Exhaust System

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Spares

"Recognition of Magnex quality is endorsed by Aston Martin and TVR Sports Cars who rely on Magnex expertise for their original equipment exhausts. If you have ever followed one of these machines, you will have heard enough already!"

So there you go - Magnex produce the exhausts for TVR according to the blurb. Another part identified - only a few hundred left!
Andrew Guy

Aug 98
Wedge Automotive can supply replacement exhaust systems for all Griffs and Chimaeras. They are made to order and cost a bit more than the factory ones, but WA claim to use better quality stainless steel and give a lifetime guarantee. Two common problems are cracking at the back of the centre box and gas leaks from the flexible section near the gearbox (Griff 500 only). The latter problem is caused by chaffing within the flexible section itself and since no-one has been able to tell me why the factory put it on the Griff in the first place it seems to be something you just have to live with. Wedge can make a replacement length of pipe including a new flexible section that can be bolted in after cutting out the worn part. The only other solution is to buy a piece of flexy pipe yourself and find someone who knows how to weld stainless steel.

Heat Damage to GRP

[More on this under 'exhaust fumes' below]

Heat Shielding

Exhaust Fumes

Cause:
When driving the car you will notice that road dirt will hit the back of the car despite the fact that it has to travel quicker than the car. This is a consequence of the (higher than atmospheric) pressure that is created at the back panel at speed. Since the pressure in the boot is normal (atmospheric) any opening in the back of the car will result in fumes entering the boot.

Solution:

• Seal off the space between the rear lights and the body WITHOUT removing the light unit. Use black silicon kit and smoothen it with your finger after dipping it into a soapy solution. Excess material can be removed from the body with a cloth and white spirit (do this quickly as white spirit may affect the paint). On later 500 models the factory is applying the same solution.
• Replace a damaged boot seal. When lifting the roof panel in and out the boot the lower RH corner of the seal may get damaged after a few years. If it is damaged it can easily be replaced (you can buy it per meter and this is not a special TVR part). When replacing make sure that:
• The open ends of the are at the centre of the top side of the boot opening
• Don't cut off too much material; the ends should meet tightly without a gap. Use some silicon kit if required.

Internet Mailing List Apr 98
I've had the Griff for a couple of months now and I'm beginning to notice a nasty sulphurous pong when I accelerate hard. I don't think it's me, so it must be the car that's doing it.

Welding Manifolds

• remove existing manifolds and TIG weld the offending cracks and then plate the area (the cheapest option, but how long will the weld hold secure?).
• buy stock TVR replacement manifolds at 300 pounds each.
• upgrade to Stainless Steel at 600 pounds each, although I've read in Sprint that these are not supposed to crack, the TVR mechanic informed that in his experience SS manifolds are equally prone to cracking.

Internet Mailing List Oct 96
Yes I've had manifold problems ranging from rusting, holes appearing and eventual replacement (350i). MIG/TIG welding works very well and the repair will outlast the manifold. I looked into stainless for mine, and I think it would be slightly more prone to cracking. The expense didn't justify the benefits, and that was at 300 quid each. You'd be better off Nickel plating mild steel ones.
Anon

Internet Mailing List Nov 96
Snap, my 4.3BV has just returned from servicing with the same problem. I intend getting my local garage to have a go at welding it . . . From what I've read this is a common occurrence in 4.3 Griffs, it's obviously a design fault, perhaps we ought to ask TVR to come clean and pay for the repairs!!
Nic Collins

Apr 97
Manifolds can develop hairline cracks, usually after 3 years on Griffiths. Weld them until you can afford a new exhaust. Welds should stay secure for three to six months.
Steve Beresford

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Manifold Gasket Leaks

Dave Donnan wrote:
"Sometimes when I lift of the throttle in the griff, I can hear a very faint ticking noise, I did wonder if this could be the tappets, but I have been told that it could be the injectors, any ideas."

This may not be of any help but I have the opposite problem. I hear this ticking noise (which is not pinking) when I open the throttle, and goes away when I lift off. My dealer says it is apparently caused by a leak in the exhaust manifold, which has yet been found on my car and corrected.
Kenny Heng

Internet Mailing List Nov 96
I recently had the same problem as Kenny, the problem being a split gasket manifold. Although the part was pretty cheap, the microscopic grooves caused by the escaping gases meant it had to go in for a second time so that a wierd and wonderful machine (allegedly) could smooth out the metal. That cost more than the part, so I'd recommend getting it fixed sooner rather than later. The gasket is between engine and manifold. If your problem turns out to be the same, it's very easy to spot and fix. The downside is the engine sounds even better with a hole in it.
Rick Eirew

Aug 98
TVR Centre Redhill tell me that the best way to get the manifold off is simply to undo the band clamp that holds the manifold onto the cat, undo the top manifold bolts then reach down from above and undo the lower ones with a short open-ended spanner. Once they are a little bit loose you should be able to rock the manifold up and down to get a bit more of a turn on the spanner. You don't need to remove anything else. It's very fiddly on the passenger side and you'll almost certainly lose bits of finger in the process, but going in from under the car is even more difficult.

Removing the cat

1. As Steve Powell said, it's illegal and invalidates the warranty. In Milton Keynes, there have been reports of "smell police" pulling over cars for on the spot emission checks, so removing the cat is a bit of risk for me.

2. Some of the cat fittings are cartridges that are dropped into the big wide pipes from the manifold and it's easy to remove the canister. The later versions had the cannister built into the pipework so removal requires that piece of the manifold to be replaced. Team Central reckoned it would cost about £100 to remove if it was the cannister type and "open to negotiation" for the other type.

3. With the cat removed, you should be able to use 4 star but this will deposit lead in the engine. When the cat is replaced, this lead *could* - I stress could - contaminate the cat and destroy it, making it useless. The possible result would be a failed MOT and a big bill for a new one. Needless to say, I've decided to keep my V8S kosher and keep the cat.

4. Changing the ECU chip etc also invalidates any warrenty and any insurance unless they agree to the mod in writing. It may result in poor performance through mismatching the maps to the engine. The ECUs are programmed/configured for different engines and therefore it is a bit of a lottery if you simply change the chip. Most mods have to be done effectively on a rolling road to ensure that they give the best results.

In terms of changing the cat, I'm not going to touch it. I am planning to get Team Central/TVR Power to enlarge/gas flow the plenum and reprogram the ECU at the next service in Feb'97 when it comes out of winter hibernation. The plenum mods are necessary to maintain the correct mixture to meet the emmission levels but get more fuel into the cylinders to give the additional power. They reckon I'll get 4.0 HC power from my straight 4.0 e.g. 275-280 BHP and 310lb torque and a few hundred extra revs (changes the limit from 5600 to 6000/6250) - so it may not sound as good/loud as a pre-cat but it'll go much quicker! They will warranty the engine and the insurance company (Pearts) won't change my premium - anymore power and it would be a 25-50% loaading!
Steve Heath

Internet Mailing List May 97
Technically the cat regulations apply to all cars first registered after 1st January 1993, but this would have been impractical to achieve, because with most manufacturers some cars being registered after that date would have been manufactured some time previously and sat in a field, or on a boat. Such strict legislation would have meant that either manufacturers would have been forced to adopt the future legislation some months in advance, or else be faced with unregistered cars at dealers which couldn't be legally sold. For practical reasons therefore, the legislation allowed for a percentage of a manufacturers cars to be registered after that date without cats. What percentage, for how long, I can't remember. Despite this exception, if any car registered after 1st January 1993 had cats when first registered then they must remain on the vehicle in working order.

I discovered all this when working the club's stand at the NEC last year when I met someone who works in this field and knows the legislation inside out. This led me to think that maybe, since my Chimaera was registered in May '93, I could take the cats off and tell MOT inspectors that it never had one. Of course *I* knew that all Chimaeras have cats, but did the MOT testers? Immediately I phoned the factory to be told that the work involved was very expensive and not to be undertaken lightly, and they wouldn't recommend it. I gave up the idea and bought a pre-cat Griffith instead shortly afterwards. I agree with Steve Heath, it's an expensive thing to do when you are making the car illegal and it can only cause more problems that it solves in the long run. Besides which, if you lot keep your cats on, it's very good for the resale value of my Griff.

I was told at Blackpool that JS Cars in Jersey exploit some sort of legal loophole and if you buy a new Griffith 500 from them, and pay them an extra £500, you can have a completely legal non-cat Griffith 500. Not sure how this works, but I suspect it goes something like: cats not required by law in Jersey, used cars can be registered in any EC country if they were legal when first registered in another EC country (Jersey is technically part of the UK), but only if the owner has already owned the car for 6 months. So I reckon your £500 probably covers storing the brand new beast for 6 months, at which point you can rumble with a clear conscience onto the ferry, and look forward to years of jealous looks from other Griffith 500 owners at club events.
Steve Powell

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Exhaust Wrapping

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Cheating

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