76 replies to this topic

[JimF]

OK... first race in flat track form.

 

I was down south at Buena Park for last weekend's flat track race on their MTT road course. I had all my various F1 chassis with me. I ran everything over several lanes and the Toronto as shown above was on average the best. I didn't do much to the set-up shown above except to add about 3 grams more nose weight, fiddle with gearing, and run through the litany of tires that I had with me. The car felt fast and easy to drive although my frame of reference for BPR is over two years old (and) the track was prepped a little weird, although I didn't know that at the time. I was practicing on Friday evening before Saturday's race and thought I had things wired so I moved out to the red lane with all my cars for some practice on this very slow lane.

• Within about 30-40 laps, the Toronto started to do oddball things. It seemed loose and tippy at the same time and chattery in some turns.
• At this point, I made a mistake and started chasing the problems.
• I added weights, I took off weights, I changed tires, I added tape to the pans.
• Eventually, I added some "L" braces to the bracket, and added a flex limiter to the fork rails.
• Finally, I soldered the floating rod that supported the rear of the center weights solid into the square tubes that it was floating in.
• All these things improved the problems a little but the car still felt rough and weird.
• Then... I switched back to a middle lane and everything was fine (even better than before).
• It turns out that the red lane had been very poorly prepped and the glue was very spotty.

Race day came on Saturday and naturally, I started on the red lane. I wasn't sure if the car was totally bad or what so I choked the car and took it very easy early on. After about two-three heats, I decided that I had something good and started pushing a bit. At the the halfway point, I was down four laps to the lead group and in fifth or sixth place. In the second half, I pushed my pace and started to come back. It is very hard to make up ground in this crowd because, they basically don't come off. I made up two laps on the eventual winner and four-five laps on everyone else and finished in second. This car was really very good and could possibly have finished better than it did (If... I had done a better job in the first three heats). This pic below shows how I have finalized the stuff that I cobbled up at the track.

• "L" braces at the rear bracket face.
• Moved the spreader bar further back and soldered the rear of the center weights to the spreader bar, thus tying the weights to the pans.
• Removed the floating rod and tubes that had supported the weights and allowed them to float independently from the pans.
• Removed the flex limiter that I had soldered in between the forward arms of the forks.
• Moving forward, I think I'll leave the bracket braces in place. I could convert this to a speedway version in 30 seconds by just unsoldering the center weights from the spreader bar and dropping them out.

[Tim Wilkins]

You did very well, Jim, especially considering your time away from the track. Debbie of BPR tells me they use a different type of prep glue on the flat track than the blue King so track conditions are always changing.  

 

Tire selection is always key and that seems to change from race to race. I'm still trying to figure it out after two years. 

[JimF]

Tim:

 

Thanks, I didn't know that about the glue difference. I do know that they use Coleman fuel as the cleaner and glue carrier media and some think that can be problematic at times. Actually, I almost never run the King so I don't compare the two that much (although that may change).

 

My problem was two-fold. After I went out on red to practice, the car was OK for a few laps and then started to get weird. It got progressively weirder and I 'chased' the problems to distraction. I hacked and ground and threw on weights and then took 'em off again. I ran through every tire I could think of and basically lost confidence when I shouldn't have.

 

The other thing was, after I realized the car was ok after all, I still didn't know if it was actually competitive or not. I didn't want to go out and be a rolling roadblock and I thought that the field might just go flying past left and right. So, I choked the car for the first two heats and tried to feel it out. After a while, it turned out that the car was really good and I could race... so I did. The car was fine all along but my brain malfunctioned.

[Joexemm]

Might i ask probably a silly question about this build as i am new to all this scratch building stuff.

 

the forks... are they soldered into the tubes at the front as well or only in the rear to the motor block? i understand the tubes are soldered to the nose piece... but inside...  i just don't know!

[JimF]

They are not soldered into the tubes. The fact that the forks turn freely in the tubes is the factor that makes this design what it is. Of course, they could be soldered solidly at the front but then the frame would work entirely differently.

[Joexemm]

okay cool beans thanks jim! we will see what i get when im done! looking forward to building this thing!

[Joexemm]

WELL THERE! what do you think there mister Jim sir?!?!

[JimF]

You did it!!!!!............................WTG.

[olescratch]

Look's good to me.  FWIW, some solder the wires in the tubes, some don't.  Soldering will make the chassis stiffer, less flex.  You can also solder the wires together to create an even stiffer result.

[Tim Neja]

Looks nice and clean Joe!! Nice job!  Mine works really well on our flat track at BPR with a little weight put in those open areas ahead of the fork!! Just like in Jim's pics!!  

[Joexemm]

Hahaha thanks guys! got a tumbler so she should be all pretty soon enough. also i started this build for a flat track race that i never made it too so i made a few changes for a king ill be on for the fall brawl at speed zone.  I went up a gauge on the main rails to stiffen the chassis. i still have to build the weight plates in the middle but otherwise its identical. I'm sure there is a better configuration for a king but if it works on a flat then i can drive it on something with a banked turn. i personally consider myself more of a flat track driver. =) im STOKED to get it on the track though!

[Tim Neja]

You probably should build "lighter" weights for the King!  I'd go with .062 for flat track and .032 for King weights! You can just place them like Jim did---attached to the outer rails and they'll shake with them!  Good luck and have FUN!! 

[JimF]

Joe:

 

Been offline for a few days but some great input from Tim. My experience with this chassis is that it works really well on both styles of track with the weights as your tuning option. In the intro to the thread, there are some that I built up mostly from scratch while waiting for the 'official' kit to get here. I have raced all of these on moderately banked tracks at weights between 94-98 gr and they have been very good. As Tim mentioned, how thick your brass weights are is another tuning option. For a very twisty, 90' flat track, I have even added lead to the tops of the center weights.

 

You can work with the fork/tube arrangement as you choose but IMO, the thing that allows this frame to be so forgiving is the ability of the forks to twist in the tubes. My personal feeling is that that feature allows an enormous amount of flex without the chassis being so "bitey" that it is difficult to drive. You may find differently however.

 

Congrats on the build and now you get to work on the next and probably most important factor which is tuning.

[JimF]

Here's an update showing a different version of the R-Geo Toronto concept. This car has been raced once with little tuning on a speedway track and also tested on two different flat tracks of varying technicity. This view shows the frame as it is now (currently being hacked on to refine a few things) This one uses the 3/4" nosepiece and bracket as issued. The stock pans are modified and used in a different way.

 

This view shows the main differences in the pan layout. 

• The front and rear sections of the pans as supplied are cut off at the dotted lines.
• These are then soldered to the center frame section, fore and aft as shown.
• Pan hinges are .055 wire in 3/32 tube for the front and .047 wire in 3/32 sq. tube at rear.
• One crosspiece ties the two pans together and also provides a rear mount point for center weights.
• As shown here, with center weights in place, this runs 107 gr. all up.

 

Nose-on view shows the usage of the cut off forward pan parts.

• Tips of pans soldered solid to center section.
• Additional front axle support runs outboard to 1.625" width.
• Additional axle support is wire tied to front axle.

 

 

Rear detail view:

• R-Geo .050 bracket plate in place and trimmed so as to tie in with pan tail pieces.
• Tail pieces of pans in place and carrying hinge tubes for rear stops. (.047 wire in 3/32" tubes)
• Also shows crosspiece soldered to pans and center weights.
• Small bits of .062 wire soldered at rear of the forks braces the front of the bracket.

 

 

Bottom rail detail. Shows that the main frame rails are 1X .047 wire and 2X .047 brass.

 

• Soldered only at front and rear.
• This chassis is very smooth and stable and tested very well on a non-tehnical flat track at 107 gr.
• With 7 gr. additional weight, it was excellent on a very tecnhical flat track.
• This car should be excellent on moderately banked hillclimbs or King treacks.
• One concern is that a track with an abrupt transition from straight>bank may induce too much flex in the main rails.

 

 

I have plenty of other, good, F-1 designs that don't need further development so this one will get the majority of my testing in the next few months.

[Rick]

Another awesome build by Jim! I think the addition of the brass rails will be a very positive one. I am sure this will spark racers to build a clone and follow your lead. I am so surprised that you have over 8000 views and so little dialog about your builds?....

[Samiam]

Rick,

I was told when the masters are at work watch and learn.

[MSwiss]

. I am so surprised that you have over 8000 views and so little dialog about your builds?....

I think this build/thread has a fair amount of feedback / dialog.

 

That said, on others, I would say the reasons they might not get more dialog are.

 

1-Jim's posts are so detailed, questions that guys would normally ask, have already been answered.

 

2-A lot of the tracks that Jim runs on are so unique, they don't translate to the rest of the country.

Guys are probably more interested how to beat Willy on a King, than Ted Essy on a Korkscrew.

 

3-While I don't disagree with the reason they do it, running the slower motor in F1, relating how the 105G F1 car is lapping faster than the 117G one, doesn't mean much to anyone else around the World, because they are all using much faster Retro Hawk's and 4002FK's.

 

4-When he relates results of his extensive testing, and opens with "When I went to test, the track was extremely loose", I switch stations. I'm not interested how cars perform in poor conditions, because the chances I'll ever encounter them, in a race, are very slim.

[JimF]

Mike, thanks for that analysis very good stuff. Some additional thoughts................

 

• #1 - Thank you.
• #2 - Yes, our flat tracks are FTMP far more technical than most and that's what we run F-1 on 90% of the time. Therefore that's often what I report on. However, we do have two King tracks and a pretty fast hillclimb. These are not outliers where the rest of the world is concerned. The slot car world does not necessarily revolve around the latest Gerding Vundertrack.
• #3 - We run a slower motor for sure and there's a reason for it. However...that does not preclude the validity of performance results in evaluating a build. As an example, an F-1 build that I posted here has won races in NorCal with slow motors and in SoCal with fast motors. A good chassis works.
• #4 - Yeah.....our conditions are often poor at best. Don't blame you for changing channels on that. It's what we have to work with. I can't report on something that's not available.

 

Thanks again for those insights. I guess if I just wanted to generate dialog, I'd stretch a build out over a week or two and discuss each solder joint and dremel cut in depth. However, that's just not me so you get what you get. Hope it's good enough.

[Tim Neja]

Jim please don't worry if it's "good enough"!! You're in depth descriptions and build tutorials are second to NONE!! Guys like me really appreciate it--I can't create anything--but I'm pretty good at copying--so your builds and pictures are like GOLD to me and I"m sure many others!! THANK YOU for taking the time to do them and relate your testing tips as well!! I've learned a LOT and will continue to learn with your guidance! Keep it up my friend!!

[Dennis David]

I agree, your build reports are the best out there. A lot of hard work with crystal clear pictures that are much valued.

 

Conditions are such because you race at four very different raceways. One that seems to cater more to the RC crowd and another that's its "own world" LOL

 

With my son moving to Fresno I hope to visit the track in Modesto.

[MSwiss]

One that seems to cater more to the RC crowd.

That helps explain the track conditions situation.

That the facility is focused on something else.

I'm just used to get taken to task, for trivial stuff, like if I run out of Twix in the snack counter, so something important, like a dirty track, has zero chance of "flying", by me. Lol

As I've said before, Jim's detailed build and test articles, along with his dedication running Nor-Cal Retro racing, is one of the many reasons retro racing in general, has had a strong 9-10 year run.

[JimF]

Conditions are such because you race at four very different raceways. One that seems to cater more to the RC crowd and another that's its "own world" LOL

 

With my son moving to Fresno I hope to visit the track in Modesto.

 

Boyoboy!...........you said a mouthful with that one. Yes.........each raceway has it's own ideas of what track maintenance (or not!) should be. Interestingly, the two that you didn't allude to are generally the best conditions over the long haul. I think you'll enjoy Motown. Like Mike Swiss, Frank Sarkela and Gene Braham are both racers themselves and often participate when retro comes their way. Gene even travels for Retro a little bit. Those guys understand that when a racer drives a long way to get there, a piss-poor tack condition is really disappointing.

[MikeC]

They both also have little to no rental traffic, so their tracks are easier to maintain...  The R/C stuff is what allows the track in reference to stay open, and provide the space necessary for 3 road courses and a drag strip.  Without the R/C stuff, there would be no tracks, at least not at that facility...

 

Track conditions may vary between races, but I don't believe the track has ever been in poor condition on race day, which I would think is far more important...

[SlowBeas]

Jim,

 

I need to thank you again for this great tutorial and test report.

 

I obtained a Toronto F1 and excitedly built it according to your instructions above, following them to a tee. But when I put the car on the track, I could NOT get the thing to stay on. One de-slot after another. I worked with a couple of well-respected and known racers who have had great results in the F1 arena, but neither could figure out what the heck was wrong with mine. Total frustration set in, and I was ready to scrap it and start over.

 

Then, just the other day, I re-read the above posts and spotted something so very simple: try soldering a small piece of wire at the junction of the fork.

 

Although I'd never inhibited the fork on any other such build I'd created, I thoughtI'd give it a shot. What did I have to lose?

 

I took the F1 back to Foothills Speedway in Inman, S.C. and placed it on the Dadds Corner Climb and ... incredibly ... it flew around the track and handled beautifully.  Now, I can't wait for a chance to put it to the real test in a retro race.

 

Sometimes, the simplest solutions can be the best.

 

Again, my thanks for all your writings.

jb

[JimF]

Jim.......thanks for that feedback. The tuning and flex management on these cars is key and sometimes you have to work on it a bit. This is why I call some cars "no-brainers" while others are not. The ones that are not no brainers can often prove out to be ultimately faster, but it can take some work to get them there and you can just plain "miss it" too.

 

The July 2016 version has now shown to be very good everywhere I've tried it without the addition of the wire bit at the junction of the forks. However, the original can often benefit from that addition. If a problem arises with one of these, the solder joint at the fork junction is one of the first things I'd try. It's super easy to do and undo. The newer version also likes to be around 115-120 for most of our twisty flat tracks.