£28k GranSport

[whereskeith]

Hey Ben, welcome back, we better have another track day down in Chepstow so you can insult the staff again

Exhaust, I take it your modding it?

Get it to Benny to have the rear cans gutted (£200 ish) and H Pipe (£160 ish) and if you can stretch to it, a pair of these (Benny can get them made for circa £600)

Then you can start upsetting you neighbours again after a quite patch!

View attachment 31836

Question.
When you delete one cat each side with a straight thru pipe does it still pass MOT emissions ?

 

[mjheathcote]

Yes!

 

[whereskeith]

Yes!

Thx

 

[hilts uk]

Thanks Matt - you've predicted my next line of thinking very well..!

I've had a read through various threads and can't quite work out the options though. I don't want Larini backboxes - too expensive and the ones I (temporarily) had on my 4200 had the drone problem. But I definitely need something.

That photo is a set of straight through pipes I take it? I think that might be a bit more noise than I can take... Really I would like a prospeed custom setup like last time - I had sports cats and new backboxes - but ideally I also would like to keep the valved bits so that non-sport-mode can be that bit quieter when needed.

What do you recommend?

PS I don't recall insulting anyone at the track days - though admittedly that does sounds like the sort of thing I'd have done.

I've installed Larini sports cats and an x pipe on mine. Kept the back boxes. In non sport mode there is not so much difference in sound. In sport its probably an 7.5 out of 10 where MAF's car is 10. No drone. Some pops and crackles on the overrun but not too over the top. Also have a noticed a pick up in performance especially in higher rev range.

 

[jayblue]

I fitted the forum X pipe and Supersprint secondary decats to my GS. The exhaust is much louder in sport mode but still acceptable in normal mode with the valves closed. For me it is a nice compromise and there is no droning on the motorway either.

 

[MAF260]

...In sport its probably an 7.5 out of 10 where MAF's car is 10...

mine's 11/10!

 

[spkennyuk]

mine's 11/10!

Yours is measured on the Richter scale !

 

[halbe01]

Interesting - two votes for leaving the backboxes alone and merely changing the cats and middle bits of the pipes...

 

[conaero]

Mod the back boxes and fit an X or H pipe. If it's not loud enough, delete the secondary cats.

If thats too loud fit some free flow silencers where the secondaty cats where, voila!

I then fitted a bypass button under the steering column so you can open or close the valves in sport. Then you have the best of both worlds.

 

[halbe01]

Right - well after a long chat with Benny yesterday, I've placed an order for an H-pipe, which should get here this week. That will be fitted by Autofficina before I collect the car and we'll see how it sounds in it's own. Next steps, if I want more (which seems likely!) will be to send off the backboxes for conversion, and then perhaps fit sports cats. I love the concept of sports cats and having a properly free-flowing system.

I'll update as I go..!

 

[MAF260]

Right - well after a long chat with Benny yesterday, I've placed an order for an H-pipe, which should get here this week. That will be fitted by Autofficina before I collect the car and we'll see how it sounds in it's own. Next steps, if I want more (which seems likely!) will be to send off the backboxes for conversion, and then perhaps fit sports cats. I love the concept of sports cats and having a properly free-flowing system.

I'll update as I go..!

You won't regret it!

 

[StuartW]

Right - well after a long chat with Benny yesterday, I've placed an order for an H-pipe, which should get here this week. That will be fitted by Autofficina before I collect the car and we'll see how it sounds in it's own. Next steps, if I want more (which seems likely!) will be to send off the backboxes for conversion, and then perhaps fit sports cats. I love the concept of sports cats and having a properly free-flowing system.

I'll update as I go..!

Another GS hooligan, congratulations!

 

[spkennyuk]

Hey Ben, welcome back, we better have another track day down in Chepstow so you can insult the staff again

Exhaust, I take it your modding it?

Get it to Benny to have the rear cans gutted (£200 ish) and H Pipe (£160 ish) and if you can stretch to it, a pair of these (Benny can get them made for circa £600)

Then you can start upsetting you neighbours again after a quite patch!

View attachment 31836

Would those get rid of the possible cat break up issue on a 2007 4200 ? I've not looked but I would think its the US spec pipes and cats on mine.

Everybody seems to go X or H pipe and then back boxes changed or modified. I don't want anything too over the top so my thought process was these down pipes and probably a H pipe to go with it. Most likely a project for next year at the moment. Would this configuration give me a nice burble and some pops and crackles on over run. ?