Replaced the 18.5 exhaust housing with a 16 cm. Didn't help much

[GTX_Joel]

Hi Guys.

I put a 16 cm on in place of the 18. 5. took about 2 hours and cost 130 bucks.

Maybe I was expecting too much? Turning up the fuel last week really kicked up the power, I kind of expected a similar gain.

But I didn't notice too much. Maybe a little quicker spool up. Max boost dropped off from 24 to 22. I still haven't messed with the high idle, defueling happens before the shift. Maybe that will be the ticket to wake up the 16 cm housing.

 

[formula]

Humm... ..... max boost dropped when you installed the smaller housing, eh. That definitely smells fishy. How are the EGT's and boost while cruising? Perhaps you have an air leak somewhere. The v-band flange connection on the outlet elbow is a place to start.



Sean

 

[BushWakr - RIP]

Sean is right, you should pick up roughly an extra 2-3psi boost assuming no other changes. .

Make sure the square cut o-ring on the outlet elbow is in place and in good shape too...



Bob

 

[GTX_Joel]

O ring? What O ring?



Ok, kidding sort of. Thats what that black stuff was. It looked more like valve packing, so if it used to be an O ring I better get a new one.



Any one have torque specs on the clamps?

Thanks, Joel

 

[GTX_Joel]

Typical call to dealer. They don't like fooling with old stuff. He can't find it in his computer. Anyone have a part# handy for the o ring? Thanks.

 

[jbolt]

O-ring part number

This came up not too long ago. Look here



Jay

 

[Scot]

I put the 16 on before I turned up the fuel. Other than spooling up faster, I could not tell much. If you want to really wake it up, get POD's.

 

[powerwagon440]

i put a 16cm housing on my 93 and i thought it really woke her up! sure would like to get some pods or some other injector that would really wake her up!! oh but what a min. i have a slush box throw that idea out the window!

 

[CDegner]

0-ring

If yours is like mine was, it is a rectangular o-ring. Don't go to the dealer ... it is a discontinued item. Cummins can get it. If it is the rectangular one, it runs about $17. If yours uses the round one, it is less than $5.



Take the part number in off your elbow coming off the turbo. Cummins can look it up and tell you which is the right one.



I picked up about 4 psi when I went from the 21. 5 to the 16. That was even with some horrendously fouled injectors. The change to PW injectors gained me about 7psi and I still have some tweaks to make.



Carl

 

[bflood]

Just my 2 cents for encouragement Joel but I did the same thing (18. 5 to 16) and experienced big improvements (more boost and quicker spoolup). Where it is most noticeable to me is when towing heavy loads.

Good Luck!

Bruce

 

[GTX_Joel]

Thanks for all the replys!

Well, I checked that online place from the other thread and with shipping and order proscessing fee, that little O ring would be close to 30 bucks!



Then I got a brilliant idea. I called the local place where I got the turbo housing, is Diesel Components Inc. He said they have a Garret part they use for that. Its a silicone O-ring for about $2. 50. I think I'll head over there in a day or two, wrench in hand. Then I can test fit it on site. So I don't take a chance on wasting two and a half bucks.

 

[Philip]

If that Garret o-ring works be sure to post the part number here.

 

[CDegner]

Kind of a "pay it forward" type of thing!

I have the o-ring I can send you if you want it. I could send it out USPS priority and depending on where you are, you would have it before weeks end.



Just to clarify, this is the ROUND o-ring, Cummins Part # 3883284, not the rectangular one that I installed (Cummins part # 3919852).



Let me know.

Carl

 

[BushWakr - RIP]

Round or square cut will work fine... . make sure your inlet/outlet are lined up nice and square, and tighten the V-Band clamp right up, you're good to go...



5 bonus RWHP for the "pay-it-forward" offer too... . way to go guys... .



Pastor Bob. .

 

[CDegner]

5 Bonus RWHP needed!!

Hey Preach,

Thanks for the 5 RWHP bonus! With my setup, I need it to even stay in the same ballpark as you POD guys. Actually, I really like what I got now. Just took a family camping trip with a big load in the bed and got 20+mpg. Considering I was getting 15, it is easy to jsutify to the wife the money I have "invested" in my truck!



Carl

 

[GTX_Joel]

CDegner,



thanks for the offer on the O-ring, but I will decline unless the local one dosen't work out. I plan to be in his area for something else anyway plus I already told him to set it on the counter for me.

But I'm not sure it's leaking, I don't hear any air leak sounds. But its hard to hear over the clanking and rattling roar of a wide open Cummins