front wishbone mod 'm' chassis.

[ivanhoew]

talking about triangulating the wishbone mounts on my car the other day ,where i took a triangle of steel plate ,and welded it into the right angle joint where the mounting flange meets the chassis rail on each lower flange . i remembered another mod i did .(sorry if this has allready been discussed )

this involved adressing the really naff design ,where the bottom wishbone is joined at the trunnion and the shock mounts ... the shocks put a twisting force on the arm sides ,and this twists the trunnion making the steering heavier .

to solve it , i took a piece of heavy pipe say 1 inch diameter and 4mm wall thickness ,that i happened to have lying around , cut it on a diagonal to match the wishbone angle ,and ,laying the wishbone flat welded it across the widest part about 2 inches down from the mounts .to create a triangle .this instantly dropped the weight of the steering by a large amount ,almost power steering sort of feel .
im using an all alloy v8 ,but do have a fairly heavy turbo and battery at the front ,the car sits at about the right hieght at the front on stock springs , so its weight is comparable .

regards
robert

[phillpot]

One picture is worth a thousand words

[Adrian@]

ivanhoew said:

talking about triangulating the wishbone mounts on my car the other day ,where i took a triangle of steel plate ,and welded it into the right angle joint where the mounting flange meets the chassis rail on each lower flange . i remembered another mod i did .(sorry if this has allready been discussed )

this involved adressing the really naff design ,where the bottom wishbone is joined at the trunnion and the shock mounts ... the shocks put a twisting force on the arm sides ,and this twists the trunnion making the steering heavier .

to solve it , i took a piece of heavy pipe say 1 inch diameter and 4mm wall thickness ,that i happened to have lying around , cut it on a diagonal to match the wishbone angle ,and ,laying the wishbone flat welded it across the widest part about 2 inches down from the mounts .to create a triangle .this instantly dropped the weight of the steering by a large amount ,almost power steering sort of feel .
im using an all alloy v8 ,but do have a fairly heavy turbo and battery at the front ,the car sits at about the right hieght at the front on stock springs , so its weight is comparable .

regards
robert

My thoughts are that you might triangulate one side of the wishbone mounts ...in an accident the forces can so huge that standard mounts bend (and can be replaced) stopping the loads from transferring into the main chassis tube and scrapping the chassis, one piece lower wishbones are a must for racing boys (and most run them) I like I me think most just mount a 1 1/2 square brace piece between the trunnion and the shock.
Adrian@

Edited by Adrian@ on Thursday 25th August 12:36

[62GRANTIII]

I did pretty much exactly what Adrian suggests
But used a bit of 1.5" round tube, tween trunnion & shock mount !
As I had a wee offcut hanging about
It is a good mod stops alot of shimmying going on !!
Cheers Ian B

[Gnasher]

Another vote for doing it, I did mine with a bit of round chassis tube.

To make sure it all lined up, I assembled the suspension, then tacked the tube in, before removing the trunnion & shocker to weld it properly

SteveD

[ivanhoew]

Adrian@ said:

ivanhoew said:

talking about triangulating the wishbone mounts on my car the other day ,where i took a triangle of steel plate ,and welded it into the right angle joint where the mounting flange meets the chassis rail on each lower flange . i remembered another mod i did .(sorry if this has allready been discussed )

this involved adressing the really naff design ,where the bottom wishbone is joined at the trunnion and the shock mounts ... the shocks put a twisting force on the arm sides ,and this twists the trunnion making the steering heavier .

to solve it , i took a piece of heavy pipe say 1 inch diameter and 4mm wall thickness ,that i happened to have lying around , cut it on a diagonal to match the wishbone angle ,and ,laying the wishbone flat welded it across the widest part about 2 inches down from the mounts .to create a triangle .this instantly dropped the weight of the steering by a large amount ,almost power steering sort of feel .
im using an all alloy v8 ,but do have a fairly heavy turbo and battery at the front ,the car sits at about the right hieght at the front on stock springs , so its weight is comparable .

regards
robert

My thoughts are that you might triangulate one side of the wishbone mounts ...in an accident the forces can so huge that standard mounts bend (and can be replaced) stopping the loads from transferring into the main chassis tube and scrapping the chassis, one piece lower wishbones are a must for racing boys (and most run them) I like I me think most just mount a 1 1/2 square brace piece between the trunnion and the shock.
Adrian@

Edited by Adrian@ on Thursday 25th August 12:36

that sounds a good idea as well adrian , i think i might add that too .

[TVR_owner]

My 3000M Race car is being re-built this winter. Areas of focus will be front uprights and front and rear wishbones, front trunnions will be dissapearing..

Will post photos as we go along.

[Adrian@]

TVR_owner said:

My 3000M Race car is being re-built this winter. Areas of focus will be front uprights and front and rear wishbones, front trunnions will be dissapearing..

Will post photos as we go along.

Does that restrict you in what your car might run in .....Adrian@

[TVR_owner]

Adrian@ said:

will continue post rebuild n
Does that restrict you in what your car might run in .....Adrian@

Not really Adrian, probably one of the few series where it would make a difference would be HSCC 70s Roadsports, which I don't do anyway cos the cars too modified as it stands and to make it eligable would cost a fortune. Been discussing diffs lately and the sierra thing keeps croping up. I've opted to have a lightweight Salisbury, the downside is needing to run a diff cooler, but I can loose that horrible diff mounting "thing".

The car will continue post rebuild in CSCC - it's nice playing with Porches, Jags, Astons, TR8s, Loti and MR2s!

Will do the Tuscan Challenge occasionaly.

[Adrian@]

Ah ...I see ...said the blind man, I am not a numbers person but it is that a 3HA diff unit, I suppose the correct question would be what is the weight saving?
Adrian@

[intermediate]

weight saving?
don't feed the driver... the best solution

[TVR_owner]

Adrian, be dissaponted if we don't loose getting on for30 kilos, it's the same diff, different material - mag casing. Target is 820 kilos after rebuild, with some fuel (not very much though)

Jos I support your don't feed the driver reasoning, but only if we are clear, beer is not food ..

[intermediate]

next Bravo race with red M in the Zolder 24H weekend. Supporting the fellow historics with a "classic" viper in the main race, we will try to keep up drinking as long as they race!

[Erich Stahler]

Adrian@ said:

... one piece lower wishbones are a must for racing boys (and most run them) I like I me think most just mount a 1 1/2 square brace piece between the trunnion and the shock.
Adrian@

Edited by Adrian@ on Thursday 25th August 12:36

Hi Adrian,

I'm just wondering if the factory didn't make the lower wishbones one piece in order to put less stress in the brass trunnion or the Triumph upright by allowing some movement?

Is the 1 1/2" brace you refer to a flat strip or a piece of box section?

Erich.

[Adrian@]

Re the wishbones, I do not know much about why OE is 2 piece (when the Vixen was already one piece) but on road and race cars the poly inboard 'shouldered' bushes stop migration of the eyelets along and into the chassis, and the central brace stops oscillation through the arc of the suspension compression controlling castor issues. I am using 1"x 1/8 wall square section tube in there.
Adrian@

[djc100]

Some pictures of the wishbone mod(s) would be helpful to those of us 'without the knowledge'.
Does the ARB / mounting not create more twist and stress than the spring & damper?

I am tempted to put a fast rack in (2.5 turns) but there are just the odd times (as above) when the std set up is quite heavy. Heavy parking I can live with.

David

[Slow M]

Erich Stahler said:

Hi Adrian,

I'm just wondering if the factory didn't make the lower wishbones one piece in order to put less stress in the brass trunnion or the Triumph upright by allowing some movement?

Is the 1 1/2" brace you refer to a flat strip or a piece of box section?

Erich.

I think the torsional load the rear half lower control arm is placed under, with the ARB acting on it, increases stress on the brass trunnion. Same with the spring/shock load on front and rear. More like lack of thought than forethought, I'd guess.

B.

[Adrian@]

djc100 said:

Some pictures of the wishbone mod(s) would be helpful to those of us 'without the knowledge'.
Does the ARB / mounting not create more twist and stress than the spring & damper?

I am tempted to put a fast rack in (2.5 turns) but there are just the odd times (as above) when the std set up is quite heavy. Heavy parking I can live with.

David

Morning David,
I do not have pictures of mine, this is after all a racer 'thing', most of the racers will of looked at the Vixen lower wishbone as a start point...The evolution of the car (the S) takes the jump from TR6 to Ford and is always worth looking at....The later griff/chim top wishbone came as 2 piece and the 1 inch piece of tube linking the 2 was the redesign (I would think pictures of those would be around). The version behind the trunnion/shock bush requires a reasonable good welder (as you are welding onto 1/4 plate items) AND the bush eyelets MIGHT need taking off and putting back on, as these can be canted on the end of the tube (which gets relevant when you asking the item to be rotationally correct) again this is something that the racer boys will have some experience of, if they have changed the top wishbone eyelets to gain more camber, again for them that is almost a requirement.
Adrian@

[ivanhoew]

all in a bit of a disgusting state ,but you can just see the bar .

[djc100]

Thanks for the wishbone picture - all is much clearer now.