TRAKCAR

The option to go silent is nice sometimes on long drives I suppose, but I cant drive with the on/off switch and the side muffler dual tone. Plus I hate the extra heat and weight in the back.

With active side mufflers the artificial change in tone drives me nuts. Quiet, then you stop for a traffic light and it goes louder, then quiets down when you take off until it automatically opens up above 4K RPM. Flip flops. Annoying to me. One solution was to unplug the valves permamently to bypass the side exhausts, but then why keep the 2 side mufflers being dead weight behind the rear axle?

If I'd keep side mufflers I'd want an override system that either keeps the valves open to the side mufflers or closed for loud sound. Milymu did that:https://rennlist.com/forums/showthre...ferrerid=59610
Carnewal sells a remote control for it also:
IMHO the M&M is so quiet under 4K RPM that I can be on blue tooth on the phone driving in normal traffic under 85MPH. Over 4K RPM it is loud enough to sound nice and be able to heel n toe on track. Best of both worlds in sound, massive weight and heat reduction and pretty cheap.

mmuller

Agreed. I have an RSS bypass on my 7GT3RS and it sounds nice and aggressive and certainly howls when your on it. It does sounds somewhat 'dirty' and can drone at some speed/gears. I have a full Akra on my 7GT3RS4.0 (with side cans) and the sound it makes is pure heaven I installed it myself which was pure joy as it fits better than a glove. Both systems retain the sport button function

On my 6GT3 track car I have a set of 7GT3RS headers with the Supersprint side delete pipes into a 7GT3RS center box (top holes on the box are blocked off), so similar in design to the M&M side delete system. It's pretty noisy (wont pass sound restriction at Lime Rock) in a good way and it did make 12hp more on the dyno so can see how improving the pipe design on these cars can really help.

Eddie - RPW

Nice combo.

I also offer the link pipes, that are made to be used with either a Cup center muffler or a GT3 OEM center muffler and block off plates.
This design is ok if you're looking just for weight savings. Power gains is almost nonexistent. Maybe your power gains were a combo of a better header design in conjunction with exhaust system ?
Either way, the design helps indeed

85Gold

I have exactly the same exhaust on my 6GT3 with a Baller CF Cup rear bumper cover, thanks Eddie, and I picked up 4mph on Sebring back straight. How much of that was the exhaust adding power or just ditching the bad Cats I really don't care as it's faster and sounds good full throttle. It is 95db full throttle at 50' as per SCCA. measuring

Eddie - RPW

Serge944

As if I wrote this myself - completely agree with every point.

RSRanger

I'm not even gonna touch this topic.
btw what was the exhaust on the van in the video? LOL

M&M


Ranger (Sua Sponte)

gtdoggie

Thanks everyone for the input. So...... I think I understand.:

Sharky center bypass: great sound, 14 lb weight savings, no power increase, no drone, still have active sport button.

M & M side muffler delete: good sound , 45 lb weight savings, most power increase for 4.0, ??artificial drone at idle but stock also has a little, no active sport button

Akrapovic: great sound, weight savings similar to MM, good power increase but less than MM, ? No drone, still keep active sport button. By the way which Akra are we talking about

Finally, from those that have heard comparisons which sounds best(I understand this may be personal opinion)

Thanks for the guidance guys!!!

TRAKCAR

M&M has no drone at all, whisper quiet at idle after the airpump stops.
Where are you located? Go for a ride in all of them?

gtdoggie

I'm in LA Peter. I will try to find somewhere or somehow to hear them. May be challenging. Is sound quality of MM as good as SW or Akra?

TRAKCAR

Too subjective, I'll try:M&M darker, quieter at low RPM, same at high RPM than Sharky.
Sharky trumpets and barks more at low RPM but M&M burbles nices when dropping revs without throttle completely closed.

There should be plenty of both in you neck of the woods.
Akra more rare due to price and i have not driven one with full akra but Izzones car has only a final akra muffler I think and it also sounds nice.

Eddie - RPW

Sharky - spot on


M&M with side muffler delete no artificial sound or drone, No Sport button active most power gains. If sport button active is a must, we also have the sport side mufflers (with increased flow for power gains) and keep the sport button active, but in my opinion it looses the purpose.

Akrapovic Cup system - which is the one comparable to my M&M, has no sport button available, and marginal power increase. If you want sport button active you need to also purchase the side muffler which is the race line.

Price between akrapovic and M&M is also not comparable.
I also have akrapovic, so I can compare all systems. Also tested them all on the dyno.

Eddie - RPW

If you like, I can provide a system, if you don't like, send it back for complete refund

RSRanger

That is awesome customer service, hands down!

Ranger (Sua Sponte)

mmuller

It was back to back runs. The motor is stock, other than no A/C and RSR Crankcase breather. Headers are stock 7GT3RS ones from my RS (its has the headers from the 4.0). It's just made more power when it went on the dyno. More importantly, it weighed 29lbs vs the stock 99lbs stock 6GT3 exhaust.