7" Wider Front Track than Rear 1

[johntrhodes81]

I am in the process of planning a major old car modification project. The original car has nearly the same track width front and back. It has wheel arch covers in back which make the rear track quite narrow compared to the body width by today's standards. The track is about 17" shorter that the body width. In the front this translates to wheels being very far inset.

I was thinking of increasing the front track width by 7" making the body width only about 10" wider than the track width, to basically make the wheels flush with the body as is typical of modern cars. I have been wondering if having a vehicle with a 7" wider track in front versus back could cause handling problems that can't be corrected or be unsafe? Interested if anyone has any ideas or comments. The car will be used mostly as a cruising car but I would like it to handle well. The wheel base is 127" and the proposed front track is 67" the original rear track is 60".

Thanks,
John R.

 

[GregLocock]

No, that is quite a reasonable approach.

Cheers

Greg Locock


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[johntrhodes81]

Greg,

Thanks for the advice. Good to know that you don't think the wider front track will be a problem.

John

 

[Tmoose]

How are you going to widen the track?

 

[johntrhodes81]

I was going to take the front suspension/ frame from a Ford F-150/ Expedition and replace the original suspension.

John

 

[MikeHalloran]

The biggest danger you'll be in is at the alignment shop.

When my friend Bruce complained that his Sunbeam Tiger was all spooky after an alignment, the tech showed him how he had set the toe, by pulling a string across the face of front and rear tires. Of course the Tiger had slightly different track front/back, so that was the wrong way to do it for that car.

I think there's another concern with the Ackerman Angle (or something like that), where the difference in turning angle L/R will be wrong if the donor vehicle's wheelbase is substantially different from the receptor vehicle's wheelbase, or you don't modify the steering arms to reflect the change. (... so that the extended centerlines of the steering arms always intersect along the rear axles' common centerline) Greg can probably explain it better.





Mike Halloran
Pembroke Pines, FL, USA

 

[johntrhodes81]

Mike, Yes you are right I have heard of the Ackerman Angle. That would need to be evaluated as well.

Thanks John

 

[GregLocock]

Fortunately the tolerance for acceptable Ackerman is quite wide, 5% means little, 20% would be OK. Basically so long as the inside wheel turns a fair bit more (say 5 degrees-10 degrees) at full lock than
the outer wheel you should be fine.

Evelrod runs at least one of his racecars at zero Ackerman, it seems to cause the occasional rollover but other than that doesn't seem to hurt.



Cheers

Greg Locock


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[johntrhodes81]

Thanks.
John