To those interested in how well the OBX longtubes do or do not go in, I'll let ya know....

 

Worked from 9:30 to 11:00.....got the truck jacked up, tires off, fender liners off, O2s unplugged, and both headers off. Would have had the stock cat pipe cut out but I broke my one metal sawzall blade (have about 6 wood blades on hand, go figure....). Tomorrow is a family outing, won't be back at it until later in the day, and won't take long before I'm sliding the longtubes in, hope they go smoothly.....

 

Awesome. Can't wait.

 

You guys are killing me, I'm wanting to do this header deal so bad right now but the weather, no time, no money and a million other things kinda hurts. Pics if you can so I may live vicariously through you's doing header swaps. I looked at my old manifolds yesterday, rusted to sh+t, ya, they gotta go. Hopefully this spring for my install. Good luck there 01Roush.

 

Yeah, I've kind of set a time limit up for myself to have them installed. I ordered my custom tunes from Troyer on Thursday with the Efans and Underdrive pulleys so that gives me about 2 months give or take to get everything installed in time for the tunes. I'm very close to ordering the headers now. Waiting to see how the install goes.

 

when installing the passenger side the heat sheild has to come out....took me a lil bit to figure that one out

 

You bought the wrong brand of headers.....

I just came in for a break after another 1:40, thats 3:10 total and both headers are bolted up, cats are bolted to them, and the other pipes are mocked up. Both headers simply slide right, I'm talking absolutely no issues whatsoever, I was stunned. Lots of clearance around both headers. Oil and trans dipstick tubes slide right back in. I put a few washers under the oil dipstick and tweaked it just a little bit to get the tube off the header flange. Taking a little break, gonna head back out and weld a few things together. The only problem I see is that it looks like OBX may have bent the S-shaped mid-pipe wrong, it will work as is but I'll provide more details later.

 

Ok......coulda probably finished tonight but I spent a bunch of time farting around with positioning of pipes to make sure I had what I wanted before welding. OBX definately has a pipe wrong, but after a bunch of looking and experimenting I went back to the first way I had it first and it works that way. I think someone just put it in a jig wrong, the O2 bung and a hanger tab should be rotated 180 degrees and it would be fine. Probably a physical mistake and not a design flaw. Still works as-is though, the end result is just that the crossover sits further back. I did fire it up for a few seconds and its pretty damn loud, hopefully not louder than I want...

 

Sounds like a minor problem. When you say that it's loud, is that with the rest of the piping inclding the muffler? Not that it's going to be a problem for me if it's loud, but I was just wondering. I can't remember what catback system you went with? Or was it one you already had currently installed? Regardless, what is it?

When you say the cats are bolted up what do you mean? In most cases they're welded. I saw somewhere where you had some work done to them to make them work in place of the resonators. Did you just have them welded in place of the resonators keeping the flange that came with them attached so you could use it again? And how did that Y-pipe work with the Lightning/Harley mid pipe? Line up alright?

One other thing, did you use O2 extensions? Do they need to be used for all of the O2 extensions or just the front ones?

 

I am curious about swapping the OBX resonators in place for cats as well. Such as the fitment, which cats, etc..?

OBX sounds legit so far!

 

Finished it up this morning and took it for a drive, its snowing here though so can't really tell much of anything about power. Plus pulling the neg. battery cable to weld reset my computer, and its always sluggish until the adaptive strategy has had a while to learn. I timed a couple of 0-60 and 0-100 'before' runs last week so I'll do an 'after' when the roads clear up. I'll have to wait until maybe next weekend to install my Innovate wideband and see where the tune is at, it was fat before the longtubes (11.5:1) so who the hell knows where its at now. Once I get that installed I'll datalog it and have Troyer retune, then get to a dyno for 'after' numbers, with how long it takes Troyer to tune that means I won't have the dyno numbers any time soon.

It sounds good accelerating, it just 'booms' a lot around 1500-2000 rpm. Thats a bad description I know, but its not resonance like I've had in Mustangs, just a too deep, too loud noise at those cruise rpms. I'll make changes down the road, will be fine for the near future. I just won't be hauling the family around for now....

The truck had a Flowmaster 3" 3-chamber catback when I bought it, sounded good at all times with the factory cats in place, but too loud for me under cruise conditions now. I may leave it in there to start and install a tee pipe in the long section between the 'y' and the muffler to cancel some of the sound waves. If that doesn't help enough I'll probably swap mufflers or catback.

You described it right, the cats are welded in place of the resonators so I could use the flanges and gaskets supplied with the OBX kit. I have good pictures to post later. The Y pipe worked great, the pipes came together a little closer than the spread of the Y so I just rotated it a little. Before I started I thought I'd have to fabricate a short length to go between the Y and my 3" catback but the Y extended back far enough all I had to do was cut the muffler pipe and slip it in. OBX supplies two band clamps for behind the cats, I welded those instead and used the bands where the OBX pipes go into the Y so thats my break point for the whole system and if I want to go true duals at some point I can just slip the Y off and replace it with an X.

I bought the BBK ones from Summit, I had considered extending the wires by hand for a while but damn I'm glad I went ahead and bought them, the time it would have taken to mess with the wiring isn't worth the $40 IMO.

 

I bought the Magnaflow 59956 spun metallic cats, the small shape makes the install simple and with a round body you can spin them however you want to orient the O2 sensors.


Check the pics for how I modified the resonator pipe...

http://www.corral.net/photopost/show...500&ppuser=685


No laughing at the sloppy looking welds in some spots....lol I bought stainless wire that I haven't used before and my 110 volt welder didn't seem to like it, maybe takes more current I don't know but I couldn't lay down a bead for **** with it....

The picture labeled 'header 51' shows the s pipe that OBX had wrong. The 'S' shaped pipe that crosses over has one leg longer than the other, and the short leg should have been into the cat instead of into my 'Y'. The O2 bung and hanger tab should have been on the other side of the pipe, and installation would have been rotated 180 degrees in a flat plane, which would move the crossover forward about 5" and under the trans tailshaft instead of under the driveshaft. I left about 1/2" clearance to the driveshaft and since that isn't gonna move vertically there no problem. When I look at the pictures in the following link I see the same problem.....

http://cgi.ebay.com/ebaymotors/OBX-H...ayphotohosting

...so if you buy them expect the same thing. No big deal but if you want to fix it just cut and move the tab, and weld another bung in the opposite side of the pipe and plug that one. There were two extra bungs in the resonator pipe too, so if you don't cut them up as I did you can just use those and plug this one, no reason to move it then. I didn't bother with the tab either, it should hit a stock mounting point but with the way I have things welded up that tab is completely unnecessary so I didn't bother changing anything.

 

Are those O2 extensions the ones for the Mustang? These? And you only need to purchase one kit correct? Your Y-pipe you said was from Summit? I just want to compare to make sure that the Magnaflow one I was looking at is the same size. I'm just hoping everything goes as smooth as yours sees to have gone. Seems like record time almost too. I heard the average time is 6 hours. Did you use the supplied gaskets? You also used locking header bolts correct? Any chance you have a link to them?

 

Yes the O2s are listed as for a Mustang, they fit most 4-wire sensors and for the F150 you just need to remove one small tab to plug in. You only need them for the front. The Y pipe I used is here....

http://store.summitracing.com/partde...5&autoview=sku

For time I'd say it took around 7-1/2 hours if you don't count extra monkeying around with the mid pipe and about 20 minutes trying to find a header bolt locking clip that I dropped in the front suspension.... I re-used the stock gaskets and just buzzed them clean with a random orbital sander. I was gonna buy a new set but they are around $140... Bolts are here....

http://store.summitracing.com/partde...6&autoview=sku


edit: BTW...that install time includes jacking the truck up, taking the tires off, opposite of those, and changing the oil...so just the parts install itself is really very reasonable...

 

I was looking at the Ford Racing locking header bolts but those are $15 cheaper and made of the exact same material so that helps out. The Y-pipe you used is the same one I was looking at but for some reason I thought it was stainless steel. Oh well, aluminized it is. It's goig to be the only aluminzed part of the exhaust I have but oh well. Now I just have to decide if I want to do this myself or have a speed shop do it. Any chance you're going to have some video up so I can hear what it sounds like?