Wheelbase vs. Front Fenders

[Couture]

If the rules allowed open wheel base (within the obvious boundaries of the block length) with no restriction on fenders - would you choose to push the front wheels out to the limit, or pull them back to allow space for front fenders?

Put another way... which is more advantageous: longer wheelbase or front fenders?

--
Steve Couture
Huntersville, NC

 

[HMH Racing]

Shorter wheel base and fenders. For several reasons. DD4H has a video showing the fender advantage.

 

[ngyoung]

You should be able to comfortably fit front fenders on a 5" wheelbase. That is with the rear axle 5/8" from the end.

 

[BlewBYu]

Got to agree with the above. See DD4H's video on fenders.

 

[BulldogRacing]

I think the shorter wheel base is harder to tune out the wiggles but potential for more speed. I think it's best to get stuff as far up the hill as possible and I'm sure there is a point where the wheel base is too short. I've been finding decent results with 4 3/4 Wheel base. I would appreciate some pros to help us out here.

 

[BulldogRacing]

Direct question is should I make my wheel base shorter than 4 3/4?

 

[Kinser Racing]

I've had fast cars at 4 3/8", fast cars at 5 1/8" and most places in between. Rarely have I gone outside of those with the exceptions being Street Rod and Unlimited.

 

[BulldogRacing]

Thanks Kinser. Wow, 4 3/8 Looks like I need to build another car.

 

[Couture]

Somehow missed that particular DD4H video. Thanks.

 

[HMH Racing]

Kinser,

I am curious as to why the unlimited's run an extended wheel base. Seems like a shorter (4 1/2" - 5)
would have same advantage as the other classes.

 

[W8NONU]

Somehow missed that particular DD4H video. Thanks.

Check out the cut axle slots on that test car.

[video]https://www.youtube.com/watch?v=slbDbbi-5MI[/video]

 

[Kinser Racing]

Kinser,

I am curious as to why the unlimited's run an extended wheel base. Seems like a shorter (4 1/2" - 5)
would have same advantage as the other classes.

I've never tried it that short.

 

[B_Regal Racing]

I am curious as to why the unlimited's run an extended wheel base. Seems like a shorter (4 1/2" - 5) would have same advantage as the other classes.

I do not race the class, but I am wondering if the same advantage really does exist, given the weight of the wheels (.3g to .4g) compared to the 2.0g wide wheels used in SS. Not sure of the weight of a bearing or axle though...

 

[HMH Racing]

I was thinking about the shorter wheelbase allowing the car to be on the hill longer. I would think it would be beneficial in both classes.

 

[GravityX]

The longer wheelbase (LWB) car gets into the transition slightly earlier than a shorter wheelbase (SWB) car. Logic would tell me the weight stays on the hill just as long regardless of wheelbase, if COM is not considered. The weight, of the LWB car, starts to transition earlier, around the rear axle, over a SWB car. So does this "planing" out of the LWB car have the advantage over the SWB car beyond the transition? The LWB car brings stability. But there are other factors to be considered like COM and steer, to name just two, when it comes to deliberating the LWB vs. SWB debate.

Front fender regardless of wheelbase. A front fender can be made for the LWB car, although it may not be as large, something is better than nothing at all. Just look at the BASX vs. SS class, records indicate a .016 second advantage.

 

[bracketracer]

Just look at the BASX vs. SS class, records indicate a .016 second advantage.

Part of that is 2.4g vs 2g wheels, part is lack of tread bumps, the balance can be attributed to the fenders.

Even if the SWB car has more time on the hill (an advantage for a very, very short distance to be sure) the better stability of the LWB car is an advantage for the full length of the flat IMHO.

 

[GravityX]

Just look at the BASX vs. SS class, records indicate a .016 second advantage.

Part of that is 2.4g vs 2g wheels, part is lack of tread bumps, the balance can be attributed to the fenders. Even if the SWB car has more time on the hill (an advantage for a very, very short distance to be sure) the better stability of the LWB car is an advantage for the full length of the flat IMHO.

Boy, I sure did forget the .4g wheel difference. /images/boards/smilies/sleep.gif My apologies folks.

 

[quadad]

I have purposely run a variety of WB's in unlimited just to show that they can all be fast (often in the same race). COM, steer and WB all have to be balanced out.

That said, I have RARELY beaten Kinser (and a few others) ...

 

[B_Regal Racing]

That said, I have RARELY beaten Kinser (and a few others) ...

I believe most of us are in that boat...in all classes /images/boards/smilies/wink.gif