Wanted - GranSport Larini/Tubi/etch end boxes

jack.pe

New Member
Messages
65
Hey, my 2007 GS is badly in need of louder back boxes, would ideally like to keep the switchable valves. Anyone have anything?

Have the x-pipe already.
 

CatmanV2

Member
Messages
48,543
Hey, my 2007 GS is badly in need of louder back boxes, would ideally like to keep the switchable valves. Anyone have anything?

Have the x-pipe already.

There's not a lot else you can do at the back if you've got the valves open, it's pretty much straight through.

Sports cats, perhaps.

C
 

jack.pe

New Member
Messages
65
Lol, so you are already modifying your "short" termed!!

Yep.. there's no way I can't live with it as quiet as it is now. The sound is a big part of why I wanted one!

There's not a lot else you can do at the back if you've got the valves open, it's pretty much straight through.

Sports cats, perhaps.

C

Interesting... I thought the back boxes did have a perforated pipe inside which did dampen noise somewhat?
If its the sports cat routes then still pretty pricey through Larini at around £1700
 

CatmanV2

Member
Messages
48,543
Yep.. there's no way I can't live with it as quiet as it is now. The sound is a big part of why I wanted one!



Interesting... I thought the back boxes did have a perforated pipe inside which did dampen noise somewhat?
If its the sports cat routes then still pretty pricey through Larini at around £1700

I could be wrong!

C
 

GeoffCapes

Member
Messages
14,000
If its the sports cat routes then still pretty pricey through Larini at around £1700

That's per side.

I had Ashford Fast Road conversions do mine for about £1,500 for both sides. Looked like a work of art underneath as well.
 

jayblue

Member
Messages
452
Make sure you check if you have the Euro or US style downpipes before pulling the trigger on sports cats. Some cars have a two bolt flange (US spec) and some the Euro spec 4 bolt flange. Euro spec flow better as the US spec have the first cat built in to the header.
 

m1980k

Junior Member
Messages
467
I think the existing boxes can be modified to make them fully straight through when the valves are open. Think this is what Matt/Conaero had on his GS? But obviously you can't put them back to standard after that.

The level of noise you can get from the car will also depend on whether you have the US or Euro spec manifolds. US spec means primary cats on the manifolds and then secondary cats in the centre section. So even if you remove the secondary cats, you still have another set of cats. A second hand pair of Euro manifolds goes for 700-800 quid and then it's about a grand in labour to fit them in a pig of a job. You can then have just one set of sports cats. I want to do this but can't justify the outlay...
 

jack.pe

New Member
Messages
65
I think the existing boxes can be modified to make them fully straight through when the valves are open. Think this is what Matt/Conaero had on his GS? But obviously you can't put them back to standard after that.

The level of noise you can get from the car will also depend on whether you have the US or Euro spec manifolds. US spec means primary cats on the manifolds and then secondary cats in the centre section. So even if you remove the secondary cats, you still have another set of cats. A second hand pair of Euro manifolds goes for 700-800 quid and then it's about a grand in labour to fit them in a pig of a job. You can then have just one set of sports cats. I want to do this but can't justify the outlay...

Yeah, I've been looking at replacing the rear silencers altogether with straight pipes. They won't be switchable but cheapish option and can be put back to standard. What is interesting though is that some claim that with baffle open the rear silencers are already basically straight through, if this is the case then no pint deleting the rear boxes. i've contacted Benny and Conanero to get their take on my best option..
 

CatmanV2

Member
Messages
48,543
They would probably be the best to know. As I said I might well be confused (again)

You could get some standard 4200 boxes and modify them, add your own valves and make them properly straight through on one section.

C
 

Ewan

Member
Messages
6,757
Let me now what you decide upon, as I could do with more noise in mine. Only modification so far is the H pipe. Any change I do make must be reversible however.
 

jayblue

Member
Messages
452
I think the existing boxes can be modified to make them fully straight through when the valves are open. Think this is what Matt/Conaero had on his GS? But obviously you can't put them back to standard after that.

The level of noise you can get from the car will also depend on whether you have the US or Euro spec manifolds. US spec means primary cats on the manifolds and then secondary cats in the centre section. So even if you remove the secondary cats, you still have another set of cats. A second hand pair of Euro manifolds goes for 700-800 quid and then it's about a grand in labour to fit them in a pig of a job. You can then have just one set of sports cats. I want to do this but can't justify the outlay...

A cheaper way of doing this is to cut open the cats in the headers on the bottom, gut them completely, and then weld them up. Then have a custom made middle section put in which replaces the secondary cats with sports cats in it. I have been told that the lambda sensor wires are long enough to relocate them to the new position.
 

jayblue

Member
Messages
452
Let me now what you decide upon, as I could do with more noise in mine. Only modification so far is the H pipe. Any change I do make must be reversible however.

I replaced the secondary cats on mine with straight through pipes. Along with the X pipe it made a significant difference to the noise levels and also freed up some nice pops and bangs.
 

gt86driver

New Member
Messages
49
If loud is what your after definetly have to do something with the back boxes my eurospec cats are fully gutted & I'm sporting an h-pipe it sounds wicked but it's not straightpipe loud.
just drony as f##k when idling..

https://youtu.be/gCb3N8HnP4k

Sent from my HUAWEI NXT-L29 using Tapatalk
 

Contigo

Sponsor
Messages
18,376
The rule is start and the back and work your way forward. Making a modification to the rear boxes is much louder so nice straight through pipes on a 4200 are the way to go for sure. The GS has lots of silencing in the cans even with the Valves open it seems whereas on the GTS valves open is straight through!
 

gt86driver

New Member
Messages
49
From the back is where I started on my gt86 by the time I got to the headers it was racecar loud

Sent from my HUAWEI NXT-L29 using Tapatalk
 

samueluper

Junior Member
Messages
103
I put the benny´s x-pipe and... a bit more powerful sound, but i still need more... Maybe we need to make a straight line through our original mufflers...
 

Caldy999

Junior Member
Messages
445
Does the GS have the squished sections under the steering rack? If so, worth considering swapping out for tubular. Seems to improve pick-up and when done with sports cars and x-pipe, plenty loud without changing the rear boxes.

Can't believe disparity between quotes for exhaust fabrication between us up north and you down south. This lot cost way less than £1k and is top notch.

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