Straight Pipe Question

[GTop]

I'm thinking about putting a straight pipe on 2001 ETH. I plan to keep the resonater. My engine is stock for now. Future plans include injectors and one of the fueling/timing boxes.

Should I go with a 3" pipe or 4" pipe from the resonator back?With the 4" pipe is there any power advantages with a bombed engine. Will 4" pipe mean lower EGT's?

 

[Fireman Dave]

I went with straight 4" from the resonator back. I don't know if it's any better than 3", but I would think so. It sure sounds nice. And the resonator looks enough like a muffler to possibly get by on a roadside inspection.

 

[LSMITH]

I don't think the 4" from the resonator back will help performance at all over a straight 3". It looks to me like the bottleneck of the whole system is the downpipe once the muffler is out of the way. Leave the resonator unless you want to put a full flow muffler on. On the bright side, when you want a full 4" system you are over halfway there! Dave's truck does have a nicer sound with the 4" from the resonator back than a 3" pipe too. It still barks, but is a lower tone, sounds nice.

 

[UKRugbyman77]

Warranty?

Adding a 4" from resonator on back... will that mess up the warranty? Plus, can I just go down to the local muffler shop and get them to make this (the 4" back), or is there a kit I would need to order? I'm sure this is custom, right?

Thanks for any help!

 

[Hammer]

Read Joe D's article

Read Joes article on AIR+Fuel=POWER in TDR#23(I think thats the issue) for your exhaust questions,,There is only a minor hp gain exhaust(7 to be exact) and your money can be better spent in the hp quest,,Larger will help in lowering egt's by allowing the gasses to escape faster,,Jstyer was at Wiredogs BBQ with his muffler removed and resonator still on and it was an ok sound,,Personally mine is just right(no cat or muffler) louder is better,,Changing the exhaust will not void any warranty,,If you want to drive one to hear the sound let me know,I'd be glad to run out your way so you could drive mine(even though mine is properly valved)so you can decide if no muffler is too loud for you or not,,You should have my home number,cvall me if you want to get together Greg I'd be glad to help... ... Andy

P. S. -I'll drop the numbers to you via pm in case you do not have them

 

[Kimrey]

I have 4" from the res. back. I love the sound. As my buddies say "it sounds like a Frieghtliner". Thats a complament to me! It didn't void my warranty. Add a K&N air filter, or a better air flow filter and it will sound even better! My 2 cents.

 

[GTop]

Well folks i did it. I'm 3" straight piped from the resonator back. Sounds good!The only problem I have now is keeping it warm in the cab while riding around with the windows down

 

[Fireman Dave]

Cool, Twin. I know the feeling (and so does my wife).

 

[Kimrey]

wait until summer, you wont use the air conditioner Try putting it under a load, the sound really bellows then! Hey fireman dave. Its good to have another firefighter on board. I'm a firefighter here in Charlotte N. C. Kick a** fighting the old Dragon

 

[Fireman Dave]

Cool! Yeah, there are quite a few Firefighters in the TDR. The Cummins must be another common testosterone outlet for us hose jockies.