EXHAUST SETUP!

[ProjectLT]

I’m upgrading to a BTR Stage 2 Truck cam in my 2011 Tahoe (5.3). The entire exhaust system on it is currently stock (has cats). Now I know I can run the cam with stock manifolds but will lose out on the full potential the cam has to offer unless I switch to headers. I have shorty headers in mind because this is a daily vehicle and not a race truck where long tubes would benefit in mid to high RPM’s. Shorty’s just seem like a better choice given it’s a daily driver and I won’t be balls to the wall redlining to benefit from long tubes. I understand when it comes to modding a vehicle there’s things you have to jeopardize to make it work. However this is my issue, If I put shorty headers on with my stock cats it will probably ruin them in no time. Which leaves me having to go high flow cats or at that point catless because if the stock cats aren’t on then it won’t pass inspection. How are you guys getting around inspections that are running headers? I know most will say just go catless but I’m trying to find a way or setup to make this thing pass inspection while still being able to run headers for the cam to benefit.

 

[swathdiver]

Richard Holdener proved the assumption wrong that long tubes are only for higher rpms.

@kbuskill has shorties on his 5.3 and can talk about what he's done.

 

[Foggy]

Shorty Headers will not give any measurable performance over the stock exhaust manifolds.
Put your money somewhere else

 

[Thrust]

Shorty Headers will not give any measurable performance over the stock exhaust manifolds.
Put your money somewhere else

How loud are long tubes with Cats?

 

[Foggy]

My long tubes with hi flow cats were not much louder than stock..
But i have the 6.2 which has a larger exhaust system to being with.
It wasn't until I cammed it that it "seems" louder. So I haven't installed my
Magnaflow system yet because I dont want it any louder..
I installed my LT headers and green cats at the same time I put on my edelbrock E Force
supercharger... The "volume" was not very noticeable over stock.. It just sounded a little
deeper.
When I removed my SC and went with a cam, the volume level increased and the
the actual tone has changed too.. I'm not yet done doing my tuning, so i'm still hoping to
tone it down a bit

 

[Geotrash]

I’m upgrading to a BTR Stage 2 Truck cam in my 2011 Tahoe (5.3). The entire exhaust system on it is currently stock (has cats). Now I know I can run the cam with stock manifolds but will lose out on the full potential the cam has to offer unless I switch to headers. I have shorty headers in mind because this is a daily vehicle and not a race truck where long tubes would benefit in mid to high RPM’s. Shorty’s just seem like a better choice given it’s a daily driver and I won’t be balls to the wall redlining to benefit from long tubes. I understand when it comes to modding a vehicle there’s things you have to jeopardize to make it work. However this is my issue, If I put shorty headers on with my stock cats it will probably ruin them in no time. Which leaves me having to go high flow cats or at that point catless because if the stock cats aren’t on then it won’t pass inspection. How are you guys getting around inspections that are running headers? I know most will say just go catless but I’m trying to find a way or setup to make this thing pass inspection while still being able to run headers for the cam to benefit.

How do you feel about a choppy idle? I had the BTR stage 2 truck cam in my 6.2 and didn't care for either the chop for daily use or the limited power gains. I redid the project with a Stage 2 truck cam from Cam Motion designed specifically for the 6.2 that I'm happier with. Better power gains and a smooth idle. The BTR cams are designed to 'function' with the 4.8, 5.3, 6.0 & 6.2 but aren't really optimized for any of them. I would rather have a cam ground specifically for the flow dynamics of the exact engine I'm working with.

 

[Foggy]

How do you feel about a choppy idle? I had the BTR stage 2 truck cam in my 6.2 and didn't care for either the chop for daily use or the limited power gains. I redid the project with a Stage 2 truck cam from Cam Motion designed specifically for the 6.2 that I'm happier with. Better power gains and a smooth idle. The BTR cams are designed to 'function' with the 4.8, 5.3, 6.0 & 6.2 but aren't really optimized for any of them. I would rather have a cam ground specifically for the flow dynamics of the exact engine I'm working with.

From what I have read, if you have a 6.2 you really NEED a cam designed for the Square Port
Cylinder Heads... As the others have cathedral heads..
I don't really like the choppy idle at all, but I'm sure I've got some more VE tables and
MAF tables to work on in my tune still.. It is way better than at first .. That's why I chose
the smallest VVT cam that I could find. If I had a "custom cam" I'd reduce my intake
by about 2* and my exhaust about 4* and then widen out the lobe sep to 114*-115*..
I think that would be a perfect daily VVT cam..
The power increase is very noticeable for sure, so that makes me happy.
I was just really surprised at the exhaust sound with just a (small) cam change for sure

 

[Geotrash]

From what I have read, if you have a 6.2 you really NEED a cam designed for the Square Port
Cylinder Heads... As the others have cathedral heads..
I don't really like the choppy idle at all, but I'm sure I've got some more VE tables and
MAF tables to work on in my tune still.. It is way better than at first .. That's why I chose
the smallest VVT cam that I could find. If I had a "custom cam" I'd reduce my intake
by about 2* and my exhaust about 4* and then widen out the lobe sep to 114*-115*..
I think that would be a perfect daily VVT cam..
The power increase is very noticeable for sure, so that makes me happy.
I was just really surprised at the exhaust sound with just a (small) cam change for sure

Yes, I agree with your opinion about needing a cam designed for the flow dynamics of cathedral vs rectangular port heads, which is probably why the BTR cam was shit for me. To be clear though, the BTR cam still had better power than the stock cam but just not as strong as the Cam Motion cam I have in it now.

Here's the cam card for the Cam Motion cam that I have and like so much. They make it in a "low lift" version as well but I have BTR springs good for .560 lift, so I went with the higher lift version. The 117 LSA seems to be the key for the smooth idle with this cam. As with yours, the power increase was very noticeable over stock. And I get reminded of it every time I get behind the wheel of our 2007 after driving the 2012. Both engines are Black Bear tuned for 91 octane, but the 2007 still has its stock cam and the 2012 feels like a gorilla by comparison. Slightly more aggressive exhaust sound as well, which affirms your point about the change in sound with your cam.

 

[Trey Hardy]

I’m upgrading to a BTR Stage 2 Truck cam in my 2011 Tahoe (5.3). The entire exhaust system on it is currently stock (has cats). Now I know I can run the cam with stock manifolds but will lose out on the full potential the cam has to offer unless I switch to headers. I have shorty headers in mind because this is a daily vehicle and not a race truck where long tubes would benefit in mid to high RPM’s. Shorty’s just seem like a better choice given it’s a daily driver and I won’t be balls to the wall redlining to benefit from long tubes. I understand when it comes to modding a vehicle there’s things you have to jeopardize to make it work. However this is my issue, If I put shorty headers on with my stock cats it will probably ruin them in no time. Which leaves me having to go high flow cats or at that point catless because if the stock cats aren’t on then it won’t pass inspection. How are you guys getting around inspections that are running headers? I know most will say just go catless but I’m trying to find a way or setup to make this thing pass inspection while still being able to run headers for the cam to benefit.

My setup on the truck is 1 7/8” Longtubes no cats 3” pipe with a x pipe under the passenger floor board going to duel flowmasters super 10s and 5” tips it sounds super clean prior to the Longtubes and x pipe it was loud even with the stock cats I was surprised it was a lil quieter after taking the cats off and adding the x pipe but the x pipe took everything out the exhaust I did not like (frapping popping)
Now it’s smooth and super clean sounding
However if I get on it I can set off car alarms at the same time but cruising is very comfortable compared to other exhausts I’ve heard in the past.
Running a cam motion stage 4 cam
Did the exhaust before the cam and head swap tbh i couldn’t tell a big difference as far as loudness

 

[FasterBass]

WH

Yes, I agree with your opinion about needing a cam designed for the flow dynamics of cathedral vs rectangular port heads, which is probably why the BTR cam was shit for me. To be clear though, the BTR cam still had better power than the stock cam but just not as strong as the Cam Motion cam I have in it now.

Here's the cam card for the Cam Motion cam that I have and like so much. They make it in a "low lift" version as well but I have BTR springs good for .560 lift, so I went with the higher lift version. The 117 LSA seems to be the key for the smooth idle with this cam. As with yours, the power increase was very noticeable over stock. And I get reminded of it every time I get behind the wheel of our 2007 after driving the 2012. Both engines are Black Bear tuned for 91 octane, but the 2007 still has its stock cam and the 2012 feels like a gorilla by comparison. Slightly more aggressive exhaust sound as well, which affirms your point about the change in sound with your cam.

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Why don't you like the choppy idle? Thought that was peak 'Murica. I got the BTR stage 2 and really like it...although I have a lowly 5.3. The added power is noticeable over 3000 but I'd love to have some more low end torque. I suppose the only way to fix that issue is boost or displacement.