195 replies to this topic

[MarkH]

Good info, Thanks

[MSwiss]

Two racers just raced them, for the first time, on my tight flat track, earlier today.
 
Rob Voska ran one in an A production car, which has a G12 motor with a saloon(?) style body.
 
He had to change the brass tubing, double pin, bite bar, to one made from piano wire before the race.
 
He had practiced enough with it, the night before, the brass tube and pin heads wore to the point of jamming in the bite bar holes in the chassis.
 
He raced the car and did OK with it, running as the only A Pro, finishing about 6th overall, against 9 other B Pro cars.(bigger downforce/slower motor)
 
The other racer, Geary Gaspord, finished 3rd, running solid, but not spectacular.
 
Kevin Van Pelt won with 296 and I had 293, both running JK's.
 
We both ran 4.49 as fast time.
 
Geary had 287, 6 laps back from me, and 9 from Kevin, with a fast time of 4.60.
 
Geary had won his 3rd Open 12 race in a row, earlier, so he's a comparable driver.
 
Geary said he really liked the chassis, but noticed he wound up having bite bar issues just as Rob had.
 
He finished the race with the bite bar as shown in the below pic, with it pulled out of the chassis on one side.
 
Apparently the soft material from the pin head either wears or deforms enough, it slips through the bite bar holes.
 
I was able to push it back into the holes, after I took the pic.

 

[Zippity]

Why not use body clips instead? 

[MSwiss]

Geary is never on here to answer.

 

Most, if not all, the fast guys in our ISRA classes, use pins over clips.

[gotboostedvr6]

Clips don't give you adaquate body movement.

[swodem]

We're testing now and have these down another 10th, and also bringing the slower lanes paces up to very close to the faster lanes, only 1/10th spread

[Rob Voska]

Questions that need answered.

 

How much is allowed to be removed from the front edges of the wings for deburring?

 

What is allowed for the bite bar?  I think it will take steel piano wire with a bend at both ends.  Not much room to do anything else.  Brass & heads of pins were pretty chewed up with not much track time.

 

Is it OK to use a JK motor brace?  Stock one hung over the back of the chassis.

 

You can find pics of the Chicagoland flat track online. 

 

I didn't get off to a great start and was a sit out so I started on Red.  Usual race with a few crashes but not bad either.  I think Green I had to stop for a crash and wait on a marshal twice.  I had the steel two piece ISRA legal chassis.  The 2015 Production body.

 

4.72, 33L Red

4.76, 32L Green

4.56, 36L Blue

4.62, 35L Purple

4.72, 36L Black

4.55, 36L Yellow

4.67, 35L Orange

4.78, 34L White

 

Flattened chassis, set pans flush with the bottom of center section, close to stock bushing height (jigged for a 43T 16 deg gear).  Removed a .005 front guide spacer & replaced it before the race.  It was acting funny in warmup and that is when I noticed the pans stuck in one position with no side play.   X25 body mount holes are same place.

 

Car seemed easy to "drive" on the tight purple & black lane.  The 3 in a row faster and faster right handers leading onto the straight were not it's strong points on Red, White, Green (to loose).  Middle lanes were fine with no comments one way or the other.

 

Got a few ideas on my long drive home to try next time.

[Zippity]

Sorry, my comment re body clips was in error. I have just realised that it was the short bite bar that was being referred too  

[kvanpelt]

Rob allowed me to run his Mosseti a dozen laps in practice. I found if to be very stiff and unforgiving. I'm sure it has more to be gotten from it with development, but at this stage it is a long way from the X25 that holds the Chicagoland A production track record of 297 laps with fast lap of 4.33 sec.

[kvanpelt]

I'm looking to run this in GTP on the king. Might be it's strong suit.

[swodem]

Kvanpelt
What is your track length and what motors are you running in this class?

[kvanpelt]

ISRA A production is c-cans with a 12 arm and spec saloon type body.

B production is c-can with contender arm and Gt coupe bodies.

[kvanpelt]

Not sure of the lap length, maybe Mike can let us know and include a picture.

[MSwiss]

Track is 117 ft. on the longest lane, Red.

 

10 turns, very tight.

 

pics to follow.

[MSwiss]

Pics, including the decreasing radius turn on the hook., with 3 different radius.

 

 

 

 

 

 

[kvanpelt]

Lol. Looks easy, but a tough littler bugger to go fast, especially black. It will make or break your race.

[swodem]

Yeah can see that, those square corners are a b*tch!

[MSwiss]

Swodem,
I wonder if the 10 choppy turns, is part of the issue with the bite bar.

Have you noticed wear on the pin heads?

[swodem]

At the start I had issues with the pins working loose, but have since designed my own bite bar so that takes care of that!

[MSwiss]

If you came up with a good fix, maybe, post a pic.

IMO, that goofy bite bar setup, is the result of trying to come up with a vusual element to make the chassis look less like a JK, and not any practical reason.

[swodem]

Mike

This was my initial issue

I'm working on a proper solution that will retain proper articulation and pan height but require no pins and be self-locking

 

[swodem]

This is the first way that springs to mind, like the ISRA guys do for the X25

This one I just made from SS rod, so prob unbalances the car a little but you could make it out of tube or add a little weight to the r/h side to counterbalance...

This is 1/16th you could make from thinner rod to increase fore/aft pan articulation.

 

[swodem]

One thing i have noticed is the tires don't wear to a cone, they remain virtually true and flat wearing. 

Don't know if this is good or bad but it does indicate (to me)  very little centre section flex or tipping

[Ralph Thorne]

Once I received my new Mossetti Patriot Striker MR1006 from Mike it sat here a little longer than I expected due to life's happenings. However I finally got around to it over the weekend. I'll give my review...

 

Pros

• Really flat out of the bag

• Very durable in crash's

• Very light weight especially with the aluminum pan

• Same pin holes location as the JK so the bodies are interchangeable

 

Cons

• Guide tongue was severely bent down out of the bag which can cause problems trying to bend it back up with the material being so strong

• Pan retainer / bite bar system is iffy at best

 

With that said and the car built I went and raced it yesterday on a 115' Paperclip, a pretty fast and smooth semi banked track. We ran RH motors with GTP bodies. The last time I raced here was a few weeks ago at the OSS race when I ran a JK X25 center section with the .025 independent pans.

 

OSS Results ( with JK )

 

TQ 3.14

 

1st - 270 Laps

 

Chassis: JK X25
Chassis builder: Ralph Thorne
Gear ratio: 13/36
Body: O/S Bentley
Rear tires: Kelly

 

 

Yesterday ( with Mossetti )

 

TQ 3.16

 

1st - 270 Laps

 

Chassis: Mossetti Stiker MR1006
Chassis builder: Ralph Thorne
Gear ratio: 13/36
Body: O/SMercedes
Rear tires: Kelly

 

Flattened on the surface plate, jigged and braced. The bracing probably isn't necessary but I did it anyway out of habit / routine.

 

 

Post race bottom

 

 

Post race top

 

[Zippity]

How were the bodies mounted to the chassis in the above examples?