conversion kit for $99 it was too attractive to hold out any longer.

Only two race days on it, but I'm REALLY liking the car so far...
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Old 12-09-2008, 04:39 AM   #29861
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Great write up Trips.

I see people all the time go out to practice without the lap timer on...even some rather talented drivers..far to many people fail to see your point..great write up I will have to check out the book you mentioned.

Another great book is "Ayrton Senna's Princples of Race Driving" it is a little harder to find as it is out of print. Great chapters on race driving,line, and mental fitness.

Cheers

Jamie
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Old 12-09-2008, 08:30 PM   #29862
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i was just wondering if anyone is using a lipo in the ae 12r5 if so what brand is it??
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Old 12-09-2008, 09:17 PM   #29863
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I am new to 1/12scale. I noticed some setups have the rear tires 1.5mm to 2mm larger than the front. Why not run the same size front and rear? Is it a tuning option?
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Old 12-09-2008, 10:50 PM   #29864
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Originally Posted by Impulse_racer View Post
I am new to 1/12scale. I noticed some setups have the rear tires 1.5mm to 2mm larger than the front. Why not run the same size front and rear? Is it a tuning option?
One reason is larger tire = more speed.
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Old 12-09-2008, 11:29 PM   #29865
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Quote:
Originally Posted by a.seffrood View Post
i was just wondering if anyone is using a lipo in the ae 12r5 if so what brand is it??
I am running an SMC 4000 1 cell in a 12r5 . . .
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