Chimaera Suspension

[chris547]

I have had a suspension job done and am very unhappy with the result.

I went to a TVR specialist who decided what to advise. I made it clear that I wanted a road set up, not a race car. I suggested Nitrons however he said they are noisy and expensive. His solution was to use Gaz dampers and to uprate the springs by 20% compared to the standard settings. I think he has fitted 340 at the front and 300 at the rear, He also fitted superflex bushes.

I think the result is a complete failure. The car pitches about all over the place. I suggest that the springs are far too stiff I and the car is making me want to be sick rather than drive it. When it hits a bump on the motorway it lifts up and then oscilates a few times before becoming stable again. Feels horrid.

I have tried the shockers at all settings from 30 down to 3 and it makes little difference.

Any suggestions? He is a rather techy person!

[deeen]

Maybe get him to give it a proper test drive with you in it and ask for his opinion?

The oscillating could be interpreted as oversprung or underdamped, and you can ajust the damping. Maybe try winding the dampers up as tight as possible - it should feel rock solid - then winding them back slowly until you get movement in the suspension, but no bouncing?

Just thinking out loud!

[joospeed]

There's a good reason why I don't use Gaz dampers, I've never got them to work and they test less consistently than AVOs on the dyno.

There's not many specialists selling them for TVR so that rather narrows the field down a bit too (!) .. and the one specialist I can think of off the top of my head sells them for the same price as Nitrons, and as the trade price is half what Nitrons are I can see why he might have wanted you to buy those instead.

The spring rates don't sound too bad, maybe little high at the rear (first thing would be to go down to 250 on the rear for a start), but equally you may have a faulty damper (it happens) or the kit is just not working in which case you need to go back and get them to sort it out pdq.

best wishes

joo

[Steve_T]

I run 325lb/in front, 275lb/in rear on Nitrons, not much different to your setup and the ride is pretty compliant and I can't ever say I've noticed the Nitrons were noisy either. Sounds like something is a miss.

Steve.

[ian8542]

The NTX version can be noisy but this is just the way the valving works.
The later NTR is built differently.

I think by reading your other posts we already know who the specialists are!

>> Edited by ian8542 on Tuesday 5th October 18:09

[chris547]

Thanks everyone. I suspect from whats been said that the front dampers are not working at all. I have absolutely no reason to think that it will not be sorted out however I wanted to hear what others could advise before going back to complain. I suspect you get the best from this garage if you can explain what you want rather than just be a lamb to the slaughter.

If the front is undamped this could just mean putting on replacement dampers. Perhaps I am lifting at speed due to that great big front underpanel which is making the front lighter and the springs effectively stiffer.

I did try to be anonymous however you all seem to have second sense somehow on who I used. To be completely fair they have worked wonders on my car. The engine is now running about 15 degrees cooler and they have refitted the exhaust which has stopped the tunnel running red hot.

The fuel consumption is up from 250 miles per tank to over 300. The engine revs very smoothly now whereas it was all noise and no go before. They put in the correct plugs and replaced the throttle pot and a lambda sensor so excellent focus on engine fault finding. I should save the cost of the work in a few months on saving fuel alone.

My steering is now spot on with new uj's, top ball joints, bushes etc so I am a happy bunny on the steering.

I also got good advice on tyres. I bought Toyos and they grip well even to the point of not losing grip on full throttle in second gear. I suspect these are excellent tyres, compliant and yet not too soft at the limit.

Do you guys have a view on whether or not a front splitter is worth fitting. My temperature reading when cruising on the motorway is now between 50 and 60 and of course in slow traffic is 90 to 95. I suspect the splitter will make it run even cooler on the motorway but will it prevent uplift at the front and improve stability at speed?

chris547

[rude girl]

Since your garage has been consistently excellent, why not talk to them instead of posting on here?

[ATG]

If the car keeps oscillating then the dampers aren't damping. I no shag all about the art of setting up a car's suspension, but the basic principle of damping an oscillationg system so that it stabilises as quickly as possible is to ensure that it is "critically damped". Depending on the starting conditions, a critically damped system may overshoot the equlibrium point once after it has been disturbed, but no more than once. So if your's is rocking, then something is wrong because it can't be anywhere near critically damped.

[shnozz]

chris547 said:

I also got good advice on tyres. I bought Toyos and they grip well even to the point of not losing grip on full throttle in second gear. I suspect these are excellent tyres, compliant and yet not too soft at the limit. Do you guys have a view on whether or not a front splitter is worth fitting. My temperature reading when cruising on the motorway is now between 50 and 60 and of course in slow traffic is 90 to 95. I suspect the splitter will make it run even cooler on the motorway but will it prevent uplift at the front and improve stability at speed? chris547

I must admit I think I'll be going back to bridgestones after trying a set of Toyos. A lot reckon them to be fine but i am adam ant that they arent quite as good as SO3s and certainly take longer to bed in.

I fitted a leven cooling kit to my Chim and the temp came down to 70 on the move and 90 in traffic. The new otter switch means it never goes over 90 and stops me crapping myself on a hot day in traffic. I was chuffed to bits whilst touring france in June.

I have bought a front splitter and its at home waiting to be fitted. I am sort of hoping it wont cool the engine much as I dont want it running any cooler than 70, especially with winter coming up. I wanted it to see if front end stays firmer at high speed (100+). It will probably get fitted over the weekend if it stays dry so will post the results. They have a tendancy to last, oooh, about a week until you go over any speed bump and then its goodbye. Going to see how I get on.

One thing I am mindful of is the fact the splitter only goes across the middle of the cars. Therefore, wind resistance will still be hitting in front of the wheels and therefore not convinced the light steering at speed will be any better. I am looking at buying some max power style corner splitters to fit low underneath the car (and out of sight thank god) so that the wind resistance is forced down in front of the wheels. Again, will let you know how i get on.

[shnozz]

oh, and I should say I have the joospeed adjustables fitted and they have helped a lot with the handling at both low and high speed. I was happy to do 100 in the wet on sunday, and that is saying something.

[targarama]

Schnozz. You might want to wait until Spring to fit that splitter then. Mind made the car run 5 degs cooler at any temperature when moving. Eg. 65 instead or 70, 85 instead of 90. I can't see you needing the stability for VMAX work in wet/icey weather anyway.

Naturally the thermostat should stop the car running too cool.

The splitter definitely helped in summer though.

[JonRB]

chris547 said:

I bought Toyos and they grip well even to the point of not losing grip on full throttle in second gear.

I think there may be something wrong with my Chimaera 500 in that case - I haven't broken traction on full throttle in second gear (in the dry) on either S02s or SO3PPs.

In the wet I've broken traction in third quite dramatically, but that was on fairly tired S02s.

[shnozz]

targarama said:

Schnozz. You might want to wait until Spring to fit that splitter then. Mind made the car run 5 degs cooler at any temperature when moving. Eg. 65 instead or 70, 85 instead of 90. I can't see you needing the stability for VMAX work in wet/icey weather anyway. Naturally the thermostat should stop the car running too cool. The splitter definitely helped in summer though.

the thermostat has been replaced with the cooling kit too so thats opens earlier as well.

5 degrees is a fair amount, but I guess shows how much air the splitter must deflect so only a good thing from the point of view of front end stability.

So I guess the question is, is 65 degrees too low as engine temperature?

[joospeed]

rude girl said:

Since your garage has been consistently excellent, why not talk to them instead of posting on here?

but that's not the PH way

[deeen]

hi shnozz, i didnt like the so3, but v happy with my so3pp.

Dont think the air hitting the wheels makes the steering go light, its just the general lift on the front bodywork, imho.

The wheels are a big source of drag tho, so if the corner splitters can reduce that and give you a bit of downforce, great!

Have often wondered about improving the aerodynamics on mine, looking fwd to hearing how you get on.


Hi chris, I havent worked it out yet! I agree with rude girl, talk to the garage. You asked for a road set up, maybe get him to drive it with you in the car, when the bouncing / noise starts say thats what you're not happy with, can he complete the setup to avoid that plz? Keep it his problem, dont make it yours, IMHO.

[HarryW]

shnozz said:

.....I have bought a front splitter and its at home waiting to be fitted. I am sort of hoping it wont cool the engine much as I dont want it running any cooler than 70, especially with winter coming up. I wanted it to see if front end stays firmer at high speed (100+). It will probably get fitted over the weekend if it stays dry so will post the results. They have a tendancy to last, oooh, about a week until you go over any speed bump and then its goodbye. Going to see how I get on. One thing I am mindful of is the fact the splitter only goes across the middle of the cars. Therefore, wind resistance will still be hitting in front of the wheels and therefore not convinced the light steering at speed will be any better. I am looking at buying some max power style corner splitters to fit low underneath the car (and out of sight thank god) so that the wind resistance is forced down in front of the wheels. Again, will let you know how i get on.

Shnozz, I remember you mentioning at the Thorney drag racing how light your car felt and didn't like the cross winds, whilst the S was completly planted IMHE.
Just a thought now that you have got fully adjustable suspension I'd be tempted to put a bit of 'rake' to the body/chassis i.e. raise the back by 5-10mm more with respect to the front on the spring seats, this might help the high(er) speed stability IMHO.
re the splitters in front of the front wheels I'm convinced it is the relatively exposed front wheels on the S that slows it down, more than say a chim or griff, post 120mph. perhaps wait for Peter Humphries to explore this one first, although he does have a racing type plywood one across the whole nose already .

harry

[rude girl]

Good advice. I think one of the difficulties is that they are doing something quite technical to our cars, and we as customers don't have the vocabulary to describe what we want, and end up inadvertantly asking for something else. For instance, 'unstable' can mean different things to different people - I'm a bugger for using 'twitchy', which doesn't really mean anything (when is it twitchy? what does it do? at what speed? etc). Your garage will be used to this and I'm sure they won't have a problem with changing it, but do try and find some defined words to describe what the car is doing that you don't like.

Why don't you turn it around a bit though? What's the point in having adjustables if you're not going to adjust them? Why not go back, ask them to help you with the setup and then ask them to explain to you what will happen if you adjust in different ways eg to fully stiff, fully soft, what a differential between front and back will do etc. Joolz did this with me when I got mine and I've had a hoot experimenting since then.

When your garage have helped you set it up right in the first place, count how many clicks it's set at, and you'll always be able to return it to that even if you've been having a play.

[shnozz]

HarryW said:

Shnozz, I remember you mentioning at the Thorney drag racing how light your car felt and didn't like the cross winds, whilst the S was completly planted IMHE. Just a thought now that you have got fully adjustable suspension I'd be tempted to put a bit of 'rake' to the body/chassis i.e. raise the back by 5-10mm more with respect to the front on the spring seats, this might help the high(er) speed stability IMHO. re the splitters in front of the front wheels I'm convinced it is the relatively exposed front wheels on the S that slows it down, more than say a chim or griff, post 120mph. perhaps wait for Peter Humphries to explore this one first, although he does have a racing type plywood one across the whole nose already . harry

Hi mate. Yep, the suspension is not set up so there is more rake and tail end sat up a little bit. Its better, but I am now on a mission

I looked at an entire front splitter option that would go across the entire front of the car, max power style. I figured that in black it may not be that noticeable, especially if it was sat about 6 inches back from the very front. Instead I have bought a factory metal splitter to fit first and then will look at appropriate corner splitters to add in front of the wheels once this is fitted. Just worried that one speed hump will take offthe lot. Not so bad with the £15 splitter but the corner ones are £60 a set so would want to try and keep them on the car if they actually work at all.

[deeen]

Yes I lowered front and kept rear std height on mine. Changing ride height changes the geometry on the Chim tho so good to try it just before a geometry setup.

[markh]

Shnozz
just athought but I've been speaking to this guy to see if this cerbera splitter could be converted to fit a chimaera?

www.carboncerbie.com/underconstruction.htm

Mark

shnozz said:

HarryW said: Shnozz, I remember you mentioning at the Thorney drag racing how light your car felt and didn't like the cross winds, whilst the S was completly planted IMHE. Just a thought now that you have got fully adjustable suspension I'd be tempted to put a bit of 'rake' to the body/chassis i.e. raise the back by 5-10mm more with respect to the front on the spring seats, this might help the high(er) speed stability IMHO. re the splitters in front of the front wheels I'm convinced it is the relatively exposed front wheels on the S that slows it down, more than say a chim or griff, post 120mph. perhaps wait for Peter Humphries to explore this one first, although he does have a racing type plywood one across the whole nose already . harry Hi mate. Yep, the suspension is not set up so there is more rake and tail end sat up a little bit. Its better, but I am now on a mission I looked at an entire front splitter option that would go across the entire front of the car, max power style. I figured that in black it may not be that noticeable, especially if it was sat about 6 inches back from the very front. Instead I have bought a factory metal splitter to fit first and then will look at appropriate corner splitters to add in front of the wheels once this is fitted. Just worried that one speed hump will take offthe lot. Not so bad with the £15 splitter but the corner ones are £60 a set so would want to try and keep them on the car if they actually work at all.