roverman Art Gertz Winchester, CA. (3188 posts) Registered: 04/24/2009 11:02AM Main British Car: 74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L |
Serrated/slotted steering arms ?
Anyone using these ? Some "Stock Cars" do. Quick and easy changing of Akerman. Onward, roverman.
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Moderator Curtis Jacobson Portland Oregon (4576 posts) Registered: 10/12/2007 02:16AM Main British Car: 71 MGBGT, Buick 215 |
Re: Serrated/slotted steering arms ?
Based on everything I've ever read, Ackermann matters a whole lot more when you're pushing cars around in the paddock than when you're actually on track. Tire selection, camber curves, roll center height, getting rid of bump steer and/or at least arranging the steering for slight roll-understeer (instead of roll-oversteer)... all are undoubtedly much more important. Kingpin inclination. Scrub radius. Roll stiffness. Spring rate and wheel rate. Shock valving. Static corner weights. After all that's figured out, come back and worry about Ackermann when you have tire temperature readings. In the meantime, Ackermann is just a distraction from the basics. Or at least that's what I've been told by people who should know.
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ex-tyke Graham Creswick Chatham, Ontario, Canada (1165 posts) Registered: 10/25/2007 11:17AM Main British Car: 1976 MGB Ford 302 |
Re: Serrated/slotted steering arms ?
Poor Ackerman geometry results in increased tire wear while cornering - I can see why the racers ignore it's contribution to tire scrub.
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Bill Young Bill Young Kansas City, MO (1337 posts) Registered: 10/23/2007 09:23AM Main British Car: '73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep |
Re: Serrated/slotted steering arms ?
Curtis, poor Ackerman isn't nearly as critical on a race car, but I can tell you from experience that it will wear tires in a real hurry on a street car and affect handling as well. If it's not too far out you may not notice it, but get it right and you will certainly feel the difference in cornering, especially on turn in where it can really affect understeer or oversteer. If your car's wheelbase is close to that of the original car that the suspension bits came off of then the Ackerman will probably be pretty close, but make the wheelbase shorter or longer and the Ackerman really changes quickly and should be corrected. This was most common on a lot of street rods where components from cars with 100+ inch wheel bases were used on T buckets and such with wheelbases in the 80 inch range.
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Moderator Curtis Jacobson Portland Oregon (4576 posts) Registered: 10/12/2007 02:16AM Main British Car: 71 MGBGT, Buick 215 |
Re: Serrated/slotted steering arms ?
I sometimes get confused with Art's posts... is he just thinking about hypotheticals (as I often do), or thinking about upgrades to his GT1 racecar, or thinking about building the ultimate Jensen Healey? Is that Jensen Healey really a street car, or is it going to end up more of a track day car? Racers do some counter-intuitive things. For example, quite a lot of them deliberately run static toe-out to improve turn-in. Some racers also deliberately run zero or even reverse Ackermann.
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roverman Art Gertz Winchester, CA. (3188 posts) Registered: 04/24/2009 11:02AM Main British Car: 74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L |
Re: Serrated/slotted steering arms ?
Curtis and clan, It's all real clear in my head, but just "maybe" I should preface with my project of the moment ? Not true to form, I'm ONLY concentrating on the GT-1 car, now. I'm on a mission to race something other than a wheelchair,(retirement home). GT-1 car appears to have stock/un-modified steering arms. Since I shan't go changing what Huffaker designed, too much, I thought the car "might" benefit from more Akerman,(turn-in). I have been reading Carrol Smiths," Enginneer To Win", so shoot me. Thanks for the help-all, roverman.
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MGBV8 Carl Floyd Kingsport, TN (4511 posts) Registered: 10/23/2007 11:32PM Main British Car: 1979 MGB Buick 215 |
Re: Serrated/slotted steering arms ?
Well, if it's Huffaker designed & built, rather than re-engineer the car, I would just strap in & drive! ;)
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