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Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 1:18 pm
by tdskip
I am reluctant to think I know better than Mr Chapman, but for a fast road car should I leave the front swaybar alone or is an updated one recommend?

I?m not going to be racing, just enjoying the car and touring.

Everything is going to be rebuilt so now is the time.

Merry Christmas and Happy Holidays all.

Re: Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 1:54 pm
by elancoupe
Hi Tom
there will likely be varied opinions on this subject, so assess all the info and make your own decision

This was a question of mine as well. I had a few conversations with Tony Thompson about this, here is a copy and paste of his email:

"Hi Mike
Antiroll bars are decided by how much grip you have so.
Std or Road work use standard bar. Road tyres have no real grip.
The reason is simple you do not generate enough grip to need to reduce the roll of the car. Never fit a larger bar to a road car it destroys the handling by causing dangerous understeer. The straight on syndrome especially in the wet.
We advise to keep your standard bar.
Cheers,
Tony."

Re: Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 2:10 pm
by The Veg
tdskip wrote:I am reluctant to think I know better than Mr Chapman


Or more importantly, his staff of engineers and accountants who compromised between performance and cheapness. :mrgreen:

Re: Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 2:29 pm
by Mazzini
Up rated is the way to go for an Elan, not sure about a Plus 2.

I run two Elan's with thicker swaybars and one on standard, there is a real difference.

Re: Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 4:02 pm
by elj221c
May also depend on whether you are using standard spring weights and dampers.

My car on the road had a standard roll bar but much stiffer springs and dampers.

Was fine.

Re: Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 4:28 pm
by JohnCh
It really comes down to what you like. My car came fitted with the TTR Fast Road & Track Days spring/shock combo, but still rolled a bit too much for my taste, particularly on quick transitions. After doing some research and speaking to someone who had made a similar change, I replaced the front anti-roll bar with a Kelvedon 22mm tubular ARB. It's about 4lb lighter than stock and 60% stiffer. Although there is still a lot of roll compared to a modern performance car, it's far less than before and just about perfect for me since I wasn't trying to replicate a modern feel. Upping the front tire pressures by 2psi (155/80-13 XAS FF) seems to have dialed out any incremental understeer from the change.

ARBs are very easy to swap over and not a big investment. If you are on the fence, I'd say go for it. If you don't like it, you could sell your nearly new ARB without a big dollar/pound loss.

-John

Re: Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 5:08 pm
by el-saturn
i also switched to the next size (from 7/8 to 1,0"??): much more BITE on the front! it's held by unibals and i run these a539 yokos (175/60/13) which will do 3000mls, so there pretty soft - i wouldn't go back sandy

Re: Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 11:31 pm
by 1owner69Elan
Another note regarding swaybars from Tony (TTR) Thompson when I inquired a few years back about larger swaybars (ARB):

"The (TTR) site's ARB's are bigger 13/16" and 7/8". They are only for competition with wide sticky tyres. No barrel bushes just metal on metal with grease. Not for street use."

Having converted to wider 26R wheels as well as wide sticky tires (to accommodate a high output engine but also done with no flares) I opted for a tubular (1") ARB from Kelvedon. Being hollow the ARB is much lighter than a solid one and equivalent to between the 13/16" and 7/8" solids in stiffness. Combined with TTR fast road springs/shocks and Toyo R888R 185/60R13 tires the car handles neutrally (also no rear ARB) with much reduced body lean. The car negotiates curves, quite flat, at as high a speed that I can muster my courage for. I am sure there is a limit but not something I am inclined to approach.

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Like most things on the Elan, you generally cannot change one element (like the swaybar) from stock without considering other elements (shocks, springs, tires, adjustable ride height, bushes, etc.). Such modifications open up avenues for "tuning", if you are so inclined, but also can turn out negatively if not properly set up. And of course you are changing the driving characteristics of the car as delivered from the factory. For some, that is sacrilege, even if the car is faster, more responsive, and fo me more enjoyable, to drive. Given the 26R and GTS variants out there, straying from original factory specs with certain "tasteful" mods appears to me to have some "justification" and even period correctness.

Re: Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 11:52 pm
by rgh0
Modern tyres even cheap 155 econobox ones have much more grip than tyres used by Lotus back in the period. They will generate much more body roll on a road car and even if changing nothing else on the suspension a stiffer front bar will improve the handling especially in fast transitions like through a roundabout. The stiffer bar does not significantly affect the ride in my experience (but ride is subjective).

Going to modern sticky track day tyres and a stiffer suspension needs a stiffer front bar even more.

cheers
Rohan

Re: Stay with the factory size front swaybar?

PostPosted: Wed Dec 25, 2019 11:58 pm
by 2cams70
Stiffer front relative to unchanged rear (sway bar and/or springs) = more understeer
Stiffer rear relative to unchanged front (sway bar and/or springs) = more oversteer

Stiffer shocks will change the transient response of the car but not the ultimate steady state balance.

Re: Stay with the factory size front swaybar?

PostPosted: Thu Dec 26, 2019 2:26 pm
by tdskip
Thanks for all of the responses and thoughts gentlemen.

Re: Stay with the factory size front swaybar?

PostPosted: Sun May 24, 2020 4:38 pm
by LotusElon
Fascinating Christmas Thread ...
Just bringing 1 more datapoint to the party...

elancoupe wrote: Tony Thompson email:
"Hi Mike
Antiroll bars are decided by how much grip you have so.
Std or Road work use standard bar. Road tyres have no real grip.
The reason is simple you do not generate enough grip to need to reduce the roll of the car. Never fit a larger bar to a road car it destroys the handling by causing dangerous understeer. The straight on syndrome especially in the wet.
We advise to keep your standard bar.
Cheers,
Tony."


2cams70 wrote:Stiffer front relative to unchanged rear (sway bar and/or springs) = more understeer
Stiffer rear relative to unchanged front (sway bar and/or springs) = more oversteer
Stiffer shocks will change the transient response of the car but not the ultimate steady state balance.


Handling is SO subjective - I'm not so much into outright grip as 'well balanced fun' - Using pretty standard road tyres 155/80 (Firestone Multihawk 2) I've been playing with ride heights and anti-roll bar diameters, to replicate 'the handling joy' I remembered form several earlier Elans.

Long story short (assume geometry, pressures etc all OK) ... Adjusted ride down about 1" to Wishbone level front and rear with TTR (medium) ARB3/4" ( 0.75" 19.05mm), this gave slightly sharper steering at 60-70mph and, at first, seemed to sharpen up the steering.

BUT once (after lockdown) I got to favourite quiet test area (empty private industrial estate @ w/e with a variety of bends and straights :mrgreen: ) where I could rally push the outer limits of the not so grippy tyres. I was disappointed with with understeer - I could force the rear out but it was not the natural balance I'm sure we all love. mmmmmm

So, as the above posts, which matched my previous experience, I went back to the original soft ARB : 11/16" (aka 0.688" aka 17.46mm), with standard front springs and rear springs adjusted in height .... and finally, after rebuild and electricery, balance at the limit of the tyres is exactly as I remembered: front and rear gently drifting together, with the option on push either end out more with throttle and steering ..... wonderfull !

I guess super grippy / wider tyres, thicker ARB's and stiffer springs might help with lap times, but for me, not necessarily smiles. :D

Having got back to base, I will continue to play with adjustable damper settings. I also still have a quicker moss rack to try with steering Ratio 12.24 vs standard 13.98. Steering ratios are fascinating and distinct from grip and balance - but may well swap back if it is a 'negative' improvement :D