[cswass]

So I see a ton of aftermarket exhausts for sale for my 97 f-250. I can get a 4" or a 5", but the downpipes are all 3". My question is can you fit anything bigger than a 3" downpipe on this year of truck?

 

[dieselcamino]

with the stock turbo 3 inch is the biggest you can start at, some make a 3 inch to an expanded 4 but i really dont see the point unless you want more head aches trying to install it

 

[bugman]

The ones that expand or bell out to 4" do so after the pinch weld so that they will go right into a 4" exhaust. Since they are 3" from the turbo down to the second section there is no more of a problem fitting them than a straight 3" one.

 

[cswass]

Is it worth doing a whole exhaust or does just adding a 3" downpipe and a cat delete kit fine?

 

[tlpowerstroke]

hi Bugman... who makes the downpipe that goes from a 3 to 4 inch you are talking about?

 

[bugman]

Give Dale at Tymar Performance a call at 509-922-8785. He doesn't have a web site but is one of the best out there and he'll take care of you. If he doesn't answer just leave a number where he can get ahold of you and he'll call you back.

 

[tlpowerstroke]

Thanks...

 

[BadDogPSD]

Anything larger than a 3" downpipe requires quite a bit of work to make it fit, and from what I've been told, 3" is large enough for 450+ HP.

 

[SMOKESKULL]

I wouldnt even bother changing it;. The stock works good enough/ its been dyno proven.

 

[Patrick Feeley]

Smokeskull, are you refering to the 99+ stock downpipes being adequate or the 94-97 stock downpipes? They are somewhat different! Cheers!

 

[Jcart]

I wouldnt even bother changing it;. The stock works good enough/ its been dyno proven.

Dude have you seen a stock OBS DP? You're thinking of the SD exhaust....

To the CSWASS yes you can put a larger than 3" DP on and some guys have done it. The challenge is getting it passed the firewall/floor pinch weld. Some guys do a body lift and a significant amount of cut weld of fore noted. Greater then 3" is really not needed unless you are running huge ponies. 3" DP and stock exhaust including stock muffler will support 400-450 HP....I say save your dough and get a 3" DP into 4" and clean out your cat and use as a resonator into stock exhaust for now. Then when you need to replace your stock exhaust go to 4" system.

jrc

 

[Mr. Neutron]

with the stock turbo 3 inch is the biggest you can start at, some make a 3 inch to an expanded 4 but i really dont see the point unless you want more head aches trying to install it

I agree 100% with this!!!

I think the world of Dale Isley, and his stuff that he sells. He's a great guy! :thumbsup: But I bought one of the first 3"-3.5"-4" downpipes he had made, and always had one heckuva time getting everything to clear. It had clearance probs between the passenger side up pipe (to the turbo), between the floor board after the pinch weld, & more other places than I care to think about. And it wasn't my "First Rodeo" on a dp install. This one called for more "creative clearancing" than I've had to use on any other dp. I even loosened up the motor & tranny mounts, and levered the whole motor/tranny/transfer case forwards as much as I could (maybe 3/8"????). It made weird in-cab "resonance" from it's rubbing, and the floorboard was always warm on the passenger's side. Nice in the winter, but no fun this time of year.... :icon_rolleyes: Maybe the newer version is slightly better. I hope so.

I just know I was glad to go back to a "conventional" 3" round (Flowmaster) dp. There's a TON of room for that one in my truck, especially after all I did to try & get the other one to clear.... It's quieter, and I don't notice any diff in performance, but have no real accurate way to tell that for certain.....

Jimmie

 

[cswass]

So I went ahead and bought the diamond eye 3" downpipe and the diamond eye 3.5" cat delete pipe. Since I am mechanically retarded I'm not sure how it all goes together. It seems there is a greater distance between the downpipe and the cat delete pipe than I have actual pipe for. Any help here would be greatly appreciated. I can't seem to find any installation directions on the net.

 

[Mr. Neutron]

Hmmm. I'm not certain about the amount of pipe between your cat delete pipe & new downpipe. You may need to find some more pipe to get it to connenct or not. I'm not familiar with the Diamond Eye stuff. Hopefully,, it'll all fit together after you get the new dp in, and the cat off.....

If you haven't gotten your cat off yet, an old member here named Kevin Ferguson posted (a very long time ago) about removing his cat with his Hi-Lift jack. The jack basically lays horizontally under the truck. He used a ton of rope hodling one end of the jack to something stable, like the front axle housing somewhere. The other end was roped around the cat, and then the portion of the jack that moves/works. You then jack the handle, & off comes the cat. He called it "Jacking off the Cat"...... It works really well. I've used my Hi-Lift jack to do that several times......

This all came about because of the the way Ford clamps, and orients (rotationally speaking) the cats on these trucks. The clamp makes a big round dvot in the cat't flange & the exhaust pipe, and there's a little "peg" on the cat to orient the cat itself. You really can't see this peg until you've removed the cat, and it prevents you from doing very much twisting of the cat when trying to remove it......

Jimmie