The Milltek cat back is an H pipe mid. Find someone with a Milltek exhaust...

 

Pops and crackles on the overrun are caused by bits of unburnt fuel igniting in the hot exhaust, usually in the cats themselves. This isn't good for the cats. Modern ECUs will cut fuel to the injectors when the throttle is closed to save wasting fuel and potentially causing issues with the cats. If you want your exhaust to pop and crackle as such then have your car custom mapped and ask your mapper to increase fuelling on the overrun.

Bear in mind that these cars are autos so the upshifts on WOT happen quickly enough that you may not get this; you might only notice it when lifting off from WOT.

 

Seems to me we are damed if we do and damed if we don't, May be best to leave alone, and be happy with just removing the fuse.

 

I only want the crackling when lifting off the throttle! Good insight about the ECU mapping--it does seem bad for the cats. I wonder of the F-Types will have premature catalytic converter failure.

 

I'll be honest, I can't be certain how much (if any) pop and crackle I get now because my car is a coupe and I live in Scotland. It's now early March and believe me, driving with the windows down is not an option. If you drive a "vert" (I think that's what you lads call them?) and/or with the windows down, you may well hear pops and crackles with this setup. I do get a little bit of that when revving while parked, in P or N, as the engine bounces off the 4500rpm limit in those gears.

Taking fuse 19 out gave me a bit more noise in the lower rev range, as you'd expect. Changing the center exhaust section amplified the noise throughout the range and it took on a slightly but noticeably changed character. When on a charge it's a more angry, bellow-y noise, fuller and more rounded. When "making progress" without totally going for it it sounds a little more wail-y, almost like a Maserati - a slightly more "tuned", European sound. When driving normally it's not really any less civilised than it was before.

All of the above was basically exactly what I wanted so I'm happy, put it that way. Decide for yourself if that fits the bill or not. You'll notice more volume for sure if you drive a convertible though.

Can't remember what car it was but sure I read some time ago that one manufacturer had engineered in a system whereby they deliberately mapped in extra fuel on the overrun and had a system to ignite it without doing so inside the cats. Maybe F-Type has something like that, not sure...

 

To be honest, I wonder how much the F-Type pops and crackles. Maybe the popping and crackling only happens when the car is cold (that seems to be how my XKR does it). Can anyone with an F-Type chime in here?

 

Thanks for that . I think thats what we are all looking for, What we need now is for some one who has installed the H type to chime in for comparison. BL

 

Standing 2 feet away from the rear end of the car at 100+ MPH on a dyno today, the exhaust sounded holy sh*t bad a*s!!! Just sayin'

 

You should hear it at 184...

 

Are you telling us that you didn't get a video!?

 

Sorry no, I had intended to but I was too busy watching to make certain my car wasn't going to go through the solid concrete wall 50 ft in front of it. Lol.

I will get one of it when I go back after the new pulley is installed sometime in the next week.