suttonbeeman

Since we installed a #10 plate power is unreal. If you are pulling a load egt gets high VERY easily. You will need a pyro gauge. However Mpg has also gone south. Loaded about the same or slightly lower (1/2mpg lower) but empty has dropped from15-16mpg to 11 mpg. We have 4:10 gears and they may effect it as the guy who put mine in has 3:73 or 3:53 and it his stayed about the same (20mpg) we also added the scotty air and you will need a bigger air system. We topped Jellico mt on I75 (7 miles long fairly steep) with a gross wt of 28,620 lbs. at 55 mph in 5 th gear with lots of throttle left....just had to back off because of engine temp and egt. If I could just get mpg back up close......I may go back to stock plate if I dont get it back up some!! Rick

DustyRock

Suttonbeeman: I really want to install the #10 plate its sitting right here next to me. I think I will wait for tranny mods before I give her more than she wants. That’s too bad about your mileage on the bright side maybe your getting to your destination twice as fast at the expense of your mileage.

2500CTD: That was $12 well spent! I bet it didn’t take you long to say yes to that deal. Have you heard Forrest’s truck? Be careful or you will be switchin exhaust systems as often as Forrest. Stacks, straight 4, straight 5, 4 with muff etc. etc.

Forrest: Can you get a sound clip of your truck? That would be cool. You did have a good pic of smoke would be nice to have some sound with it. Some things just go better together.

Forrest Nearing

yeah, I've changed exhaust configs about 15 times in a year's time! LOL!!

currently 5" straight pipe and lovin' every minute of it! it sounds awesome!

Forrest

DustyRock

Some sellers of 4 inch systems are claiming 15-25 HP gains, up to 60 lbs. of torque and up to 150° F lower EGTs. Have you guys experienced this for yourselves? I am guessing that these numbers would vary between trucks because of plugged cats etc. But what could you realistically expect from a normal operating truck with a stock exhaust?

Dr. Evil

I was thinkin about a 5" straight....but Rip was telling me he tested just about everything on his 24 V and the 4" was the way to go.....said the 5" made 10 more HP but resonated in the cab like crazy....

Forrest Nearing

I've done a lot of work to get rid of the resonance!

when I first installed it, the in-cab resonance was INSANE

but I licked it!

Forrest

Dr. Evil

Thats right...I forgot about that radioactive lead.....

Forrest Nearing

lead isn't radioactive... it protects me from x-rays and nuclear blasts!

Dr. Evil

Both of which you're bound to run into when in the DFW area....Ive heard lead causes sterility as well.....

Forrest Nearing

only if you eat it

Fueling around

I tried a few different exhaust combos.

• Full straight pipe on factory exhaust: I hated it. Too much noise and resonance. Neighbor's didn't appreciate it either.
• Straight pipe with 4" tailpipe. A little better than before, Lowered the tone, but still snarls.
• Added 4" resonator. Mellowed the tone, but drone increased.
• Turbo to tail 4" with Allied muffler. A lot better, but still a drone around 2,100 rpm.
• 5" Magnaflow SS tip. Looks really nice. Got the soot off the panel by extending the pipe.
• I still have the resonator plus purchased another Allied muffler. Will add one of them as far forward as possible to try cut that drone.

DustyRock

Fueling:
Thats some excellent info. I remember reading in a post about the stock 3 inch that was straight piped being "raspy" sounding. I dont want a drone or any resonance. I am leaning towards a 4 inch system that includes a muff but really want to try straight piping it just to try it, see how bad it is. I really would like to find out if the HP, EGT #s with a 4 inch system are close to being accurate as stated by the sellers.

Fueling around

Raspy is a good term. A 4" system with a straight thru muffler is still plenty loud. Never tried it without a muffler.

I will add this, a straight piped Cummins sounds better than straight piped Ford PS or GM Duramax.

-John