What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[randeez]

Yup forgot about that thanks, they spelled my name wrong anyway.

**** heaver, got it

 

[89Suburban]

**** heaver, got it

Randy Heaver by injection

 

[Doubeleive]

well looks like i'm going back to a single tip, tried adjusting this dual and no luck whistles more actually
they had to order one which should be here in the morning, weird I had a chrome dual tip and it never whistled but the metal monsters already grabbed it yesterday

 

[Charlie207]

Reinstalled both front axles that I had been too lazy to stick in when I swapped front diffs. It's getting close to slippery road season, but managed to be 72° and sunny today.

 

[kbuskill]

How is that even possible if adding LT headers - effectively letting the engine breath a ton better right off the cylinder heads - instantly increases HP/TQ across the entire RPM range?

I don't want to start another "backpressure is needed" debate, because it's not a debate, and has been debunked many times.

I guess I missed the LT header part of the discussion. I can tell you with stock manifolds, or shorty headers like I have, getting rid of the cats makes for a noticeable loss of bottom end power. It has less to do with back pressure and more to do with losing heat which slows the exhaust gases down and therefore it doesn't scavenge as well. Reducing the diameter of the Y-pipe doesn't allow the exhaust gases to expand so rapidly, which means the gases can't cool as fast, so it keeps the velocity of the gases higher creating more scavenging. At least that is what my research after the fact shows. All I know is having a smaller diameter Y-pipe made restored the bottom end power. Now the argument could be made, I guess, that I somehow have restricted the flow for optimal top end performance. To that I say, I don't really care as this is a 6k lb brick and I spend more time below 4k rpm then I do winding it out to 6k rpm.

To each their own, I was just relaying real world experience to try and save someone else the aggravation.

 

[j91z28d1]

ugh. noticed my right front tire is showing some Feathering on the outside is less than 10k miles. I knew they didn't actually do the alignment I paid for, but since it went straight I got side tracked and forgot about it. blah guess I Gotta handle that and rotate them to the back or something.


annoying, I literally hate shops. even good ones are awful. maybe I'll just get out the string and do it myself

 

[j91z28d1]

I guess I missed the LT header part of the discussion. I can tell you with stock manifolds, or shorty headers like I have, getting rid of the cats makes for a noticeable loss of bottom end power. It has less to do with back pressure and more to do with losing heat which slows the exhaust gases down and therefore it doesn't scavenge as well. Reducing the diameter of the Y-pipe doesn't allow the exhaust gases to expand so rapidly, which means the gases can't cool as fast, so it keeps the velocity of the gases higher creating more scavenging. At least that is what my research after the fact shows. All I know is having a smaller diameter Y-pipe made restored the bottom end power. Now the argument could be made, I guess, that I somehow have restricted the flow for optimal top end performance. To that I say, I don't really care as this is a 6k lb brick and I spend more time below 4k rpm then I do winding it out to 6k rpm.

To each their own, I was just relaying real world experience to try and save someone else the aggravation.

alot of times louder feels slower too. especially at part throttle as they drone alone.

atleast to my old or ears haha. I tend to like really quiet daily

 

[89Suburban]

ugh. noticed my right front tire is showing some Feathering on the outside is less than 10k miles. I knew they didn't actually do the alignment I paid for, but since it went straight I got side tracked and forgot about it. blah guess I Gotta handle that and rotate them to the back or something.


annoying, I literally hate shops. even good ones are awful. maybe I'll just get out the string and do it myself

Make some toe plates like I did.