New owner - TVR Chimaera 500
Discussion
Hi all,
I’ve just acquired a Starmist Blue 1996 TVR Chimaera 500. It’s my first TVR and V8, and I’m rather excited by it all!
It’s been fitted with the ACT carbon plenum with twin throttle bodies. I think it may have been chipped (possibly Tornado) but I need to check this out to confirm.
It was running pretty poorly when I got it - it wouldn’t idle on it’s own and needed input from the throttle to keep it going. It was also running incredibly rich (I think it might still be) and kangarooing, only one fan was working and the temp gauge wasn’t working. The stepper motor had been blanked off as well.
I browsed the forums for help (I wasn’t able to post due to a forum lockdown on new members) and have done the following up to now:
Changed ECU coolant sensor.
Ditched the TVR temp sender and bought a new LR one, and using the resistor method got the gauge working.
Cleaned the stepper motor and reconnected.
New oil, oil filter, spark plugs, air filter.
All of the above dramatically improved the running! It is now able to idle on it’s own, running at least less rich than it was, and the kangarooing has almost subsided completely. I’ve also got both fans working.
Here’s a quick picture - I’ll update with more when I get the chance (I’ve a busy day ahead prepping for the MOT, new rear discs and pads plus new upper ball joints on the front).
I’ve got a few problems/questions that I’ll list:
1.When starting the car it idles at around 1000rpm, but as the car warms up this rises to 16-1800rpm. I’ve read that this could be the stepper motor not working correctly, or perhaps the base idle needs adjusting? I’m not sure how to do this on the ACT set up. Is anyone able to offer some help on this?
2.The 100A fuse underneath the car has been bypassed and the cables just linked up. Should I be re-fitting a 100A fuse?
3.The battery doesn’t seem to hold charge. It’s less than a year old and seems to be a robust AGM type (Exide EP450 Dual AGM (Maxxima MAX900DC)) that should cope easily I believe. I’ve been using a Ctek AGM charger overnight - it then performs fine but if the car is used during the day it gets to a point where it won’t turn the car over and needs charging again.
I’m not entirely sure yet if something is draining the battery or the battery is knackered…my next steps were to try disconnecting it for a couple of days and then trying to use it - does this seem sensible?
If it is the battery, it should still be under warranty so I should be able to get a replacement, hopefully.
4. At the risk of starting a huge debate again, I need 4 new tyres. The car has raceline RL-7 alloys, all of which are 17” and 8J et30. It’s currently got 215/40/17 on the front and 245/40/17 on the back. Are these sizes correct for the alloys? The 215 looks a little stretched but I’d imagine any bigger may well rub at the front?
Uniroyal RainSport 3 seem to come recommended - I don’t intend on taking the car out in the wet, and probably not any track days at this stage, is this still a good tyre to go for?
For those sizes the fronts would be 87Y XL tyres and the rears 91Y (not XL). Would these match OK? If you change the size at the rear to 235/45/17 you can have 94Y or 97Y XL.
That’s already looking like a lot of questions so I apologise and I’ll stop there!
Any help is much appreciated, and I look forward to being part of the community going forward
Cheers,
Gareth
I’ve just acquired a Starmist Blue 1996 TVR Chimaera 500. It’s my first TVR and V8, and I’m rather excited by it all!
It’s been fitted with the ACT carbon plenum with twin throttle bodies. I think it may have been chipped (possibly Tornado) but I need to check this out to confirm.
It was running pretty poorly when I got it - it wouldn’t idle on it’s own and needed input from the throttle to keep it going. It was also running incredibly rich (I think it might still be) and kangarooing, only one fan was working and the temp gauge wasn’t working. The stepper motor had been blanked off as well.
I browsed the forums for help (I wasn’t able to post due to a forum lockdown on new members) and have done the following up to now:
Changed ECU coolant sensor.
Ditched the TVR temp sender and bought a new LR one, and using the resistor method got the gauge working.
Cleaned the stepper motor and reconnected.
New oil, oil filter, spark plugs, air filter.
All of the above dramatically improved the running! It is now able to idle on it’s own, running at least less rich than it was, and the kangarooing has almost subsided completely. I’ve also got both fans working.
Here’s a quick picture - I’ll update with more when I get the chance (I’ve a busy day ahead prepping for the MOT, new rear discs and pads plus new upper ball joints on the front).
I’ve got a few problems/questions that I’ll list:
1.When starting the car it idles at around 1000rpm, but as the car warms up this rises to 16-1800rpm. I’ve read that this could be the stepper motor not working correctly, or perhaps the base idle needs adjusting? I’m not sure how to do this on the ACT set up. Is anyone able to offer some help on this?
2.The 100A fuse underneath the car has been bypassed and the cables just linked up. Should I be re-fitting a 100A fuse?
3.The battery doesn’t seem to hold charge. It’s less than a year old and seems to be a robust AGM type (Exide EP450 Dual AGM (Maxxima MAX900DC)) that should cope easily I believe. I’ve been using a Ctek AGM charger overnight - it then performs fine but if the car is used during the day it gets to a point where it won’t turn the car over and needs charging again.
I’m not entirely sure yet if something is draining the battery or the battery is knackered…my next steps were to try disconnecting it for a couple of days and then trying to use it - does this seem sensible?
If it is the battery, it should still be under warranty so I should be able to get a replacement, hopefully.
4. At the risk of starting a huge debate again, I need 4 new tyres. The car has raceline RL-7 alloys, all of which are 17” and 8J et30. It’s currently got 215/40/17 on the front and 245/40/17 on the back. Are these sizes correct for the alloys? The 215 looks a little stretched but I’d imagine any bigger may well rub at the front?
Uniroyal RainSport 3 seem to come recommended - I don’t intend on taking the car out in the wet, and probably not any track days at this stage, is this still a good tyre to go for?
For those sizes the fronts would be 87Y XL tyres and the rears 91Y (not XL). Would these match OK? If you change the size at the rear to 235/45/17 you can have 94Y or 97Y XL.
That’s already looking like a lot of questions so I apologise and I’ll stop there!
Any help is much appreciated, and I look forward to being part of the community going forward
Cheers,
Gareth
I would suggest that you have the alternator checke out and replace that fuse. It sounds to me like the regulator in the alternator at least is faulty possibly the alternator itself. If the alternator is over charging then it would blow the fuse I am thinking and seeign as how it's been bypassed it has now cooked that expensive battery. Hopefully somone far more familar with the TVR's will come along and point you in the right direction. But having the alternator tested would be my first thing to do.
Nice looking car
1 - idle - the ACT plenum could possibly be leaking air in from worn spindles. Might be worth approaching Tim at ACT - he's very helpful - re a base idle setting, and whether the throttle pot is standard Lucas - this needs to be set right to tell the ecu it's supposed to be idling. Rovergauge or ecu mate are useful tools to see what's what - see the classifieds for the rovergauge lead.
2 - yes, get another 100A fuse - only a couple of quid on ebay or tvr parts (discount for tvrcc members)
3 - battery could be alternator as already said
4 - tyres - I have toyos but the rainsports get a good rep and I'm tempted to try them next. Your raceline wheels are very rare now
1 - idle - the ACT plenum could possibly be leaking air in from worn spindles. Might be worth approaching Tim at ACT - he's very helpful - re a base idle setting, and whether the throttle pot is standard Lucas - this needs to be set right to tell the ecu it's supposed to be idling. Rovergauge or ecu mate are useful tools to see what's what - see the classifieds for the rovergauge lead.
2 - yes, get another 100A fuse - only a couple of quid on ebay or tvr parts (discount for tvrcc members)
3 - battery could be alternator as already said
4 - tyres - I have toyos but the rainsports get a good rep and I'm tempted to try them next. Your raceline wheels are very rare now
The best wheels 
Get yourself a 100amp midi fuse and holder if there's nothing there, much more reliable than the old style. I would suggest that either an air leak or your battery problems could be the reason for the weird idle and running issues, I'd sort the battery problems before searching for other reasons.
Get yourself a copy of rovergauge and a lead, helps heaps when trying to find problems
Get yourself a 100amp midi fuse and holder if there's nothing there, much more reliable than the old style. I would suggest that either an air leak or your battery problems could be the reason for the weird idle and running issues, I'd sort the battery problems before searching for other reasons.
Get yourself a copy of rovergauge and a lead, helps heaps when trying to find problems
Brithunter said:
I would suggest that you have the alternator checke out and replace that fuse. It sounds to me like the regulator in the alternator at least is faulty possibly the alternator itself. If the alternator is over charging then it would blow the fuse I am thinking and seeign as how it's been bypassed it has now cooked that expensive battery. Hopefully somone far more familar with the TVR's will come along and point you in the right direction. But having the alternator tested would be my first thing to do.
Thanks, I'll look into this. I think it can be done at home with a multimeter? I'll have a search. I did test the voltage of the battery with the engine off and running, it was only a quick one and I can't actually remember the results but I know there was a higher voltage when the car was running.
andy43 said:
Nice looking car
1 - idle - the ACT plenum could possibly be leaking air in from worn spindles. Might be worth approaching Tim at ACT - he's very helpful - re a base idle setting, and whether the throttle pot is standard Lucas - this needs to be set right to tell the ecu it's supposed to be idling. Rovergauge or ecu mate are useful tools to see what's what - see the classifieds for the rovergauge lead.
2 - yes, get another 100A fuse - only a couple of quid on ebay or tvr parts (discount for tvrcc members)
3 - battery could be alternator as already said
4 - tyres - I have toyos but the rainsports get a good rep and I'm tempted to try them next. Your raceline wheels are very rare now
Thank you! I'll get in touch with Tim. 1 - idle - the ACT plenum could possibly be leaking air in from worn spindles. Might be worth approaching Tim at ACT - he's very helpful - re a base idle setting, and whether the throttle pot is standard Lucas - this needs to be set right to tell the ecu it's supposed to be idling. Rovergauge or ecu mate are useful tools to see what's what - see the classifieds for the rovergauge lead.
2 - yes, get another 100A fuse - only a couple of quid on ebay or tvr parts (discount for tvrcc members)
3 - battery could be alternator as already said
4 - tyres - I have toyos but the rainsports get a good rep and I'm tempted to try them next. Your raceline wheels are very rare now
Yes I'm quite happy with the alloys! Just the tyres that are a pain ha! I'm pretty set on the rainsports now, just need to finalise the sizes...
s p a c e m a n said:
The best wheels
Get yourself a 100amp midi fuse and holder if there's nothing there, much more reliable than the old style. I would suggest that either an air leak or your battery problems could be the reason for the weird idle and running issues, I'd sort the battery problems before searching for other reasons.
Get yourself a copy of rovergauge and a lead, helps heaps when trying to find problems
I'll agree with the best wheels! Get yourself a 100amp midi fuse and holder if there's nothing there, much more reliable than the old style. I would suggest that either an air leak or your battery problems could be the reason for the weird idle and running issues, I'd sort the battery problems before searching for other reasons.
Get yourself a copy of rovergauge and a lead, helps heaps when trying to find problems
Will do on the midi fuse, they look good. Worth sticking to 100A? I've seen some people mention 125A before.
Will try and get to the bottom of the battery!
Agreed - will tidy up the cabling as well!
Small update on the battery front - I tested the battery after a charge (12.8V) then disconnected it and left it for 24 hours before testing again (12.8V) so doesn't appear to be an issue there.
I then started the car and tested again (14.2V) so this would tell me the alternator is working?
Whilst my head was deep in the passenger footwell I noticed (amongst a variety of other random cables and connectors) a couple of audio leads plugged into the battery. I know from my young(er) big loud subwoofer days that sometimes amps can drain a battery quickly. So i hunted around and found two amps (still don't know why you'd want to do this in a TVR but anyway) behind each seat, neatly tucked behind the carpet I must say.
As a quick measure I removed the fuse from both amps. I've not had any issues with the battery since, albeit over a short time, and the battery was still reading 12.8V at the end of the day with everything connected.
Solved? Maybe (hopefully!) - I'll keep my eye on it.
Whilst I was in the footwell I checked to make sure I had a connector for a Rovergauge (I did, and am now ordering one) and also decided to take a look at the ECU. This is what I found:
Looks like I do have a Tornado chip, then!
Small update on the battery front - I tested the battery after a charge (12.8V) then disconnected it and left it for 24 hours before testing again (12.8V) so doesn't appear to be an issue there.
I then started the car and tested again (14.2V) so this would tell me the alternator is working?
Whilst my head was deep in the passenger footwell I noticed (amongst a variety of other random cables and connectors) a couple of audio leads plugged into the battery. I know from my young(er) big loud subwoofer days that sometimes amps can drain a battery quickly. So i hunted around and found two amps (still don't know why you'd want to do this in a TVR but anyway) behind each seat, neatly tucked behind the carpet I must say.
As a quick measure I removed the fuse from both amps. I've not had any issues with the battery since, albeit over a short time, and the battery was still reading 12.8V at the end of the day with everything connected.
Solved? Maybe (hopefully!) - I'll keep my eye on it.
Whilst I was in the footwell I checked to make sure I had a connector for a Rovergauge (I did, and am now ordering one) and also decided to take a look at the ECU. This is what I found:
Looks like I do have a Tornado chip, then!
Ok - I'm about to pull the trigger on buying some new tyres...
I'm going for the Uniroyal RainSport 3's
Front size - 215/40/17 87Y XL
Rears...it's between 2. Currently the car has 245/40/17 - the rainsports come in this size but not extra load (XL). But you can go 235/45 to get XL. So here are the two choices:
1. 245/40/17 91Y
2. 235/45/17 97Y XL
What should I go with?
I'm going for the Uniroyal RainSport 3's
Front size - 215/40/17 87Y XL
Rears...it's between 2. Currently the car has 245/40/17 - the rainsports come in this size but not extra load (XL). But you can go 235/45 to get XL. So here are the two choices:
1. 245/40/17 91Y
2. 235/45/17 97Y XL
What should I go with?
Yes, you're right - they have a 94Y in 235/45/17 as well.
Problem is, you can only get XL in 215/40/17 which is what I believe I'd need on the front - narrower won't fit and wider or higher profile will/may rub?
In my head I ideally don't want to be mixing XL and non-XL tyres, but in honesty I probably don't understand matching up tyres well enough to be sure!
Problem is, you can only get XL in 215/40/17 which is what I believe I'd need on the front - narrower won't fit and wider or higher profile will/may rub?
In my head I ideally don't want to be mixing XL and non-XL tyres, but in honesty I probably don't understand matching up tyres well enough to be sure!
I think you will find that "Classic Chimaera" is running 215/45x17 on the front of his car with no real problems.
There is a thread on here you might want to read.
It's called "tyres and sidewall heights" I think. My inability with computers means I don't know how to post a link, sorry!
Regards Chris.
There is a thread on here you might want to read.
It's called "tyres and sidewall heights" I think. My inability with computers means I don't know how to post a link, sorry!
Regards Chris.
s3c chris said:
I think you will find that "Classic Chimaera" is running 215/45x17 on the front of his car with no real problems.
There is a thread on here you might want to read.
It's called "tyres and sidewall heights" I think. My inability with computers means I don't know how to post a link, sorry!
Regards Chris.
Funnily enough I'm just working my way through that thread now - hopefully it'll clear things up and help me make a decision.There is a thread on here you might want to read.
It's called "tyres and sidewall heights" I think. My inability with computers means I don't know how to post a link, sorry!
Regards Chris.
For reference, here's the thread: https://www.pistonheads.com/gassing/topic.asp?h=0&...
Hi, yes it's correct I'm running Rainsport3
215/45/17 87Y
235/45/17 94Y
If your running the correct ride height at around 150f 155-160r you shouldn't get any rubbing.
I'm on 17 x 7.5 rims allround
I'm very happy with my set up, I've raised my ride height at the rear to compensate the larger dia front tyre to keep the castor angle correct but that's about it. It doesn't make a great deal of difference so not necessary anyway.
215/45/17 87Y
235/45/17 94Y
If your running the correct ride height at around 150f 155-160r you shouldn't get any rubbing.
I'm on 17 x 7.5 rims allround
I'm very happy with my set up, I've raised my ride height at the rear to compensate the larger dia front tyre to keep the castor angle correct but that's about it. It doesn't make a great deal of difference so not necessary anyway.
ClassicChimaera said:
Hi, yes it's correct I'm running Rainsport3
215/45/17 87Y
235/45/17 94Y
If your running the correct ride height at around 150f 155-160r you shouldn't get any rubbing.
I'm on 17 x 7.5 rims allround
I'm very happy with my set up, I've raised my ride height at the rear to compensate the larger dia front tyre to keep the castor angle correct but that's about it. It doesn't make a great deal of difference so not necessary anyway.
Thank you!215/45/17 87Y
235/45/17 94Y
If your running the correct ride height at around 150f 155-160r you shouldn't get any rubbing.
I'm on 17 x 7.5 rims allround
I'm very happy with my set up, I've raised my ride height at the rear to compensate the larger dia front tyre to keep the castor angle correct but that's about it. It doesn't make a great deal of difference so not necessary anyway.
I've got 17 x 8 rims all around, with a et30 offset. You probably know more about what that means for me than I do
So I'll go with:
Front: 215/45/17 87Y
Rear: 235/45/17 94Y
Are we all in agreement? Suppose I could try 245/45/17 95Y
There's a good site that's easy to use and shows a sectional drawing of the difference from the standard wheel and tyre size to what you wish to try. This will give you the info you need to make a choice.
235/45/17 is a big tyre and i think is more maluable than a 245 so gives better grip in most conditions but that's just my feeling.
Will they fit .com enter your offsets etc and it will calculate your new sizes. Both these tyre's are bigger than standard and its important for you to know what effect this may have.
I'm not sure on 8 in rims without doing the calcs, they may rub on the fronts on full lock etc so check carefully how much your wheel and new tyre will be further in towards body using that site or similar.
235/45/17 is a big tyre and i think is more maluable than a 245 so gives better grip in most conditions but that's just my feeling.
Will they fit .com enter your offsets etc and it will calculate your new sizes. Both these tyre's are bigger than standard and its important for you to know what effect this may have.
I'm not sure on 8 in rims without doing the calcs, they may rub on the fronts on full lock etc so check carefully how much your wheel and new tyre will be further in towards body using that site or similar.
So according to that website, I believe going from 215/40/17 to 215/45/17 on the fronts will just make the tyre taller by 21.5mm - about 3.5%.
The rears from 245/40/17 to 235/45/17 will increase the tyre diameter by 15.5mm - about 2.5%.
I don't think I'll have any issues with that?
Out of interest, going up to a 245/45/17 will increase tyre diameter by 24.5mm - a little under 4%, so would probably keep things more similar to how they are now (and in relation to the original tyres, I believe), although it's probably pretty negligible, and I'm still not sure it would actually fit.
I think choosing tyres is the most complicated thing to do on these cars!!
The rears from 245/40/17 to 235/45/17 will increase the tyre diameter by 15.5mm - about 2.5%.
I don't think I'll have any issues with that?
Out of interest, going up to a 245/45/17 will increase tyre diameter by 24.5mm - a little under 4%, so would probably keep things more similar to how they are now (and in relation to the original tyres, I believe), although it's probably pretty negligible, and I'm still not sure it would actually fit.
I think choosing tyres is the most complicated thing to do on these cars!!
If you don't know already and I'm slightly scratchy on this myself.
Measurements for offset arebtaken from hub face ( where the wheels clamps to the car)
So if my memory is correct and I've only done this once or twice
Inset = how far the wheel goes in towards the car body from hub
Poke = how far the wheel pokes out from the bodywork from hub
If you are already using the same wheels take measurements from the car as to the tyre position in relation to wishbones and inner arch area etc and then look at your calculator to determine whether the new size will fit and not rub.
Yes the fronts on my sizes are larger in % than the rears.
I've only gone to a 45 on the fronts because it allows for compliance over bumps
So went up on the rear to 45 to keep a reasonable balance. I feel 245 is to big for my wheels and my needs, often notice 245 is a cliff edge from tread to tyre wall and are often to stiff, depends on tyre though!
The other aspect that makes all this guess work is the tyre's are different sizes depending on make and although a 235 by numbers alone might seem small in reality on the car it's almost as wide, higher side wall allows less air pressure so tyre squats and looks very wide. I didn't like the idea of taking the dia up so much on the rear as it will effect gearing also.
I considered the front tyre's and the effect increasing the dia would have.
Brakes are not as sharpe on first application, caster can change slightly, possibly more wander when driving in straight lines but this is very minimal for my driving, I've got used to it all now and it's better everywhere other than my brakes are not as good. I have big Brembo so they are still brilliant and actually easier to control when close to locking them up, all from a slightly larger dia tyre so it does have an effect.
I don't wish to encourage someone who doesn't consider this as you might not like the results.
Steering is slightly heavier on Rainsport at slow speeds simply because they are softer and grab the road more.
I took a risk and it's working out and in fact one of the best things I've done because my car takes bumps and grips far better than other tyre's I've used.
235 you won't get wheel spin and they work in corners better than the 245 I once had on.
Avon ZZ3 so a road tyre that was hard then Toyo T1R which were very similar in hardness and no grip!
Measurements for offset arebtaken from hub face ( where the wheels clamps to the car)
So if my memory is correct and I've only done this once or twice
Inset = how far the wheel goes in towards the car body from hub
Poke = how far the wheel pokes out from the bodywork from hub
If you are already using the same wheels take measurements from the car as to the tyre position in relation to wishbones and inner arch area etc and then look at your calculator to determine whether the new size will fit and not rub.
Yes the fronts on my sizes are larger in % than the rears.
I've only gone to a 45 on the fronts because it allows for compliance over bumps
So went up on the rear to 45 to keep a reasonable balance. I feel 245 is to big for my wheels and my needs, often notice 245 is a cliff edge from tread to tyre wall and are often to stiff, depends on tyre though!
The other aspect that makes all this guess work is the tyre's are different sizes depending on make and although a 235 by numbers alone might seem small in reality on the car it's almost as wide, higher side wall allows less air pressure so tyre squats and looks very wide. I didn't like the idea of taking the dia up so much on the rear as it will effect gearing also.
I considered the front tyre's and the effect increasing the dia would have.
Brakes are not as sharpe on first application, caster can change slightly, possibly more wander when driving in straight lines but this is very minimal for my driving, I've got used to it all now and it's better everywhere other than my brakes are not as good. I have big Brembo so they are still brilliant and actually easier to control when close to locking them up, all from a slightly larger dia tyre so it does have an effect.
I don't wish to encourage someone who doesn't consider this as you might not like the results.
Steering is slightly heavier on Rainsport at slow speeds simply because they are softer and grab the road more.
I took a risk and it's working out and in fact one of the best things I've done because my car takes bumps and grips far better than other tyre's I've used.
235 you won't get wheel spin and they work in corners better than the 245 I once had on.
Avon ZZ3 so a road tyre that was hard then Toyo T1R which were very similar in hardness and no grip!
Thanks for the comprehensive reply!
I will get measuring tomorrow, I'm quietly confident that the new sizes will be ok given what's already on there, but will double check!
I'm now sold on the 215/45/17 fronts and 235/45/17 rears so will bite the bullet once I've done the measuring.
Looking forward to the grip!
I will get measuring tomorrow, I'm quietly confident that the new sizes will be ok given what's already on there, but will double check!
I'm now sold on the 215/45/17 fronts and 235/45/17 rears so will bite the bullet once I've done the measuring.
Looking forward to the grip!
Gassing Station | Chimaera | Top of Page | What's New | My Stuff