Dervish

Thought I would do a write up about my recent exhaust experience with as much info as possible so others can judge.

I first started looking at exhausts at the end of 2011 as the system at the time (stock headers, Miltek 200Cel Cat, modified stock muffler) was raspy and felt like it was letting the rest of the car down.

Straight away I found that no manufacturer would (or could) give an accurate dB level. Here in the UK the static measurement for dB readings is standardised to be ¾ max rpm at a distance of 50cm from exhaust. Not 1 manufacturer I spoke with could give me an accurate number for their systems. For example check out my post here https://rennlist.com/forums/9049778-post15.html where fvd quote their system as 103dB. Only to be told here https://rennlist.com/forums/9282019-post6.html that the system is closer to 113dB.

I went back and forth between manufacturers, researching, looking at youtube videos, checking install threads, speaking with service specialists and finally decided that M&M would be the way to go, being European and Manthey suppliers I figured this was a good choice. I had also previous experience dealing with them when I had bought Manthey (M&M) mufflers for my old 996C2. The sound was easily one of the best I’d ever heard and construction was first class.

Decision made I then set about contacting fvd who are the main M&M agents about what system would be best. I did some calculations and was willing to go up to £2700 for Cat and mufflers. By chance another rennlister and also UK forum member emailed me saying he was in process of becoming UK agent for fvd so conversations started about choices. This was tedious to the extreme, through no fault of the rennlister. FVD’s customer service is next to redundant. For more than 4 weeks the emails went back and forth. I gave options, they took ages to reply. Long story short, after much internal debate, I decided on a single unit 200Cel Cat and small muffler 'Cup' system. I was then told there would be a 2 week minimum lead time before it could be manufactured even though the website stated ‘expected 6 days’. By now I was anxious to get a new system on for a fast approaching track day at Spa. Purely by chance a rennlister was selling the identical system so I purchased from him and had the system in my hands within 4 days.

Looking back on it now fvd could have cut the back and forth BS and sold me a X-Cat and mufflers, made money and created a happy customer. Instead I got ‘we don’t recommend that system’ even though they sell it, then not reply with alternative for days, if at all.

To top it all off I ordered a set of 90mm round end tips from them weeks later, thinking that because they were listed as in stock for immediate despatch I wouldn’t have any problems, wrong! The order was confirmed straight away with note saying it was being despatched that day. 4 days later and still no despatch note. More emails the following week, called my bank and they hadn’t even processed the payment. I then tried calling, a lot, and nothing. I eventually had to resort to posting an email on fvd’s facebook wall, good business! Finally I got an answer and they eventually despatched the item.

Ok, enough of the history, here’s the install and videos:

Old Miltek system:


There was actually a crack in a weld which had previously been repaired.


Old system off, you can see that the ends of the stock mufflers had to be modified to fit the larger diameter CAT tube:


New M&M 200Cel ‘Cup’ system on:


With bumper back on showing rotating end tips, these can be angled to allow for reduction in noise on drive by measurement:


As soon as I started the car up after fitting I knew I had a problem, it was just way too loud at idle and droned really badly when driving. I had borrowed a professional dB meter from work and measurements were:
95.5db cold start
78db warm idle inside cabin
93.1db idle 50cm from exhaust
95.8db measured at ear level whilst driving along IN CABIN!
110.4db @ 3/4max rpm 50cm from exhaust

This was too much and I needed to sort this asap so I took it to an exhaust fitter the next week and they fabricated a joining pipe between the stock muffler and larger flared end of the Cat system. Remeasured at:
67db warm idle inside
77.8db idle 50cm from exhaust
80db driving in cabin
96dB @ 3/4max rpm 50cm from exhaust

Here are pictures with new 90mmm round tips:




You can see the weld join between CAT and muffler. The eventually plan is to use something like the afterhours or GMG type muffler and tig capable fabricator to join everything together. Very much like the Manthey system which incorporates the exact same Cat I have with their larger diameter mufflers. I emailed fvd 4 weeks ago about fabrication of this and as yet have had no reply, surprise!

Here are videos of the system, it sounds great outside but not driveable for any period of time without a helmet. I also noticed loss of low end torque but don’t have dyno evidence.



Passing friends Aston in a tunnel:


Inside cabin through tunnel:


Another tunnel:


Just driving:


With mufflers added just for fun with friends, can barely hear it!

Dervish

***Reserved for update with fabricated muffler***

DHI

Thank-you for documenting this.

First video;
Fackin' loud. Would never pass the sound police at the local tracks here.

Last video;
Way too quiet. I guess going through two sets of mufflers will do that.

With your recent experience, would you have considered going with a catted x-pipe through the stock cans?

Cheers!
David

PS. With all the cars... You seem to belong to a good tribe.

Dervish

The small straight through muffler barely does anything on its on but in combination with the stock mufflers certainly helps.

In retrospect I would 100% have gone with 200cell x-cat and separate muffler combo. This was one if the options I enquired about but lack of response and info took me down the route above. If I was given a good combo in price range I'd have bought there and then.

HiWind

Hi Stuart - useful insight Thanks. I'm on that same decision tree - exhaust thread a few days back ie this week. I agree 100% that its nuts how hard it is to get accurate figures - db or weights - sometimes/too often from manufacturers. I asked a brake guy for rotor weights last week ... He replied 1-2 weeks! Lol

Heard fvd/m&m get v busy round euro race season whixh likely explains the tardiness to some degree ... but shdnt make service claims they cant meet.

Dervish

UPDATED:

So I finally got round to getting a better fix/solution to the too loud problem and temp fix of stock mufflers.

I bought a set of these at the end of last year with the purpose of fitting at some point. 2nd generation with no drone.




This is a video showing the 997 version but basically the same, you can see the lightweight design, much lighter than stock.


GMG do a very similar design but with 1 muffler section, thoughts were this would still be too loud when combined with the M&M race system. The plan was/is to keep the whole system as free flowing as possible but reduce loudness to an acceptable level. Searching Rennlist came back with decent feedback on Afterhours as a company.


Anyway, I needed to get the M&M race exhaust mated to the Afterhours mufflers and needed someone who could fabricate and TIG weld. Did plenty of research and came across these guys just west of London.

http://www.styledynamics.co.uk

They know 911s as they do a lot of PSE type hacks and also have a lot of experience in strange and troublesome requests, which this was.
So a good few hours with the guys there and this is the results:

Craig at work...



Modification of Afterhours pipe ends









Finished





Now for the numbers:

87.3db cold start idle
72db warm idle inside
88.7db idle 50cm from exhaust
88db driving in cabin
103.6dB @5000rpm 50cm from exhaust


The sound is just what I was after, louder than stock but not intrusive on start up and idle, nice little pops in second gear through traffic and then...
OH MY GOD, when you hit 4k plus it's just epic!
I even think the pick up has improved, no loss of low end torque like before. Just enough back pressure to do it's job. And more importantly, no drone in the cabin. It's actually a pleasure to drive, I haven't turned the radio on yet, even stuck in nose to tail traffic.

Thanks to the guys as Styledynamics, no affiliation to them but would definitely recommend to anyone London/UK based wanting some exhaust work done, they go above and beyond to get it right as proven by my b**ch of a request.



I'll post some video clips next weekend, I tried today but camera freaked out on me.


:thumb:

Dervish

Videos:

Incar with window down, spot the MP4-12C Spider:


Drive by(s):


Just so happened another UK forum were doing a group rolling road round the corner so I went along. Here's the results, I understand the subjectiveness of dyno graphs and I don't have any before runs.

Flywheel:



Wheel:



AFR:

Serge944

What a journey! I'm glad the end-result was just what you were searching for.

PS, with all that work, you're making fitting a 997 style exhaust + new bumper cover look cheap.

Dervish

Updating this thread with today's addition:

FVD/ M&M sport headers for 996GT3 (49mm)

These were always on the list of parts to buy to make a more 'complete' exhaust system. The headers match the 'Cup' exhaust that I fitted at the start of this thread. In effect the system now makes up this but with additional light weight mufflers:

M&M Race 996 GT3




First off, presents in the post, always makes a day at work more fun.



Then it was home to fit. First look after unpacking.



Proof of manufacturer pedigree and date stamp.



Some merge collecting.



As this was always on the list to do last summer I had OPC West Byfleet remove and replace all the manifold bolts. From what I gathered from the final labour costs this was something I did not want to do at home. This meant that all bolts minus 1 came out without hitch. The very last bolt (always the way) was very stubborn and required a lot of slow steady force. It didn't help that it was 1 of the ones that a socket couldn't be used on and had to use a 13mm spanner with sore hands.

Header to CAT bolts are another b*tch all together, access is almost impossible and I hope no one was around to hear the swearing.

6 hours later and the old were off and the new (shiny) on.



Lining the holes up with gasket whilst holding the header was painful, using a ramp rather than jack stands is probably a lot easier.

A quick start up whilst still on jacks and inspection showed all good. Warmed up and a drive did show a world of difference but I do think there is a bit more 'go' and feels slightly smoother, could just be placebo.

I'll do a dB test next weekend to see if there is any noise level increase.

Raven 666

Looking forward to hearing this with the new headers .................

Dervish

And the story continuous…

So after fitting the fvd headers I went down to Surrey Rolling Road as the car didn't feel like it had the torque it had prior to fitting. SRR is where I've done all previous dyno runs so I know the baseline on that machine. The graph below shows the resultant loss of power due to lean running, AFR around 13.8.



Apparently this was to be expected after making the air in and air out more efficient without mapping for fuel. I was a bit pi55sed as there was no mention on fvd site to say a tune would be required when fitting. Other products do mention the need for ECU tune but not the headers I purchased.

Anyway, I figured if fvd sold the headers they would be able to tune so back I went to their website. Turns out they now have a 'tool' which allows you to read the stock ECU file, email it back to fvd with the list of mods. They say they will turn around a new tune file within the day and then you upload back to the tool and flash the car, seemed pretty simple…

MYGenius Tool

So a couple of days later I received the My Genius tool, installed the software on a PC, updated the 'tool', plugged it into OBD2, downloaded stock file and emailed it to fvd, seemed pretty simple…

A couple of days later due to the German Holidays I received the tune file back. This is where problems started.

The upload failed half way and threw an error, luckily the file didn't load as apparently this would have made the car undriveable and would require sending the actual ECU back to fvd to fix. Emails back and forth to fvd didn't really help as they had to contact the 'tool' manufacturer who eventually advised a tool reset. Searching forums didn't help either as it appears only BM forums have had any decent experience with this kit, not exactly confidence inspiring from fvd.

So tool reset and eventually I get a new tune file as we had to go through initial stock file process again. Flash the car successfully and book in for new rolling road, result below, stock with headers against fvd 'tune', no change…



Getting a little annoyed, contact fvd, get new tune, flash car, wait until following weekend and go back to SRR, result again below:



So still lean after 2 'tunes' and 'only' 10bhp down on original baseline dyno. Not exactly simple plus time consuming and costing me for multiple rolling roads. At this point I voice my dissatisfaction to fvd and request my money back, the whole process from order to this point was almost 30days and the money back guarantee only lasted this long.

The only good thing I have to say about fvd is they refunded very quickly once they received the 'tool' back with log showing I flashed back to original stock file.

Back to square 1…

During the end of the fvd episode I contacted Regal Autosport in Southampton who are EVOMSit suppliers/tuners in UK with their own rolling road, not to mention Sharkwerks suppliers for UK. I had previously used them to tune my Carrera and was very pleased with the results, why I didn't do this at the start I don't know… Maybe because I had previously been burned by another Southampton tuner that the thought of going back to Southampton was not pleasant…

So off I went down to Regal to see Chris, Ash, Karen and the Regal team. They know their stuff and was greeted by the site of Chris' lovely Cobalt 997.1GT3 with Sharkwerks exhaust, that thing is loud.





Straight away my car went on their Mustang Dyno to get a baseline.



Car still running lean but baseline higher. At this stage I'll state the obvious that all dynos are subjective and vary, I am looking for delta change, AFR improvement and better drivability, not final numbers.

Chris took a list of all modifications including details like the size increase of larger MAF housing for 82mm throttle body. He then sent this info together with the stock file to Todd Z @ EVOMS in Az and we waited for him to wake up. It wasn't long before Chris received the tuned file back which had been tweaked for all mods and AFR requirements. Chris flashed the tune and took the car for a drive before putting back on the dyno. Seems Todd@EVOMS nailed it on first attempt (we were prepared for multiple), comparison with baseline shown below.



AFR is back in a good place, torque is up and peak power is up but more importantly the car feels back to how you would expect the Mezger to feel, alive…

Can't thank the team at Regal enough, I have no connection with them at all other than a twice satisfied customer.

Lesson learned that there is no easy DIY tune option. With all the back and forth it would have been far easier, and cheaper to do it properly first time.

DHI

Thanks for taking the time to post all this information.

The placebo effect usually takes the regular Joe over when spending so much time and effort. Good on you for being so persistent and forthright.

cello

^ +1. Well done.

lax01

I'm wondering if my car exhibits the same issues (can't really tell, never driven with the stock headers) as I have Fabspeed headers and mufflers. I probably should put it on a dyno and get tuned...

ad93

I was thinking the same thing as you since my car also came with fabspeed headers and exhaust. If you do end up putting your car on a dyno please share the results.

Thanks