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Author Topic: Wheelbase, spacing and handling  (Read 17599 times)

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Offline Jonny Hotnuts

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Wheelbase, spacing and handling
« on: September 06, 2007, 11:15:34 AM »
The MS class allows a 130" wheelbase and forward streamlining (ahead of and including the cowl).

I am thinking what I would like to do is stretch the wheelbase to 130" and move the 2 front tires closer (they are about 4' now and was thinking somewhere about 1.5-2').

I was wondering:

A-is this legal in my class to move the tires closer together

B-would moving the front tires closer adversely affect handling

C-will doing this much BS be worth the time and effort
(the reasoning behind wanting to move the front wheels closer is because I can go crazy with streamlining the front end.....a benefit for me because the car is a mid engine and don't have to worry about engine fitment in the front).


Good idea.....bad idea???????

-JH
jonny_hotnuts@hotmail.com

"Sometimes it is impossible to deal with her, but most of the time she is very sweet, and if you caress her properly she will sing beautifully."
*Andres Segovia
(when Im not working on the car, I am ususally playing classical guitar)

Offline Sumner

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Re: Wheelbase, spacing and handling
« Reply #1 on: September 06, 2007, 11:40:37 AM »
The MS class allows a 130" wheelbase and forward streamlining (ahead of and including the cowl).

I am thinking what I would like to do is stretch the wheelbase to 130" and move the 2 front tires closer (they are about 4' now and was thinking somewhere about 1.5-2').

I was wondering:

A-is this legal in my class to move the tires closer together

B-would moving the front tires closer adversely affect handling

C-will doing this much BS be worth the time and effort
(the reasoning behind wanting to move the front wheels closer is because I can go crazy with streamlining the front end.....a benefit for me because the car is a mid engine and don't have to worry about engine fitment in the front).


Good idea.....bad idea???????

-JH

Sounds like the rules are very similar to comp coupe.  If so then I would think you could change the front track width and I would do it.  There is no need to drastically narrow the front as the air will still see the car at it's widest point, but narrowing it some sure couldn't hurt and would give you the option of better directing the air that does go towards the body as you have talked about. 

     

You could then also work on the front wheel openings and try to avoid them acting like parachutes.  If you can totally cover them then the narrower track would be worth it right there.  If not again look at the deflectors that Blowfish uses at the front of their wheel-well openings that deflect the air just enough that it reattaches right behind the wheel opening.  Of course they used a wind tunnel to find the perfect solution.  If you don't have a wind tunnel you might try Hooley's Okie wind tunnel.  We use an air hose pointed at the part of the car in question and sprinkle baby powder into the air stream and see where it goes  :-o .

The longer wheelbase should help with the handling and would help to move the CP rearwards (good).  Now once the car is in a spin, hopefully you will avoid this, then the the long/narrow wheelbase might be a negative.  I would really work on the CP/CG thing and get it right and get the weight in the car you need so that a spin is less likely to happen as a result of tire spin on the top end.

Is it worth it.  Depends on much you want to hand that 250 mph time slip to Dan  8-) ,

Sum
« Last Edit: September 06, 2007, 11:51:18 AM by Sumner »

Offline tortoise

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Re: Wheelbase, spacing and handling
« Reply #2 on: September 06, 2007, 12:39:44 PM »
Has anyone built a competition coupe with front wheels in line or nearly so, ala the Teague, Costella, and other streamliners? There appears to be nothing in the rules prohibiting same.

Offline Sumner

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Re: Wheelbase, spacing and handling
« Reply #3 on: September 06, 2007, 01:10:19 PM »
Has anyone built a competition coupe with front wheels in line or nearly so, ala the Teague, Costella, and other streamliners? There appears to be nothing in the rules prohibiting same.

Not to my knowledge, but wonder if it would help with a coupe as you still have the body.  A streamliner can make their body any width they want.

c ya,

Sum

Offline jimmy six

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Re: Wheelbase, spacing and handling
« Reply #4 on: September 06, 2007, 01:17:27 PM »
What would Jack Costella do? I'd do that!!!!!!!!!!!!!!!!!!!
First GMC 6 powered Fuel roadster over 200, with 2 red hats. Pit crew for Patrick Tone's Super Stock #49 Camaro

Offline tortoise

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Re: Wheelbase, spacing and handling
« Reply #5 on: September 06, 2007, 01:58:58 PM »
Has anyone built a competition coupe with front wheels in line or nearly so, ala the Teague, Costella, and other streamliners? There appears to be nothing in the rules prohibiting same.

Not to my knowledge, but wonder if it would help with a coupe as you still have the body.  A streamliner can make their body any width they want.

c ya,

Sum
It doesn't do anything to reduce the frontal area on Costella's 'liners, either, especially the V8 powered one.  Frontal area isn't everything; the friction drag is reduced by reducing the skin surface area.

Offline Glen

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Re: Wheelbase, spacing and handling
« Reply #6 on: September 06, 2007, 02:09:34 PM »
The way I read the rule book on page,19  PP2.H Tread is defined as the measurement from the centerline of one tire to the centerline of the opposite tire of paired wheels.
The minimum tread dimensions for all vintage category vehicles is 44" front and 50" rear. Special construction vehicle are not subject to this rule.

JD or Dan W. need to clarify this for comp.coupe and MS
Glen
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Offline tortoise

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Re: Wheelbase, spacing and handling
« Reply #7 on: September 06, 2007, 02:23:18 PM »
The way I read the rule book on page,19  PP2.H Tread is defined as the measurement from the centerline of one tire to the centerline of the opposite tire of paired wheels.
The minimum tread dimensions for all vintage category vehicles is 44" front and 50" rear. Special construction vehicle are not subject to this rule.

JD or Dan W. need to clarify this for comp.coupe and MS
The way I read the rule book, the modified category, [5.D],  is not part of the vintage category, [5.B].

dwarner

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Re: Wheelbase, spacing and handling
« Reply #8 on: September 06, 2007, 02:28:10 PM »
Already in the works for cars other than streamliners.

DW

Offline JackD

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Re: Wheelbase, spacing and handling
« Reply #9 on: September 06, 2007, 02:35:05 PM »
"Reading is FUNdamental. writing is elemental, and the results are sometimes astounding."  (me):wink:
"I would rather lose going fast enough to win than win going slow enough to lose."
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Offline tortoise

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Re: Wheelbase, spacing and handling
« Reply #10 on: September 06, 2007, 02:43:34 PM »
Already in the works for cars other than streamliners.

DW
Even lakesters? Will minimum tread widths be 44" for all non-special construction classes?

Offline Sumner

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Re: Wheelbase, spacing and handling
« Reply #11 on: September 06, 2007, 03:14:30 PM »
Has anyone built a competition coupe with front wheels in line or nearly so, ala the Teague, Costella, and other streamliners? There appears to be nothing in the rules prohibiting same.

Not to my knowledge, but wonder if it would help with a coupe as you still have the body.  A streamliner can make their body any width they want.

c ya,

Sum
It doesn't do anything to reduce the frontal area on Costella's 'liners, either, especially the V8 powered one.  Frontal area isn't everything; the friction drag is reduced by reducing the skin surface area.

Good point.

I wonder about the difference in the ratio of the width of the front of the car to the widest point on one of Jack's car to say using the same width of the front to the widest point of say a wider comp coupe car.  Would the angle out to the sides and then the angle created where the front meets the body not be good.  I don't know???

One thing about what we are doing is often opposite designs result in about the same results  :-) .

I personally feel Jack's car's are successful for what isn't there.  As Stainless likes to say you don't have to worry about the Cd of what isn't there, or something like that :|.

c ya,

Sum

dwarner

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Re: Wheelbase, spacing and handling
« Reply #12 on: September 06, 2007, 08:03:31 PM »
44" has yet to be mentioned.

DW

Offline sockjohn

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Re: Wheelbase, spacing and handling
« Reply #13 on: September 06, 2007, 08:47:46 PM »
You could then also work on the front wheel openings and try to avoid them acting like parachutes.  If you can totally cover them then the narrower track would be worth it right there.  If not again look at the deflectors that Blowfish uses at the front of their wheel-well openings that deflect the air just enough that it reattaches right behind the wheel opening.  Of course they used a wind tunnel to find the perfect solution.  If you don't have a wind tunnel you might try Hooley's Okie wind tunnel.  We use an air hose pointed at the part of the car in question and sprinkle baby powder into the air stream and see where it goes  :-o .


Using taped on tufts and a video camera would work too and is probably a cleaner way to do it , but I'm sure a bright green non-street legal Fiat attracts unwanted attention on the road!

Johnny,
Borrow a copy of "The Leading Edge" as there are some interesting things about nose sweep angles in it that seem to indicate narrowing the front in may not be advantageous.  Maybe I can do a scan when I get home.

Offline Unkl Ian

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Re: Wheelbase, spacing and handling
« Reply #14 on: September 07, 2007, 12:54:53 PM »


Borrow a copy of "The Leading Edge" as there are some interesting things about nose sweep angles in it that seem to indicate narrowing the front in may not be advantageous.

I just won a copy of that book on Ebay,less than $6 including shipping.
I guess the answer is "a Secret" .