LegendsRacer - Legends & Bandolero Racing Forum
LEGENDS => Setup and Handling => Topic started by: VMS Motorsports on November 30, 2007, 09:22:46 am
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Alright, this is the only thing I can't figure out (yeah, right) on this car, We've tried all different suspension geometry and adjustments I can think of, and I can't stop spinning the wheels all the way down the straight (dirt). Im already way over the weight minimum with my 250 pound posterior, so I really dont want to add a bunch of lead in the rear. 1/3 mile high banked clay oval, open 1200, in 4th gear with a 373 rear. Can't use 5th, I lose seconds off my lap time, but of course dont spin-em in 5th either.
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If you haven't trid this yet ( I DO NOT know much about dirt) but, on asphalt and we are lacking forward bite, we add a little pinion angle to it. It might cause you to loosen the car upon entry but it usually helps us some.
xtime
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We've run the full realm of pinion angles...it helped, but not enough...Ive got a buddy who ice races and they heat up their tires and press crushed walnut shells into them for grip...maybe I'll try that along with 100 lbs of lead;D
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Jim,
I really don't think the walnut shell thing will help you . JMHO
Not sure of your tire rules, but what about a different tread design? Is tire grooving legal? Air pressure changes?
How about different rear end gear? Try to borrow a set to try out.
Have you checked the thread on gears? Tom has a spreadsheet that might help.
Spring rates? Shock rates? Have you asked around at your track? Not saying that just because that's what somebody else runs, that it will work for you. Driver style? Can you change when you get on and off the pedal?
Is this an INEX legal class???
There are a lot of variables. You don't give a lot of information. I'm just throwing this stuff out for you to think about. I'm also not sure how many here race on dirt. Have you tried DCR? Lots of dirt guys there. Maybe they could point you in the right direction.
Just Random Thoughts,
Steve
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I was kidding about the Walnut shell thing, I couldnt believe it when he told me ???
We are INEX, so we need to have unadulterated Legends tires. Most of the guys at my track run 9-12 lbs in the rear, I was hooked up real good at 8, but since we cant run bead-locks, that didn't last too long >:(
Tried soft springs for transfer to the rear, hard springs for weight, we're getting closer, but still spinning. I was going to try a different gear, but was hoping to not have to go that route. Thanks for the input...I love this place!
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Sorry! Forgot to post the site for you.
http://www.dwarfcarracing.com/
Steve
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Run traction control.....JK. Try softer rear springs.
Mike.
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what r u runnin for rear springs?
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VMS Motorsports, if you were hooked up running 8lbs. check out tech bulletin L-31507-1 dated 04/11/07, it allows you to run I beleive 8 screws thru both rims into the tire beads to secure tire to the rim, dirt only..... www.600racing.com/inex_info/tech_updates/
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Sounds to me like your running to low of a gear ratio. Try a higher gear selection. This will allow the engine to spin a little slower at the same speed. Just about the same HP, but less torque. With a low gear ratio, like in the 4:10 area, that engine will brake the tires loose in a hurry. The gear reduction will put allot more power to the ground, to the point where nothing will stop it spinning. *except pavement* ...or a wall, but that is another problem for another thread.
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Im running a 373, everyone else is running a 342 or 358
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I run a 373 on a low banked paved oval in 5th gear. Lots of power. The guy that owned the car before me won lots of races that way. Don't know how well that translates for a dirt track...
Mike
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I tried 5th, way too slow...I dont know. It was an asphalt car when I bought it, and I never scaled it or anything, just changed the springs and camber. Now that its apart Ill put it together right and see what happens
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The lad that runs a racing school out our way is fond of saying "Smooth is fast" I believe he's right. The more I tried to make my entry and exit of corners smooth, the faster I got.
Good luck with your car setup.
Mike
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Yeah, Ive been hearing the pretend theres an egg under the throttle...dont mash it! I know a big part is my driving style, I was a bottom feeder last year, Im going to have to try the outside line to stay on the throttle more. Who knows, I just know I have 4 more months of off season to do nothing... :'(
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Yeah, Ive been hearing the pretend theres an egg under the throttle...dont mash it! I know a big part is my driving style, I was a bottom feeder last year, Im going to have to try the outside line to stay on the throttle more. Who knows, I just know I have 4 more months of off season to do nothing... :'(
Higher gears will allow you to put the power down all you want at lower speeds *coming and out of corners* with out putting down the full hp and torque thus spinning the tires. The full grunt of the engine will only come into play once the rpm's pick up when your in the straits.
It sound to me like you have the perfect setup on your car, getting all you need to the ground. If your track were paved, you would be kicking some major butt!
So, change your gears, and put hammer down all you want :)
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in 5th gear, 3000 rpm.
4.10 70 mph
3.73 77 mph
3.56 80 mph
3.42 83 mph
Ya' get the idea :)
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Tried 5th my first race. Got lapped in an 8 lap heat race. everyone runs 4th gear to the floor
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well mr. Einstien, we run the 3.73 in 4th at 10,000 rpm...whats that tell ya? ;D
I think what Pegalis is trying to tell you is that if you put in a 3.58 rear gear it will allow you to hook up better and give you more speed on the top end. This difference between a 3.58 and a 3.73 is hardly noticable except for coming off the corners. The other fast guys at my track (paved) run a 3.90 gear I run a 3.70. I beat them off the corner because I am full in the gas at the center of the corner. They need to be a little less aggressive with the go pedal. Also they will run out of steam half way down the straight which allows me to pull away. I would advise trying the 3.58 gears.
Geoff
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For the life of me, I cant find the gear ratio's of our transmission. So I used the gears of a Pantera ZF Transaxle to show what a different set of ring and pinion can do to the characteristics of the car.
If you can get me the tranny gear ratios, i can calculate the exact speed you will be going at what rpm. Off topic, i know.
Anywho... Thanks, Geoff. Your way of putting it reads a hell'of a lot better than mine :D
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Well, Geoff, I was hoping it wouldnt come down to this, I really dont feel like spending any more money this off season. Most of the guys I run with run a 3.42 or 3.58, I was hoping there was something my simple mind couldnt think of. Oh well, more duct tape on the kids shoes...they should last another year or so ;D
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Pegalis,
try this link for the gear ratios...
http://www.600racing.com/inex_info/gear_charts/516999.html
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Here is a speed chart http://f1.grp.yahoofs.com/v1/gA6ER7CYE4mJj1om6oKny54d7bsIeuYAFr87SWza5iVK-WT0Gq6bEKact3oRCT4rh-zNGtFK2TYOPyUtt_uauKoyAQE/Gearcht.txt .
Here are two gearsets a 3.42 and a 3.58 http://p206.ezboard.com/fdcrmessageboardfrm7.showMessage?topicID=6264.topic
Geoff