Ade-TR4 Posted April 30, 2007 Report Share Posted April 30, 2007 Hi I've been toying with the idea of creating some negative camber on the front of the TR4. Modern radials do not like positive camber and progressively loose grip in the corners. I've obtained a pair of Moss's Neg-Camber vertical links (I assume they just offset the stub axle to acheive the required camber setting). Has anyone tried these? I know Tony and Andy (Lane) have neg cambered their rally cars and report good things, however, I don't want to go to the extent of reworking the whole upper arms' assembly etc to make the changes. The vertical link sounded like a simple way to do it. Thoughts anyone? Cheers Adey Quote Link to post Share on other sites
stuart Posted April 30, 2007 Report Share Posted April 30, 2007 Hi I've been toying with the idea of creating some negative camber on the front of the TR4. Modern radials do not like positive camber and progressively loose grip in the corners. I've obtained a pair of Moss's Neg-Camber vertical links (I assume they just offset the stub axle to acheive the required camber setting). Has anyone tried these? I know Tony and Andy (Lane) have neg cambered their rally cars and report good things, however, I don't want to go to the extent of reworking the whole upper arms' assembly etc to make the changes. The vertical link sounded like a simple way to do it. Thoughts anyone? Cheers Adey Adey you can achieve some Neg camber by adding shims to the lower wishbone to chassis brackets. You are slightly restricted by the bolt lengths but it make an appreciable difference. Stuart. Quote Link to post Share on other sites
Ade-TR4 Posted April 30, 2007 Author Report Share Posted April 30, 2007 Hi Stuart, not on a TR4 matey!!! Lower wishbones are fixed to the chassis: So it's major surgery to the upper wishbones or these neg-vertical links. Glad to hear it makes a positive improvement though. Cheers Adey Quote Link to post Share on other sites
stuart Posted April 30, 2007 Report Share Posted April 30, 2007 Hi Stuart, not on a TR4 matey!!! Lower wishbones are fixed to the chassis: So it's major surgery to the upper wishbones or these neg-vertical links. Glad to hear it makes a positive improvement though. Cheers Adey Sorry Adey must have been a senior moment or the fact that I am up to me armpits in fitting a new loom to a right hand converted 250 so not much concentration left for other things!! Stuart. Quote Link to post Share on other sites
Ade-TR4 Posted April 30, 2007 Author Report Share Posted April 30, 2007 It's sooooo nice to have a decent loom in a classic car. My 43 year old TR4 has more reliable electrics than my missus' "modern" car!!! Quote Link to post Share on other sites
Tr4Tony Posted April 30, 2007 Report Share Posted April 30, 2007 Adey You need to have a look at BST82B when you have a minute (and have a little pootle down the road!) .... Ive tried a few things; 1. Shortening the top wish bones - my conclusion is fine for track and fast road when suspension travel is small. No good for rallying. 2. Nefarious fiddling with the top wishbones, repositioning of top fulcrum etc. - absolutely unmeasurable, unrepeatable and therefore didnt work so well ..... but the rigt idea. 3. Revington TR's adjustable top fulcrum kit - its not truly adjustable (tried that with 2. above) but its does allow you to adjust and position the top fulcrum to give the desired negative camber, then you weld it in place. It also allows you to use the standard length top wishbones so the steering geometry 'trapezoid' remains 'in shape' throughout normal suspension travel. Ive not used the MOSS kingpins, but in theory it should give you the same effect BUT, are you moving the roll centre of the suspension off line ..... my suspension book says so ...... so my experience to date would suggest that its not as good a solution as Neil's (apparently designed by a proper suspension engineer). Let me know you you get on. BST82B will be at the International weekend (with bumpy hardtop ....... which Im going to patent !!!!!!!) so we can sneak off for a quick squirt through the lanes if that would be helpful! Regards Tony Quote Link to post Share on other sites
Ade-TR4 Posted May 1, 2007 Author Report Share Posted May 1, 2007 (edited) Sounds good to me. I'm using the TR far too much to strip the front down just yet anyway! How good is this weather??!!! Cheers Adey photos of hardtop please.... Edited May 1, 2007 by Ade-TR4 Quote Link to post Share on other sites
john minchin Posted May 2, 2007 Report Share Posted May 2, 2007 I have just been reading Kas Kastner's book just obtained from the TR Register shop and he states that reducing the length of the bar which links the two turrets will have the effect of giving the camber change. He used to do it allegedly (not in the race rule book). Pretty easy to do if you have a welder, however how you make sure both come in the same amount is another matter. Cheap as well, thats good ! Quote Link to post Share on other sites
BrianC Posted May 3, 2007 Report Share Posted May 3, 2007 I have just been reading Kas Kastner's book just obtained from the TR Register shop and he states that reducing the length of the bar which links the two turrets will have the effect of giving the camber change. He used to do it allegedly (not in the race rule book). Pretty easy to do if you have a welder, however how you make sure both come in the same amount is another matter. Cheap as well, thats good ! He does emphasise that you need to "jack up the chassis in the middle at the front", so that should spread the two sides evenly. It's also a carefully written piece, so he doesn't actually admit to having done it (at least not in competition). Quote Link to post Share on other sites
jonlar Posted May 3, 2007 Report Share Posted May 3, 2007 He does emphasise that you need to "jack up the chassis in the middle at the front", so that should spread the two sides evenly. Wouldn't that give Positive rather than Negative camber? Quote Link to post Share on other sites
Ade-TR4 Posted May 3, 2007 Author Report Share Posted May 3, 2007 I was thinking that too! Either way, it sounds like a recipe for potential problems. I'd prefer to do it with the body removed and on a jig that could accurately measure the adjustments. I enjoyed the story of the "one-sided handbrake" Kas used in racing to effectively mimick a limited slip diff in the corners: He'd throw the car in so it lifted the inside wheel, pull on the handbrake to lock the lifted wheel and give it full beans, which all went to the outside, driving wheel. Only worked in left OR right corners, not both! not a mod' for the road adey Quote Link to post Share on other sites
Tr4Tony Posted May 3, 2007 Report Share Posted May 3, 2007 Hi Racers still use that mod on tracks which are primarily one handed ........ still good. I use it on my TR4 if I know the majority of the tests are clockwise etc. The cutting top wishbones thing isnt so clever. It gives poor turn in at speed and on my car heavy steering, so no good except for track use ! been there done that. Regards Tony Quote Link to post Share on other sites
jonlar Posted May 3, 2007 Report Share Posted May 3, 2007 The old hill climbers used to be fitted with "fiddle" brakes for hand-brake turns in both directions - don't think that would be quite acceptable to today's MoT test stations............ Quote Link to post Share on other sites
BrianC Posted May 3, 2007 Report Share Posted May 3, 2007 He does emphasise that you need to "jack up the chassis in the middle at the front", so that should spread the two sides evenly. Wouldn't that give Positive rather than Negative camber? I assume that when the car is jacked-down, the turret tops close up (evenly) onto the newly-shortened cross-tube giving the negative camber? Whilst I wouldn't try this myself, Kas didn't often make mistakes and some of his bodges and quick-fixes seem to have turned out remarkably well. Quote Link to post Share on other sites
jellison Posted May 4, 2007 Report Share Posted May 4, 2007 Hi Stuart, not on a TR4 matey!!! Lower wishbones are fixed to the chassis: So it's major surgery to the upper wishbones or these neg-vertical links. Glad to hear it makes a positive improvement though. Cheers Adey Beat me too it! Easy on a 6. Mine it is easy on 4 too. Two ways to do it. 1. cut the top wishbones an have welded back together a tad shorter. or 2. I think you can swith the lower wishbone arms over and invert them this does the same but no cutting. Think I have tried both - but hen done alot to mine over the years - all very blurry now;) Quote Link to post Share on other sites
marvmul Posted May 4, 2007 Report Share Posted May 4, 2007 I assume that when the car is jacked-down, the turret tops close up (evenly) onto the newly-shortened cross-tube giving the negative camber?Whilst I wouldn't try this myself, Kas didn't often make mistakes and some of his bodges and quick-fixes seem to have turned out remarkably well. I've done this on my TR3 race car and it works very well, not much force is needed to fit a cross bar that is 1" to 1.5" shorter. I didn't get enough neg. camber by doing so, I've also bent the uprights, after making them red hot : If you bent the uprights too much, the extremities of the uprights can fool the wheel rim when taking sharp turns. Quote Link to post Share on other sites
MadMarx Posted May 6, 2007 Report Share Posted May 6, 2007 I use shortened upper wishbones (~1,3cm) to have -1,7° negative at my current ride hight. With standard right hight it is -1,5°. The handling is greatly improofed and tire wear reduced. I still use my car at everyday traffic and found no trouble with the shortened wishbones. Also the bumpsteer is is reduced. If the ride height is increased on a rally car then it might be an disadvantage because there is a strong camber change on the whole travelway. Suspension full out is -2.5°, at ride hight -1.7, full in -2.2 at my car. Cheers Chris Quote Link to post Share on other sites
MadMarx Posted May 6, 2007 Report Share Posted May 6, 2007 (edited) 2. I think you can swith the lower wishbone arms over and invert them this does the same but no cutting. Very easy done but with two disadvantages.... 1. The track becomes too wide, especially with wider rims an tires. 2. If wider tires are used they will touch the fenders. With a shorter upper wishbone wider tires can be used. Edited May 6, 2007 by MadMarx Quote Link to post Share on other sites
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