Clive F GT Manifolds + Sports Cat

[GRC85]

Hi All,

Bought a Chimaera with Clive F GT manifolds (no precats and longer headers) and a Clive F 200 cell sports cat. With the exhaust system that's on it (some form of cherry bomb), the idle and low down revs are a bit too quiet for me and want to liven it up. I've got it booked in for the exhaust sleeving, but from reviewing endless videos I am concerned that it will be too loud for my European road trip at highway speeds.

Can anyone confirm what noise levels they are getting with GT manifolds and sports cat with either fully sleeved, half sleeved or even somewhere in the middle? Will it be just as loud as a fully decat Y piece or will the sports cat muffle some of the harshness and overall sound?

The only video I can find of this setup is a Griff;
https://www.youtube.com/watch?v=JutCY-h3_NY

Not looking to buy the ACT cherry system which I know is popular.

Edited by GRC85 on Tuesday 4th June 17:51

[Johno]

Std manifolds no precats, decat Y piece, straight thru system from there …essentially a straight through system.

https://youtu.be/_ESL1oWHmN4?si=6xOkPwGW7QAK0QhZ

Summary, bonkers loud. They could hear us leaving Mont Ventoux in Avignon.

[BritishTvr450]

At a guess and assuming Clive’s smaller cell cat is louder than a standard Y piece then with a sleeved exhaust your talking 96-100db or more and I seem to remember one chaps car recorded 104 with a non cat set up at motorway speeds and after 500 miles your brains will be bleeding out your ears.
One owner once pronounced somewhat proudly his car was 117db!
Being exposed to anything over 85 db for extended periods will cause hearing loss.
The higher the db the faster that hearing loss occurs.
Funnily enough my car was 84 db fully Catted and standard exhaust as measured on Bedford and Snetterton noise monitors.
It was 94 db with decatted Y piece but standard exhaust.
With Catted Y and sleeved exhaust it was louder still so I guesstimate around 97-98 and far to loud so I removed the sleeved exhaust and sold it.
A numb headache and general feeling of horribleness will come over you and extreme noise will ruin long journeys.
It’s the last thing i’d be doing if touring unless you want to go deaf.

Half sleeved is another option but drone is mostly the problem and why Cherry bombs keep it raspy when hard on it but restrict that drone.

You have already got the best system other than adding an ACT full sports system.

Edited by BritishTvr450 on Tuesday 4th June 20:29

[GRC85]

Johno said:

Std manifolds no precats, decat Y piece, straight thru system from there …essentially a straight through system.

https://youtu.be/_ESL1oWHmN4?si=6xOkPwGW7QAK0QhZ

Summary, bonkers loud. They could hear us leaving Mont Ventoux in Avignon.

Johno, that made me laugh, I am literally driving from the UK to Avignon via Ventoux on the 1st July! Any idea what the actual noise levels are? Were you doing highways with roof down? I read another post that said the following;

Pre cats out, decât y piece, fully sleeved 500
Roof off + targa up measured inside the cabin with sound meter fixed to headrest

Idle: 90 dB
30mph in 5th low revs: 95 dB
70mph motorway: 101 dB
80mph motorway: 104 dB

At those levels surely serious ear damage could occur? Did you wear earplugs for the long stretches?

Thanks

Edited by GRC85 on Tuesday 4th June 20:39

[GRC85]

BritishTvr450 said:

At a guess and assuming Clive’s smaller cell cat is louder than a standard Y piece then with a sleeved exhaust your talking 96-100db or more and I seem to remember one chaps car recorded 104 with a non cat set up at motorway speeds and after 500 miles your brains will be bleeding out your ears.
One owner once pronounced somewhat proudly his car was 117db!
Being exposed to anything over 85 db for extended periods will cause hearing loss.
The higher the db the faster that hearing loss occurs.
Funnily enough my car was 84 db fully Catted and standard exhaust as measured on Bedford and Snetterton noise monitors.
It was 94 db with decatted Y piece but standard exhaust.
With Catted Y and sleeved exhaust it was louder still so I guesstimate around 97-98 and far to loud so I removed the sleeved exhaust and sold it.
A numb headache and general feeling of horribleness will come over you and extreme noise will ruin long journeys.
It’s the last thing i’d be doing if touring unless you want to go deaf.

Half sleeved is another option but drone is mostly the problem and why Cherry bombs keep it raspy when hard on it but restrict that drone.

You have already got the best system other than adding an ACT full sports system.

Thanks for this, you might have just referenced a post I read around the 100 dB ish mark at motorway speeds.I was wondering about those motorbike earplugs for the 3-4 hour journeys and then enjoy the volume over some shorter journeys at lower speeds. I actually feel like I would be happy with a Clive Decat Y, but since mine already has the expensive Clive sports cat, seems a bit daft to change it, especially given the MOT convenience (no one friendly near me).

Can't find any vids of half sleeve to reference. Any idea if there is much difference in volume between full and half? I could potentially tolerate some drone if I knew I would still have hearing at the end of it.

Edited by BritishTvr450 on Tuesday 4th June 20:29

[Johno]

GRC85 said:

Johno, that made me laugh, I am literally driving from the UK to Avignon via Ventoux on the 1st July! Any idea what the actual noise levels are? Were you doing highways with roof down? I read another post that said the following;

Pre cats out, decât y piece, fully sleeved 500
Roof off + targa up measured inside the cabin with sound meter fixed to headrest

Idle: 90 dB
30mph in 5th low revs: 95 dB
70mph motorway: 101 dB
80mph motorway: 104 dB

At those levels surely serious ear damage could occur? Did you wear earplugs for the long stretches?

Thanks

Edited by GRC85 on Tuesday 4th June 20:39

I needed ear plugs and I was in the black Griffith leading the charge, it made your ears bleed.

The yellow Griffith with the straight pipes belonged to Ballistic Banana, The Griffith Pages. It was nuts loud and I wouldn’t for a second consider it for euro trips.

That trip we did a LOT of pure driving roads, tying together AdZ, Col d’Turini, Ventoux, Col du Vence, corniche des cevennes, route napoleon, gorge verdun and a whole load of stuff in between in 7 days. All with roof off. Even BB said it was a bit too much for cruising/long runs. It was fun in short bursts, but personally I think the less and less silencing you have the more agricultural they sound and on long runs it’s really tiring. The flames it spat out were entertaining though

Here’s another before the trip after we’d got it running on the Emerald.

https://youtu.be/2TXYT9nMPS0?si=Msee7JcrUteOuueo

I can’t say how much a cat would quieten this down, there are some other examples on the Griffith pages YouTube channel with different setups.

[BritishTvr450]

Those numbers inside the cab sound very accurate to me.

Ear plugs will be your only solution and god forbid you lose them

Have you had chance to drive the car much since buying it. Have you done any distance or high speed motorway type drives yet?

My hearing was lost somewhat from spending to much time on and around 500cc single cyl grass/speedway bikes in the 1980’s. My muffler at that time reduced the engine noise down to a legal 105db but still made your ears suck in and out if to close to it
I never thought it effected me at the time but it did and I rue the noise of them now.
I’d be very careful you don’t ruin your Tvr soundtrack and you could definitely damage your hearing.

The term often used to describe a sleeved Tvr is that of the sound of a “tug boat” and it’s very true. Becomes agricultural sounding.
Not very subtle and just a bit obnoxious.

Other people seem to like it but for me it changes the car from a usable tourer fun car to a very noisy one dimensional car that sounds angry crawling along but far to loud at cruising speeds.

I’d get severe headaches but I was prone to doing long distance journeys almost every weekend so in the end I realised the standard system was actually the best sound overall and I could drive all day and not be effected by it.
Each to there own and the one caveat which might just cancel out a lot of what I’ve said is Clive’s manifolds are more straight through and probably make less drone than the standard ones and dustbin type cat.
How does this new and very rare system of Clive’s sound at 3200 revs and 70 mph. If his system reduces drone at high speeds it is indeed a very good thing as that’s what causes the hearing problems.

[BritishTvr450]

Johno said:

I needed ear plugs and I was in the black Griffith leading the charge, it made your ears bleed.

The yellow Griffith with the straight pipes belonged to Ballistic Banana, The Griffith Pages. It was nuts loud and I wouldn’t for a second consider it for euro trips.

That trip we did a LOT of pure driving roads, tying together AdZ, Col d’Turini, Ventoux, Col du Vence, corniche des cevennes, route napoleon, gorge verdun and a whole load of stuff in between in 7 days. All with roof off. Even BB said it was a bit too much for cruising/long runs. It was fun in short bursts, but personally I think the less and less silencing you have the more agricultural they sound and on long runs it’s really tiring. The flames it spat out were entertaining though

Here’s another before the trip after we’d got it running on the Emerald.

https://youtu.be/2TXYT9nMPS0?si=Msee7JcrUteOuueo

I can’t say how much a cat would quieten this down, there are some other examples on the Griffith pages YouTube channel with different setups.

You’ve done some great roads.
That yellow Griff,,,, I love it on a race car that I might drive for an hour at most.
That’s insane yet I’m still laughing.
Griff owners,, it’s all chest hair and medallions,, and flame throwers

[mk1fan]

Wind noise at motorway speed is considerable too.

I wear my over ear headphones on trips. While not specific ear defenders they do make a big difference. Plus I already had them and usually take them with me to listen to music, take calls when out of the car.

[dutydog]

Have a look at Matthew Poxon website down the right hand side your find things that he has done to his car
matthewpoxon.wordpress.com