Hey guys my mods are in the signature below.

I saw some dyno graphs and the threads on those running high flow cats on the forum. I was wondering if I added high flow cats, would it drastically change the loudness of the exhaust note?

I do like the added power that high flow cats add, but do not really want to sacrifice the quietness/comfort in the cabin. Just was wondering if it was a big change of sound or just made it sound more aggressive.

For those of you with high flow cats, please chime in. Thank you =)

 

Hi there.
I too was looking for some info or advice on this
Thanks

 

Sound isn't much louder, more like an aggressive growl. From the interior you can barely notice a difference unless the window is open. I did both the high flow cats and a magnaflow resonator.

 

Hi there
Thanks for that
Just what I wanted to hear as I would like a more aggressive growl form my car.
Are there specific parts/part numbers you could recommend?
I've seen a few different high flow cats etc and unsure what would be best to get.
Cheers, Steven

 

Depends on your definition of "high-flow"

We've put 100 cells on a few 4.2L cars and they got considerably louder.

In the UK 200 cell seems to be the norm and they still have a bit of a muffling effect.

 

It will count as a mod so tell your insurer (who may not care unless you fail to tell them).

 

Funny you should say that as I've actually had one of my insurers try to add an extra premium to one of my insurance policies for alloy wheels after they had received detailed photos (which they had requested) of a totally standard car with factory standard alloys

 

Seems to be a common theme from people in the UK, insurance insurance insurance.

I have absolutely no problems with my insurer in Australia. If I ever do anything interesting with the cars I call them up and they say "that sounds pretty good" and add it to the policy.

The only time I had an increase in premiums was when I upgraded the brakes on the Freelander to the Volvo XC90 calipers, and even then it was just $20 a year more.

 

They're a pain here. But contract law means if you fail to tell them then you've broken the contract so can be uninsured and breaking the law (as insurance is required by law and it's a criminal matter if you haven't any).

Many firms are OK so long as you do tell them.

 

Yeah I don't mind paying that little extra if it's a mod I've done myself, at least then I know I'm going to be fully covered in the unfortunate event of an accident.
Refused to pay the £50 and £25 admin charge for what they had claimed was a modification when it was in actual fact a set of wheels that the car had rolled off of the production line with.
Had a little rant over the phone to the insurer that day on the definition of the word 'modification' . Ha ha.
Back on topic..
I think I'll go with the 200 cell cats but unsure what to get in regards to x-pipe or mid section.
Think I need to be careful due to emissions regulations in the uk though.
Any suggestions?
Thanks, Steven

 

Try a search here & US site for
drone
(and any other keywords that seem appropriate, er, like exhaust or pipe bear in mind they say tailpipe)
as it might be what caused that?

I doubt anyone knows much about UK & emissions who's also done a mod.

 

Thanks.
I'm going to need to do a bit more research into uk emissions before deciding on anything as I don't want to have to swap back over for mot.
Really do want more of an aggressive growl from the big cat though but not too keen on the drone

 

Ok gentlemen, in terms of part numbers here is the setup I've been running for a few years now and I'm very happy with it.

Magnaflow 59975 high flow cats
Magnaflow 11385 tru-x resonator (replaces the stock resonator)

Still run the stock boxes in the back. In my opinion it sounds great if you like a bit of a growl however nothing obnoxious or overbearing. Cruising on the freeway you don't even hear it until you floor it. With the windows open its very subtle.

Cheers,
Adam

 

Based on what I read on this forum, I got Magnaflow 99675HM cats, but haven't fitted them yet. Real soon now. Also have Magnaflow 11385 resonator, and will keep stock mufflers.

I believe the 99675 is a later model, not sure.

 

!!

 

Thanks for that guys.
Just a question about the magnaflow 11385.
Does this fit straight on to the car without any alterations?
Cheers

 

Correct. You will need a muffler shop to do the welds for you, but it's a very straightforward job. I had the car in and out of the shop within an hour for both the cats and the 11385.

 

Id like to hear what it sounds like,kinda like the quiet cabin

 

Guys
I put the high flow cats on my STR and it is not much louder. As far as installation is concerned the guy did not seem to have any trouble welding them in there.