Exhaust drone question

[JimRN]

I have read the extensive exhaust thread and thank everyone for all of the wonderful posts. I have listened to sound clips and reviewed everyone's opinions and have narrowed down to three choices in this order: 1) MAP catback for the awesome deep tone 2) Borla catback due to it's wonderful tone and burbles and 3) the Cobb catback. All three are very similar. The Borla surprises me as it has a resonator whereas the other two do not which, leads me to the "drone" question. I assume the resonated exhaust attenuates the drone better and makes cruising more tolerable. The MAP has the deepest tone out of anything I have heard in comparison. What is everyone else's experience with these 3 choices? All are very good choices and I feel the drone issue is the deciding factor.

 

[ChicaneR]

I have the Map catback and first of all, it does have a resonator. I have literally 0 drone , none of it. It really sounds like an exhaust you would find in a high end sports car from the factory, very deep burble especially at idle but instead of getting loud and high pitched it keeps its deep grunt through the rev. Along with my other Map stuff the quality is top notch. The fitment is pretty good but it does need adjustments . Tips are welded in so it's only 3 pieces altogether ( and two sleeve joints ). It's hard to hear just cruising and gets louder the more you step on it but not very loud at all. Like I said the easiest way to describe it is a high end sports car like sound and loudness. I just love the way it sounds at idle it almost gives it a cammed profile kinda like my stage 2 cams b20 I had. All things considered if you dont want a loud exhaust or trying to extract every single hp possible with a big turbo , it's easily the best choice. Quality from map has always impressed me with consistency . The only thing I was worried when I was buying this was the diameter ( 2.5") . After I read DHM's comment about making like 330whp on stock exhaust I was relieved. He was calling out everyone saying stock exhaust was not restrictive at those power levels which means Map catback is at least good for 400 wheel , which is my ultimate goal. I'll update with a pic or video if you still need proof how good this catback is . But like I said if you want a good tempered not obnoxiously loud exhaust and can live with 2.5" diameter look no further. Quality/dollar is wayy up there...

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[JimRN]

Ahh yes! I see the midpipe resonator now! Thank you for your report, it helps my decision making process. I understand the pipe diameter issue. I had a 2009 gti and remembered this was a hotly debated topic with tuning. It turned out that the 2.5" exhaust on the Gti was ideal for the bottom end but when you went with a 3" pipe, you would lose some of your bottom end torque. A 3" pipe was best when going with a big turbo hence the APR stage III setup. Then Milltek had their "tween" pipe of 2.75" which I believe they do for the Fist as well.

 

[ChicaneR]

Haha yea I had a mk5 gti as well, I’m aware of this debate , the thing is I had an instructor in my technical school that had a load of experience with racing cars and building racing engines and he told me that with turbo cars , turbo becomes the restriction point . After the turbo the more flow you have or the more open the exhaust the better , there is really no downsides to having as wide or as short of an exhaust you can have . So ,Actually it’s the other way around the larger diameter or more flow you have after the turbo the better the spool AND the top end. If you think about it makes a whole lot of sense. Only time you can go with a “too large” exhaust is NA engines. That being said I like the 2.5” dimeter for two reasons, biggest is the clearance , both for ground clearance and clearing the mid brace and as little of a difference it may be the weight is also slightly less , although non resonated or straight-pipe would be lighter but you know the consequences. On top of that the same thing applies for the GTI’s as our cars and most others nowadays , stock system is adequate for lots of power, but like I mentioned it will hold you back a tiny bit with a big turbo , I really don’t mind because I love this exhaust and the grunt and sound level and I know once I go big turbo / decat setup it’s gonna be right where I want it !


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[JimRN]

With the MK V gti, I had an Induktion motorsports catted downpipe that was 3" after the turbo with a nice smooth bend. It tapered down to the 2.5" diameter to connect to the exhaust. It allowed the turbo to spool better and the butt dyno realized more torque however... in about 6 months the stainless steel braids on the downpipe started to rip apart. Verdict? The rear motor mount allowed the engine to twist the exhaust. So guess what my first engine mod will be? :O

 

[ed_the_sledd]

cobb catback def drones. it’s annoying going 80 on the expressway. It gets loud around 3,200 RPM

 

[TDavis]

Don’t want drone but great, throaty sound? I choose Thermal. Mine still doesn’t drone and I have a catless DP.

I’ve driven the car to NY and back and it wasn’t unpleasant at all

 

[TyphoonFiST]

Don’t want drone but great, throaty sound? I choose Thermal. Mine still doesn’t drone and I have a catless DP.

I’ve driven the car to NY and back and it wasn’t unpleasant at all

This makes me even more excited when I pickup my exhaust after the ceramic coating and install it coming up!

 

[Dpro]

This makes me even more excited when I pickup my exhaust after the ceramic coating and install it coming up!

Are you ceramic coating your Thermal? Thermal is what is going on my car.

 

[TyphoonFiST]

Yeap....titanium....every inch except the tips....I'm doing it for thermal retension and corrosion purposes.

Are you ceramic coating your Thermal? Thermal is what is going on my car.

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[DangerMouse]

+1 million for Thermal. I wish I would have coated the whole exhaust, I only did the tip.

 

[Fridge]

cobb catback def drones. it’s annoying going 80 on the expressway. It gets loud around 3,200 RPM

I know this is old but did the drone get any better after putting some miles on it? Just put my Cobb on yesterday, the drone is very subtle but it’s there when RPM’s are low in 5th or 6th gear. Almost sounds like the back window is rattling. Thanks

 

[Melow]

i've had the Cobb for 23000 miles now and the drone only gets worse with time. I absolutely love the sound, but the drone is horrible. Looking to get new exhaust myself.

 

[DangerMouse]

i've had the Cobb for 23000 miles now and the drone only gets worse with time. I absolutely love the sound, but the drone is horrible. Looking to get new exhaust myself.

Could try a vibrant ultra quiet resonator, I’ve seen some people add them to the Cobb system. Unless of course you are just looking to get a new exhaust.