267 replies to this topic

[slotbaker]

Rocker Panel...

 

[Martin]

Do not attempt to straighten these rockers out. You will just get aggro.

 

[Pablo]

I thought you could straighten the rockers. Maybe I misread the rules?

 

Rotor

Body rule # 9: "Cannot trim bottom of body".

I'm just building within the confines of the rules

 

 

Thanks to slotbaker for the definition, I honestly did not know that.

And thanks Martin for the humor   

[eshorer]

I think it'd be best to ask Keith for a "ruling" on straightening the body sides, before just deciding that it's a definite "no go." I don't know how easy it would be to do the straightening. Probably very difficult if the plastic is brittle. But is your concern that if you were able to straighten them, they would hang down too low, and that's why you'd want to trim them? In any case, check with Keith. 

Eddie

[Martin]

Why would any one want to change the shape of that body.   I like the way the body rolls under. Classic look.

[Jaeger Team]

Why would any one want to change the shape of that body.   

Racing mentality. If you cut that "rocker panel" and replace it with a flat one you could gain about 1/2" in frame width.

[Pablo]

I think it'd be best to ask Keith for a "ruling" on straightening the body sides, before just deciding that it's a definite "no go." 

Straightening the sides is impossible to do to a curved skirt without violating the "no trimming of the bottom" rule.

 

Let's remember, the body was a gift to be built into a car and I thought it would be cool to make it legal at BP. If my original intention had been to create a BP race car, this would the probably the last body I'd pick.

 

I knew it would be a challenge to fit 150 grams of weight and bulk into such a little narrow car, and I think I did a pretty good job with what I have in front of me. If Eddie gets even a mid-pack finish with it I'll do a backflip 

 

Pans are hung and I ain't turnin' back. Joints are still rough and wires remain to be trimmed. Once I had two sets of dual-wire hangers on each side, I realized that was plenty of strength and didn't install the center one. I left the center hinge tube pieces on as more bulk to lay the bite bar over. Onward …….

 

[Don Weaver]

Sure is interesting to watch this beautiful Lola T70 come to life.  And you're right, Pablo, this isn't a full blown race car body but damn it shore is purdy  !  And you're doing a great build on your 1st hardbody  ...

 

Don

[eshorer]

It's looking great. You're right: With this particular body style in particular, it would look odd to not have curved sides, "handling be damned!" :-)  Sometimes the racer in me pushes the rest of me out of the way. I'm sure it'll get around just fine with a few tweaks at the track. When's the last time you did a backflip? Better get a spotter ready, just in case!  

Eddie

[Pablo]

Thanks    I think the width of the rear wheels is much more important than the pan widths. I mean, look at retro F1's, they fly around a flat track with narrow pans. You better believe I'll do everything I can to squeeze 2 7/8 out of the rear track if possible 

[Pablo]

It's all coming together quickly now - bite bar today, front wheels are curing, rears due to arrive any minute, Gene ZR1 showed me an ultra-cool body mount method, and a complete set of "Betta & Classic" stickers arrived from Bulgaria this morning:

 

 

[Pablo]

Floating bite bar and pan stops complete. I added .032 wire strengthening gizmos to the square tube pieces both fore and aft    Pans have a good amount of lift and about 2 thou droop    Eddie can tighten everything up as he sees fit at the track 

 

Please forgive the Dremel scratch wheel marks - the excessive solder removal isn't cosmetic as much as an effort to provide as much level surface area for Eddie to place weights in as many places as possible 

 

[Pablo]

Front wheels trimmed and trued to .860 X .235", pair of 3/32 keepers, straight piece of 3/32 wire, and some 1/8 square brass tube ready to make and hang a set of Fernandes split independent axles

 

 

Axles and tube ends polished down to 2,000 grit

 

[Pablo]

This is hard to describe but I'll try. The Fernandes setup appears to have the hubs snugged up on the axles and the rotation is via the axles rotating inside the tubes. The reason I assume this is, I see set screws in the hubs.

 

I tried it like this and found it to be kind of wobbly. I tried it with the hubs rotating on the axles instead (just like a retro car) and it appears to be much more precise. Not saying my way will be better, just saying, I'll give my wheels two methods to rotate instead of one. 

 

Keepers soldered on both sides of the hubs, then a spacer, then the tube, then another spacer, then a ChiTown aluminum collar (Collars are on order, for now I'm just using old hubs to hold them). This method gives the wheels 2 different methods to rotate, and allows me to adjust the track width via spacers and setting the ChiTown collars

 

 

[Pablo]

Tube pieces placed appropriately, now it's simply a matter of hanging them 

 

[Pablo]

Fernandes tubes are done, not exactly same as on Marcos' car, but close. I used .055 for the rear "Z" wires, .047 for the front uprights, and .039 for the cross connector. No camber on mine

 

 

 

I can't say all the connecting parts are perfectly symmetrical but what counts is, the tubes are in the right place, strong, and have a little flex. The split front axle/wheel sets do not need to go in the tumbler - they will be installed afterwards - and will be spaced outwards as far as I can

[Pablo]

I chose Slick 7 racing bushings instead of ball bearings because:

-in (long periods) between races, they won't oxidize

-when set up carefully, they give perfect alignment

-they never fail and will last forever (unless you forget to oil them)

 

 

Tumbler time …….

[Pablo]

Swiss plated rails, Fowler Deck, Fernandes split axle tubes, BP Platform Lola chassis complete. Weight as-is: 71 grams. The rear end will only get stronger once the motor is soldered in

 

 

 

 

 

 

[Martin]

Hey Paul, I do not understand the advantage of putting weight behind the rear axle. Is there a theory for this design.

I have always thought less weight swinging around make's for a better handling car.

[Pablo]

All I know is, the fast guys at BP are using them on hardbodies on the flat track, and loading them with big chunks of lead.

That's all I need to know. Eddie can probably explain it much better than I could.

[Ecurie Martini]

Hey Paul, I do not understand the advantage of putting weight behind the rear axle. Is there a theory for this design.

I have always thought less weight swinging around make's for a better handling car.

 

I rather suspect the effect would be similar to the observation I made the first time I drove a Porsche 356 - the rear end hangs in for a long time but, when it lets go, you really need to know what you are doing and apply that knowledge very quickly.

 

The disadvantage that I can see in weight behind the rear wheels instead of directly in front of them is contribution to a moment that will tend to lift the front, - as a rule not a good thing.  Conversely, the same weight behind the rear wheels will produce more vertical force at the rear than it would positioned in front of them.

 

EM

[GE53]

One of the innovations that really works with Hardbody cars is to put a slab of brass weight behind the rear axle. It helps to keep them from tipping. Check out Keith Tanaka's excellent website for recent pics here: https://socald3.smug.../Hardbody-races

Eddie

Post #11 first page.

[Martin]

I have a angle winder (old school) I have 2 bodies I raced with. One was a long tail and one was short, as in cut off and trimmed so that no body was behind the tires. Well in that testing the short tail got the lap record the long tail was so tail happy as you would guess and un-driverble. Just my experience.

Any Porsche,VW, Corvair  car with weight hanging out the rear is going to have a greater swinging moment. Does not sound like a good idea to me. 

[eshorer]

I think the key is this: Hardbodies tend to be top-heavy, and the weight behind the rear axle, while in a Lexan-bodied car would make it tail happy, here it provides a good balance against the body. In addition, weight could be added on the left side of that plate to help it get around the left-turning donut better. Beyond that explanation, I'll leave it to the rocket scientists here to explain the physics. We'll see soon enough, won't we?  :-)

Eddie

[Ecurie Martini]

Not a rocket scientist - but I did serve on an advisory panel to the SkyLab project in the middle 70's

 

EM