front end weight

[scoutdad]

Hopefully someone can shed some light on this for me. My car body with no weights weighs .58 oz. With weights I am at 4.90 without paint yet. COG is at 1.25". Currently the front end weight is 21 grams (weighed with two identical scales) The track we are racing on is a Supertrack with no center rail and a pretty steep drop. I believe it is 42' long. Car is set up for a straight runner. Rears canted 1.5 degrees and all 4 wheels touching. Anybody see any issues with the front end weight being to light. I have heard that on this type of track cars can get some wiggle pretty good with a light front end. Just wondering what is considered too light of a front end. First time racing on this track.

 

[B_Regal Racing]

I not sure it is mathamatically possible to have only 12g on the FDW, yet have a COM of 1 .25" inches, but to answer your question about setup, see this thread:

http://www.pinewoodderbyonline.com/post/how-to-adjust-from-a-best-track-to-a-plastic-track-8008086

Here is a good COM calculator:

http://jsfiddle.net/minionsracing/UUnT5/embedded/result/

I would think with 12g on the FDW, you should have a COM of approximately 3/4".

 

[scoutdad]

21 grams on the front not 12. both front wheels are touching per rules

 

[Gtdhw]

We are running on the same track. We have a car set up for straight, and a few set up for outer RR'ing. We did not cant any rear wheels, as we didn't want them touching the outer rail. Some are very light DFW weight, and some are not. Going to race them all together after the race and get video,and see some side-by-side comparisons of the different set ups.

Tiger Car -
9/16" COM
11g Chassis
138g (pre tungston-putty final weight)
LFW weight - 6g
RFW weight - 6g
LRW weight - 62g
RRW weight - 64g
Straight BSA Polished Axles
BSA/USA Wheels trued to -.0005 (polished hubs & graphite rubbed outer side walls)
Straight Tune (+/- 1/2" over 4')

(Webelow II car)
9/16" COM
13g Chassis
138g (pre tungston-putty final weight)
DLFW weight - 12g
NDRFW weight - 4g (trying to experiment with limits of "4 flat & touching" rule)
DLRW weight - 57g
NDRW weight - 65g
1.5* Bent Front BSA Polished Axles (negative cant)
Straight Rear BSA Polished Axles
BSA/USA Wheels trued to -.0005 (polished hubs & graphite rubbed outer side walls)
Outer Left RR tuned at 3" over 4'

Boy Scout/Dad Build (sibling race car)
17/32" COM
11g Chassis
137g (pre tungston-putty final weight)
DLFW weight- 11g
NDRFW weight- 0g (disc'd)
DLRW weight - 60g
NDRRW weight - 66g
2.0* Bent Front BSA Polished Axles (negative cant)
2.0* Bent Rear BSA Polished Axles (positive cant)
BSA/USA Wheels trued to -.0005 (polished hubs & graphite rubbed outer side walls)
Outer Left RR tuned at 4" over 4'

Dad Build (sibling race car)
3/4" COM
143g (Went crazy on clear coat & added way too much weight. Was @ 154g, then shaved all possible to get back down to a too heavy 143g)
DLFW weight - 33g
NDRFW weight - 0g (disc'd)
DLRW weight - 40g
NDRRW weight - 70g
1.5* Bent Front BSA Polished Axles
Straight Rear BSA Polished Axles
Revell BSA Wheels trued to -.0005 (polished hubs & graphite rubbed outer side walls)
Outer Left RR tuned at 3" over 4'

 

[Gtdhw]

double post