7 replies to this topic

[Barko1]

I'm contemplating adding a 4" turbo back exhaust on my 99 7.3 diesel. I have a mild DP Tune and the Ford AIS air intake opened up for additional airflow. The MBRP seems to be pretty well thought of. They have aluminumized steel and stainless versions, the aluminum versions hundreds less which is the direction I was thinking as exhausts seems to last forever here in the desert. Hoping for a little more performance and to keep the EGTs low although I'm doing fine on both accounts right now but more is better, well not egt. Any recommendations or experiences?

[Desert Rancher]

I went with a turbo-back 3" down-pipe into a 4" exhaust from Diamond Eye. It is the aluminumized version purchased here: http://www.dieselpowerproducts.com.

Shipping was free which is important as you will get a very big box. Living in the arid southwest, I see no advantage to stainless. That's for folks that live in the rust belt.

I did the install myself without any problems.
The only thing I would suggest is getting the better muffler. Mine is a straight thru type. At highway speed you get a low drone which makes the cab loud. I will probably change this out. Also, It's nice to hear that turbo whistle as it spools up.

Also have the Donaldson air filter and a chip.

Mine is a '97 OBS, so I don't know what the new body style requires.

It's definitely worth it.

[1tonpaulie]

Hey Barko
I changed out my down tube from the turbo to the cat. The stock tube looked like it was ran over before ford put it on. Lots of restriction. The new down tube is 3" and I got rid of the cat and added a pipe in its place. After our first trip to the U P Michigan my mpg went up by 5 mpg. Not bad for $200.00 investment. Last fall I went to Ely Minn and through the U P with Grandby on top, towing a trailer with 2 atv's and got 18 mpg. Hope this helps.

[Barko1]

Thanks for the info, is the Diamond Eye an decent quality?

If you are using the Ford/Donaldson AIS here is an option that provides less restriction without changing the degree of filtration.

http://www.ford-truc...werstrokes.html

[ntsqd]

With a cat there is a significant amount of water generated. Stainless after the cat would be a good call if the majority of use is short runs. On long runs the water goes out hot enough to not condensate in the tube.

[Barko1]

Good point but my short runs are like 500 miles A lot of the systems delete the cat.

[Desert Rancher]

I researched the diesel forums and found no complaints with the Diamond Eye. I did the install myself and it was easy, fit very well. Used a sawzall to get the original downpipe out. It is very restrictive.

Mine is only started for long trips. Yes, the cat delete is an option and those cats are heavy...
Be sure to look for free shipping if you get one!

I run a Tymar open element filter on mine. Unfortunately, the AIS is not offered for the OBS (old body style) model.
It is surprising how air the turbo moves even at an idle. It's like putting your hand on a shop vac.

[Barko1]

I researched the diesel forums and found no complaints with the Diamond Eye. I did the install myself and it was easy, fit very well. Used a sawzall to get the original downpipe out. It is very restrictive.

Mine is only started for long trips. Yes, the cat delete is an option and those cats are heavy...
Be sure to look for free shipping if you get one!

I run a Tymar open element filter on mine. Unfortunately, the AIS is not offered for the OBS (old body style) model.
It is surprising how air the turbo moves even at an idle. It's like putting your hand on a shop vac.

Thanks for the info. I was kind of looking for an OBS when I found my 99. Never had a diesel, didn't like them, but now am a big fan. I'll do that airbox mod and then one of these days I'll pop for the exhaust. I added gauges and am glad to have done that. Should be done playing with it then, will just try to keep it reliable. Going in for the cruise control and CPS recall tomorrow, a couple years overdue.