113 replies to this topic

[John C Martin]

I've colored several bodies with a black chisel tip Sharpie pen... done many Tony Stewarts. I do a freehand on the outside with a fine tip Sharpie, showing where to do the black paint. Taking the chisel tip to the inside, just color between the lines. Works great instead of masking.

You can do any designs, stripes, or numbers. You wipe off outside marks with lighter fluid. Let it dry a couple hours... I'm ready to paint my other colors, can or airbrush. I think it should be lighter than black paint, but it's far easier for me than masking.

[John C Martin]

Also with the chisel tip Sharpie you can color those pink spur gears that no one can read the tooth count on... when you do find out what tooth it is color the whole gear a color different for each size. Red, blue, black, and yellow show up best..

[DannyHotShot1]

When racing stop for accidents it costs you more laps and can potentially damage your car if you get tied up in one.

[flem1959]

You can spin the pinion with your fingers if you have a light touch, as there isn't much surface area on the edge of the teeth.

That said, once or twice, I've grabbed it a bit too hard and wound up with tooth marks in my skin. LOL.

Not sure if these tips were already mentioned:

1) If you don't see solder flowing out a tiny bit on the inside towards the can bushing, to be safe, you should pull the pinion and re-tin the shaft with more solder.

2) Cut notches in the shaft with your Dremel disc. Two or three on each side, 180 degrees apart. That will both "key" in the solder and increase the surface area for the solder to stick to.

I wish I would have spent a little more time soldering my pinion at the Nats last year! LOL.

Hand-out motors, I like working on my stuff at home instead of at the track.

[John C Martin]

4.5 NASCARs and trucks... this will not be one for a concours look, but for speed and handling.

I'm running 4.5 Champions, and they have the shortest distance between the uprights, so I'm cutting the front axle down to 1-5/8" and running the lightest tire and wheel combinations I can find... .675" x .400"... the tires do not touch the track, but do rotate. I use the set screw on both sides to shorten axle as much as possible... this shortens axle about 1"... about 1 gram doesn't sound like much but that along with lighter front wheels and tires at a higher center of gravity... key is lighter.

Kelly Racing for one has a new tire out on a mini hub, these with a soft compound tire, weigh next to nothing. You just need to cut wheel and tire to tech... also available in harder compounds for rear.

I've been running this combination for three years now with success. Just as tires are not needed in 4" NASCAR, they're not needed in 4.5 either... I typically run a 10 thou. guide shim for every 10 thou. of braid recess and I always run a cut-down guide.
to support this reasoning if your front tires are rolling on the track ,,as your rear tires wear your back end lowers ,,this allows guide and braid to raise allowing less braid contact and more burning braid & arcing,also your braids are flatting and wearing, because it's a see-saw effect..( front wheels between guide and rear wheels)..
Stay tuned more tips on 4.5 to come... my favorite class...

[Pablo]

Oh, but they ARE needed in 4.5" - they are mandated by the rules.

[Tex]

He may be drawing a distinction between "needed" and "required". While they are "required" by the rules, they aren't actually "needed" to make the car handle.

[John C Martin]

Pablo & Tex,

You're both 100% correct... Also this procedure allows you to not cut the wheel wells out allowing for more strength... and better aero package... just leave them clear... IF RULES ALLOW!!

Thanks for clarification, guys.

[gotboostedvr6]

The body moves better with cut-out front arches.

If the front tires touch on 4.5", the car will be better balanced and will go through the turns flatter.

IMO the wings and tires should touch at nearly the same time with the tires being ever so slightly first. With this method use very, very hard fronts.

Are you allowed to use a fixed front axle and tires that spin independently in your 4.5" rules? Do you have a front tech height?

I ran 4.5" Nastruck S16D on an oval and used to kick the sh*t out of everyone, being nearly 4 tenths faster in every lane.

I avoided using lead, I tuned with left/right tire compound, L/R hub size, tire width, etc. Mostly used Flexi 2 chassis but had a Champion or two that were faster.

To be honest I miss the 4.5" classes... might bring it up next race...

[John C Martin]

David,

We really appreciate your input, but your way of doing that is the way I did it about two score ago. But also you need to share your knowledge with your locals , you should be bored to death and your raceway should be losing racers if you do not. If you and your faster racers would schedule classes to bring these guys up to speed you'll all be happier, especially your track owner. Believe me I've been there, done that...

But thanks again. That's what this thread is all about. I would just like to help others in this hobby before they get too disgusted and quit... 4.5 NASCARs do not run well in parking lots...

[John C Martin]

I'll give you more of what I've learned from others or what I found works for me...

4.5 NASCAR, tri-oval... yes, you can use outside front tire but a hard one. I don't, I'll take a softer one, smallest hub I can get... first I true it down to .675" x .400", put on a coat of brush-on super glue or clear nail polish and let dry, true back down to .675" then repeat same process again to get a hard shell coating... and a very slick finish.

My theory is what happens with the hard tire is a wall shot as a rider or collision with someone in your lane, unless you're running a thick body, you'll bend or break you're axle. If your axle is what bends it will bend backwards and this will cause the front to be steering your front end outward... not good. Or bend the upright and chassis... then your chassis is toast until you find it and have time to fix it.

After the race... a softer, small hub tire, prepared this way, will take a much greater hit without any damage as it will cushion the blow... and the hard shell finish will keep your chassis up.

Just as the hard one would, I really just like this tire to hit about the same time as chassis... just a rub... also I do not let inside tire touch at all, nor the ear. Just take your car to inside lane coming out of the bank... you could discover sometimes the inside will be touching but the outside will not be. This will cause car to push out like it was a tricycle.

I also jig front axle geometry to angle front tire turning toward inside at least. 20 thousands... this helps steer blade toward inside of slot and helps turn front end in flatter corner. Just remember your front tires are scrubbing off speed by running through the same glue as your back tires do.

Have much more on this topic... stay tuned...

[John C Martin]

Thank you, David. I'm goin to borrow that IMO a lot, perfect for what we're talking about here...

These tips may not work for all, but they work for us. 4.5 tri-oval cars. IMO i like offsetting the rear axle as i did the front one .. i just jig chassis by adding about 10 to 15 thou. to inside pin ,in between axle and front pin on my chassis jig.. pushing axle back on inside allows car to enter turns faster futher ,,( car does'nt drift out as fast,as front & rear are turning left... sometimes a tri-oval will become a oval ,or thats the goal..) also i like to run a tire appox. 5 thous.larger dia.on the outside rear ,,much softer tire on inside, while trying to get the hardest wonder rubber i can to hold on the outside..reason for this is hardest tire will always be faster in high banks (,car does'nt scrub off as much speed.from the down force.& also does'nt change handling,, as tire does'nt wear.) also be sure to tru tire on inside as well as outside to cut down on inconsistant side-bite as inside tire drifts across slots.. .still would like everyone to put in more I.M.O. s .. would like more people to join as members ,and ask questions about anyones I.M.O.s we're doing here, with 4000 views in less than 2 months we're drawing lots of interest from you,, so help us help you

[dingleberry]

great thread John. Thanks for posting

[Gator Bob]

When applying acid flux to parts about to be soldered, I try to let the acid sit on the parts a short while and "micro-etch" into the material, creating a rougher surface for the solder to adhere to. I don't know if this REALLY happens(I'm not small enough to see what actually happens down at that level), but my brain likes to think so.

Along similar lines to what others have said before, I take my Dremel and buzz a line down 4 "sides" of an armature shaft in order for the solder to get more grip when soldering on a pinion. Of course, I let the acid flux sit on the pre-buzzed arm shaft before tinning.

Incorporating bits of what I've already said, when soldering 2 flat pieces of brass together(ex: homemade guide tongues), I Dremel buzz some squiggly lines into both flat surfaces to be soldered together and coat those surfaces with acid flux for a bit before tinning and then soldering together. I should mention that I file any rough burrs down, before tinning/soldering, that were created when I buzz the lines with my Dremel.

On motor shafts . . I acid flux, heat till it smokes off, acid flux again and tin. More flux, set pinion and heat with a clean untinned iron.

No buzz lines, just 320 paper, CRC Brake Cleaner is used before and after each step.