27 replies to this topic

[Pablo]

I am no expert on tracks and my question is about adjusting a car to adapt to a specific problem spot.
Specifically, bad spots in the braid that happen from time to time.
 
Example, somebody deslots in the same place lap after lap then says "Braid is up on orange." "Track" is called, somebody gets the roller tool and runs it back and forth pushing the braid down. Somotimes when it's really bad, out comes the braid glue, the roller, and a heat gun.
 
The term "braid is up," to me, means it has come loose from the glue and is lifting vertically. Correct?
We adjust when going to a race at a different track that has deeper braid recess by adding flag spacers, correct? Then we return to our home track which has less recess, and remove the spacers. OK?
 
Here is the part that has me confused. I've been trimming the braid back, or swapping to thinner braid, and/or removing a spacer. Last night a smart racer recommended adding a 10 thou spacer - and it worked!
 
Totally backwards from my experience. What am I missing? Call me perplexed or dazed and confused.
 
Please help.  
 
Pablo

[Bill from NH]

I've not heard of setting the guide deeper for worn braid, but since it works, keep it up. You could do yourself a favor when setting up a car by always putting a .010" spacer on top of the chassis before adding the guide nut. That way you'll always have a spacer to use whenever you run into bad braid. 

[Pablo]

Thanks, Bill. Yes I'm aware of that trick and always put one above.

 

The only insight on the question "why does planting the flag/braid deeper when the track braid is raising up" I've received so far is this:In my own words - It's counterintuitive. Theory says it's the wrong way to do it, yet it works anyway.

 

The cars don't like being down super-low through the bad spots.

 

Not always. And, not on all chassis and/or all cars. But right now it's working.

 

I learned some other things today:

- It may not always be the braid upsetting the car. 

- The braid heights on each side may be unequal.

- Sometimes running the braid full length alleviates the problem.

 

Onward.... 

[Dominator]

Guide spacing is dependent on the type of car.  With Retros .005" can make the difference between an average car or a great car depending on the track.

 

When setting up for a new track with Retros, I'll look to see how recessed the braid is (say .015"). Then use a set-up block with the guide in the .015" slot so when I push down on the guide post the rear wheels don't lift but they do at .020". Adding/removing spacers as needed. 

 

After that it's to on track testing. If the car is loose I'll add a .005" spacer to see if there is improvement and keep adding until times improve. I"ll do the opposite if the nose of the car is tipping out of the corners.  

 

For LMP/flexi type classes too much front drag will slow the car down. A little rub is a good thing.  

 

Adjusting the braid length also adjusts the guide spacing. Adjusting the braid length is more common in wing car but some retro racers do this to help reduce drag. I've tested and have gotten mixed results.  

[NSwanberg]

Perhaps the smart guy knew that the car was not popping because of a bad spot in the braid but because of a bad or high spot on the track. Stranger things... have happened.

[Bill Seitz]

I've discovered slot tracks with "quirks," as I've begun calling them, are not uncommon. A "quirk" can sometimes be sections of lifted, frayed, or uneven braid (undulations in braid height aren't uncommon either), but I've also seen track roadway surface irregularities that lead to cars de-slotting or not holding the track as well as they might.

 

Sometimes these get referred to as braid problems if no one realizes the true cause. A situation where raising the front ride height by adding a guide spacer helped is probably a track irregularity or "quir.," I'm often surprised at how many fine-looking tracks have drooping turns, shallow dips and bumps, excessive gradients, and sections that meet at angles – all of which aid cars in de-slotting. Sections can meet flush but still not be "flat." that is, meet at a 0 angle. I've been told this adds driving challenge and character to a track, but it also usually causes plenty of de-slotting and sometimes spectacular launch pads, and unfortunately there's not much that can be done to the car setup to improve things – they mostly have to be driven around.

[Pablo]

Makes me wonder if anybody ever tried building a track out of synthetic wood like they use for house decks.

[Mark Onofri]

The coefficient of expansion is extreme.
 
One of if not the best thing I've done as far as setting up the car was to purchase a braid depth tech plate. PCH also has braid in different thickness for the true fanatics. It allows for quick adjustment from lane to lane.

[Cheater]

As I related almost 20 years ago in my so-called 'T-Flex Tome,' my approach was to test guide height on the track to determine what spacer stack generated the best lap times and/or best driving car.

 

"It's worth mentioning that testing guide flag spacer height is extremely important. Once you get the spacer height you think is best, it is almost always worth testing spacer stacks of plus and minus .005- and .010-inch, as you will often find the car feels better or is faster with one of the other spacer heights. In general, we want the front of the chassis to just barely clear the track surface on the straights, about the thickness of a piece of typing paper. But again, the quality of the track will affect this, which is why you have to test guide flag spacer height on the track."

Where the braid depth varies around the track, using a set-up block to set to a particular height can't account for that variance. Testing to see what guide height gives the bext lap times is IMO the best approach. As Dom said, .005" can make the difference between an average car or a great car.

[Mark Onofri]

I wish I'd known that 20-50 years ago. When you consider what 0.05" is in 1/1 as opposed to 1/24 it makes sense.
 
Haven't decided yet if the weighted flag is as effective as the depth but, the combination is definitely apparent.
 
Now I only deslot 10-15 times in a 2-minute heat as opposed to 20-30 times.

[Bill from NH]

Are your 10-15 deslots caused by driver errors or mechanical issues on the cars? I would consider that many during a complete race as high.

[Mark Onofri]

Dane bramage.

[Rob Voska]

Through a great friend who was a Lee Gilbert customer... run as high as possible until the car slows down. 

 

But I don't like tippy cars either.

[Mark Onofri]

Couldn't understand why, aside from de-sloting a bazillion times, why I was getting my 🫏🫴ed to me that I was using the o'll faithful Champion gauge when everyone else was at
》=0.055"🙄

[Dave Crevie]

50 years ago everyone ran drop arms. Variances in braid depth weren't such an issue.

[Bill from NH]

Dave, I missed your postings. Have you been well?

[John Luongo]

Great topic and information.

 

For some tracks that appear to have more irregular braid depth and/or track surface issues that "cause" me to de-slot, I will install a small, very thin bellville spring washer between the guide flag and the chassis to act like a reactive cushioning spacer to minimize de-slotting due to track and braid conditions. I adjust the spring tension by cutting internal slots in the washer. i have found this usefull especially when setting up one chassis for a particular track without having to add additional front end weight. as mentioned above.

 

A decent drop arm arrangement could resolve this issue.

 

Warmest regards,

[Dave Crevie]

Dave, I missed your postings. Have you been well?

 

In November I had a serious health issue and am still in the hospital. Just recently become lucid enough to post on Slotblog.

[John Luongo]

In the words of lone watie, "endeavor to persevere," my friend.

[Mark Onofri]

John is not alone in missing your imput.

To clarify my "50 years" of deslotting, I was referring to my lack of driving prowess.

But, I can put a 280ZX in a drift like a it's out of hell

[Bill from NH]

John, wouldn't it be easier to set up a drop arm Retro chassis?

 

When he lived in California, I recall Greg Gilbert running some competitive drop arm Retro chassis built by Dennis 'Foamy' Hill at Buena Park.

[John Luongo]

I think it would be, Bill. I have Can-Am and Stock Car Retro chassis with drop arms. A bit more complicated on an F1 chassis, but still doable. It alowes me to mount a different front body height or use a body that would otherwise drag on the nose.

[Mark Onofri]

John, didn't you post/reference a 1/32 drop arm car for your home track?

[John Luongo]

Yes, I did. I built three modified Womp chassis with drop arms. The home track is fairly smooth with even braid depth but the excercise was to see how a relatively short angular drop arm Womp chassis would do on other tracks. It showed promise even though the grand kids didn't notice it.

[Dave Crevie]

I got away from drop arms even in the early sixties. I learned to "feel out" the bad spots, and blip if necessary. But tracks got better, and drop arms weren't needed any more. Bad braid really is the responsibility of the track owner, and reflects the pride he takes in his facility. { it's why I stuck with Chicagoland for all the years }