Grooved axles

[SPEEDQUEST]

Attempted to align car last night. Car specs:
Extended wheel base 5 1/2" axle-to-axle
Rear axle-5/8" from rear
COM .6875" in front of rear axle
0.66 oz on DFW
1 deg cant on rears
DFW drilled straight 2 1/2 deg bend

Tested rear axles holes after drilling with polished 0.92 gage pins. Wheels slowly migrated away from body.

Using aftermarket grooved axles and 2g wheels.

When rolling car on tuning board last night, right rear goes in toward body after about 2'. Tried to adjust steer. Only gets worse. I tried swapping axles on rear, tried different sets of wheels.

Finally switched rear axles to non-grooved and the problem was resolved.
What am I doing wrong or missing?
Race is Saturday. I will have to remove weight if I stay with the non-grooved axles. About 0.4 oz

 

[Vitamin K]

You gain .4 oz from going with non-grooved axles? Or do you mean .4 grams?

 

[SPEEDQUEST]

Sorry!! .04oz

 

[LightninBoy]

Attempted to align car last night. Car specs: Extended wheel base 5 1/2" axle-to-axle Rear axle-5/8" from rear COM .6875" in front of rear axle 0.66 oz on DFW 1 deg cant on rears DFW drilled straight 2 1/2 deg bend Tested rear axles holes after drilling with polished 0.92 gage pins. Wheels slowly migrated away from body. Using aftermarket grooved axles and 2g wheels. When rolling car on tuning board last night, right rear goes in toward body after about 2'. Tried to adjust steer. Only gets worse. I tried swapping axles on rear, tried different sets of wheels. Finally switched rear axles to non-grooved and the problem was resolved. What am I doing wrong or missing? Race is Saturday. I will have to remove weight if I stay with the non-grooved axles. About 0.4 oz

What kind of axles were the non-grooved ones? 92s from DD4H, or standard BSA, or ??

A 1 degree cant is pretty shallow. I assume you did that because the rules wouldn't allow the standard 3 degree cant on the rears. That shallow cant will make it more susceptible to slight toe-in errors.

 

[B_Regal Racing]

I can tell you that there are a number of things that could cause the wheel to migrate inward. In your case, I would say there are two items I would start with. Is the grooved axle straight (which is why I believe LB was asking where they were purchased from) assuming that you are not intentionally attempting to bend he rear axles? Did you cover your car with monokote and use heat? I feel that this could potentially warp a lightweight body?

 

[SPEEDQUEST]

Both sets are DD4H 92 BSA axles.
The body is a 1/2 ladder design covered with 1/32" Basswood plywood on top.
3 light oats of Duri-Color Automotive primer, sanded smooth. 2 coats of Duri-Color paint. Paint added 0.2 oz weight.
Covered the weight pockets with vinyl tape.

 

[Bullet]

My 2C, I'm going with the fact that a 1 deg camber may not be enough to keep the wheel out with steer set to anything but straight. Is it right or left steer? Are the axles pushed in far enough to keep the grooves fully in the wheelbore? Just some thoughts...

 

[Bullet]

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[SPEEDQUEST]

I may have figured something out.
With more time last night, I went back to the tuning board. Like I mentioned before, the right rear wants to walk in after about 2ft down the board.
I believe the problem is the bent front axle. With the bend I cannot get the gap on DFW close enough to body. I guess my bend was too far from head. So the groove was not completely inside bore of DFW. The front wheel would wobble causing DRW to walk in.
Re-installed grooved axles on rear, installed a bent non grooved on DFW. Rolling like a dream. Set drift to 2.5" at 4'. (49' wood track)
I hope she is fast! We race Saturday.

Thanks guys!

 

[HurriCrane Racing]

2.5" on a wood track will be interesting. Tell us how she runs.

 

[B_Regal Racing]

It is a VERY rare occassion when I have gotten 2.5" or less to run and be stable on a Besttrack, but then I'm far from the best builder out there. I would not consider it on a wooden track.

 

[SPEEDQUEST]

We were the fastest car today of 80+ cars.
49' wooden track
Graphite
12 heats
3.215 fastest time
Won by .022 sec total avg time