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What to expect from Compomotives


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Hej All,

Of my 4 Compomotives only one runs really true measured at the edges. And that's despite all four having complete new outer rings...

Now I wonder what to expect from 3 piece wheels produced in that way. Can we not expect them to be as precise as modern casted alu-wheels?   My Esprit DOES vibrate a at 80-90 kph, but it could be due other things as well of course. Eg. very, very slight play can be felt at then inner end of left tie rod... 🤔

How precise are your Compomotives?

 

BR /tka

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Hi Thomas

Mine are good but they are 15" and were original from new. I presume with an S2 they are 14 inch and non standard as S2's usually came with Speedlines.

Perhaps that's got something to do with it?

I did get mine balanced on the car and that made a big difference from being balanced in the normal way. I'd say that they are as good as single piece alloy wheels.

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As I understood few S2's came with Compomotives, or could at least be ordered with them. However mine may have come from an early Turbo too… Don't know, the car has clearly been in many hands.

I would still be little surprised if EVERY wheel had been deformed, that's why I suspected maybe they were not perfect from manufacturing. I think it IS possible to balance although wheels don't run perfectly true... Also learned somewhere that wheels or tyres not being 'entirely round' would be mostly felt at low speeds, but I don't know really. My vibrations are at 80-90 kph.   ...Haven't tried balancing with the wheels mounted though...  

Edited by tkathulevej
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I have seen several Turbos with bent/out of round rims...usually on the inside.

Have them measured with a dial indicator (on the car if possible) both on the inner rim and outer rim.

 

If within 0.5 mm should be OK, in that case have the tires balanced with a Road Force Balancer. This type can measure both rim and tyre run-out. Often the tyre will have a 'hard spot' and the RFB machine can compensate for that (it applies pressure to the tyre as it spins).

Atwell Haines

'88 Esprit

Succasunna, NJ USA

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@Bazza 907 - looking at LEW Tyre Pressure page - interestingly there is an entry for S3 on 14" wheels with 205/60 and 205/70 tyres - here's the image (5 stud)

S3_wheel2.jpg

@tkathulevej - do you have a picture of your wheels? Also pictures of your Esprit would be good :)

 

 

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Hi Chris @ChrisJ

I think the LEW page is wrong. For example under the picture you shows a 15 inch BBS wheel  for an '85 Turbo with the wrong size tyres.

As I recall the S3 was originally offered (for a very short time) with S2 Speedline wheels or with the bigger 'standard' 15 inch BBS wheels. I've never seen an S3 on 14 inch wheels but they might exist. I've seen 14inch Composites on an S2 but I'm pretty certain they would have been aftermarket wheels.  

Yes, pictures are always good. 😀

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Hi,

I seem to recall having read somewhere that late S2's (or S2.2's) were offered with same 15" Compomotive as the very early Turbo.. Was it in Jeremy's book? Anyway my car was originally S2 but altered to turbo-look (like they did it those days). So very likely the wheels were not original either.

Since wheels were rather poor condition I ended up buying new outer rings from Image Wheels (unfortunately rolled edges were no longer an option). Inner rims seemed okay, and I also had an ekstra set floating around so I picked what I thought were the best… Although it seems now that none of them are running perfectly straight. @CarBuff You say they should be within 0.5 mm to be alright. Is that really so? It seems very, very tight??   What I wonder about is that I seem to have also some run out on the (all new) outer rims. That would mean center pieces are bent, which I would imagine to take a very serious impact….

...Well, I also have a set of speedlines, and using them there is also bit a vibration (80-90 kph)… So still maybe the problem is totally elsewhere… Running out of bright ideas though 🤔 

 

/tka

 

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IMG_20171028_152054.jpg

Edited by tkathulevej
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10 minutes ago, tkathulevej said:

Anyway my car was originally S2 but altered to turbo-look (like they did it those days). So very likely the wheels were not original either.

I think this probably explains it.

If it is happening with both sets of wheels around the same speed, maybe a steering issue rather than a problem with the wheels?

I had a vibration around 70 mph on my Excel. Thought it was the wheels, had them balanced and tracking done, but turned out to be steering. Once this was all fixed, the vibration went away and all is fine now.

Edit to add: the conversion was probably done after 1985 as the colour coded bumpers were introduced for that MY. 

Are you going to keep the turbo look, or switch back to the standard S2?

What's the interior? I think the cloth S2 interior is the best of the lot.

 

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Hi @ChrisJ

What was the exact problem with your steering then? I have a very tiny (almost can't be felt in fact) play from my left inner steering rack tie rod.... Could be that, but wouldn't expect much effect from it (...but should be solved anyway, so will have to go on 🙂 )

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The .5 mm spec was from other cars I've owned...but granted, I'm proof that Americans cannot deal with the metric system. 🥴 I meant to say 0.004". (four thousandths)

What's that in Kilometers? 😆

 

Are the wheels hub-centered on early Esprits, or lug centered? Maybe wheel centering rings would help.

 

+++++++++++++

 

The seldom-accessed parts of my memory seem to recall that some early Esprits (before 1985) suffered from road vibrations when suspension components got old, but I can't remember the fix.  ????

 

Edited by CarBuff

Atwell Haines

'88 Esprit

Succasunna, NJ USA

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Not sure what the problem was (I'm not a mechanic), but it was fine at lower speeds, just started to shimmer at ~70 mph, would come off the throttle until it stopped and it was then OK - first noticed it on a track day at Hethel at around 85 mph, the speed it juddered at reduced over time until it stayed at around 70 mph - which I could sort of live with. However the power steering fluid started leaking quite badly and got the whole lot fixed at the last service a year ago. 

I've had an issue on my Esprit with the UJ sticking, but that manifested itself in really really heavy steering and the wheel not centring after a corner.

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On 11/04/2020 at 19:41, CarBuff said:

The .5 mm spec was from other cars I've owned...but granted, I'm proof that Americans cannot deal with the metric system. 🥴 I meant to say 0.004". (four thousandths)

What's that in Kilometers? 😆

Ha, ha   ….Should be 1.016x10E-7 Km I would say 🤣 

Would expect though a lot more play would be required to affect anything. Would also expect split wheels being bit less precise than casts due to manufacturing process, but might be wrong here. Well decided to take my wheels to professionals having it judged. We will see then...

 

Thank you all for inputs 🙂

 

/tka  

 

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