1997 TVR Chimaera 450
Discussion
My Griff has the factory power steering and it’s woefully light / lacking feel and feed back. It’s worse since fitting a new PAS pump a few years ago.
I’ve heard of the Impreza rack conversion, but never tried a car with it.
I am interested in some rack mounts etc, if you are having some machined up.
I’ve heard of the Impreza rack conversion, but never tried a car with it.
I am interested in some rack mounts etc, if you are having some machined up.
Well the power steering conversion is now complete and the car passed its MOT on Tuesday. The first experience is that it is in general an improvement and is perfectly acceptable but could do with a bit more self centring, so ideally a bit more caster. As the caster adjustment is already maxed out this will mean modifying the wishbones, but this isn't a massive job. Maybe one for later in the summer.
Unfortunately the rack brackets haven't arrived (the supplier cant give me a delivery date due to covid delays), but I managed to use the Subaru brackets and some formed steel plates to mount the rack in the same place. I'll swap these out for the proper brackets when they arrive.
I made a bracket to mount an 80amp fuel alongside the alternator fuse and wired the astra pump control signal to the alternator light, which all seems to work perfectly. The pump starts up when the engine starts and stops if it stalls.
I flattened off the manifold faces, fitted new gaskets and resealed the Y piece to the manifolds, and also removed and resealed the sump by removing the cork gasket, cleaning up the faces and using locitite 5980 gasket sealer. The result is an exhaust that doesn't blow and no drips! Its also received a full 12000mile service including fuel filter (what a b
d of a job that is!) and Castrol 10w60 oil.
Waiting for its MOT:
I also decided to have a go at the passenger side window which had all but ground to a halt. Getting the door card off is fairly straightforward if you have pipe-cleaner arms like mine, but I can see why some struggle! A realignment of the window in the runners and a bit of red rubber grease and its (almost) as good as new.
Back in the garage waiting for some good weather!
Unfortunately the rack brackets haven't arrived (the supplier cant give me a delivery date due to covid delays), but I managed to use the Subaru brackets and some formed steel plates to mount the rack in the same place. I'll swap these out for the proper brackets when they arrive.
I made a bracket to mount an 80amp fuel alongside the alternator fuse and wired the astra pump control signal to the alternator light, which all seems to work perfectly. The pump starts up when the engine starts and stops if it stalls.
I flattened off the manifold faces, fitted new gaskets and resealed the Y piece to the manifolds, and also removed and resealed the sump by removing the cork gasket, cleaning up the faces and using locitite 5980 gasket sealer. The result is an exhaust that doesn't blow and no drips! Its also received a full 12000mile service including fuel filter (what a b
d of a job that is!) and Castrol 10w60 oil.Waiting for its MOT:
I also decided to have a go at the passenger side window which had all but ground to a halt. Getting the door card off is fairly straightforward if you have pipe-cleaner arms like mine, but I can see why some struggle! A realignment of the window in the runners and a bit of red rubber grease and its (almost) as good as new.
Back in the garage waiting for some good weather!
Adam205 said:
I should probably add that that the power steering conversion cost me just shy of £300 of new parts + some left overs from previous car builds (hose fittings etc). It would probably have been doable for £350 from scratch though.
Hi Adam - Were you following the footsteps of others or is this something you worked out?On my list as next car, planning to buy an earlier one which needs work, then spend the money getting chassis sorted and any other work, I would rather a fully sorted early one than spending my full budget on one and then trying to save up to fix it.
Just trying to find the right one, must not have the later wings as they look crap imho, and trying to find one that hasn't got hearing aid beige or clown soul grey interior
Just trying to find the right one, must not have the later wings as they look crap imho, and trying to find one that hasn't got hearing aid beige or clown soul grey interior
B'stard Child said:
Hi Adam - Were you following the footsteps of others or is this something you worked out?
Very much in the footsteps of others! There's a massive thread on subaru steering rack conversions in the Chimaera section, you have to pick through the useful information and red-herrings but overall its pretty straightforward. Obviously being a complete reconfiguration of the steering system its not a novice job, but perfectly doable by the 'home engineer'.pits said:
On my list as next car, planning to buy an earlier one which needs work, then spend the money getting chassis sorted and any other work, I would rather a fully sorted early one than spending my full budget on one and then trying to save up to fix it.
Just trying to find the right one, must not have the later wings as they look crap imho, and trying to find one that hasn't got hearing aid beige or clown soul grey interior
I took a similar approach, although I was after a facelifted one in a dark colour. I went and looked at a couple of 15-16k cars that, although shinier and with PAS, were otherwise in the same condition as this one. The money saved will pay for a full chassis refurb, respray and re-carpet at some point!Just trying to find the right one, must not have the later wings as they look crap imho, and trying to find one that hasn't got hearing aid beige or clown soul grey interior
PrinceRupert said:
Lovely colour and good thread :thumbsup: Watching with interest.
Thanks!Adam205 said:
B'stard Child said:
Hi Adam - Were you following the footsteps of others or is this something you worked out?
Very much in the footsteps of others! There's a massive thread on subaru steering rack conversions in the Chimaera section, you have to pick through the useful information and red-herrings but overall its pretty straightforward. Obviously being a complete reconfiguration of the steering system its not a novice job, but perfectly doable by the 'home engineer'.Good to see you are enjoying the car
Are you still competing in the 7?
B'stard Child said:
Adam205 said:
B'stard Child said:
Hi Adam - Were you following the footsteps of others or is this something you worked out?
Very much in the footsteps of others! There's a massive thread on subaru steering rack conversions in the Chimaera section, you have to pick through the useful information and red-herrings but overall its pretty straightforward. Obviously being a complete reconfiguration of the steering system its not a novice job, but perfectly doable by the 'home engineer'.Good to see you are enjoying the car
Are you still competing in the 7?
Adam205 said:
I cant imagine you without a LC!
Strangely I find it easy to imagine 
Adam205 said:
Didnt get out in the Westfield last year (hence I've had a bit of time on this), but hoping to at least get a few events in this summer.
Funny a photo cropped up on the blue forum the other day (celebrating 17 years old)
I thought I bloody know that Polo
Was that Gaydon in 2008? I'd only had a license for a few months at that point! A years insurance on that was more than I pay for all three cars now....
If you want to see what the steering conversion feels like and you happen to be a long way west you're more then welcome to take it for a spin. Its a tad slower than the standard TVR power steering which I think is a good thing.
Took it for a proper run out this evening as the weather was nice and the steering has definitely changed the character of the car. In some ways I miss the event of wrestling it around roundabouts with two hands and feeling every cats-eye and manhole cover, but its gained the ability to be a comfortable summer cruiser.
And i've missed that noise!
If you want to see what the steering conversion feels like and you happen to be a long way west you're more then welcome to take it for a spin. Its a tad slower than the standard TVR power steering which I think is a good thing.
Took it for a proper run out this evening as the weather was nice and the steering has definitely changed the character of the car. In some ways I miss the event of wrestling it around roundabouts with two hands and feeling every cats-eye and manhole cover, but its gained the ability to be a comfortable summer cruiser.
And i've missed that noise!
Adam205 said:
Was that Gaydon in 2008? I'd only had a license for a few months at that point! A years insurance on that was more than I pay for all three cars now....
I think it was - Insurance costs is one of the advantages of getting old Adam205 said:
If you want to see what the steering conversion feels like and you happen to be a long way west you're more then welcome to take it for a spin. Its a tad slower than the standard TVR power steering which I think is a good thing.
Took it for a proper run out this evening as the weather was nice and the steering has definitely changed the character of the car. In some ways I miss the event of wrestling it around roundabouts with two hands and feeling every cats-eye and manhole cover, but its gained the ability to be a comfortable summer cruiser.
Nice of you to offer - furthest west I get is Shelsley for the Gathering Took it for a proper run out this evening as the weather was nice and the steering has definitely changed the character of the car. In some ways I miss the event of wrestling it around roundabouts with two hands and feeling every cats-eye and manhole cover, but its gained the ability to be a comfortable summer cruiser.
Adam205 said:
And i've missed that noise!
I must confess they do sound great 
Next thing on the list of things to sort is the brakes.
In general the power is there (if anything a bit too much), but they lack feel and do some odd things on the limit. Doing some calcs on the brake specs its becomes obvious why this is.
The front discs are 260mm (~105mm eff rad) with a 59.9mm piston, the rears are 273mm (~112mm eff rad) with a 42.9mm piston. As the mastercylinder size is the same front and rear the bias comes out around 64% front. The optimal brake balance for this car is around 69-70%, so the bias is naturally a bit rearwards. TVR overcame this by fitting a pressure limiting valve in the rear circuit (from a Mondeo), however the cracking pressure of ~35bar is right around the locking pressure of the system with a half decent pad. This is sudden change of brake bias is quite unnerving and makes modulation a bit difficult.
The solution.... smaller pistons in the rear calipers and remove the pressure limiting valve. The correct size piston for the rear calipers turns out to be a 38.1mm, and luckily there is a bolt on solution for this one.
They are aluminium calipers from a mk4 Golf V6 4Motion / Audi TT, a bit lighter and with a slightly better handbrake mechanism inside.
I am also planning to upgrade the front with 300mm discs and wilwood midilite calipers, more on that one to come.
In general the power is there (if anything a bit too much), but they lack feel and do some odd things on the limit. Doing some calcs on the brake specs its becomes obvious why this is.
The front discs are 260mm (~105mm eff rad) with a 59.9mm piston, the rears are 273mm (~112mm eff rad) with a 42.9mm piston. As the mastercylinder size is the same front and rear the bias comes out around 64% front. The optimal brake balance for this car is around 69-70%, so the bias is naturally a bit rearwards. TVR overcame this by fitting a pressure limiting valve in the rear circuit (from a Mondeo), however the cracking pressure of ~35bar is right around the locking pressure of the system with a half decent pad. This is sudden change of brake bias is quite unnerving and makes modulation a bit difficult.
The solution.... smaller pistons in the rear calipers and remove the pressure limiting valve. The correct size piston for the rear calipers turns out to be a 38.1mm, and luckily there is a bolt on solution for this one.
They are aluminium calipers from a mk4 Golf V6 4Motion / Audi TT, a bit lighter and with a slightly better handbrake mechanism inside.
I am also planning to upgrade the front with 300mm discs and wilwood midilite calipers, more on that one to come.
Rob-c33sg said:
Nice work on the brakes, hope they feel a lot better. I find my Tuscan brakes feel very 'wooden' in terms of feel but they do seem to work with a shove. Certainly feel quite different to my Integra that's for sure.
Interesting the 'wooden brakes' description, in my experience that's generally a result of incorrect pad selection, either pads that require a bit of heat being used on the road or poor quality road pads being used on the track. I'm planning to use mintex m1144 pads which I have used on our last few hillclimb cars. They have good bite from cold but can withstand quite a lot of heat, the slight compromise is that they can be a bit noisy when cold.I'm going to do the actual fitting once I have all the parts together, I want to minimize the number of time I have to bleed the brakes!
shalmaneser said:
Great thread, looking forward to further installments. I'd love a TVR as it would allow me to indulge my natural inclination to tinker! Steering rack swap looks great. Any plans for the motor? I would be tempted to modernise the ecu for example, should release some ponies too...
You definitely have to enjoy tinkering to get the most out of them! The basic principle is brilliant, just the execution that can be a bit rough and ready.The engine is running really well at the moment and the power delivery of the 4.6 V8 actually suits it quite well. It doesn't feel like it needs any more torque to be enjoyable, maybe just a bit more cam and induction/exhaust improvements to free up the top end a little. When this reaches the top of my list I will probably look at an ECU update at the same time. The Westfield will be going motec in the near future, if that works well then this may follow suit.
Currently there's more to be gained in the suspension/brakes area than the powertrain to unlock the driving experience in my opinion.
Taking a break from the brakes while I wait for parts for the front, I thought I would take a look at the stereo. A half decent sound system is a must for me if for longer drives, and the 24 year old pioneer speakers powered off the bargain basement headunit wasn't quite cutting it.
I went for a vibe powerbox microamp which fits behind the headunit and will offer 65w rms to 4 channels:
This will power a pair of Audison Prima APK165 6.5" comps in the front and 2 AP8 8" woofers in the rear.
Chimaeras were originally fitted with 160mm speakers, and the door card will just about fit 165mm, so the APK165 is the perfect fit. The grills that come with them are not, but I think I have a way to attach the originals.
Tweeter position, going to remove the ash trays and print some mounts:
Door cards required the hole enlarging slightly, but a nice fit!
Crossover in the door:
Amp tucked away:
I'm waiting on some spacers to get the rears mounted up, but just the amp and front woofers are a massive improvement!
I went for a vibe powerbox microamp which fits behind the headunit and will offer 65w rms to 4 channels:
This will power a pair of Audison Prima APK165 6.5" comps in the front and 2 AP8 8" woofers in the rear.
Chimaeras were originally fitted with 160mm speakers, and the door card will just about fit 165mm, so the APK165 is the perfect fit. The grills that come with them are not, but I think I have a way to attach the originals.
Tweeter position, going to remove the ash trays and print some mounts:
Door cards required the hole enlarging slightly, but a nice fit!
Crossover in the door:
Amp tucked away:
I'm waiting on some spacers to get the rears mounted up, but just the amp and front woofers are a massive improvement!
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