Jump to content
si-g

E39 M5 Exhaust Manifold

Recommended Posts

Hi all,

 

I want to buy new performance exhaust manifolds for my E39 M5 but undecided whether to go for replacement cats. A part of me would like to retain the original cats but im worried as to how the new manifolds would attach to them, I wouldn't want a single piece exhaust from the engine back to the cans, would want to be able to unbolt the cats from the new manifolds as you can do today. Has anyone fitted them like this? Do the original cats cause a performance concern over the sports cats?

 

The option is there to go for 200 cell sports cats but im worried that it might make the system too loud, im not really after the noise, i want the performance gains that come from the headers, although a slight little bit more noise that stock would be nice :)

 

Do you have to get the car remapped to take advantage of the new manifolds, or are there gains there straight away? 

 

Thanks

Share this post


Link to post
Share on other sites
On 9/16/2018 at 12:39 AM, sayanthan said:

100 cells. DMS did the mapping 

Is that the 4-2-1 manifolds, cats and remap but with standard air intake?

Share this post


Link to post
Share on other sites
On 9/15/2018 at 7:22 AM, si-g said:

Hi all,

 

I want to buy new performance exhaust manifolds for my E39 M5 but undecided whether to go for replacement cats. A part of me would like to retain the original cats but im worried as to how the new manifolds would attach to them, I wouldn't want a single piece exhaust from the engine back to the cans, would want to be able to unbolt the cats from the new manifolds as you can do today. Has anyone fitted them like this? Do the original cats cause a performance concern over the sports cats?

 

The option is there to go for 200 cell sports cats but im worried that it might make the system too loud, im not really after the noise, i want the performance gains that come from the headers, although a slight little bit more noise that stock would be nice :)

 

Do you have to get the car remapped to take advantage of the new manifolds, or are there gains there straight away? 

 

Thanks

You could get a V band attachment between the headers and cats which would make swapping them about very easy. I have a set ready to go on which have this arrangement.

 

It would be interesting see if anyone has tested the sports cats over standard as I am having the same dilemma st the moment. Apparently sports cats can be difficult come MOT time and I don't believe they have much bearing on power, its the headers where the restriction lies.

 

There are gains to be had pre-mapping for sure, in fact most of the dyno results originally provided by Evolve and others were on standard mapping. Its definitely worth having it done though to realise maximum potential and improve throttle response. 

Share this post


Link to post
Share on other sites
On 9/17/2018 at 1:14 PM, Jameswsb said:

You could get a V band attachment between the headers and cats which would make swapping them about very easy. I have a set ready to go on which have this arrangement.

 

It would be interesting see if anyone has tested the sports cats over standard as I am having the same dilemma st the moment. Apparently sports cats can be difficult come MOT time and I don't believe they have much bearing on power, its the headers where the restriction lies.

 

There are gains to be had pre-mapping for sure, in fact most of the dyno results originally provided by Evolve and others were on standard mapping. Its definitely worth having it done though to realise maximum potential and improve throttle response. 

 

I don't think there are virtually any gains to be had with the sports cats. My concern though is that my oem cats are now nearly 19 years old, done over 100,000 miles, would they now not be performing at their best and causing a restriction... Im also curious over the quality of the sports cats vs standard, Evolves sports cats are £900, Russ Fellows £600 and supersprints are a lot more! Is there something I'm missing? Are some better than others? Should I just keep standard cats... I can't decide!! 

Share this post


Link to post
Share on other sites

I wouldn't worry about the cost difference. Russ's work is up there with the very best, i think that the price differential will be more to do with the fact that Evolve and Supersprint have far bigger overheads than Russ (who is a much smaller entity), rather than any gulf in quality.

 

Personally, unless there was a specific problem I wouldn't worry about your standard cats. My totally standard, but well maintained, car made very good numbers on the dyno with original cats that have done well over 100k miles.  Maybe head to the dyno for a health check and speak with Russ?

 

Ultimately it comes down to whether you want the hassle come MOT time or not.

Share this post


Link to post
Share on other sites

Thanks for that, I'll get in touch. Though not really needing anymore power, was just looking as there's a new clutch/ flywheel being made for it and the gearbox being out to take the opportunity.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×