OK I have been getting into the whole realm of motor building and Im making a little progress. At least they are getting more efficient and better power numbers. So this leads me to problem #1. I have a decent grasp on rollout gearing to the actual track I race at. But I dont know how that should change based on the motor you have. Most people think you should run higher rollout if the motor is a slug. But what Im concerned with is torque and rpm's. For example lets say Im using a Monster HP. I have a fantom dyno and at 20 amps I usually make around 54watts, 14,500 rpms, and 0.360trq. So with that in mind I dont consider it an overly impressive motor so I have been gearing the rollout around 2.25. Im way off the pace compared to where the A main gents are. So Obviously either my motors suck OR Im not gearing according the torque and rpm's the motor has.

My local track has some decently sharp corners so I would assume torque is very important. So if a motor has higher than average torque and lower RPM's how should I gear the motor accordingly?? If I have a motor with higher RPM's I can always get rid of that by changing brushes and springs. But since Im going to assume torque is the big factor here how would you normally change in gearing? Any comments or ideas on this would be awesome because I am seriously struggling with these monster motors. My older Green Machine3's make as much or more power and torque than these things. :confused: Thanks guys!

I have been playing around with stock motors lately since there is no one in my area to really run modified and this is what I have found. Higher RPM motors, run less roll-out, higher torque motors run higher roll-out. There are guys at my track that do both. I run between a 1.89-1.93 roll-out in stock at my local track, where other guys who are fast and a-mainer every week are running almost 2.20. I let to set my car up a little on the free side, so it is easier to keep my RPM up through the corner, so I don't use the lower power band of the motor where you see the torque much. Other guys like the car to pivot right in the middle, which hurts rpm, so they gear for the torque band of the motor. Personally I think gearing for the RPM and lower roll-out is better, because the motors seem to stay cooler. I have also been using ther Low Range number and 20 amp number to determine how good the motor is versus the max power number on the dyno. Normally the higher the 20 amp number the better the motor period. Hope this helps.
-Jeff Patch

Putnam Propulsion
TQ Cells

More spring means more out of the corner Torque ....SRM

Gearing can be very tricky. You almost have to figure out the best gear for each individual motor. Certianly what Jeff said is true... more RPM less rollout. The only way to really know for sure is by looking at your lap times, but a good starting point is to get the motor hitting tops speed just as you enter the corner. But then at many tracks the really good guys don't slow down much in the corners and well their top speed is not that much differnt then their corner speed... The more corner speed you carry the more rollout you can handle... a really good driver/setup can ussualy run a higher rollout then a B-main driver can. I don't think there are any magic forumlas for picking the right gear for a motor.

No magic formula,just good ole simple lap times.

Bewstdgt,

One thing I noticed about your post. You said that you are way off the A-main pace so your problem must be either the motor or the gearing. Have you considered that maybe your set up is way off? If you car is scrubbing a lot of speed in the corners that may make it seem as though the motor or gearing are wrong. Unfortunately the crappy thing about 4 cell stock racing is that the car can feel like it is cornering great but in reality it's really slow. If you gear in the same neighborhood as the front runners and if your motors are even half way decent you won't be far off speed wise. Basically focus on your set-up. If you don't believe set up is the problem ask one of the front runners to trade motors with you for a heat and run his gearing. I'm willing to bet he'll be just as far ahead as he was before.

BewstdGT - Have you used the oval gearing recomended by the Fantom software, its usually fairly close. Assuming motor, gearing and battery's are all good your problem ciold be chassis. If one of the top guys at your local track is willing, try trading cars during practice you should get some useful info. Good Luck.
Doug P

What professor Miller said is true also, generally speaking more spring means more torque, but another thing I have been finding is that people are over springing their motors. Now this is just personal opinion, but when I have a new motor with good magnets, I have generally been using 2 green springs with the best success (on a flat track with a runline of roughly 180) as the motor gets older I go to a red + and green -. On banked tracks i always run a red and a green spring. Softer springs generally allow more rpm. Like PMsimkins was getting at it all boils down to set-up. And as I have explained to many other people, a car can "feel" great in the corners, but that doesn't mean it's fast.

Motor wise Im getting there, but as you said springs are crucial as it gets a little tired. But Im going to build one motor for all out RPM and one for all out torque and see how they compare at the same gearing.

As for my setup, it's terrible! I know thats my first problem. Its all tires! :rolleyes: The local track has nothing in the compounds I need so Im getting them elsewhere. But my problem was I have tires that are 3 years old, so when I reconditioned them and cleaned them they turned into sponges. So its really glued to the track. I had about 10% tweak so it shouldnt have been tight but having 4 tires that are equivelant to greens its never going to work on a banked oval. When I get tires Im positive I will gain 1.5-2 laps easily because Im a smooth enough driver. Just been out of the game for eons heh! But setup aside, going down the straits it didnt have much umph to go anywhere. I was the slowest car on the track in stock 4 cell no doubt about it. You could say Im the man! :p

OH also, gearing to where the fantom dyno wants me to be I wouldnt even be in the same ball park as the other drivers. It wants me to rollout at 2.58 heh, most others are rolling out around 2.2.

Very few people actually use the gearing feature on the Fantom correctly. The way to do it is to take a motor and find the roll out that works the best on the track. Then dyno that motor and adjust the RPM factor of the fantom until it gives you the same rollout that you found to work best on the track. Now the dyno will be set up correctly to gear other motors for that track.

Very few people actually use the gearing feature on the Fantom correctly. The way to do it is to take a motor and find the roll out that works the best on the track. Then dyno that motor and adjust the RPM factor of the fantom until it gives you the same rollout that you found to work best on the track. Now the dyno will be set up correctly to gear other motors for that track.

:thumbsup: You just made my day. I couldnt remember how to do that. But first I have to get a car that works so I can test and get some good runs to mak sure Im going the right direction!

When I had my dyno I would try and get one of the "fast" guys to dyno his motor on my dyno, save the info then get his gearing and laps run etc. and use that for a base. Ralf 13

If your setup isn't right (and it isn't by your own admission) then all the motor and/or ideal gearing in the world isn't going to help you much. I suggest you get a decent motor keep it fresh by rebuilding every 2 or 3 runs, find a half way decent gear. (which for you and your terible setup will likely be lower rollout then the fast guys run) Then spend more time on your chassis. I know this from doing it the other way... I worked on motors till I was blue in the face so to speak, and never got close to the fast guys. I've given my motors to the fast guy and he was able to run just as fast or faster with my motor as he was running with his own, but I still was and am way off the pace.

This year I'm running brushless... No rebuilds, no maintances at all on the motors. I'm gaining on the setup and the faster guys. I still am off the pace, but I am getting better... and well I am no 200% convinced it's all in the setup. At the end of last year I was just 100% convinced, this brushless has just helped me pry myself from the dyno...

In my own defense... I always knew my setup was bad, but I loved working on motors, so I didn't really care if I was all that fast compared to others anyway. This year I don't have time to work on motors, I have a one year old kid and a wife... so I had to stop spending so much time fiddling with something that didn't help my enjoyment at the track...

When I had my dyno I would try and get one of the "fast" guys to dyno his motor on my dyno, save the info then get his gearing and laps run etc. and use that for a base. Ralf 13

That way works as well and it's simpler than what the way I suggested. The problem with that is everyone sets up their car differently and runs a slightly different line, which means everyone will need a little different gearing to get the most from their set up and driving style. That is why it's best to find the optimum roll out in your own car on the track. That way you know you'll have your dyno tailored to your style.

Personally, I hate using a Fantom to find gearing. In my opinion all the Fantom dyno is really good for is a pass/fail kind of test. For example if I find myself to be running slow on the track I'll throw my motor on the dyno and it either passes or fails. If it passes then I know it's just my set up or the line I'm using, if it fails then I'll throw in a differnt motor. The people who sit and dyno 10 different motors thinking they are gonna truly find the best one are kidding themselves. The same goes for the people who sit there and try to turn a 65 watt motor into a 68 watt motor. Waste of time!

Like I said before and others have said it is all about set-up. Beside I agree with Dynohohum brushless is by far more fun anyway!

I guess I have MUCH to learn. I understand handling is what wins races and gets a car around the corners. But how many things can there be to make it better? Having the proper tweak and cross weight is one, havin ghte right tires so you dont scrub is 2, having bump steer setup decent is 3, and maybe having the right front springs. I dont have a tire sponsor like half the guys I race with so there's no chance of me getting 5 different compounds for each wheel to test and play with. So Im somewhat limited by money. Not a good sport/hobby to be in with limited cashflow I guess.

I don't have a tire sponser either I just buy used tires, I too have limited funds but the biggest thing is watch and learn from the FAST guys most of them will be willing to help.

http://www.iroaronline.org/dannyb.html

Read through this it's a good start on chassis tuning.

I agree that most fast guys will help you... some will even go as far as to give you a set of tires... They generaly help cause they are nice guys, but also because part of their sponsorship is to help promote the products they use, etc... they also have incentive to help you get up to speed if for no other reason then to keep from having to find away around you so often when your slow on the track...

Even so, you eventualy need to figure it out yourself... and well things like tires will have to be replaced and it does cost money to go as fast as the winner of the A main is going. He's got a whole box of tires, batteries, motors, and knows how to use them all... So... eventualy you have to compromise between how fast you want to go, and how much your wallet will let you go, as well as how much time you are willing to spend on figuring it all out... Personaly I suspect I'll never win any A-Mains arouind my track... I just don't have the willingness to devote as much as it would take... and well I'm 43 years old, and my eye hand coordination just aint what it really needs to be to go super fast for 4 minutes... If you miss your mark by a couple inches you'r going to loose a tenth of a second on that lap...

Anyway, at some point you just have to work with the goal of improving your own skills and times, and not compare yourself so much to what the fastest guys can do... unless of course your really prepared to dedicate alot of time and money to it all...

BewstdGT,

I hate to tell you this but you left about 25 things off your list of chassis adjustments you need to use.

From front to back. (not including the ones you mentioned)
Camber
Caster
Front End postion (short-long), (wide-narrow)
Damper Fluid on kingpins
sag (front)
Ballast (where your lead is sitting on chassis, I'm assuming you need some to make weight)
Ackerman
Center Shock (angle, length, oil, piston, spring, preload)
T-Bar (spring steel, fiberglass, bias cut, stiffness, etc.)
Battery Position (forward-back)(left-right)
Side Shock (angle, oil)
Pod (offset, straight, length (on some cars))
Sag (rear)
Axle Spacing (left and right hubs)
Body (type, rake, mounting position)
Wing (type, mounting position, mounted on pod or mounted on body)
Spoiler (height)
Ride Height (as low as your track allows, or just so it doesn't drag)

I'm sure I'm leaving plenty off the list since I'm at work and there is no car in front of me. Now before you get scared off, many of these adjustments are set and forget type type of things. The key is that they need to be set reasonably for your track. What I would do if I were you is sit down with a fast guy at your track who runs the same car as you and go through this stuff. You may find that just a couple of these adjustments are way out in left field on your car. If you get them right you'll pick up a couple laps right there probably. When you talk to the guy who's helping you make sure to get explanations on why he has the things the way they are. You can't learn anything by simply blindly copying someone.

The advantage that good racer with unlimited money has over a good racer with a limited budget is only a couple seconds at most. If you are four laps behind TQ it has NOTHING to do with money. If you are 2 seconds behind TQ then I'll admit that guy ahead of you may be simply outspending you. When main time comes it doesn't matter anyways because that 2 second advantage will be out the window with one bobble or a subpar start.

Couldnt agree with you guys more. Thanks for all that info. And yes I know all those little things are critical but not the major concerns. I do need to go thru the front end again because its a little off. I have a good guestimation on where to run the camber and caster from when I was fast before. As far as shocks and T-plate I am running what most guys run. All the other little things are food for thought. Back when I was always in the top 3 in the A mains I had LOTS of help and rarely setup my own chassis. So this is a very awakenning experience. Gotta learn to crawl again before I can sprint.

Im gonna spend a couple hours working on the car tonight and hopefully will click at the track tomorrow. All the things I fix will only help. Becuase I honestly couldn't get any slower! :lol: