What size OD for cutout? 3" or 3.5"

[justinp95]

I wanted to install an electric cutout, but what size would be best? 3" or 3.5"? I THINK the exhaust size is 3.5", not completely sure. Thanks

 

[Joseph Garcia]

@iamdub

 

[Dantheman1540]

3" is probably fine unless your engine makes a crazy amount of power. My single 3" cutout sounds pretty wild at idle and absolutely savage at WOT.

 

[justinp95]

Ok, Ill try a 3". 3.5" are a lot more expensive.

 

[iamdub]

I wanted to install an electric cutout, but what size would be best? 3" or 3.5"? I THINK the exhaust size is 3.5", not completely sure. Thanks

Pretty sure the stock size after it merges into a single pipe is 3.5". For a cutout on a Denali, 3" will be fine unless you're doing it for all-out power at 5,000+ RPM for track duty. I have a feeling you're wanting it for sound, and the 3" will be plenty for that.

 

[Ghost10]

Pretty sure the stock size after it merges into a single pipe is 3.5". For a cutout on a Denali, 3" will be fine unless you're doing it for all-out power at 5,000+ RPM for track duty. I have a feeling you're wanting it for sound, and the 3" will be plenty for that.

do you have a recommendation for a Sheep cut out electronic and expensive cut out?

 

[13UpInSmoke]

I have the qtps on my 300, been solid for about 5 years

 

[Ghost10]

I have the qtps on my 300, been solid for about 5 years

Under $400 shipped isn't bad.
Albeit this is extreme illegal here in Cali and if pulled over I'm sure it's easy to spot by CHP or local cops.

 

[iamdub]

do you have a recommendation for a Sheep cut out electronic and expensive cut out?

I've found that you get what you pay for. For the cheap ones, they're pretty much all the same Chinese junk and you can just take your pick. The expensive ones (Quicktime, Doug's Headers, etc.) are known to seal better and have better quality motor drives, especially the Doug's due to the design. For the cheaper ones, replacement motor/gear drives are cheap and easy to swap. They're just repurposed power window drives.

If it were me, I'd get a standard 3" DIY cutout mount (like this) and weld that to the stock 3.5" pipe. This would eliminate cutting out a section of the stock pipe and welding in a smaller diameter section (unless you bought a 3.5" cutout Y). Then, you could bolt on whatever 3" electric cutout (more common and cheaper size than 3.5") you want. If it fails, Amazon Prime or eBay yourself another $30-$50 one.