3.5" Exhaust for 2018 Tahoe 6.2L?

[J5races]

Anyone know of a 3.5" Stainless exhaust cat back kit for a 2018 Tahoe with 6.2L? I see MPRB sells a 3.5" kit for a Silverado but they said they dont make one for Tahoe. It looks like a few bends are missing on Silverado version.

I dont have a TIG welder or any fab tools to mod it myself, does anyone know who would sell one or make a 3.5" Exhaust ?


I want 3.5" for better flow with the 3.0L Whipple I have on my Tahoe. I would love an exhaust that doesn't drone, so one of those capped anti-drone tubes would be amazing.

Thanks All

Jon

 

[Thrust]

Do you need stainless?
You might talk to a local muffler shop that makes custom systems to see what they could do and charge.

 

[Joseph Garcia]

Go with a cat-back dual exhaust system with dual 3" pipes after the split (3.5" pipes before the split), and you will have plenty of exhaust freeboard to accommodate your Whipple. I use a Gibson Extreme cat-back dual exhaust with these specs, but I'm sure that it is too loud (and drone) for your preferences.

 

[J5races]

Does anyone know how different a Tahoe exhaust is from a same year Silverado?

 

[k_arnold72]

The silverado version is longer. I picked up a silverado oem catback to modify(and retain my stock exhaust to swap back one day) and it's noticeably longer than what's on my 2018 Tahoe.

I'll try to get a picture of it next to the truck in-line with where it mounts up to the y pipe for reference...

Silverado catback seen here would def hit the rear axle unless shortened

 

[swathdiver]

Anyone know of a 3.5" Stainless exhaust cat back kit for a 2018 Tahoe with 6.2L? I see MPRB sells a 3.5" kit for a Silverado but they said they dont make one for Tahoe. It looks like a few bends are missing on Silverado version.

I dont have a TIG welder or any fab tools to mod it myself, does anyone know who would sell one or make a 3.5" Exhaust ?


I want 3.5" for better flow with the 3.0L Whipple I have on my Tahoe. I would love an exhaust that doesn't drone, so one of those capped anti-drone tubes would be amazing.

Thanks All

Jon

Gibson made or makes a 3.5" exhaust for the GMT900 trucks and SUVs. Check them out.

It amazes me that these exhaust companies sell an inferior product by using 3 inch tubing when our factory exhaust is 3.5 inches. What's worse is that folks buy it!

 

[J5races]

Gibson made or makes a 3.5" exhaust for the GMT900 trucks and SUVs. Check them out.

It amazes me that these exhaust companies sell an inferior product by using 3 inch tubing when our factory exhaust is 3.5 inches. What's worse is that folks buy it!

I didn't realize stock exhaust is 3.5" Seems like I would want a 4" exhaust to breathe better. Anyone know a place that would sell and ship a 4" cat back exhaust that isn't too crazy expensive?

 

[homesick]

Four inches may be past the point of diminishing returns.

joe

 

[swathdiver]

I didn't realize stock exhaust is 3.5" Seems like I would want a 4" exhaust to breathe better. Anyone know a place that would sell and ship a 4" cat back exhaust that isn't too crazy expensive?

Too big unless you are pushing 500+ horsepower. The 6.6 Duramax diesel's though use that size or larger so you may want to check with those who make their systems.

 

[J5races]

Too big unless you are pushing 500+ horsepower. The 6.6 Duramax diesel's though use that size or larger so you may want to check with those who make their systems.

Whipple claims the Gen V kit makes 535hp to the wheels. I gotta think bigger exhaust piping will help at that power level.

 

[gtrslngrchris]

You guys are way overstating the "problem" of 3" aftermarket exhausts. A 3" system is likely to actually improve the power curve for the way most people drive these anyway as a larger system might actually lose you some torque in the middle of the power curve where you don't want to. If you don't at least have a whipple or similar on your 6.2L then I think you are kidding yourself about exhaust and the effect of larger pipe.

As far as Duramax's go I've personally seen more than one "sleeper" LB7/LBZ Duramax making well over 500whp on the factory 3" exhausts (I really think 600whp+ but I'm being conservative). My LB7 with a built trans and upgraded turbo stood no chance even with my giant 5" exhaust.

 

[homesick]

Some of y'all might benefit from watching 'Engine Masters' on Motor Trend TV. They do dyno comparison testing, in-depth and technical.

joe

 

[Thrust]

I would worry about your flat section in the y pipe first.

 

[J5races]

I would worry about your flat section in the y pipe first.

Did you replace yours with something larger and get a worthwhile gain from that?

 

[swathdiver]

Whipple claims the Gen V kit makes 535hp to the wheels. I gotta think bigger exhaust piping will help at that power level.

Maybe so, there's a math formula for that but I don't remember it anymore. Banks and Hennessey are on top of that, I'd ask them.

 

[Joseph Garcia]

As stated above, bigger diameter exhaust piping is NOT automatically better. There is an actual 'tune' of exhaust fumes air flow, volume and velocity, involved in exhaust system engineering. With too little piping diameter, you get restricted flow due too much exhaust fumes trying to flow through the piping, with a resulting back pressure and a slowdown in exhaust fume velocity through the piping. With too much piping diameter, you lose the exhaust fume velocity momentum achieved from from the exhaust manifold/headers, and you get velocity dead spaces in the downstream piping, with a resulting slowdown in exhaust fume velocity through the piping.

 

[hagar]

The factory 3.5 inch moves plenty of air. One of my trucks runs a single turbo 416 stroker through a factory 3.5 exhaust and muffler (no cats or y pipe,) and makes 900 hp. I am building a single turbo srt10 right now that is way bigger of an engine than the 6.2, and will make around 1000 hp, and it is only running a single 3.5 inch exhaust. Just change your muffler for sound if you want it louder, as for flow, your whipple is a fart in the wind for a 3.5 inch exhaust. Heck, I made 720 wheel hp through a single 3 inch once on a supercharged fourth gen camaro, and 3.5 inch is a massive increase in flow over 3 inch.

 

[buckwild27]

These guys make great stuff. I have a full system from them on my 800hp Sierra. They are spendy though.

https://stainlessworks.net/by-vehicle/gm/tahoe/

 

[MWR Denali]

When I last shopped for a 3.5" exhaust for my Avalanche (admittedly it has been a few years) some of the Escalade aftermarket options were 3.5" and should either bolt up or require minimal mods. Another option would be a 3.5" takeoff, delete the resonator and swap mufflers. If your 6.2 already has the 3.5" factory exhaust, that's probably the route I would choose.

 

[Doubeleive]

I have seen those engine tester video's one in particular they take a sledge to the stock exhaust smashing it on purpose to restrict the flow and it made no difference other than at one point while making various smashes and re-testing power actually increased.
as noted already the stock 6.2l pipe is already 3.5 or larger in some spots, your pretty much waisting your money, if you can find 4" pipe then order it and have a local muffler shop build you a exhaust. most places do not even stock 3.5" let alone 4" and good luck finding a 4" muffler, probably have to modify a straight thru one like a borla
4" will make it louder, I put 3.5" on my 03 5.3 silverado you could certainly hear the difference. did it make more power? no idea, sounded good though