LT ARH question

[Blackened 1]

When I had my true duals done a few months back the exhaust shop said the ran all 2.5” pipe. The shop that’s installing the LT headers sent me a picture showing that the exhaust shop ran 2 1/4 not the 2.5 that they said. Do you think dual 2 1/4 will be sufficient with the American racing LT headers or should I go back and demand the previous shop to redo the work with what they said they were doing?

 

[Lyle Longboat]

You should measure the piping while taking picture/vid. If you have the receipt still that shows 2.5 piping installed. Take the picture/vid and receipt and talk with the manger/owner and get them to install correct size that you paid for. I have the true dual x pipe 2.5 exhuast with long tubes and the truck is great.

 

[Blackened 1]

Thanks Lyle. I attached the picture of the measurement that clearly shows 2 1/4. The receipt shows 2.5.

 

[crazykid1994]

I would complain. If they charged you for 2.5 than it should be 2.5.

 

[crackerjack1957]

Hope that's not on the truck......they didn't cleanup burrs from cut.

 

[Wild one]

When I had my true duals done a few months back the exhaust shop said the ran all 2.5” pipe. The shop that’s installing the LT headers sent me a picture showing that the exhaust shop ran 2 1/4 not the 2.5 that they said. Do you think dual 2 1/4 will be sufficient with the American racing LT headers or should I go back and demand the previous shop to redo the work with what they said they were doing?

If they re-used the original pipes from behind the muffler to the back bumper they're 2.25". Did they charge you for a complete system from the collectors right back to the rear bumper,or just from the collectors to the mufflers.
If all you have is a bolt-on truck with a set of long tube headers and tune,you won't notice much differance by increasing the size of the pipes to 2.5",in fact you might even lose a bit of bottem end torque.Remember you only have 345 cubes feeding the exhaust,and it's only revving to maybe 6,000 depending on your tuner and where he's shutting the truck down.In most cases 2.25 pipes will match or exceed 2.5 pipes under 5,000 rpm,unless you're boosted or spraying it

 

[Blackened 1]

Ok just got back from picking up my truck. Here is the last run on the dyno. He said he still has to get it dialed in some more. It was 9pm so we called it quits. With me being very new to all this I’m not sure what to make of the results.

 

[Blackened 1]

Cracker Jack. That’s when they did the cut to show me the size.

 

[Blackened 1]

Hey Wild one. Yes they ran the 2.25 all the way. I guess I’m not to concerned with the size. I’m just hoping the tuner can dial it in better. If not I guess I’m spending more money with Hemifever or Jay Green.

 

[Wild one]

Hey Wild one. Yes they ran the 2.25 all the way. I guess I’m not to concerned with the size. I’m just hoping the tuner can dial it in better. If not I guess I’m spending more money with Hemifever or Jay Green.

Those aren't bad numbers if all you've added are headers and tune.You're right in the ballpark for Dynojet numbers.

 

[Blackened 1]

That’s pretty much it except foe the S&B CAI and BBK 85 MM TB

 

[Wild one]

That’s pretty much it except foe the S&B CAI and BBK 85 MM TB

Neither of those 2 mods are going to add anything to the dyno numbers,lol

 

[Hookedup87]

Is that after the LT install? Reason I ask is 333 to the wheels, figuring a 20% loss over the driveline, is about 400 HP at the motor. Aren’t these engines 395 HP stock? I would definitely have my tuner keep working on it because you should get more than 5 HP from LT’s and a tune I would think.

 

[Gone]

I would keep the 2.25 they make more torque down low than the 2.5 and in a heavy truck like this perfect

 

[Wild one]

Is that after the LT install? Reason I ask is 333 to the wheels, figuring a 20% loss over the driveline, is about 400 HP at the motor. Aren’t these engines 395 HP stock? I would definitely have my tuner keep working on it because you should get more than 5 HP from LT’s and a tune I would think.

He's right in the ballpark for long tubes and a tune.A dyno's only a tuning tool, they aren't really all that exact. Way to many variables to use their numbers other then for tuning

 

[Blackened 1]

Hey Hookedup87. Yeah I definitely was expecting more. I’m going to let him play around with it some more. He had it higher but the dyno was showing a knock, so he pulled out some timing.The last pull was the 12th time and the and the engine as he said was heat soaked. ‍