BPK806 1969 +2 Rear Suspension upgrade

[BullAndrew]

Planning to upgrade to 2.25? springs so replacing the strut tube with an adjustable one, new strut, fast road spring.

What about the top mount, is there any value for a road car to change the Lotacone to a solid mount ?? or would it just be unnecessary expense and a noisier car

Adjustable Wishbone ? are they worth it ? the original ones look OK.

Rubber bushes over Polyurethane, again for a road car ?? would you spend the extra, I have had the comment that as the bushes are small the amount of rubber moving around is not great, so the Poly bushes give a harsh ride although they would last longer

Thanks for thoughts, I am just about to place my parts order, and would welcome any thoughts and advice.

[john.p.clegg]

If your tracking is out fit adjustables,if not don't.....poly is better than rubber long term,how long will you be keeping it? I have but wouldn't go for 2.25" springs...why?

John

[512BB]

Cleggy wrote: I have but wouldn't go for 2.25" springs...why?

Could not agree more. Nothing wrong with the original set up. A mate of mine fitted adjustable suspension all round on his car, and it is undriveable. He has spent many an hour trying to get it right, to no avail. The more you make adjustable, the greater the chance to mess it up. In my humble.

Leslie

[BullAndrew]

John, Leslie,

My thought was adjustable would give more scope, but also I would like to fit something prettier than the steel wheels, I have not seen the +2 alloy wheel available so thought minilites and spider do a 14" option which gives more tyre choice but I thought it needed the narrow spring for clearance. And see note below about the chassis, thinking that adjustable would give more scope if the chassis is not as true as it could be.

I don't know that the tracking is out, but I inherited the car with a galvanised chassis, has not been rebuilt, I understood the Hot dipping could create misalignment in the chassis, so that is why I thought the adjustable wishbones would make sense, and although I could fit them at the end of the job, if I fit new bushes to the old wishbones they would probably be wasted as its always a challenge to get bushes out without damaging them

As for how long I keep the car...... I hope its until I have to stop driving (or can't get in the car) which should give me 15 years, I can't see the boss in doors giving me an opportunity to have another project, so its build her properly now and then its small projects in the future, I guess that means its worth the expense of the poly bushes.

[john.p.clegg]

" Make the suspension adjustable and they will adjust it wrong -- look what they can do to a Weber carburetor in just a few moments of stupidity with a screwdriver. " CABC

John

[7skypilot]

Fitting narrower springs really does increase your options. My experience is with an Elan S4, but I guess much is the same on the +2.

2.25" springs and adjustable platforms have made my coupe much, much more fun to drive. The only real disadvantage of 2.25" springs over the existing is that the original Aeon bump-stop wont fit. IIRC Rohan fits 2.5" springs to allow the use of the original Aeon unit. The bump-stop really is an integral part of the suspension and I suggest that it would be unwise to leave it out. I used an equivalent unit from a VW Passat - very similar in performance. Adjustable springs (of a higher rate) have meant that ground clearance has not been a problem even during 'spirited' driving on Alpine passes with a nav & luggage.

If the Lotocone's are sound, I'd retain them. If not, buy some new ones - a solid upper mount will be stiff and noisy and reduce the compliance that the chassis offers on the road.

The inner wishbone metallastic bushes can deteriorate pretty rapidly in the oil that tends to congregate round them. I replaced those with a 'polybush' derivative but retained the (rather flimsy) outer wishbone metallastic bushes.

Most tyre fitters will offer a rapid, and accurate, check of rear tracking. Then you'll know if your rear tracking is outside tolerance and may need to consider adjustable rear wishbones.

14" wheels will offer a greater range of tyres. They also avoid the need to 'fettle' the outer of the rear wishbone to avoid contact betweed the inside of a wider rim & the outside of the wishbone. Only minor adjusments are required, but it is another job... I used 13" Minilites.

When I was changing the suspension during last winter, I had excellent advice from this wonderful forum, and also from Lotus specialists. I'm sure they will suggest spring rates & dampers to suit your planned usage.

Have fun...

[Spyder fan]

" Make the suspension adjustable and they will adjust it wrong -- look what they can do to a Weber carburetor in just a few moments of stupidity with a screwdriver. " CABC

John

Who is CABC? is he a relative of ACBC?

Fitting the narrower springs gives the option of using 14 or even 15 inch minilites on a +2, although I think 15's look wrong. The tyre choice should be 185x65x14, don't be tempted to go for 185x60 or everyone will say your +2 looks like it's riding too high. Spyder made a schoolboy error a few years back and fitted 185/60 profile tyres to everything that left their workshop until just last year when I sorted it out for them

[john.p.clegg]

" in just a few moments of stupidity with a keyboard. " CABC"

John

[Chris]

I fitted 2.25" adjustable sleeves to my 130/5, to allow room for 185 tyres. I measured the wheel arch to deck height prior to removing the originals, and adjusted the new ones to give the same height. They work very well but can sometimes be noisy due to the spring contacting the threaded sleeve under certain conditions. 2.5" springs would have been better.
Chris

[h20hamelan]

I used rubber for up and down, poly for side to side

[gus]

Just as a side note I have been running 205/60-13s for almost 30 years with stock springs. Cut back the spring perch and grind a small flat on the bottom[non moving] coil of the spring. Not so much for wanting the width but the tire height is right

[alan.barker]

Andrew said "I don't know that the tracking is out, but I inherited the car with a galvanised chassis, has not been rebuilt",
Sorry but All cars with galvanised chassis have been rebuilt.
They never had a galvanised chassis when built

Alan