bstorey - I've got good HV3000's. I've been running a D3.5 11dbl and a D4 10dbl. Full 4383 brushes (I think) with green springs. I've geared down but it didn't have a drastic improvement. What kind of timing are you guys running? I've been around 20 degrees.

Out of my league...I'm nothing but a stock guy myself...Try asking Big Jim in the Motor Forum. He should be able to get you setup just right.

Blake

You mention that you are just 'barely' making it with run-time. If your car is still pretty strong come the 8 minute mark and hasn't fallen off much, then you are fine. You aren't going to end up with 100 seconds of run-time - especially with mod motors.

If you are finding the car to be pretty much dumped at the 7:30 mark, then here is some info. This is my own opinion, so if others feel I am off the mark, feel free to correct.

When running 1/12th scale (especially mod) the biggest factor for run time is how much corner speed the car carries. Also, your throttle finger affects run-time. And, corner speed and throttle go hand in hand. If to get the car to carry corner speed you have to stay on the throttle, then you are going to burn up more battery than someone who can let off earlier yet still carry good corner speed.

One of the ways I measure how well my car is working is checking tire wear (especially for the rears). You can typically check this by seeing how much foam dust is in the rear wheel well of the body (the more "scientific" method is to use a pair of calipers to measure the change in tire diameter). If after one run there is a lot of tire dust in there (and other folks don't have as much tire dust in there), then my feeling is that the car is scrubbing a lot of speed because the car has to work harder, which is causing faster than needed tire wear. (But, this is also affected by how much track traction is available. If the track doesn't have much traction, then the tires are potentially going to spin more and wear faster).

In regards to throttle finger, if you find you are using the brake a lot to slow down the car for turns, then that is also going to use up a lot of battery. It takes power to slow down the electric motor, and you also have to accelerate harder out of the corner, which also uses more battery (back to the whole corner speed thing). For me, the only time I use brake is in passing situations when I'm trying to out-brake someone entering the corner.

Hope that helps.

-Rich

Rich - Thanks. A lot of my problem is throttle finger. I'm just getting used to 12th mod after touring cars. the car seems to roll through the corners ok but I may get on the throttle too early without really needing to. I think I try to hard the first 5 min. I'll give that a try the next couple of weeks before the regionals. They're are fast down the 150ft straight!

Yeah - another thing is the start of qualifying. The biggest amp draw occurs during the first part of the race (like the first 30 seconds). If your track does IFMAR starts, don't mash the throttle out of the gate (if you do that) - just roll on to the throttle.

Some of the folks I race with go as far as to jam one of their fingers in between the trigger and the radio so that they don't go full throttle for the first 30 seconds or so.

Oh, that's ridiculous. No one has that small of fingers. :p

Originally posted by rchang
Some of the folks I race with go as far as to jam one of their fingers in between the trigger and the radio so that they don't go full throttle for the first 30 seconds or so.

Keith does. :-P

Thanks - I'll try a little more throttle control this weekend.

What would be a good starting rollout for a Rev2 with an MVP, Sanyo 3000HV's. I'm going out to Y-City Hobbies in Zanesville Friday evening to get my FIRST 1/12th scale experience. I figure it's best to drive without racing first...

Blake

I asked some of the pros about 1/12th motor timing and they all seemed to be in the 10-12 degree range. If you needed more speed, go to a lower turn arm.

I am not a mod guy and a have pretty heavy trigger finger and had no problems making time with 357 sec 3000 HV's. I also had plenty of power to use. You can always try a hotter wind than needed and not use full throttle.

bstorey - use a 40 to 42mm rollout with that MVP. I also suggest narrowing the brushes if the motor is too hot to touch as it comes off the track.

Thanks for all the info. I've never had trouble with runtime except on this track. It's 150x80 it's pretty big with the front straight of 150ft.

WOW - that is a big track to run 1/12th on. We have a nitro track near that size and we are winding out the 1/10th nitro TCs on the straight.

The nitro's on that straignt are fast! The TC's with 8 turns are too. My fastest laptimes in 12th scale are mid 19 seconds. The sraight runs alonge side the main road. It's cool to see the little cars passing the big cars. Take a look at the track http://www.hobbyracing.com/NorthAlabamaRaceway/
The Region 3's are in 3 weeks.

When racing do you want to keep all 4 tires at the same diameter?

I see you set the rear ride height with the adjusters...how do you set the front ride height on a Rev 2?

Thanks,
Blake

ts-your home track rocks!!! I love it!!! Looks nice and smooth too!!!

Blake, YOu adjust Front ride height by picking a diameter that you want to run that gives you the ride height you are after. You could use shims under the front arms, but then yuou would forver be changing the toe in/toe out, camber and caster (however slightly).

Now-having said that, you also would want to start the tires a little bit bigger so that you can -for example- start ride height at 5.2mm and when the tires are worn, you are still at 4.8mm.

In the back you can start with tires new out of package and say use a #1 pill upside down. After they have worn a bit-you can move to the #4 pill upside down!!! And you can also buy the IRS lowered pod plates and get another weekend out of every pair of tires!!

I dont try to keep tire diameters equal front to rear. Luckily the Rev.2 nd 3 are not Super critical to ride height like the 12L3 is. In fact-I have sold almost all of my used front tires to owners of 12L3's because they need to get there ride heights lower. That and the Reactive caster front ends can use smaller tires than the old style arms allow.

Again, I hope I helped more than confused!!

It's an awsome track. It's extremely smooth. We hope to have a big crowd for the Regionals in 3 weeks. We've been having around 70+ entries on regular race days!

The paved on-road nats are in Denver next weekend. I heard last night that 1/12 scale modified has been cancelled due to lack of interest. What's up with that?

I thought I'd heard that 1/12th scale was making a comeback?

A buddy just said he thinks that all traction compounds have been banned for this race, so who would want to send there factory team to a foam tire-no traction compound allowed event??

Heck, if we get one heat, lets go!! Then we all make the A-main and we are all qualified for the Worlds!!! WHooo HOooo!! BTW-who gets the next on-road worlds?

Some guys around here were using sunscreen when they couldn't use traction compound...worked ok I guess.

Ray - I think you've got an idea there...That would make a great story...My first 1/12th scale race and I qualify for the worlds? HA!

Blake
www.2brainsdesign.com

My source made it sound like both Trinity and AE discussed with ROAR that they weren't going to participate in that class, and this is the result.

I ran about 6 packs through my Rev2 tonight at Y-City hobbies in Zanesville. Thanks to everyone for helping me get the car setup. The setup was great!

I might need a bit more rear end traction. I think I have losi heavy hydradrive fluid in the side dampers. Am I supposed to be using medium? If so, would that give me more rear traction?

Also, without any shims, what is the caster & camber set on the Rev2's old skool front end?

One other thing, the tires after 6 packs showed no wear whatsoever, no tire dust anywhere and they are exactly the same size as when I started. Traction was great so I'm not complaining...just curious.

Thanks again!
Blake

bstorey,

Can you give me any info on the track? Such as, when they race, what classes they race, and track times (practice also)? I'm going to be in Columbus for three weeks and thinking about stopping in.

I sent an email to the address on the web site but have yet to receive a response.

Thanks,

Brian

Right now they aren't racing at all. As for practice, whenever they are open, you can practice. Let me know when you're going to be there and I'll use it as an excuse to head up there too. When they do race they typically have 1/12th scale, various oval classes, and touring cars.

If you are into touring cars you could race at CORCAR (www.corcar.com). That's the local parking lot racing. Great outfit there...about 70+ entrants per weekend.

Blake
www.2brainsdesing.com

bstorey - yes, move to medium or light losi damper fluid. The heavy weight fluid is taking away a little rear traction. The "old skool" front suspension is 0 deg caster and -2 deg camber. The camber is good, but you may need more caster. I have had my best runs with either 1 or 2 deg caster.

Thanks to all the help here I've picked up a lap and easily made runtime yesterday in practice for the Regionals.
Would changing to the 0 degree from the 10 degree reactive blocks help and on a large track?

The reactive caster issue has been discussed for years and will continue. Actually, you should find out which is best for you on a particular day on a particular track. Also, the "Old Skool" front suspension is not like the Dynamic Strut suspension with no reactive caster. The Dynamic Strut does have camber gain that gives you another option. The "Old Skool" suspension does not have camber gain. But don't forget that practice is the most important thing. The rest of this just makes you practice at a different level.

Thanks. I'm running out of practice time but I might get a chance to try out the 0 degree block. The car's much better now.

ts This is going to be hard to put into words, but if your on the fence about re-active or not-think about it this way!!! Are you in a position where you need a more turn in-but do not want to sacrifice the mid-turn grip you have. IN another word-if you are happy with how planted your 12th scale is and you know that reducing caster (spindle standing up straighter) will help car turn in, but makes car wash out at the apex. re-active caster may be for you!!!


In the opposite way of thinking-lets say you are already runing re-active caster why would you want to get rid of it? I personaly can think of three reasons.

1. Car feels inconsistent

a. could be from binding arms on complex Re-active set-up.
b. Could be from turning in at different speeds due to driving.

2. Car turns in too hard and then feels too planted or too slow at apex.

3. You want more turn in.

I hope that helps make the decision!!!
Ray

Oh, it helps alright. No 1/12th scale for me anymore. You've confused me even more than Rich.:D

Originally posted by rayhuang
I hope that helps make the decision!!!
Ray

Hey guys, I just bought a CRC 6-Pack last weekend, spent more time building than any car I have ever built, and love it!! I knew I had to spend the extra time and make the suspension supper smooth, so I did. I knwo this will make for a much better racing platform.

Fortunately the Trinity carpet race is held at the track I will be racing on, so I got a good starting set-up from the Calandra site.

I did stop by the track and practice for a battery pack, and found 2 things.... (1) I need traction compound.... hehehe I forgot it.....
(2) I touring cars have spoiled me.... I can't just yank the throttle, or steering wheel like on my mission.....

How do I properly set tweak using the side springs and tweak screws on the CRC suspension? I don't know how much tension should be on the springs, and don't want a car that looks tweak free on my speedmind guage, and then have a funny handling car on-track.

Impactplayer.

Given the time, you should set tweak in several differnt ways. You hit it on the head that setting tweak in the pits can be very different than on the track. But, always start with the old quarter trick on top of the tires!! First start by getting a set of tires that are trued evenly side to side. Also find the center of chassis and mark it on front and rear of car. Next make sure you are tweaking car for the battery you are going to be racing. Changing batteries throws off tweak on a 12th scale. And last, make sure nothing is biding or bent on car, wheels spin freely, etc. No reason to start chasing your tail with a stupid problem!!! Next set car on smooth surface and tap car a few times on center shock. Place a quarter on the top-trailing edge of each front tire, making sure that quarters are as even as you can eyeball them. Place a X-acto blade under the center of the front of the chassis and slowly lift up the car. The goal of course is to have both quarters (qrtr) fall off at the same time. Now lets say the left qrtr falls off first. Turn clockwise the right rear tweak spring!!! Just like on a TC!!!

The reasoning behind this way of setting tweak is that while accelerating out of a corner, the front lightens and starts to unload. If the car unloads on one front tire more than the other, you will have to make steering adjustments all the way dwon the straight, which is a 12th scale no-no!!!



Ray

Now that tweak is set in the pits, hit the track and while driving, notice if car pulls one-way or another!! At this point, either make an adjustment and go back out, or go to your radio settings!!! You might have too much EPA one way than another!!! DO some circles to determine that you have equal steering gright to left!!!

ALso, the Tweak boards are a fine and quick way to set tweak as well, especially for checking the rear of the car, but no where near as accurate as the qrtr trick.

Last thing for now-and very important-is if no matter what you do, the tweak wont stabilize, something is bound up, bent, wrong, etc in car for sure!!! It may take awhile to find it, but its there!!!

Ray

I was primarely asking about how much tension should be on the side springs at rest, I know if you get to the point where both springs are being compressed then the car will handle funny, and show signs of tweak, but how much tension should there be??

Sorry-about that!!!

You should have very little pre-load on springs (at least on a Rev.3). Unfortunately its a feel thing. SOmetimes when I get lost on pre-load I just back them both off and start from the beginning.

I like your dissertation Ray...yet another reason I'll avoid the 1/12th cars...:lol:

I think Aaron will like 1/12th scale alot more when there is a foot of snow on the ground.

I just spoke with a guy at Windtunnel Racing, one of the RCV board sponsors...he said that he could make a Rev3 chassis and associated parts for the following prices:

Main Chassis - $24.95
Bottom Plate - $8.95
Top Plate - $7.95

I've bought his parts before and they are awesome quality. Now I just need to get hold of a new chassis and bottom plate to get over to him so he can program it. Anyone have one of these?

Blake

Also, I'm brand new to 1/12th scale and I think it is by far, the best class I've ever run in. The cars are simple, durable and easy to setup. They run on 4 cells so the battery costs don't kill you. Just my .02.

Blake
www.2brainsdesign.com

Why would you want to send a chassis that someone put their time and money into developing (Speedmerchant) to some 3rd party just so they can copy it and sell it cheaper?

Buy the stuff from Speedmerchant and support the manufacturer.

I can understand buying from someone else if they do something different (ie: much thicker chassis that the manufacturer doens't offer; different layout, etc). But, you are asking for an exact copy.

Most stuff in the r/c world is not copyrighted. It doesn't mean we should abuse that. :)

Good thought...is there anyway I can buy direct from Speedmerchant then? I HATE working with Hobby Etc. Their site sucks, descriptions are worse than tower and their customer service is one of the worst. Not to mention that I've sent 3 different e-mails to Speedmerchant asking for information and had 0 returned to me.

I'm all for supporting the manufacturer, let them support the community as well though. If anyone from Speedmerchant is listening out there give me a shout, I'd like to hear from you.

Blake

Yeah, good point about getting replies. Companies definitely need to support the racers quickly.

You are in a bit of a delimna since Hobby Etc. is owned by the same guy (Bruce Carbone) who runs Speedmerchant.

Were you having problems ordering stuff through the Hobby Etc. web site?

main chassis part # is: SMR1419
top plate: SMR1262
bottom plate: SMR1253

Two problems:

1. As I mentioned very few descriptions on either site for product information.
2. A while ago I had a problem with a mini-z ball diff and called them about it, they said they would send a replacement and after 2 repeat calls never sent it. I ended up selling the car so I don't need it any longer. It just left me with a bad taste in my mouth about Hobby Etc.

It looks like I'll have to go with them anyways...thanks for the part numbers.

Blake

Shoot.. that sucks and is unfortunate. Hopefully you have better luck with the rev.3 parts order.

Impactplayr-

If I remember correctly some of the team CRC guys that run the 6-pack did not use side springs. Check out the CRC forums and you will find a better answer.

As for tweak you want to back the springs off and adjust the tweak through the t-bar first. After that is set you want to screw down the springs until they barely touch the balls on the plate. you don;t want them to compress but you do want them to touch. After you do this recheck your tweak. This time if the tweak is off you want to back out the side springs to bring it into tweak. I hope this helps.

Xpressman is exactly right. Set it flat with the T-bar, then set the springs so they just rest on the balls at static ride height. If you've tweaked the car flat with the T-bar, the springs should be set so that as soon as the pod shifts in one direction, the spring on the opposite side lifts off the ball. If they each lift off for the same amount of pod travel the car will be on tweak.

Aaron: 12th scale sounds complicated, but like any other form of racing, once you learn the routine, you're all set. I personally really prefer 12th scale because the 12th scale cars are normally way quicker than TC's, yet they have about 500 less parts to worry about, and 100 less screws to tighten after every run. Just my .02!

bstorey: I'll try and get a hold of Bruce for you. With it being the off season he tries to get all of his other business in line, as well as get in some "recreation" during the summer. What parts do you need? :devil:

Ian Ruggles
Team Speedmerchant

On the 6 pack when you use the side springs you don't use the tweak screws on the t plate, thanks for the replies, I followed the "set the springs so they just touch theballs at ride height" and it works well, now to get to the track for practice this weekend.

Some very fast people use both the tweak screws and side springs and some use one or the other. Its a preference thing!!! SOme even use that as a tuning option during a race day.

Hey hey hey CypressMidWest what's going on? You getting geared up for another big 12th scale season at Ultra? Sounds like it :) Believe it or not, I may be jumping back into the 12th scale game come winter. Things will slow down for flying and the wife and I are a little more used to having the little one around. (Only a few more weeks.....)

With that being said, I'll probably be running a majority of my free weekends down at Y-City due to the fact it's so close to home. Tell Pulfer I said hello and I'll probably be going Six Pack this time :)