Steering, Suspension, & Brakes

tips, technology, tools and techniques related to non-driveline mechanical components

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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

Akerman Update, life is change
Posted by: roverman
Date: June 08, 2011 11:57AM

Latest "Hot Rod" mag, quoting Carrol Smith,r.i.p., "with modern, wide sticky tires, akerman may be shortened to perhaps 1/2 the wheelbase". Too much is when the car gets "darty", then back-off some, on the amount. Adjusting from toe-in to toe-out will help on turn-in, but too much = "darty". Hope this helps, roverman.


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

authors avatar
Re: Akerman Update, life is change
Posted by: Bill Young
Date: June 08, 2011 02:16PM

Interesting Art. Problem on most MGs is that the steering arms point forward and to shorten the Ackerman you'd have to angle the arms out more towards the outside reducing the clearance for brake discs and wheels to steering links. On a rear steer car it's not really a problem in most cases. I suppose when designing a suspension for a racing car then fabricating or modifing steering arms isn't that big a deal so "backing off some" is acceptable. For the average street car going to that sort of modification and expense hopefully would be a one time thing.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Akerman Update, life is change
Posted by: BlownMGB-V8
Date: June 08, 2011 04:38PM

It certainly has an influence on what you can get by with on the brakes, and becomes a fight between space for the tie rod ends vs space for the calipers vs wheel recess outboard of the wheel mounting flange. Like most things it's a compromise.

JB


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: Akerman Update, life is change
Posted by: roverman
Date: June 08, 2011 08:00PM

Of course there are purpose/bent steering arms,(Datsun Z comes to mind), bent "around the rotor" ? Biggest dia wheels possible-helps. I've seen oems'.-somwhere with steering arms on top. Really doesn't matter top,bottom or in between, as long as you get the pivot points and angle correct, to prevent bump steer. Cheers, roverman.


flitner
John Fenner
Miami Fl
(168 posts)

Registered:
03/11/2010 10:58AM

Main British Car:
1972 MGB 350 CHEVY

Re: Akerman Update, life is change
Posted by: flitner
Date: June 10, 2011 01:53AM

After reading about this here and on other forums, I look at the kids' gocart and walk away shaking my head thinking I've gotta fix that!!!!


flitner
John Fenner
Miami Fl
(168 posts)

Registered:
03/11/2010 10:58AM

Main British Car:
1972 MGB 350 CHEVY

Re: Akerman Update, life is change
Posted by: flitner
Date: June 10, 2011 01:57AM

From the HAMB
[img864.imageshack.us]
I couldnt find the one that was a pic alone.



Edited 2 time(s). Last edit at 06/10/2011 02:06AM by flitner.


DiDueColpi
Fred Key
West coast - Canada
(1365 posts)

Registered:
05/14/2010 03:06AM

Main British Car:
I really thought that I'd be an action figure by now!

authors avatar
Re: Akerman Update, life is change
Posted by: DiDueColpi
Date: June 10, 2011 02:38AM

It takes a while to wrap your head around gokart steering and chassis tuning John.
If you built a car like a kart you couldn't drive it. If you build the kart like a car it won't turn.
As far as the ackerman goes. Shortening it up only works on a heavy race vehicle with a lot of grip and large slip angles. Toe out compensates for the angle change in a turn and makes the turn in more predictable at the expense of straight line stability.
On a dry track it has advantages. On a wet track almost undriveable.
On a street car tire life would be short, around town driving and parking would be a chore. And the car would follow every rut in the road like it was on rails.
Probably good for something like Nascar not so good for something small and light like us.
Just my opinion FWIW.
Cheers
Fred



flitner
John Fenner
Miami Fl
(168 posts)

Registered:
03/11/2010 10:58AM

Main British Car:
1972 MGB 350 CHEVY

Re: Akerman Update, life is change
Posted by: flitner
Date: June 10, 2011 09:28AM

Thank You Fred!!
I gathered the basic concept but didnt take into consideration the road course and racing aspect with IFS, all I was picturing was hot rods with straight axles and skinnys for some silly reason. Lack of sleep I guess.


DiDueColpi
Fred Key
West coast - Canada
(1365 posts)

Registered:
05/14/2010 03:06AM

Main British Car:
I really thought that I'd be an action figure by now!

authors avatar
Re: Akerman Update, life is change
Posted by: DiDueColpi
Date: June 10, 2011 12:01PM

Nothing wrong with straight axles and skinnys.
My A sedan wouldn't look right any other way.
Cheers
Fred


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

authors avatar
Re: Akerman Update, life is change
Posted by: Bill Young
Date: June 10, 2011 01:46PM

As Fred says "My A sedan wouldn't look right any other way."
I don't want to think of all the early Ford spindles I've heated and bent the steering arms on to reset the ackerman. I even did it on a shortened Corvair once and that was a front steer, but used a drag link and idler arm setup so the steering arms pointed inwards instead of out like our MGs with the rack and pinion steering.


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