Cats - in or out? (not the furry kind)

[pete]

Hi all,

I've been ruminating on the subject of de-catting for a while. I've recently had a 4.3 upgrade by Dom at Power, who confirmed that my cats are completely healthy, and my car has always passed MOTs with boring regularity. However I've also read the recent reports about reducing heat soak by removing the cats, and given that I'm due a final mapping session in Coventry any day now, I thought it might be an opportunity to de-cat properly.

What's the recommendation - anyone decatted a car with perfectly good cats and noticed an improvement? In noise terms, I'm working on the assumption that I'd have to go back to my standard cans to avoid deafening everyone; will it sound dull after the CCCs?

Cheers,
Pete

[so called]

I had my cans sleeved to improve the rather quiet Mk2 Tuscan (at my wifes insistance).
Didnt make much difference and so went for the decat option. (The cats were fine).
NOISE, WOW now wish a could get the sleeves out but never mind.
Result apart from the noise was that I thought I had always previously been driving with the hand brake on.
The engine suddenly felt like its chains had been removed (not the timing ones) and it just wanted to go, fantastic.
Not forgeting that I had to have her re-chipped as well but that was a few weeks later.

[Daston]

I am very very tempted to get mine done when it goes in for its new head. However with CCC's I fear it may be too much

[Robertjp]

It is loud, no getting away from it. On tickover its not much different, but when you open the taps its something akin to letting the devils toy car loose at playtime....after 100 years on aleash A cross between a lambo and the cerby V8 IMHO, better than any other straight six...its sounds good anyway

I found when i had her de-cat chipped it made the car feel just that little bit more alive...worth doing.

[WhyTwo]

I put my cats back in and sold the decat pipes and chip. Bought it with decat but I prefer the sound of cats in and CCC's - sounds less manufactured and more how I think a SP6 should sound if that makes sense? Also sails through the MOT without having to take it to a erhum 'TVR friendly' test centre.

I never really noticed any performance improvement over my previous Tuscan or a reduction with this one when I put the cats back in. I'm sure somebody will chip with the stats and graphs to prove it's got a few more hp at the wheels but I didn't notice it, maybe its the placebo effect...

[Mark A S]

My 4.3 is de-catted, with a standard exhaust and is 98 db, not too loud, but enough to please.
IMO, removing cats, increases your torque more that it does power letting the engine breath better especially in the mid range, so my advice would be to remove them.
It will also stop burning off the paint on the chassis by the Cats as well

[Daston]

Robertjp said:

It is loud, no getting away from it. On tickover its not much different, but when you open the taps its something akin to letting the devils toy car loose at playtime....after 100 years on aleash A cross between a lambo and the cerby V8 IMHO, better than any other straight six...its sounds good anyway

I found when i had her de-cat chipped it made the car feel just that little bit more alive...worth doing.

What is it like at cruising speeds say 2 - 3k rpm. I had a Supra with a large exhaust (as you do) and that droned quite a bit and gave you a head ache after an hour or two

[Flintstone]

Mine is a Power 4.3. De-catted and sleeved, MOT not a problem.

[Robertjp]

Daston said:

Robertjp said:

It is loud, no getting away from it. On tickover its not much different, but when you open the taps its something akin to letting the devils toy car loose at playtime....after 100 years on aleash A cross between a lambo and the cerby V8 IMHO, better than any other straight six...its sounds good anyway

I found when i had her de-cat chipped it made the car feel just that little bit more alive...worth doing.

What is it like at cruising speeds say 2 - 3k rpm. I had a Supra with a large exhaust (as you do) and that droned quite a bit and gave you a head ache after an hour or two

I actually dont find it much different to standard until you get to higher RPM, say 4k+, or your giving her some beans. Just cruising, i dont find it intrusive at all. Yes, its a little louder than standard, which i found to be painfully quiet and restrained!

[Buffoon]

Cerb interloper I know, so my exhaust sounds different to the Tuscan but has anyone tried the Sports Cat option as a halfway house? This would be my preferred option should the Cats give up, but would be interested to know if there is much differerence to heat and breathing.

[so called]

Daston said:

Robertjp said:

It is loud, no getting away from it. On tickover its not much different, but when you open the taps its something akin to letting the devils toy car loose at playtime....after 100 years on aleash A cross between a lambo and the cerby V8 IMHO, better than any other straight six...its sounds good anyway

I found when i had her de-cat chipped it made the car feel just that little bit more alive...worth doing.

What is it like at cruising speeds say 2 - 3k rpm. I had a Supra with a large exhaust (as you do) and that droned quite a bit and gave you a head ache after an hour or two

Just drove around Spain in mine with lots of motorway distance driving. Cant say it was any worse noise wise than my previous TVR's. (whats a couple more db's )

[Daston]

Its just I hear people with CCC's puting original cans back on or cats back in.

Ahhh its only £150...can just tell her its because its had a rebuild

[pete]

Thanks all - some good advice both ways. I shall have to look at my options for cat removal before it goes up to Dom again

Pete

[The Pits]

I took the cats out and with CCCs it was painfully loud. Seriously, I used to keep the windows up in tunnels which is sacrilege in a TVR. It didn't feel any faster either. Certainly not fast enough to justify the noise. It seemed offensively loud to other road users too and turned a simple overtake into some kind of insult!

I've now got sports cats from TVR power and things are much better. The best it ever sounded was CCCs and standard cats. The sports cats are definitely louder but the noise is more aggressive and raw. It's a little harsher, even with standard exhausts on. Most would probably like the extra rough edge to the noise but I occasionally miss the glorious sounds it used to make. It was just like a jaguar D-type up to 5k then sounded altogether more modern and vicious above that. Now it's more beastly all the way through the revs but it's more like one savage noise than the multi-layered, ever changing mechanical music it used to make.

At least it sounds more like an offshore powerboat at tickover now!

[WhyTwo]

The Pits said:

Seriously, I used to keep the windows up in tunnels which is sacrilege in a TVR. It didn't feel any faster either. Certainly not fast enough to justify the noise. It seemed offensively loud to other road users too and turned a simple overtake into some kind of insult!

This is the experience I had. I would refrain from hitting the VERY loud pedal whilst going through tunnels as the reaction from other road users or pedestrians was not exactly encouraging. Their expressions suggested that I was viewed as some sort of hooligan and certainly not a great advert for the TVR brand! I'm now happy to nail it through tunnels as although it's still very loud it's not 'abusive' and sounds like I think it should. I guess it's a personal preference but I'm in the same boat as The Pits.

Good luck in making your decision and which ever way you decide to go I hope you're happy with it

[phil78tintin]

Im just about to buy a tuscan. What is CCCs? I want to get a good sound, I had a chimaera and had the silencers taken out for £150 and it sounded amazing. How much do these various options cost for a tuscan?

[softtop]

phil78tintin said:

Im just about to buy a tuscan. What is CCCs? I want to get a good sound, I had a chimaera and had the silencers taken out for £150 and it sounded amazing. How much do these various options cost for a tuscan?

CCC is the Carbon Can company. They tend to be cans with straight through pipes in them so nothing to baffle the noise.

[so called]

As I mentioned above, I have decatted and sleeved my cans to make it louder (at my wifes nagging !!!)
Anyway my wife has now ordered CCC's (Carbon Can Company) for me for Xmas so maybe I will be recatting soon. We will se.
Before this I may also try de-sleeving my original cans to try with the decatted pipes.

I understand the "too loud" feeling of being offensive but on the other hand I was in Spain this year in the Tuscan and had a great evening watching Spain v Germany. On the way out of town later I was "forced" to rev my engine like a mad bull as the celebrating Spanish teenagers 'Toro'ed me round a roundabout. Magic night never to be forgotten and all down to my offensive TVR.
Spanish Police did stop me as soon as I had got out of the bullringabout.
Sorry officer wont do it again.