Chimaera throttle cable

[danno38]

Hello All

I recently bought a Chimaera and while admiring in the garage the other day I stated it up and the throttle pedal was sticking down temporarily. I have looked at the throttle cable and its minutes from snapping. I have ordered a new complete cable but the thought of doing the work for me is a bit daunting. I am booked into a company on the 1st May to inspect the car but I am now worried that I might not make the distance to the garage.

I have tried you tube to see if there is anything but I have had no joy. I think I can do it but need someone to hold my hand ha ha. If you live near Bicester and can offer any advice or any on here I would appreciate that a lot.

Thanks Dan

[Zeb74]

Alternative solution is to go to the garage with a piece of string, if the cable breaks, you can attach the string under the bonnet and pass through the opened side window to accelerate with the hand. We have already seen this during a TVR meeting, the chap managed to return to the hotel like this.
I would also hesitate to change my self this cable, doesn't sound as an easy task.

[nawarne]

IF the outer looks OK, and it is just the inner failing, then just replace the inner.....It used to be "Clevor Trevor" that held the 'kits' .
Essentially it's just the inner cable with a screw on/secured nipple for the engine butterfly end. The correct nipple is fitted for the pedal end.

Nick

[danno38]

Zeb, Nick thank you both for your replies.

I was thinking the cable out is fixed in position and looks pretty good. A cable replace would be a much easier option I think. The cable I have purchased has the bracket with the split pin at one end and what looks like a bike cabe nipple at the other. I am presuming if I remove the small bike nipple just like feeding through a push bike the cable will then feed through?

Sorry to all who have heard this before, please feel free to laugh at my utter newbie novice q's. As soon as the cable arrives I will let you know how it goes.

Edited by danno38 on Wednesday 7th April 20:25

[never_thought_id_buy]

The inner cable is fairly easy to change, just pigging awkward to get to at the pedal end. It's easiest with the roof off, lying on your back with your head down the footwell and your body and legs on the seat...

And to avoid embarrassment on the road if (when) it snaps, it's worth carrying a couple of suitable sized cable ties so that you can tie the throttle open on the engine to about 2500 RPM and then just drive using the gears. I did about 10 miles like that with the RAC van following me (his idea). He then very kindly spent about an hour fixing the cable, which was going above and beyond. But I'm sure more interesting than dealing with another flat tyre/ flat battery/ empty tank.

[danno38]

Thank you I am loving these little tips and hints. The joys of the car being 27 year old is that has simple things like cables and easily accessible parts.
I am looking forward to tackling the challenge now.

Think the boot will have such a mad array of items if I am ever stopped by the police " can you explain the tie wraps,wrags,pliers and petrol" ha ha.

thanks again for the help

Dan

[Hedgehopper]

About 10 years ago I noticed that the inner cable was badly frayed at the the butterfly end. I replaced it with a pushbike brake inner cable from Halfords and it’s still going strong to this day.

Edited by Hedgehopper on Wednesday 7th April 21:00

[nawarne]

never_thought_id_buy said:

The inner cable is fairly easy to change, just pigging awkward to get to at the pedal end. It's easiest with the roof off, lying on your back with your head down the footwell and your body and legs on the seat...

And to avoid embarrassment on the road if (when) it snaps, it's worth carrying a couple of suitable sized cable ties so that you can tie the throttle open on the engine to about 2500 RPM and then just drive using the gears. I did about 10 miles like that with the RAC van following me (his idea). He then very kindly spent about an hour fixing the cable, which was going above and beyond. But I'm sure more interesting than dealing with another flat tyre/ flat battery/ empty tank.

^^^That's what prompted me to buy the 'kit' from Clevor Trevor.

Luckily the RAC van that turned up when I snapped my cable had an array of bowden inners in different diameters. He guesstimated length, soldered on a nipple for the pedal end threaded it through to the butterfly crank and had a suitable screw on nipple to secure it at that end.
This happened late'ish on a bank holiday Monday....just giving it some beans as the single carriageway road opened out ont a dual carriageway....Oh the ignominy as I coasted onto the hard shoulder!

Nick

[Steve_D]

May not be relevant in many cases but the biggest killer of throttle cables is having the tension wrong which breaks the cable when you 'Pedal To Metal'. There is a limit stop at the pedal but if the cable is too tight the cable will be stretched before the pedal meets the stop.

The correct setting is with the pedal held down to the stop you should be able to open the butterfly just a little more.

Some may say you are then not getting full throttle but a few degrees of movement when the butterfly is directly in line with the airflow fill not make a difference.

Steve

[bobfather]

This appears to occur because there is a lot of spring tension causing the inner cable to rub excessively on the sheath. At the throttle butterfly end there are three springs, two identical springs that sit either side of the throttle cable lever and one on the butterfly shaft. When you reassemble your new cable I suggest removing one of the two throttle cable lever springs. Many owners have done this as a pre-emptive action, myself included. The result actually makes the throttle pedal more responsive as you are no longer fighting excessive friction resistance in the cable. It's worth a try, the spring can easily be refitted after the job is done if you decide you prefer the stiffer pedal

[QBee]

Hope this helps.......



The star of the show is well into his 60s and 14 stone, so if he can do it (with much grunting and cursing) so can you

[Loubaruch]

bobfather said:

This appears to occur because there is a lot of spring tension causing the inner cable to rub excessively on the sheath. At the throttle butterfly end there are three springs, two identical springs that sit either side of the throttle cable lever and one on the butterfly shaft. When you reassemble your new cable I suggest removing one of the two throttle cable lever springs. Many owners have done this as a pre-emptive action, myself included. The result actually makes the throttle pedal more responsive as you are no longer fighting excessive friction resistance in the cable. It's worth a try, the spring can easily be refitted after the job is done if you decide you prefer the stiffer pedal

I would be very wary of removing any springs on the throttle cable. Many years ago Colin Blower in a racing Tuscan had a throttle stuck at maximum and it nearly killed him. Throttle springs are there as a fail safe.

[Zener]

Yes but you dont need all three

[bobfather]

Zener said:

Yes but you dont need all three

Actually there's 4, there's one in the TPS. Any one of them is capable of independently slamming the butterfly closed. The true danger here is throttle cable fraying and jamming open. Removing one spring makes this less likely.

[Classic Chim]

Two springs are a safety device. If there was no risk of butterfly staying wide open they would have used one spring.
The correct approach is to replace one of the strong springs for a weaker one thus keeping two springs on the car incase one snaps.
Try taking the two springs off, it feels like no resistance at all really.

Edited by Classic Chim on Thursday 8th April 22:44

[bobfather]

Classic Chim said:

The correct approach is to replace one of the strong springs for a weaker one thus keeping two springs on the car incase one snaps.

Edited by Classic Chim on Thursday 8th April 22:44

I like that solution, we are getting tied up in a belief that this is a TVR designed system. Actually the throttle linkage comes from another car which most likely didn't have such a twisted cable route

[Classic Chim]

bobfather said:

I like that solution, we are getting tied up in a belief that this is a TVR designed system. Actually the throttle linkage comes from another car which most likely didn't have such a twisted cable route

Absolutely.
I remembered when this came up years ago I too liked the idea of less strain on the cable but loath to remove the spring.
Strange really because only a week or so ago I refitted my plenum after a long lay up and noticed my weaker spring which in turn reminded me how much better it is. I don’t like the throttle to light though so for me the best solution.

[QBee]

//Start Personal view mode

I removed one spring 8 years ago, and 45,000 miles later I have yet to think "I really wish I had a heavier throttle on this car".
Ditto clutch (servo assisted), ditto steering (power assisted), ditto brakes (servo assisted).
I must be getting weak in my old age, but I like the sensitive feedback I get from the car without the feeling I am lugging something from the Lancashire Stone Age around the lanes and tracks. I leave that to the Lancashire Stone Age man himself, Freddie Flintstone.

//Personal view mode over

[Zener]

bobfather said:

Zener said:

Yes but you dont need all three

Actually there's 4, there's one in the TPS. Any one of them is capable of independently slamming the butterfly closed. The true danger here is throttle cable fraying and jamming open. Removing one spring makes this less likely.

Not with the throttle cable attached its not the TPS internal spring sole purpose is not for closing the throttle plate other 3 are

Edited by Zener on Friday 9th April 10:32

[bobfather]

Zener said:

Not with the throttle cable attached its not the TPS internal spring sole purpose is not for closing the throttle plate other 3 are

Edited by Zener on Friday 9th April 10:32

I know, I'm just letting readers know there are more than two springs acting on the butterfly. Like it or not, the TPS spring does act to close the butterfly even though that is not its purpose