replacement front anti roll bar

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David Broadhurst
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replacement front anti roll bar

Post by David Broadhurst »

Having this year replaced the rear springs and bushing with fast road bushes and noted a much improved stiffness to the backend I was considering fitting the 3/4 inch front anti roll bar and fast road bushes currently on offer from MGOC. Any thoughts or experience of same gentlemen?
David Broadhurst
1967 Mk1 GT
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ROGER COOPER
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Re: replacement front anti roll bar

Post by ROGER COOPER »

Hi David, That is a mod which has often been suggested to me to make an improvement to the front suspension but I have to confess I have never got around to doing it. I have not heard of any problems arising from the "upgrade". Presumably if you get the larger diameter roll bar it will come with suitable bushes as I am not sure it would fit the existing ones - just a surmise not a known fact as far as I am concerned as I have never investigated.

Having said all that may I suggest you go ahead and report back on the results - we are all dying to know!

Rog C
Roger Cooper
1974 MGB GT
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ROGER COOPER
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Re: replacement front anti roll bar

Post by ROGER COOPER »

Hi David, I should have said that UAE57N has been fitted with V-8 hard bushes at the front for many years and they ARE better than the original rubber ones. That far I HAVE gone!

Rog
Roger Cooper
1974 MGB GT
David Broadhurst
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Re: replacement front anti roll bar

Post by David Broadhurst »

I put V8 bushes in all the suspension of my LE that I had. Made the car stiffer to drive but it squeaked the whole time unless a passenger, ie Management, was in the car as well.
David Broadhurst
1967 Mk1 GT
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George Wilder
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Re: replacement front anti roll bar

Post by George Wilder »

1965 Roadster
Fitted a 3/4 inch anti-roll bar 11 years ago. Coupled with the then nearly new - not recon - front shock absorbers and V8 bushes.
I aIso have 50% stiffer front coil springs ( basically GT spring rate) fitted as well as GT rear springs mounted on poly bushes. All running on 165/80 x 14 radials.
The result is precise handling car with much reduced body roll - firm ride but ideal when laden with two adults and luggage. Others who have driven say its a well sorted car. Pity it is in East Anglia to far for a demo run!

V8 bushes should not be the cause of any squealing - fit them using red rubber grease - not washing up liquid as some do because this will lead the raubber to degrade - slide in quite easily in a vice.
George Wilder
1965 MG MGB Mk1
1995 MG RV8
2005 MG TF 135
1959 BSA D7 Bantam
Bob Featherstone
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Re: replacement front anti roll bar

Post by Bob Featherstone »

I have just had fitted to my 77 B roadster a 3/4" front anti roll bar, together with new link arms, and V8 wishbone bushes and top bushes, lower 480 lb front springs and fast road rear poly bushes - all intended to stiffen and steady the handling. Wet roads have stopped any proper road testing yet. Any comments?
Bob in Devon.
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Peter Cresswell
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Re: replacement front anti roll bar

Post by Peter Cresswell »

Quite a thorny problem is anti roll bars!
The standard one is 9/16" diameter and basically provides reasonable roll resistance and a small amount of understeer. A 3/4" bar which is recommended for racing is around 350% stiffer than standard and will increase roll resistance, but also increases understeer, and the B understeers already. This can be corrected by using lower ride height front springs (which usually means a higher spring rate), and when the lower suspension arms are parallel to the road, then you will have a small amount of negative camber which reduces understeer. More negative camber can be obtained by using negative camber bottom arms. Alternatively you can fit a rear anti roll bar from a late B which will reduce the understeer, but on an early B there will not be any threaded holes in the chassis legs to fit the brackets so these will have to be fabricated. Increasing front tyre pressure above the rear pressure will also reduce understeer, but you should really stay within the range of pressures in the handbook for normal and fully loaded high speeds.
A slightly thicker bar is the one recommended for rallying which is 5/8" and is about 125% stiffer, which might be a good compromise especially for a road car, and will not greatly increase the amount of understeer. So if it is a problem, then increasing tyre pressures might get rid of it.
Increasing the spring rate will decrease the roll as will stiffer dampers (use the 25% increase valves in good condition dampers) but it comes at the penalty of a harsher ride. Having said that I currently use 600lb 8.5" free length springs in my B and they are only marginally harsher on the road.
All anti roll bars should be fitted with the correct mounting rubbers for the diameter, the correct diameter location stops and the brackets must be in good condition as the twisting load on them will be increased.
Spring rates and free lengths are another real issue!
Pete
Pete
1969 MGB Roadster
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2007 Mercedes SLK
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Bob Featherstone
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Re: replacement front anti roll bar

Post by Bob Featherstone »

Further to my previous message, I have now road tested my B and find that the handling is much improved, having lost all that 'wallowing' sensation and have even lost the rear nearside tyre from rubbing on the wheel arch as the whole body stays much flatter. The whole car is much tauter and even the acceleration feels more direct and sharper. Very pleased!
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Adrian Oliver
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Re: replacement front anti roll bar

Post by Adrian Oliver »

Peter, I know I'm resurrecting an old thread here but do you run with V8 wishbone bushes or poly?

Which do you recommend for normal use...

Also, as a point of interest, my 1962 car has an anti roll bar and I believe it was fitted from new as an option.

Cheers,
Adrian
1962 Chelsea Grey MGB
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Peter Cresswell
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Re: replacement front anti roll bar

Post by Peter Cresswell »

Hi Adrian
I haven't tried V8 bushes, as I went for a poly bush kit after speaking to Malcolm at B&G. I suspect RV8 ones may be somewhere between the standard B rubber bush and a poly bush. I have used RV8 bushes for the shackles on the rear springs.
Have raced for some considerable time I enjoy the increased accuracy poly bushes give the steering and I am prepared to put up with a slightly harsher ride.
I also use a 3/4" anti roll bar which is mounted with poly blocks.
Pete
1969 MGB Roadster
2020 MG HS Exclusive
2007 Mercedes SLK
Plus 34 other cars since 1965
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