Tuning the Scalextric '70's Camaros

[TuscoTodd]

After seeing dreinecke's post referencing tuning the 70's Camaros, it got me looking through the boards to see if I could find any posts in regard to getting this chassis/body combination to handle better and couldn't really find anything (if there is a posting I missed - if you could point me to it, I would appreciate it!)
:)

Our local commercial track runs a vintage TransAm series using Scalextric cars on routed wood with magnabraid and epoxy painted surface (144' U.K. Black track - Mark's Model World, Canton, OH) The '69 / '70 Mustangs and '69 Camaros dominate the field and are the normal top finishers. The '70-'73 Camaros, while having the same straight away speed, just don't seem to be able to hang with the older body styles in the corners.

We are restricted to keeping the the factory tires (can be glued and trued - but no diameter change), using stock magnet (can only install it in factory magnet locations), no weight removal (lead can be added to help tune) and bushings/motors can be glued in place. (I think that covers the big items)

Any tips/tricks you guys can share (working within the restrictions noted above) that can help get this chassis / body combination to handle similar to how the '69 Camaro / Mustang handle would be greatly appreciated! (my C3065 Camaro thanks you!)
Thanks guys!
:D

[HomeRacingWorld]

Well, can you remove the 2 screws in the center that go into the interior? These can cause binding.

I would imagine you could true your wheels too. Make sure they are free of any flash molding so the tires are as true as you can get them.

Check the side to side freeplay in the rear axle. Sometimes there is excess and the tires can rub inside the body. Look at the distance of the top of the tire compared to the inside rear fender well. VERY close.

If so, shim the rear axle to minimize/eliminate it.

They didn't say you couldn't :)

[dreinecke]

On all of my 1970 Camaros, I've had massive chatter in the corners on wood. I've done the superglue/oil trick to the bushings to tighten up the diameter on all of them. I've shimmed the axle on 3 like Harry said. I would also see if you can get some float. The '70 Camaro has a very tight rear valance panel. I'd sand that and the chassis all the way around if allowed and ream the chassis holes out slightly for the screws. Back the screws out about a full to full+half turn and it will handle like a totally different car. True the wheels, tires, and front tires I'd lightly true as well.

I think the bushing trick will help immensely in the corners. I'd also give the motor a nice alcohol bath if allowed to get everything properly seated.

[TuscoTodd]

Harry -
Thank you for the things to look at!
I have run the body screws loose - but never tried removing the ones tied to the interior - I'll give that a shot.
I did true the wheels before I glued the tires on (should have mentioned that). I will double check the tire to body clearance / axle side to side play though - because you are definitely right about there not being a whole lot of room there! :)
Thank you for the things to look at and check.

Also for reference - I have never tried "adding" weight to this type of car - do they respond similar to how the pan cars do? Or does it just slow these cars down due to more rolling resistance / mass to accelerate?

(for reference - here is the track that I am running the car on: - in the video, you can get a feel for the track surface and general layout - and as can be seen, it is a fairly high speed course, where corning speed can really make/break you)

[HomeRacingWorld]

This sheet lead does help. Like any car there is that sweet spot where you have added too much and you begin to hurt instead of help.

Testing is the only way you will that spot.

And Doc is right, think about the ye olde bushing trick.

[TuscoTodd]

David -
Thank you for the additional suggestions! I have been experiencing that same chatter effect when you push it too hard and actually hang the back end out and that chatter just KILLS the speed off the corner! I will have to search for the super glue oil trick you mention - not familiar with that - but the left side bushing definitely has a good amount of play in it - so if there is a method to tighten that up - it would be awesome!
I will have to check the rear valance panel - I do remember the body being "tight" to the chassis - similar to the L88 Corvette (those are basically pinned by the lights - so not a whole lot of options while staying "stock").
Thanks again!
:D

[TuscoTodd]

Harry -
Thank you for the quick reply! I will have to start experimenting with the lead - I am assuming the standard "centered" as low as possible in the chassis, located somewhere between the front and rear axles applies to this chassis design, the same as the brass chassis lexan bodies cars? (or is there something quirky with these - as I thought I saw something in a post a while back about putting lead behind the front grill?!?)
Again, the insight you guys are offering is definitely appreciated!
:)

[HomeRacingWorld]

Well not sure on that part?

I am NOT a great tuner. Nor do I race in any series. I make mine smooth enough for my taste, but milking them for all they are worth is something others here can assist with a lot more knowledge.

I used sheet lead down low and it helped mine. Our track is smaller, but the results are that we have a pretty even field and the driver is difference.

[TuscoTodd]

OK - found the link on the super glue and oil trick and had a couple questions...
Can you use C/A glue for this - or do you need to use standard superglue?
Similarly, can the "gel" style super glue be used - or does it need to be the liquid type?
I definitely want to try this in conjunction with checking my side to side today! :D
Thanks!

[HomeRacingWorld]

I would use thinner glue. Cheap super glue works, but I have used CA.

Make SURE you oil that axle :)

[TuscoTodd]

Harry -
Again, thank you for the quick response. That is what I am hoping to do with this car/chassis type - get it competitive with the '69 type so I can do more than bring up the back of the field with it, as I really like the '70-'73 body type and would love to be able to run mid pack with it. :)

[TuscoTodd]

[Nor Cal Mike]

Todd,
No mag, my 70 Camaros are as good or better than the 68-69's although I do have one stock 68-69 that is unusually quick for reasons that I do not know.

You never mentioned what the car was doing as compared to those early Camaros & Mustangs that are beating you. Do you have a greater roll tendency? Add weight low. Is the car tail happy? Add weight high. Is the car leaving the slot front first? Add weight forward, check guide height and for bouncy front wheel/axle. But these are all no mag tricks so they won't have as much of an effect with a magnet applying force. Like Harry and David said, smooth rolling round wheels that don't have excessive play aka, blueprinting, is the key to a smooth,fast rolling car. Usually excessive play in the bushings, as all Scaley cars have, is overcome by the magnetic downforce so isn't as much of a factor in magnet cars compared to no mag racing. But you can't go wrong with accuracy and it surely wouldn't hurt to get rid of excessive play. Your rules sound prohibitive so It might be wise to check if the super glue trick is legal. If your group is running magnets, a lot of stuff that might show itself without a magnet is being masked by the downforce of the magnet. I suggest that you take the magnet out, do your tuning without it, then replace it and see what you find. There are other factors in mag racing that I have no experience with, such as mag placement (where in the chassis) and magnet height (distance from rails). Differences in these could make one car faster than another. You would have to talk to a mag racer to find more info. Does your group check downforce with a magnet marshall? If not, those fast guys may have some less than stock magnets in their cars.

[TuscoTodd]

Mike,
Thank you for the detailed reply!
I guess more detail regarding my handling deficiencies would be beneficial wouldn't it!
As noted, we do run with magnets and what I am experiencing is that she wants to tail out / drift when you try to push it on cornering speed, at which point if the drift gets much beyond about ten degrees rotation, it will start chattering the rears which scrubs a lot of speed and results in it tailing out even further and/or deslotting via spin out.
I really appreciate the general guide line on the "if this" - "do this" for where to place any added weight. I am sure that the magnet will mask this effect somewhat, so I will look at following your suggestion of first trying to tune it without the magnet first. That will eliminate the potential of the magnet "masking" the tuning and allow me to get a feel for the balance of the car and how much weight has what effect. Then after I get it running "smooth" pop the magnet back in and see how much that throws it off.

For regular racing, I don't think that we are allowed to run without a magnet based on the "stock" requirement - but I will check on that. I'm not sure if the track has a magnet marshal or not - I've never seen one used, but then again, I don't think I have ever seen anyone "protest" a car either. The general feeling I have gotten in taking to some of the other racers (although most of the fast guys don't really allude to anything one way or another) is the more magnetic pull you can get, the better, as it allows for raster corning speeds. But while that added pull does aid in that arena, it also adds a lot of drag to the car - which doesn't help it's acceleration / top speed. :-/
If I can get this sorted out on the Camaro, I will have to tackle my '69 charger next to see if I can't help it's handling as well - as it has the same "tail out" corning issue when pushed, which while fun, doesn't make it too competitive for use in our catch all "touring/stock car" class. :)

Thanks again guys!

[Nor Cal Mike]

When the tail is out, most of your magnet is away from the rail. This reduces it's effect. It also changes very quickly. That alone could cause the car to do weird things. From my limited experience driving with magnets, it seems that magnet cars can to go around the corner pretty fast without much tail out going out. Even without magnets, the quickest way around a corner is generally not with the tail out at wide angles.

I re-read you post and noted that you are running on wood with magnibraid. That means you have less force than you would have with the average plastic track. The no mag tuning tricks will likely be helpful. I suggest that you do a search for the oil/superglue trick. It has been discussed here a lot in the past. If you can stick a little weight up high which is hard to do with a full interior, that might give the outside tire a little more bite. You might also try easing up a bit on your throttle finger coming out of the corners and check to see if your lap times improve. If you use one of those fancy electronic controllers with all the knobs and doo dads, you can dial in the throttle curve to get the same effect electronically. The more you can keep the magnet over that rail the better off yo will be. You never mentioned the magnet marshall, Does your group use it. If not, how do you know that those fast guys don't have more downforce?