76 replies to this topic

[JimF]

Here's a quickie update based upon some additional testing of prototype #1 and first tests of prototype #2 (the 95 gram one)

 

Something to keep in mind here is that the real key to this chassis is Rick's original fork/main rail set-up (and) the pan limiter. The bits and pieces that surround the concept, are (I think) peripheral.

 

Prototype #1... the light one.

• I have left this one alone other than tire tuning and gearing.
• This is a spectacularly fast car on our speedway tracks with our S7 Mini Brute motors.
• I have tried this one now on two different flat tracks with just a gearing change.
• On the flatsters, this car was better than expected, very fast, but... a little tough to drive.

Prototype #2... the heavier one.

• Car #1 is closer to the way the kit will build out, but #2 is closer in weight.
• Car #2 tested faster than car #1 in its first speedway outing.
• The little flex limiter explained here was an improvement to some extent in wheel hop on startup.
• However, that little part in between the main rails and fork rails was not enough and the 'V' limiter was needed.
• The heavier car #2 was notably easier to drive on the flat track. Still no center weights.
• I think that the heavier layout with center weights such as shown in the article will enable this to be killer for flat tracks, too.

[Rick]

A very easy option for the center weights. Use a piece of .062" tube on the static end. Slide a piece of .039" thru with a small hook/"L" on one end. Tack the end of the wire to the pan to install, unsolder to remove. Can add or take away center weights at will...

[Horsepower]

Geez, that is some beautiful stuff. Jim! Sweet!

[JimF]

Thanks very much, Gary.

[JimF]

Update from Race #1 on the Toronto chassis.

 

I raced the heavier of the two cars shown above to a win and fastest race time in its first outing on the fast Hillclimb at Motown raceway in Modesto, CA. Scotty Campbell borrowed the lighter car and ran it to third place one lap back and the second fastest race time. Both cars were exceptional and I was on the fence about which one to race myself. Eventually when I found out that Scotty wanted to borrow a car I just sort of grabbed one for him and he almost beat me with it.

 

After setting them up and racing them, I'd say the Toronto is very easy to tune. Both cars ran well with a variety of tires and I raced a JK 8763 treated and narrowed while Scotty ran an 8713 untreated full width. There was little to choose between the two and either car could have won this race.

 

This is a gooood basic platform. I'll be converting both to flat track configuration and testing again starting late this week.

[Rick]

For the left coast BP racers that like light, I can make the kit with .050" pans and .040" motor box and drop another 6 grams off the car. Git ya some of that!...

[Michael Rigsby]

Jim,

 

I am going to build my Toronto F1 kit using the guide you generously published here. 

 

In your opinion, on a 153 ft Oglivie high speed Hillclimb, would you use the 4-1/16" wheelbase, or tend to use the 4-1/8" wheelbase? I'm kind of leaning toward the smaller wheelbase with .047" rails to build the lighter car to tune with lead if need be. Most of our tracks in Florida are Hillclimbs with only one King track on the race circuit, and ours is the longest Hillclimb in the series.

 

Typically, most of the racers here run lighter cars then add weight.

[Michael Rigsby]

My Toronto F1 build. With bearings, less front axle 48.0 grams. 4-1/16" wheelbase.

 

[Rick]

Looks good, Mike. The torsion wires from the tuning fork to pans should not be soldered to the pan, it just lays on top of the pan...

[Michael Rigsby]

Easily fixed. I can see now in his description that the "V" is soldered to the tuning forks themselves and rests on the pan. Will fix that tomorrow if the axles and wheels get here to finish it off.

[SlowBeas]

So the tuning fork is inclined to bend downward rather than upward? This is why I read the advice of others before building.

[Rick]

Jim did a terrific pictorial on the build. This is a pretty easy build for a novice builder to follow and complete.

 

The wire(s) that are soldered to the tuning fork/wishbone can also be used for tuning the car. One can try different diameter wire here to get different torsion actions. I prefer my wires not joined like JIm prefers, but this is probably more driving style. On the maiden run of my Toronto, it was the fastest F1 at the Penn-Ohio race at REM, not with me driving it (of course). But it was the only F1 that logged a sub-5 (4.90) second lap in practice Friday night...

[Tim Neja]

I'm just finishing up my build like yours Jim!! Hoping to use it on the flat track at the upcoming Checkpoint Race!!  Very nice simple build with RGEO parts!! Nice kit Rick!! I'll post a pick when it's done!  Thanks for the tutorial Jim--makes an easy build!!! 

[Tim Neja]

OK – finished up my project.  

 

First pic shows the center section per Jim's instructions! Basic and assembled per his suggestions of making sure that none of the wires has ANY tension in any direction.  Heated all the joints on a flat block to let them "settle" where they wanted to be – then checked on the jig to ensure all alignment was still correct.

 

 

Second pic is the rails and axles added. I have not added any of the torsion limiters yet at this point. I though I'd run the car first and see what it needed, as these are all additive in nature. 

 

 

Third pic is the completed frame with all the bits attached. And the final pic is RTR – should be able to get over to BPR after Christmas and test this baby. AUW came in right at 96 grams. I'm not sure that "ultra" lightweight is so critical to going fast in F1. It's more about the handling!! I'll let you know what the drive tests are like both on the flat track and the King.

 

 

 

Merry Christmas

 

OK, per Rick's suggestion, the last pic shows the little "V" dampener!! It will be interesting to see what it does against some of my more standard fork/wishbone builds! 

 

 

 

[Tim Neja]

OK, I'll update this latest build! It really did work great. Thanks, Jim and Rick!!

I ran this on the flat track at the Checkpoint Cup race and placed fourth in the A Main with it! The car needed a little weight – I should have built the little weights for the middle like Jim did – but I just added stick-on weight to the side pans, and adding only 6 grams for a total weight of 106.  

The car was very smooth and predictable. I ran a Retro Hawk with an 8 tooth pinion. I've never run smaller than a 9 before on the flat track but the 8 gave great brakes and made the car really pull out of the corners!! I think a 9 may have been faster and could have got me over the top for the win... but a cleaner drive may have done that as well. The race was very clean, but still the usual assortment of "offs" from flat track racing.  

All in all, very satisfied with the car and the parts Rick sold me!! I'll have to build a couple of more of these, maybe a lighter one for the King track as well. But it really turned into a very drivable fast car!!
 
A couple of observations. The little "V" dampener worked great – eliminated any wheel hop or chatter!! It did add 4 grams to the build so all up weight without lead was 100 even!
 
And this car makes bite!!! I ended up running JK 8713 treated tires 1/8" narrowed!! The usual tire of choice on the flat track is 8713p or 8703p as we are usually looking for bite!! My other cars needed 8713ps to get the same bite as this one with the treated tires!! I could almost get away with Wonder rubber, but not quite! This car should work fine on the King, too – but I was too burned out and tired to make it three days in a row!!

[Michael Rigsby]

Nice build, Tim. 

 

I did change mine over to a floating front pin tube mount like you have on yours and dropped the crossbar pan stop I had, and it did stop the chatter coming out of the deadman on our Hillclimb. In the original build iteration, even with the V pieces over the fork, I was getting some chatter, so changed to the floating tube and it stopped... go figure.  Will have to get to a King track to see how it does on a King.

 

In race trim, mine came in about 102.5 grams. Seems on our track the couple extra grams of weight added to the rear of the pans made it quicker through the donut.

[George Blaha]

Thanks, guyze, great pics and descriptions!

 

Shakey George

[Rick]

Duran Trujillo just chimed in and reported he TQ'd the Flat track race at the Checkpoint Cup by about a tenth, then went on to win the race by 10 laps. Says it was smooth, fast, and consistent. Bryan should have pictures up soon of all the cars.

 

Thanks and congrats, Duran...

[Tim Neja]

Oh yeah, Duran's car was just a little quicker than mine through the donut and the kink on the flat track.

 

But I'm not sure if it was his car, or his ability to simply outdrive me with just about anything!!  I don't think you could get any car that was easier to drive than mine. I DO think I needed to go with a 9 tooth pinion as it may have been a little faster – I really only needed about 1/2 a tenth – but I didn't try it when I got the car handling so smoothly. I just "went with it"!!

[Rick]

Tim, it was Duran, he would have probably done the same thing if the cars were switched! Damn kids!!

[DCR]

A very nice-looking F1, Rick!

 

DC

[JimF]

Thanks very much to all for the additional input on this frame and design. As most probably know by now, I have been really ill for some months and have had no interest in slots at all. Today is first log-in to the Blog since around Thanksgiving or so. I'm stll not in race or build mode for a while but will check the blog periodically, for updates and questions.

 

Thanks again to all...

 

JF

[Mike K]

Be well, Jim!

[SlowBeas]

Jim F,

 

Glad to see you're bouncing back. We've missed your insights.

 

Best always,

 

Jim B

[JimF]

Here's a long overdue update on the Toronto in flat track form. Since my last posts, it has raced twice more in speedway form, at ~94 grams (no center weights). Got a win and a second. This frame is exceptional for such a light car, but it's just too light for our more technical flat tracks. Recent testing has been on the twisty 90' Korkscrew at Motown raceway in Modesto.

 

The bar was set by my multi rail F1 that has won the last two here that I've made it to. The multi rail is smooth, easy, and does nothing dramatic. It races at about 120 grams and always likes treated tires on this track..

 

Stage one for the Toronto was to fill the spaces in between the fork rails with 1/16" brass plate and a small dollop of lead under the front axle. Set up that way, it was about 110 grams. The Toronto was immediately a little bit faster than my target car but not real easy to drive. It was just a little jerky in the connected turns. I ran through tires and it got a little easier (but no faster) with untreated small hub JKs (8703 PP) So, I added what weight I could fit on top of the weight plates and it came together.

 

So... stage two (shown below) has the weight plates made from 3/32" brass plate. With no extra lead on the plates, the car was now at 116 grams. I left the little dollop of nose weight where it was. In this form, the car was tested on the flattish Kingleman at Fast Track Hobbies vs all the other flat track cars that I have. This was the fastest of the bunch and handled the fairly tight donut/lead-on combo better than my other cars. For the Kingleman, the car was actually heavier than it needed to be but all the other cars were weighted up too so it was a fair test. I won't be at Motown to go back on the Korkscrew for about a week but I'm guessing that this may be my new best car for that track.

 

(Although I do have a couple a couple of other new cars that show great promise as well.)

 

 

So... I'm not bailing on the simple, multi-rail cars yet. They work everywhere. However, the Toronto has already proven that is can be faster on speedway tracks and it may just may turn out to be faster on flat tracks as well.