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MG MGB GT V8 Factory Originals Technical - Rear Shocks ...(Please look if you have tried teles!)
|I am sure you may have been down this thgread before, but I trawled the archive....)|
I have tried the 'Moss' Spax rear conversion for my MGC, and found the car almost undriveable, and have gone back to the stock lever arms which work just great, however I do want to fit some anti-tramp bars to the car 'cos I use it for sprints, and I neeed to stop the axle from winding up. SO
Does anyone know of a combination of shocks and anti tramp bar kit which will work and stop the axle windup, without giving the hugely hard ride the Spax gave even on their lowest settings and longest stroke.
I have left over from the Spax debacle a pair of RV8 lower spring mounts, and the spax upper mounts.
The RV8 mounts would allow fitting of the matching anti tramp bars, (if I could find some together with the front chassis mounting). Would the RV8 Koni shock also then work??, or is there a better choice.
Sorry if I may be going over old ground, but having tried the teles once I do not want to go that route again unless I have some certainty of the desired result, which here is just better axle location, not a stiffer ride.
|Chris, the gas Spax are truly an awful product. I don't know why they are even sold. IMHO you cannot do better than the OE lever arm shocks, provided they are in excellent condition, whether you have 4, 6 or 8 cyls.|
You may find that the anti-tramp bars are to a great extent obviated if you use the fiberglass springs. IME they give a fabulous ride and they wind up quite a bit less than the steel ones.
Now I have a question for you, seeing that you have an MGC. I have a bead on a very nice MGC GT shell without a motor. My thinking is to buy it for conversion into a V8. But the C's front suspension is built for the much heavier C motor ... so maybe this would allow one to use a heavier motor, like a Ford 302 or something, or even a heavier motor than that (all the way to a small-block Chevy? ... man would that be incredible!) since the C lump weighed something like 600 pounds. Otherwise, if you do convert a C to a BOP/Rover V8, that motor's so much lighter that I would think you'd just have to intall a B's front suspension in the C (which I imagine is not a trivial task), or the thing would be all out of whack, no?
I'm just not very erudite on the C. Tell me if I'm wacked.
|Harry, fit a V8 to a C???. There is a chap in UK who races such a beast with Rover V8. My guess is that with the torsion bars the springing would work just fine, and you can buy stronger ones if you really want to put in a heavier lump, but a Rover V8 on standard or uprated bars and adjustable shocks should work fine i'd have thought especially as the suspension is adjustable for height easily. |
The competition dept at abingdon ran one of the Sebring GTs with a B motor before the C was launched and it raced fine....
However i'm missing the anti tramp bars....
|Ive had the same experience with Spaxes on my first V8 conversion. The car hopped all over the road.|
My roadster v8 has Konis which seem to be not too bad . My GTV8 has uprated Armstrongs.The rear axle desperately needs better control with 215 odd hp at the wheels. I am in the middle of fitting a Panhard rod to the GT - which will be completed with John Bourkes help this Summer -
(Stronger boot floor bracket) I should then like to fit rear axle location arms - not anti tramp bars but true trailing arms. Doug Jackson Of British Automotive in Ca is developing a kit to go with his Panhard. John I believe has used RV8 brackets tubular arms and spherical joints to accomplish this. If everyone would pester Doug, maybe we could get something done.
|I was in Doug's place 3 weeks ago, picking up composite springs for my V8 :-)|
He had his development car on the ramp and we discussed both the panhard rod (complete but having a stronger boot floor bracket developed) and the antitramp bars/trailing arms. The latter are I think at the stage of 'he knows how he's going to do it but hasn't finished them yet'. If you want to pester him, check his web site or phone him ONLY between 5.30 and 6 pm PCT.
|What about the anti-tramp bars sold by Moss - anyone had any experience with them?|
I have been driving with Spax shocks for 5 years now and yes they are hard. I have a set of Koni's ready to put on but I am building a Volvo rear end to replace the "B" rear end. How do you like the composite springs and what price are we talking? Is there a difference in composite springs for the CB and RB cars?
As for anti tramp, I would go with a V-link set up. Or just a panhard rod will do but doesnot help with tramp.
|Werner Van Clapdurp|
|Yes I'm pretty sure you order composites by C/b or R/b. They are around 350 bucks right now if you are close enough to collect.|
Chris, on the torsion bars, if they use the same mounting system as the good old Morris Minor (and I expect them too) then they are very easily adjustable for different ride heights and therefore different weights of 'lump'.
|Haven't tried, but check this out as an alternative. It sounds like several are pleased with this route, and it's a lot cheaper. |
|Does anyone esle have trouble with the URL Rob gave ?|
|Didnt work for me David.|
|I believe this is what Rob meant:|
|Thanks Guys, have looked at http://www.mgb.bc.ca/service/rear-shock.html and it all seems to make good sense. Do these US shocks have UK equivalents or do I need to do some transatlantic shopping..?|
I think that this will work with my RV8 lower mounting plates too, Now does anyone know a good 'inexpensive' source of the RV8 anti tramp bars and the front mountings for me to weld onto the chassis, or a pair of alternative a/t bars which will fit the RV8 mountings and have the front mounting brackets too..... I am trying to persist with these as I have them already and they are really neat castings compared to the fabricated brackets I have seen on some cars.
|Sorry about the mix-up guys. Thanks Carl. Hope it helped.|
|Shocks and kits are available from various places in the UK. I bought my factory V8 with Spax (I think, the ones with the adjuster screw, anyway) already on. The hard was as hard as a brick until I turned the adjuster to its softest position, then it was fine. I had to replace them because one started leaking and found that there are different shocks and kits for rubber and chrome bumpers (the diameter of the lower mounting pin) and my RB had the CB items. Again, the new items give a comfortable ride on their softest setting.|
|Just occured to me that my C is lowered around 1" all round, do I have to do more checking on the 'closed' length or should I just try the sensa trac 5877st?|
Please don't fit 'RV8' style tramp bars as I think that you will find that they will just bind up the rear suspension.I have been into this a few times before and my previous comments are probably in the archive somewhere but I'll recap:
The underslung tramp bars availible through Moss et al are an aberration and the RV8 version is just an upmarket version of the same thing.THe moss type will rip out of the floor at the front if you really hook up some power.Rover knew this when they modified the B shell and devised a strengthening strap to feed the loads up into the heel board and a new top hat section running forward from the spring mount with triangular flange plates.
I find all of this smacks of sticking plaster design-you get yourself into a problem where you shouldn't be in the first place them massively engineer your way out of it.In this case the rover engineers were trying to get the rubber bushes -not the mountings-to distort to allow for the binding action endemic in the design-the front half of the spring wants to change length under flexure.There is also the fact that roll understeer is built into the design to stabilise the rear end in roll and this relies on the axle being able to move forwards and upwards on each side.The binding geometry also will screw up the spring rate picture that the dampers will see.....
In my opinion the last decent live axle design to come out of BL/Rover was that found under the rear end of a Rover SD1.The torque tube is one of the best ways to deal with live axle torque.I'd love to get into a discussion with sonme one who has tried a decoupled torque tube setup,brake floaters,birdcages et al on a B rearend.......
I reckon that the British Automotive composite rear springs really do look the business esp for a car with 4cyl power.I'd fit some but I'm still experimenting with a pair of RV8 single taper leaf springs(see the V8 conversion site).
I have tried to fit a pair of adjustable Armstrong lever arm shocks-and had a pair specially overhauled.They would be ideal but simply will not fit with my own design of tramp bars(see the V8 conversion site)which have forward compliance to prevent binding.
I'm currently having Leda Suspension build me a pair of 24 position adjustable tubular dampers as a direct replacement for my current RH Bilsteins which I think are way too hard and are ruining the compliance that I should be getting from the RV8 springs.I'll let everybody know how that works out as soon as I get hold of them.............
|There have been many threads on the best rear-end set up for our V8s. It is a complex issue. One setup that is available but which I have heard nothing about is the Trevor Taylor (?) one advertised here. Does anyone have any info about this setup? Good? Bad? Etc.|
|I did have a good look at the Trevor Taylor set up when it appeared at Stoneleigh this year.It is too easy to be critical when someone has spent a lot of time working out how to get a working independent rear suspension assembly under a C/B B-without moving the battery boxes and so that it can be marketed as a bolt on piece.|
I think that that that is where it is compromised.The cage assembly shown on the web site is not complete-there are two links which run diagonally forward to the front spring hangers from the front corners of the square frame at the base of the diff.These have to be cranked to miss the battery boxes etc and do not look strong enough to stabilise the diff cage assembly which is mostly supported from a tube spanning between the old damper mounts.The diff cage supported by this tube has to take all of the suspension loads including braking and traction forces.To my eyes the lower diff frame needs a stiff flat member-shaped like a T-working in a similar manner as the lower X member on a Jaguar XJ40 .
Apparently Trevor has taken plenty of orders for the suspension- so we will no doubt be hearing a lot more about it.There will probably be a road test in the MG press soon if I'm not much mistaken.I understood from the show that the kit(which seems to comprise of the diff cage, suspension arms,mounts,hub carriers,hubs,modified Sierra Drive shafts,coilover units- would be around £1500-you have to source the diff,brake calipers and discs.
I think at that at that sort of price you have to think about what you you are trying to achieve-do you want handling on undulating roads above all else a la Lotus or do you want good handling mostly on smooth roads-which is achievable with a live axle set up?
|I would agree with John's comments and add that the 'on paper' benefits of an exotic suspension spec are easy to project. However it is a completely different ball game when trying to turn those 'on paper' benefits into quantifyable improvements. |
It is far easier to end up in a worse position than you start with, as there are so many variables that demands a huge investment in time, money and testing to arrive at the ideal compromise.
|I am really suprised at the difference the low friction fiberglass spring makes to the ride with the solid axle. It obviously is more compliant and seems to keep the wheels on the ground even with the hi unsprung weight. If you consider one bump at one side at a time rather than both rear wheels being lifted simultaneously the change in unsprung weight difference is not as much as you would expect. If you take the other wheel as being the fulcrum point rather than the center of the axle you are only handling half the differential weight. The increased performance of an independent suspension is in large part related to being able to use a low friction coil spring rather than the multileaf spring. Most independent rear ends weigh overall as much or more than the stock system. Positive axle location is also a benefit of a IRS system. However a panhard rod can also solve that problem on the live axle system. The major area to save weight is the brakes, solid axle weights and the wheels. Is the old banjo tube axle system better? Brake drum systems are generally lighter than disk brake systems.|
|Speaking of the fiberglass rear spring, and I know that there have been many positive threads on this, I have a '67 BGT that I have lowered about 1 1/2". What would this fiberglass spring do to my lowering job? |
|check with www.mgbmga.com Doug I recall says the spring without lowering blocks reduces height about 1/2". The spring is thinner than the original spring and extra plastic spacers are provided. The spacers can be put over the axle, instead of under and will lower the car further. (or vice versa)|
Barry. My 67 gt with plastic springs, with bumpers off and no spare, rides at 14 1/4" center of wheel to bottom of trim strip.
|does anyone know of a web site that sells these compsite springs. how much are they.|
both price and (sole) supplier are mentioned in earlier postings within this very thread - it's worth reading.
All of you have been very helpful, but I think I have now become confused! (Not difficult).
My requirement is to try and prevent axle wind up from my 'C' away from the line and in tighter 'full throttle'
corners taken in low gears, where I can feel (and see from video evidence) the rear axle winding up and the car corners in a series of small hops from the rear. I currently have Moss 1" lowered std springs, std (and good) lever arms and poly bushes throughout. I have a 3.9 B diff so torque at the rear wheels is increased.. .
Am I reading the thread correctly in thinking that the anti tramp bars (from whoever) will upset significantly the good ride I currently enjoy, but composite or taper leaf RV8 springs may help limit the wind up and retain the ride, and a Panhard rod will do the trick to get off the line without tramping?. Or do I also need the telescopic type shock to help in the slow corners?.
|I think from the summation of all the info on this subject over the last few months that your conclusions should prove correct. Fitting teles on the back usually seems to make the back too stiff and increase the 'spinning inside wheel' syndrome when pulling away on lock eg at T junctions - or hairpins.|
|Guys...I'm just getting into the whole conversion thing & want to do it right (if there is such a thing) the first time...my bodyshell is up on stands & everything is out of it, so its easay to build whatever works best...I'm going to use MGC gears w/OE shocks, hopefully in an MGB rostyle rear....have already removed the rear spring shackles & shortened them 1"...plan on redrilling front locator point 1" higher on body..theoretically, that should drop rear end of car 1"? have been reading everything ya'll are saying about panhard bars & think I need to install one...where can I get one? Is that all I need to do to the rear suspension?|
If you actually shortened the rear shackles, spring wind up and binding are likely to occur. Shortening shackles is not a good method for lowering.
|George..I did shorten the rear shackles by 1" (center of original old bottom hole-the one in which the spring is attached-to center of new bottom hole)...seem to have clearance between frame rail & spring when refitting sprins w/o rear end attached...if clearance is there, how would i have binding?...oh, talked w/Doug Jackson & am ordering his panhard bar kit for rear end...also, have studied discussions on rear shock mods & determined that I will probably go w/Gabriel tube shocks instead of oe units|
If the shackles are not long enough, the spring will have no choice but to wind up (become S-shaped) when it flattens on bumps or cornering. They have to be long enough to handle full suspension travel.
|George..so, how does one lower the rear of a rubber car to chrome specs-short of those gosh awful expensive fiberglass springs ('cause I have new OE springs already)?|
Lowering blocks between the springs and axle are the simplest and most cost effective method. This does give a longer twisting moment on the axle, but most people just live with it.
|George..you are correct...went out this pm & installed a spring w/shortened shackle...took back off & threw shackles in trash...pulled another set of shackles out of my parts bin to use in original condition....looks like I'll buy a set of shortened springs from Moss & use a panhard bar....thanks for your advice.....tony|
|Hi, I have been trying to find Doug Jacksons telephone No and website, but have drawn a blank|
anyone know how to get in touch with British Automotive?.
|chris...just spoke w/him y'day....1-415-883-7200...or...email@example.com|
|when i talked w/doug, he seemed ready to ship his panhard bar kit to me....ran into a small problem geting the "b" gears out of case to insert the "c" gears so will hold off a week or soon ordering...has anyone gotten a kit from him yet?|
|To George B in Wildomar, CA: figured out how to lower rear end w/o using shortened spring or lowering kit! i was on the right trtack but got hung up trying to shorten shackles....the rear spring mounting position is just a piece of metal spot welded onto "frame rail" drill out spot welds & behind it is the dimple for the chrome bumper mounting point; drill it out, weld in a tube & the shackle fits like a chrome bumper...& the front spring mounting location i drilled an inch higher into the spring mounting location is exactly where it was on a chrome bumper car....now, my rear end thinks it was always chrome bumper!! for NO COST!!!|
while you are drilling cutting and welding, you should cut out the crescent welded in to lower the rear axle bump stop. Cut out the crescent and you can raise the bump stop to the cb location for more rear axle travel. By the way you should now be using cb rubber straps and the shorter shock rod also from the cb.
|Barry...thanks will do that..yes, am using cb straps but am going to use gabriel tube shocks-unless someone knows the bilstein or koni #'s....tony|
|Doug Jackson does not think his Panhard rod will fit an MGC because of its Girling Brakes and their handbrake linkage. Anyone know of any other sources of an MGB/C panhard rod kit??|
|adrian s...sent you an e-mail about success i had removing the rb rear spring hanger "tits"..works great & you were correct, the cb dimple is behind the piece of metal spot welded to frame rail!! easy job, now, all i have to do is drill hole large enough for tube that holds schakle rubber & reweld the holes from where i drilled out factory spot welds...will put photos on my web site next week...thanks for tip|
After you modified the rear spring mounting from RB to crome bumper do you have to use crome bumper springs, or, can you keep the rubber bumper springs?. how do you plan to lower the front suspension? what i did on my 1976 was: cut and rewelded the sring pans adding 1" of tubing of the correct O.D. that way i kept the stock springs and the correct ride, but, the lower "A" arms hung at a steep angle I thing 1/2" lowering would had been enough.
|romney...i'm planning on using chrome rear springs (have lots in my mg graveyard...check w/some other guys but i believe the only difference is one has 5 leafs & the other has 6...i'm also going to use chrome bront beam & springs (also have several)...will put all together with tube shocks...can see progress on my web site (www.theAutoist.com)|
|There were several types of rear spring used over the years, 5-leaf vs 6-leaf can relate to roadster vs GT. Spring rates also vary between CB, RB, roadster, GT and various years. |
|paul...okay, now you've muddied the water even more...if a person were going to use original chrome bumper springs, what type are they looking at...i have many springs sitting in a corner of my "mg graveyard"..some are 5-leaf, some 6...i also have many chrome parts cars from 1964-1974 w/springs still ubnder them...what do you suggest?|
|About the rear and front suspension from Trevor. This units were just tested against a stock V8 GT and a RV8 and Trevors V8 with the front and IRS set up. The unit out perform the competition. Should be an article pretty soon in the Uk with the results of the test. I met Trevor here in the US while on Bus. I know his set up for the front is totally awsome and I am going to install it on my project car. The rear set up is very nicely design and pretty strong I would not be afraid to use it on my Ford V8 project. If anyone has any questions about the IRS suspension, just drop an e-mail to Trevot. He will gladly answer any questions you may have about anything to do with the unit or any other matter about cars.|
|Apologies for the mud. "Original" could be taken to refer to the year of use. E.g. MGB CB roadster always had 5-leaf and GTs 6-leaf (excluding the very short leaf) but interleaving was only used from May 63. MGC had 6-leaf on both but the GT had increased free camber and higher load rating. V8 had 6-leaf but with a higher load rating than the standard GT. 4-cyl RB cars had stiffer springs, the roadster had 6-leaf until Sep 75 when it reverted to 5-leaf. RB V8 was the same as the CB. Therefore a CB roadster should always have 5-leaf and the CB GT 6-leaf, and if you wanted to be really pedantic a pre-May 63 roadster should have 5-leaf with no interleaving. 6-leaf, or RB 5-leaf, would definitely give a higher ride-height than 'normal' on a CB roadster.|
This thread was discussed between 27/04/2000 and 20/06/2000
This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.