Jessopia74 Posted December 30, 2020 Share Posted December 30, 2020 Found the thread, and Post from @rutts. some interesting info within the thread, so will link it at bottom of this post, however the picture is for the setup I described using the torque tube mounting x-member as the pickup for the top links. This idea would be considered an Axle change ( 2 point deduction) and no modification to shell as it utilises all original pickup points 👍 I really think this is a cracking idea for mounting the rear axle top arms, but would have solid bushings made for the pickup points so it does not flex and promote axle tramp. Quote Link to comment Share on other sites More sharing options...
rutts Posted December 30, 2020 Share Posted December 30, 2020 3 hours ago, Jessopia74 said: Found the thread, and Post from @rutts. some interesting info within the thread, so will link it at bottom of this post, however the picture is for the setup I described using the torque tube mounting x-member as the pickup for the top links. This idea would be considered an Axle change ( 2 point deduction) and no modification to shell as it utilises all original pickup points 👍 I really think this is a cracking idea for mounting the rear axle top arms, but would have solid bushings made for the pickup points so it does not flex and promote axle tramp. Bushes are rose joints 3/4 inch to body/chassis. Bushes in lower axle are polyurethane. slightly harsh but should stop tramping. 2 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted December 30, 2020 Share Posted December 30, 2020 39 minutes ago, rutts said: Bushes are rose joints 3/4 inch to body/chassis. Bushes in lower axle are polyurethane. slightly harsh but should stop tramping. Do lower arms collect on the std pickup or need the 400 additions ? Quote Link to comment Share on other sites More sharing options...
rutts Posted December 31, 2020 Share Posted December 31, 2020 (edited) Too short by about 30mm. There are three lengths of bottom arms. Think record ones are longest but don't know there exact length. They need to be 609mm from hole centre to hole centre to fit. Edited December 31, 2020 by rutts More info 1 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted December 31, 2020 Share Posted December 31, 2020 5 minutes ago, rutts said: Too short by about 30mm. There are three lengths of bottom arms. Think record ones are longest but don't know there exact length. They need to be 609mm from hole centre to hole centre to fit. Thanks, I guess I could always just add adjustable links to the ends to make up the length Quote Link to comment Share on other sites More sharing options...
rutts Posted December 31, 2020 Share Posted December 31, 2020 Couple of pics. Can send more if required. 1 1 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted December 31, 2020 Share Posted December 31, 2020 Yeah, it was probably that what Zi was thinking of. Have you got any measurements off the pigs head for the pickup points? Quote Link to comment Share on other sites More sharing options...
rutts Posted December 31, 2020 Share Posted December 31, 2020 Yes will find them and send them over weekend 1 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted December 31, 2020 Share Posted December 31, 2020 8 minutes ago, rutts said: Yes will find them and send them over weekend 🍻 Quote Link to comment Share on other sites More sharing options...
stumpy Posted December 31, 2020 Share Posted December 31, 2020 ide be interested in this also please Quote Link to comment Share on other sites More sharing options...
stumpy Posted January 3, 2021 Share Posted January 3, 2021 just a thought on ths but surely the guys at retro power who i have had help from in the past and found to be fantastic guys and made time to offer me free advice over the phone and on here...they wouldnt be able to supply a car to a customer knowing its going to be subjec to vosa/biva/iva/sva tests when presented for anMOT 1 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted January 3, 2021 Share Posted January 3, 2021 46 minutes ago, stumpy said: just a thought on ths but surely the guys at retro power who i have had help from in the past and found to be fantastic guys and made time to offer me free advice over the phone and on here...they wouldnt be able to supply a car to a customer knowing its going to be subjec to vosa/biva/iva/sva tests when presented for anMOT That is for them to argue mate, as it could be 'for off road use only'. but ultimately if you chop the shell like they do on many cars,the type approval is void. If you Google it, many kit cars that based of VW beetle (as an example) would no longer qualify, they need to have the shell floor too. VOSA and DVLA are slowly changing the rules, and it is only going in one direct, make it harder to keep that historic vehicle status. 1 Quote Link to comment Share on other sites More sharing options...
®evo03 Posted January 4, 2021 Share Posted January 4, 2021 Very interesting in this modification acceptable and grey areas, im sure the acceptable ones where grey areas, otherwise they would have been done originally, max linked axles, raised floor pans, and other countless 400 mods. I am currently researching another high performance make, and what i am learning from others is unreal, post all legal acceptable aftermarket mods, polybushed, uprated arms etc, even after cages fitted, there are further mods, not cutting, but adding braces, the amount of braces available is unreal, one example is a boot floor brace that is about 2ft away from rear turret braces, and about two inches away from an external heavy plate bumper bar. Interesting as the owner chased flexes around the shell. Braces ive seen so far, is boot floor, rear turret, parcel shelf top turret brace, floor bar behind front seats, sill to sill, A post subframe, external sill strengthening bars, chassis to bulkhead, front bar to chassis leg, all this on a standard 300bhp, to 800bhp plus monster. In race trim, there are 4 further external chassis braces, very interesting, ive never seen a higher braced chassis, most run these cars without any of these mentioned. In the future are these considered mods? They are all bolt on, was well designed and thought of. Further point is, whats safer, a car with a cage or without? Ask a rally driver this? Then your car sales man? 1 Quote Link to comment Share on other sites More sharing options...
novaman Posted January 7, 2021 Share Posted January 7, 2021 On 31/12/2020 at 21:55, rutts said: Yes will find them and send them over weekend Hi Rutts Have you investigated the amount of pinion angle change on this setup? Ive briefly toyed with the idea of equal length upper & lower links, so find your proposed setup interesting. However with the pivot point of both being so close this would appear to have a larger impact on the rear axle pinion angle with a deflection of around 7 degrees over a suspension compression of 100mm. In addition with the top links pointing down the forward bite is reduced. If you used a higher point for the top link location the pinion angle change would lower, the manta 400 used shorter top links, with that setup the pinion angle change will be significantly reduced. From a very brief cad model it would appear that a top link of around 300mm (similar to 400 mantas) centred vertically from the lower link arm set rearwards of the axle centreline as per your welded bracket above would create a pinion angle change of just over 2 degrees. There is much to review in a 4 link rear axle, i'd be very interested to see how your setup ends up, I am not an expert & I am not being critical, just extremely interested. 2 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted January 7, 2021 Share Posted January 7, 2021 1 hour ago, novaman said: Hi Rutts Have you investigated the amount of pinion angle change on this setup? Ive briefly toyed with the idea of equal length upper & lower links, so find your proposed setup interesting. However with the pivot point of both being so close this would appear to have a larger impact on the rear axle pinion angle with a deflection of around 7 degrees over a suspension compression of 100mm. In addition with the top links pointing down the forward bite is reduced. If you used a higher point for the top link location the pinion angle change would lower, the manta 400 used shorter top links, with that setup the pinion angle change will be significantly reduced. From a very brief cad model it would appear that a top link of around 300mm (similar to 400 mantas) centred vertically from the lower link arm set rearwards of the axle centreline as per your welded bracket above would create a pinion angle change of just over 2 degrees. There is much to review in a 4 link rear axle, i'd be very interested to see how your setup ends up, I am not an expert & I am not being critical, just extremely interested. 100mm movement is probably 4x what is likely on a road car ( potholes excepted) If rallying better going the top link boxes imo. But I think the yanks always set the diff angle slightly high so it goes zero deg on hard acceleration ( when it matters). 1 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted January 7, 2021 Share Posted January 7, 2021 Found what I was looking for, sorry having to use web cache due to web site BS. https://webcache.googleusercontent.com/search?q=cache:hNw5eVk0elEJ:https://www.hotrod.com/articles/91758/+&cd=4&hl=en&ct=clnk&gl=uk&client=safari Quote Suspension specialist Dick Miller bases pinion angle settings on horsepower. Miller likes to see 2 degrees of negative pinion angle (relative to the driveshaft) on applications in the 400hp range, 3 to 4 degrees in the 500hp to 650hp range, and up to 7 degrees with 700 horses or more. Miller also acknowledges that the greater the pinion angle, the more horsepower the driveline will consume, but its a compromise that must be made. Miller notes that these angles are merely guidelines, and each individual combination should be fine-tuned. https://www.onallcylinders.com/2014/11/20/setting-pinion-angle/ Not sure about that -7deg though 🤔🙈 1 Quote Link to comment Share on other sites More sharing options...
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