Building a D3 Canam chassis

[dennist]

Started designing(on graph paper) some new chassis for a friend to race and I would like to clarify some points before starting and ordering some parts.

Can someone clarify (I've read the rules) that there is no restriction on the no of main chassis rails?

I gather that "offset brackets and appropriate gears" are the way to go - gearing is around 9/32?

I presume most bodies have a wheelbase of around 4", but what are the average axle to guide length? (I suppose it depends a bit on what body is used).

I hope to use some ideas from the last of my "wire" cars in the late 70's and current eurosport designs as well as the hundreds of pictures of D3 cars on the net.

Thanks,


Dennis Traeger

[Koford1]

Dennis,

You could go 2 ways, purchase a S7 kit, choose rail diameter, and have the thing on the track in a couple of hours or revert to bending, cutting, soldering like we used to and end up with something that is a little short of what allowable modern techniques give the Slotter, in terms of a modernised Brass/piano wire chassis.

Up to you, will send some pics if I get round to it of both types of construction.

Regards and hope you are well.

Charles

[dennist]

Charles,

Thanks gfor the reply, but "scratch" and designing stuff has always been more satisfying to me than buying a kit, if done sucessfully it also used to give a competative advantage.

I see quite a few racers at Buena Park are very creative and a lot of these designs have won races.

Still would like some further answers guys.

[stoo23]

Hey Dennis,

Great to Hear from / see you on the Forums.
May I say I would Love to see your 'Retro' Efforts, as would Many on here I would suggest!

Yep,..No Restrictions on the Number of Main Rails.

I guess 4" is 'about Normal',... But I have found that for a 'Lot' of the available bodies, (especially as they came from that late '60's era), a Wheel base of Slightly Less than 4", say 3 7/8th's is More appropriate.

Guide Lead, Depends, (as you suggest), on the Body of Choice,..BUT Also the Track you intend to Race on.

At HSC, experience has headed us Towards running 'Longer' Guide Leads, Some Over 5", If one was running on a King or Kingleman, one would think a Shorter Guide Lead and possibly even WB could be more appropriate.

As a Weight Guide, once again, I guess depends Very Much on the Track and car design, but once again as a Guide, at HSC, we have found Slightly Heavier is Probably Better, but Once again, on a faster Swoopy Track like a King, you Could be Effectively Lighter.

We are running Cars from about 116 grams upto about 130, say 119 to 126 grams.

The Standard Slick 7 chassis builds up to about 109 Grams and around HSC, Definitely Needs the 'addition' of Lead to achieve a Good Handling car.

9/32 !! Gee!,..What rear Tyres are you Using?

I have Occasionally run a 30, but That would realistically be the Limit with the Minimum size rear tyres.
Where are you running?
At HSC we have been running anything from 8/27 up to 9/30, there it depends on the car and perhaps your Driving Style.

Chassis Wise, You Can Run Hinges in ONLY One Direction!
So in Other Words, you can Run 'Hinged' Pans, but Not Plumber Hinges, OR you could Run a 'Plumber', but No Pan Hinges.
You CAN However have a Drop Arm Hinge.

As to Motor brackets, as can be seen by Many of the US cars, Many still build wih the Standard Bracket, but personally I have always chosen the 'Offset' style as you mention.

I guess One Could argue the 'Merits' of Lower Friction etc with a Perfectly aligned gear set, but IMHO, it has Not appeared to make much difference, as with the Parma 'Pink' gears and the Angled ARP/GT1 pinions, the Mesh is Excellent and Very Quiet (if you get it Right), so should Not be a Problem.

Hope that Helps.

Cheers,
Stewart

[dennist]

Thanks Stoo, that was just the info I was after.

Also I know that heavier/longer is better for slower "flat" tracks - nothing seems to have changed much there over the years,

I remember back when we started to get some faster King tracks in Australia, my cars were around 1/4" shorter than all the "off the shelf" perimeters and that certainly gave me an advantage at one time.

With the "1 directional hinge rule" there are certainly some very creative ways of doing it.

It's good to see a standard "scratch build class" back in the popularity stakes.

I always admired people like Mark Fox, Kym Axton, the Professor Graham Roberts etc etc who back in the old days would come up with revolutionary new scratchbuilt designs and ideas.

[Koford1]

Dennis, A few pics a promised of my first attempt.

[dennist]

Chucky,

Looks great,good work, now that is what I call a strong rear end.

How does it go?

Can I get all the bits from HSC?

[chadly]

looks like a heavy rear end too!
do the D3 cars bennefit from this? I've seen weight around the back end on many D3/Aussie Retro cars.

Dennis, John Ward was playing with D3 cars up at Bills. Have you got his number?
The guys at Neils and Steve Kerr's are looking at running a soft body can am class soon too.

[stoo23]

Solid Rear End,..Yes !!,..In Fact Chucky's Whole Car was both solidly and beautifully made,..(as one would suspect from Charles!).

Benefit from it ?,..Well I guess sort of,..as with some of the Thinner Guage Brass in line motor mounts, one Does need some Strength built in to provide a Solid 'Non Flexing' motor and axle mount, plus added strength for those Wall Hits !!,..



Chucks car is possibly a bit Stiff compared to what we are running now, but it Was the Yardstick at one stage.

[dennist]

Chadly,

Yes I have recently caught up with John after not seeing him for some time, he has actually motivated me to build a D3 - I have been "hovering" for some years and kept up with things, but not having a King or similar in Adelaide is frustrating.

I might venture up there one Friday night with John.

[chadly]

unfortunently Neil and co. dont race at Bills anymore.

calendar for Neil's and Steve's here -