G12 motor performance drop off

[Ron]

spring tension is to light . Use a 5 coil spring if you can . I have had a lot of success using Camen regular springs . I have noticed that the Cahoza 5 coil spring has exactly the same tension as the Camen regular the only difference is that the Cahoza springs are plated . I dip my Cahoza springs in arm dye to stop them from rusting .Use shunts if the rules allow them .

[Crash]

Hi Guys, Not sure if I have the answer.. However, it definately sounds like with the long chutes and 8T pinions that the motors are getting hot and losing performance.. Had that same problem in old Hobby Town location prior to big dia arms...Yes it even happened with small arms...Though not as bad as what you guys are describing here.... Though that would be my first try at solving the problem...Try going back to old school small dia arms, .530-.532 hole, with those 8T pinions, maybe 42 deg arms, even old style cans for better magnetic field.. Something to try with big arms, 7/40 for a bit more chute speed. You are going to have a more violent motor with the old stuff...But it might help using the old setups, RF,PS,Mura??? for a stronger field.. Here I would use full brushes to keep tension as well... In my flat track racing I have not used full brushes in years.. Too much brakes at 7/42...Slot the hardware and use short brushes... Always have to have some brake dialed in instead of no brakes and too much brakes.. Only my best buddy Radisich can drive them them way... Not me anymore... I know this is a bit late and youi might have solved it already but here's my two cents worth... Lots of testing to figure it out..

[Crash]

Where restricted to 3 coil springs in NCal.. I've used PS and Cahoza springs..The medium springs... Don't remember what numbers I got with my fiddle stick... I don't use new springs... I test run new ones and after a few hundred laps if they read the same as before they become race springs... If you are not restricted to 3 coil then use 5 coil Camen springs...There are several different tensions available... At least there were in the past.. I have not talked with GEEZ in a while about springs... All of mine are at least 25 years old..Hope this helps a little..
Keep me informed... Later Crash

[Ron]

If your springs are 25 years old then throw them away . Cahoza make a heavy 3 coil spring CAH-255

[Crash]

I guess I should have pointed out that my 25 year old springs still work just fine.. The point I tried to make was that I do put "new" springs on a race motor.. I test them in a potential race distance before ever "trusting" them to be a race set of springs...This is why I stay off of blogs and sites... Looks like I made another mistake in trying to help...

[Bill from NH]

You made no mistake Fred. You passed on information that could become very useful to others. I've got one of John Thorpe's original brass fiddle sticks & some old springs I ran back in the 70's. There's not many shops left in this region where I could still use either.

[swodem]

How does it go now?
The more you run them the more familiar you’ll be with what’s needed
Maybe that gap is a little large?

[Sam pan]

Crash,
Before you leave blogging, could you tell me the major differences between how a Box-l2 wing car motor is built vs. a ES flat track car. I have gp-l2 motors that were all originally built for wing. I think all the arms are .5l3" but I have to check them.

[Crash]

Crash,
Before you leave blogging, could you tell me the major differences between how a Box-l2 wing car motor is built vs. a ES flat track car. I have gp-l2 motors that were all originally built for wing. I think all the arms are .5l3" but I have to check them.

I'm not sure what you mean by "a ES flat track car" If you want to know difference in how I built 12 motors for air car tracks Vs how I built them for flat track racing.. Here goes: I never raced box12 air cars. But with long chutes a small dia arm ".510-.518" should be in .530 range. I've had motors lose brakes with .532-.533 hole and 8T pinions. Might even go down to .528-.530 range and try that. now for flat track racing: small arms my usual gap was .535, I've gone as big as .540 but found that too soft, however that was a long time ago and chassis's and bodies have improved tremendously so it might work now. Over in England I've seen a trusted motor builder go as big as .545 for their short tight tracks.. 7T and even 6T so gear them correctly. That seems to work here and there. Now for the big dia arms.. I use .560-.565 hole with .537-.538 arms.. That's what they read after returning from GEEZ who made the round and rebalanced them after I put on the 150-200 lap first heat cycle.. I use 42-45 deg arms from PS.. the larger arms seem to get round the tracks faster, less torque, makes a smoother motor. I want to be WFO long before the lump ever hits the straight bits..When ever possible..Hope this helps...
Crash

[Crash]

Sorry guys, I also forgot me mention that every time my lumps hit the track they have fresh com You mightcut and zapped. In this situation with Cahoza setups, T5's might be a slightly better. Also might try 7/40 to gain a little speed Vs the 7/42 trial and error... You might also put in full length brushes if you didn't already. I don't use them as I want to have some brake dialed in , not brakes all the way off and too much brakes..Hope some of these things helped a little... It certainly is no fun when brakes go away... Thankfully that has not happened to me a a long time...keep em in the slot

[nswanberg]

Cut the shunts.

[Wallbasher]

Ran a Cahoza with a small dia Koford X12 on a flat track. Geared 6/42. Was fast for around 80-100 laps & would flatten off and start slowing down. Motor ran very well, no heat, great lap times on flat tracks. Tried brushes, springs, weaker mags and nothing helped. Gave up on it when it was time to put a new arm in and didn't want to cut another shaft to 1.5mm. Simply ran out of things to try. 7/42 gearing & it would run just fine.

[Crash]

This has gone one for a long time now, HEY JENSON46, has anything posted here helped with your problem??? Someone said in their post that motor would go away in second race.. I'll try and make it as simple as possible: Since the 7T/72P and now 6T/64P pinions have become available I have never lost brakes with a GT12. Every time one of my lumps hits the track for a race, it has fresh com cut, fresh brushes/whatever length you choose, fresh zap, approx 10min breakin on 3-4 V, and then when it hits the track, several laps cruizing round graduially before wide open, just in case power is hot, don't want to glaze the com's, that's an old air car habit from back in the day in glue when it was easy to glaze the com going to full power too soon in glue and hot power.. Probably doesn't do a thing now, just old habit from an ole fart..... THE LUMPS NEVER GO ONTO TRACK FOR A SECOND RACE WITHOUT ALL THE PREVIOUIS THINGS BEING DONE... Note: I call all my cars lumps everyone else's lumps/lumps as well.. Please tell me this problem is solved, it's been waaaay too long for this to still be an issue.. keep em in the slot

[Crash]

Hi Wallbasher, i assume the first run was new out of the bag??? After it slowed did you cut the com before changing brushes, springs?? Weaker mags means you removed the originals and installed new ones and nothing helped... sounds like 6/42 was a bit too low and it was running out of RPM on main chute or chutes, causing brushes to bounce, soon as that happenes it just gets worse, the more the bounce the more the com goes out of round, and remember they ain't round to begin with. Since you now have found that 7/42 works just fine, that pretty much solves the issue, 6/42 was too low geared. maybe slightly stronger springs could have helped the first run.. Probably 6/40 could have been better.?????
Where are you located and how long are the chutes... I plan on doing some testing with 64P gears on the couple of short tracks here in NCal, especially in Modesto where the things never peak out geared 7/42..I have several 6T in 64P so I don't have to ruin a shaft by taking it down to 1.5.. keep em in the slot

[Wallbasher]

Both Chicagoland's Fiedler flat and Mid Americans Monster. Never tired a 6/40. I worked on it about 8-10 attempts. Always fresh. Com got small and I moved on. It was fast but not raceable. Funny thing is it showed promise but eventually the door was the wrong choice.