|
|
|
|
|
My C-reg talbot Alpine should soon be getting some restoration/upgrading-type attention, if i can ever get in my dads fuggin garage that is  It has torsion bars on the front. What is the best way to lower & stiffen this up? I know its easy to lower them but thats no good if you don't change the spring rate. Can you get torsion bars re-tempered? I don't think i'm going to find a go-faster spring option for one of those cars. One thought I had was to leave the existing suspension in place, lower it a bit and bosh some motorcycle coilovers on in addition. Obv I would have to work out roughly what I want in terms of spring rate etc. What options have I got for stiffening it all up a bit? |
| |
1972 Fiat 130 1985 Talbot Alpine 1974 Lancia Beta Saloon 1975 + 1986 Mazda 929 Koop + Wagon 1982 Fiat Argenta 2.0 iniezione elettronica 1977 Toyota Carina TA14 BEST CAR EVER!!!!!!!! 1979 Datsun B310 Sunny 4-dr 1984 Audi 200 Quattro Turbo 1983 Honda Accord 1.6 DX GONE1989 Alfa 75 2.0 TS Mr T says: TREAT YO MOTHER RIGHT! |
|
|
|
John
Part of things
Posts: 347
|
|
|
|
|
Lowering is dead easy. The bars will be splined so just fit the arm one spline round.
Stiffening is not easy. The only real way is a thicker bar but that is not practical. An auxillary spring like you say is one option. I often thought about wrapping the bar in something like a coil of wire. You could tightly wrap the bar so effectivly making it stiffer. Just make sure you go the right way so it winds up. You would have to secure the ends somehow.
The other possibility is a composite outer, kevlar or glass that will also stick well to the bar and act like a spring.
You could put half an anti roll bar on each side to stiffen it up only in bump.
John
|
| |
|
|
slater
Club Retro Rides Member
Posts: 6,390
Club RR Member Number: 78
|
|
|
|
|
Change the shocks? i know its a bit of a bodge but it will have the same effect! Take minis for example, no one ever changes the springs (much) they just change the shocks to make it firm!
|
| |
|
|
|
|
|
|
|
|
with vw torsion bars, when you lower them it stiffens anyway. Not because the spring rating has changed, but because the new angle of the trailing arms creates less torque to twist the torsion bars.
Does that make sense? I don't know the layout on your car, but thats why slammed dubs are so stiff at the front, less leverage.
|
| |
|
|
|
|
|
|
|
|
Try dropping it and see what its like. If it needs stiffening up after that I would recommend coilovers its probably the only way you can control the rate you have. I have seen a quite a few 205 track cars set up like that
|
| |
|
|
Saru
Part of things
No Brand Loyalty
Posts: 460
|
|
|
|
I was just thinking the same thing about my 16TS. The purists seem in indicate that lowering = bad for 16s however with all around torsion bars it's just crying out to be dropped 3" or so. Besides, it works for the lovely blue R4. I'm a bad. bad man.  |
| |
1974 Saab 99 EMSI bought a new car. It's 35 years old. My friends said I was mad. We'll see.
|
|
|
|
|
|
|
|
It probably depends on how much you lower it as well. A moderate drop (say 1"-1.5"), would probably be OK with the stock bars. Try dropping it and see what happens.
|
| |
1953 Minor (Long term project)
PT Cruiser
|
|
DutyFreeSaviour
Europe
Back For More heartbreak and disappointment.....
Posts: 2,944
|
|
|
|
Not sure how yours is set up - but I know my Alfa is ready for it - but if I change the bar one spline (at the rear I think ) it drops it way down - if I alter it one spline (at the front) it's a small drop - or the other way around - I have an article from an ALfa guy linked........ www.hiperformancestore.com/AlfaSuspension.htmDon't know if that'll help at all. ;D |
| |
Back from the dead..... kind of
|
|
|
|
|
|
|
|
Stiffening the front up will make the understeer worse, just drop it and see how it feels
|
| |
|
|
|
|
|
|
|
|
aye, you change the effective spring rate by lowering it. Although the tensile strength or whatever is the same the amount of weight required to deflect it a given distance is increased. Same with cutting coil springs. I do not understand how this works physically.
Also a lower COG will mean the car will tend to lean less anyway giving the feel of stiffer suspension even if it isn't.
With torsion bars theres no excuse - just get the spanners out and see how it looks and feels once its done. You can always put it back if you don't like it.
|
| |
1941 Wolseley Not Rod - 1956 Humber Hawk - 1957 Daimler Conquest - 1966 Buick LeSabre - 1968 Plymouth Sport Fury - 1968 Ford Galaxie - 1969 Ford Country Squire - 1969 Mercury Marquis - 1970 Morris Minor - 1970 Buick Skylark - 1970 Ford Galaxie - 1971 Ford Galaxie - 1976 Continental Mark IV - 1976 Ford Capri - 1994 Ford Fiesta
|
|
|
|
|
|
|
|
|
|
Dropping torsion bar suspension doesn't change the rate at all. In theory you could stiffen a torsion bar buy clamping a small section of it solid so it couldn't twist but in reality i suspect that would be hard to achieve. To have the same effect as shortening a coil spring you would need to do the same with a torsion bar.. shorten it. However this is obviously not really possible.
Unless you were absolutely slamming it on the deck I wouldn't worry too much. Just drop it and go.
|
| |
1962 Datsun Bluebird Estate - 1971 Datsun 510 SSS - 1976 Datsun 710 SSS - 1981 Dodge van - 1985 Nissan Cherry Europe GTi - 1988 Nissan Prairie - 1990 Hyundai Pony Pickup - 1992 Mazda MX5
|
|
|
|
|
|
|
Dropping torsion bar suspension doesn't change the rate at all. In theory you could stiffen a torsion bar buy clamping a small section of it solid so it couldn't twist but in reality I suspect that would be hard to achieve. To have the same effect as shortening a coil spring you would need to do the same with a torsion bar.. shorten it. However this is obviously not really possible. Unless you were absolutely slamming it on the deck I wouldn't worry too much. Just drop it and go. No, it doesnt change the spring rate, but as the angle of the trailing arm has changed the leverage forces change, effectively stiffening the car. |
| |
|
|
|
|
|
|
|
No, it doesnt change the spring rate, but as the angle of the trailing arm has changed the leverage forces change, effectively stiffening the car. Sorry but I don't buy that. If the distance between the load and the pivot is constant which it would be then the rate would still be the same unless the arm was at some ludicrous angle to the applied load. I can't see lowering would achieve such an angle. |
| |
1962 Datsun Bluebird Estate - 1971 Datsun 510 SSS - 1976 Datsun 710 SSS - 1981 Dodge van - 1985 Nissan Cherry Europe GTi - 1988 Nissan Prairie - 1990 Hyundai Pony Pickup - 1992 Mazda MX5
|
|
425ci
Part of things
Posts: 518
|
|
|
|
. . . the rate would still be the same unless the arm was at some ludicrous angle to the applied load. If you accept that a ludicrous angle would have an effect then you must also accept that any change in the angle will have an effect. The laws of physics still apply to things that aren't obvious :-). Mike |
| |
Current vehicle: Mountfield Mirage 3.5hp (18" cut)
|
|
|
|
|
|
|
If you accept that a ludicrous angle would have an effect then you must also accept that any change in the angle will have an effect. The laws of physics still apply to things that aren't obvious :-). Mike Assuming the arm would go from just below horizontal to just above horizontal I can't see there would be any real difference. Now if the arm were beyond 45 degrees then it might but somehow I can't see that being the case. The effect of the kind of angle change we are talking about would be immeasurably small if indeed it had any at all. |
| |
1962 Datsun Bluebird Estate - 1971 Datsun 510 SSS - 1976 Datsun 710 SSS - 1981 Dodge van - 1985 Nissan Cherry Europe GTi - 1988 Nissan Prairie - 1990 Hyundai Pony Pickup - 1992 Mazda MX5
|
|
425ci
Part of things
Posts: 518
|
|
|
|
|
I agree that the effect may be immeasurable, but nevertheless it will be there, if indeed we are talking about something that would have a measurable effect with a more obvious change :-).
Mike
|
| |
Current vehicle: Mountfield Mirage 3.5hp (18" cut)
|
|
|
|
|
|
|
|
all I'm going by is VW's, it does obviously depend on how much you lower it.
This is from experience, not guess work.
A bugs trailing arms are just below horzontal, this makes it easy for them to twist the torsion bars. You lower it, about 4-5" by turning the center fixing of the torsion bars (although changing the fixing on the end is the same). This puts the trailing arms quite far above horizontal.
In the stock position the suspension is easy to compress, lowered you can jump up and down on the front of the car and it hardly moves. Both tests done without shocks and already making sure the ball joints arent at the end of their travel.
It makes a HUGE difference to the stiffness of the suspension, not just a little.
As i say, this is from experience as ive tested this myself.
|
| |
|
|
|
|
|
|
|
all I'm going by is VW's, it does obviously depend on how much you lower it. This is from experience, not guess work. A bugs trailing arms are just below horzontal, this makes it easy for them to twist the torsion bars. You lower it, about 4-5" by turning the center fixing of the torsion bars (although changing the fixing on the end is the same). This puts the trailing arms quite far above horizontal. In the stock position the suspension is easy to compress, lowered you can jump up and down on the front of the car and it hardly moves. Both tests done without shocks and already making sure the ball joints arent at the end of their travel. It makes a HUGE difference to the stiffness of the suspension, not just a little. As I say, this is from experience as ive tested this myself. Ah, I see know why we are oddson this. On a bug front the trailing arms are really short aren't they? This would mean not only would the given drop change the arms angle massively the stiffening effect would be increased due to the limited leverage the arm had due to it's short length. I'm thinking more of torsion bar sprung cars with longditudional bars and lower arms that are longer than VW's. I can see where you are coming from though on Bugs. |
| |
1962 Datsun Bluebird Estate - 1971 Datsun 510 SSS - 1976 Datsun 710 SSS - 1981 Dodge van - 1985 Nissan Cherry Europe GTi - 1988 Nissan Prairie - 1990 Hyundai Pony Pickup - 1992 Mazda MX5
|
|
|
|
|
|
|
 As already mentioned, the best thing is to just slam it and see how it rides ;D
|
| |
|
|
|
|
|
Dec 10, 2006 15:09:42 GMT
|
|
Hmm. I somehow thought it might be!!!!!
|
| |
1972 Fiat 130 1985 Talbot Alpine 1974 Lancia Beta Saloon 1975 + 1986 Mazda 929 Koop + Wagon 1982 Fiat Argenta 2.0 iniezione elettronica 1977 Toyota Carina TA14 BEST CAR EVER!!!!!!!! 1979 Datsun B310 Sunny 4-dr 1984 Audi 200 Quattro Turbo 1983 Honda Accord 1.6 DX GONE1989 Alfa 75 2.0 TS Mr T says: TREAT YO MOTHER RIGHT! |
|
|
|
[*]
