2.5" Straight Pipes Installed Today!! - Page 2

JetTech · 08-19-2004, 08:09 PM

Although I've been considering this mod for some time the credit goes to pciley for motivating me to do it by having his done. I didn't go with the 3" pipe like he did but it's still a heck of a step up as to what's on there. The factory pipes are necked down below 2" where they go into the resonators. Huge backup...

Slurppie · 08-19-2004, 08:12 PM

would it be possible to just cut the resonators out of the loop instead of replacing the whole section?

JetTech · 08-19-2004, 08:17 PM

we looked at doing that but the factory pipe is still barely 2" along that whole section and I really wanted to up it to 2.5". That's the size of the pipes on the Gibson Y-pipe I have installed so I just wanted it to flow smoothly from there on out.

I now have these 2.5" straight pipes from the cats to the 2.5" Gibson Y-pipe that goes to 3" at the collector, 3" pipe all the way to the muffler and 2.5" duals out of the muffler.

pciley · 08-19-2004, 11:03 PM

Looks AWESOME Jet!

I think that's smart of you to match the pipe diamaters.. wouldn't make sense to go to 3", might even have an issue at the rear fitting for the Gibson.

Also, you're right where I'm at on the mods... except I really don't want the JBAs.. I'm hoping those rumored Banks headers are not just... a rumor...

Until then, I won't even flange the cats and sub in some straight pipes there because I don't want the dealership to see the flanges and know that when I'm not in for service, that the Cats are gone.

hmm.. you'll think of something

On those unwelded fittings... your guy probably suggested those so he wouldn't screw up the clocking... My guy said if "the clocking was off, bring them back to get them rotated.." luckily they fit. I don't know if those flanged pipes will cause any issues with sealing? How flush of a fitment are they? Are the inside rings of the flanges recessed to house the pipe flange?

caltitan · 08-19-2004, 11:36 PM

Quote:

Originally Posted by JetTech

There's actually been a lot of discussion about this lately on another thread because it appears some of the trucks have what mine does (resonators), and some have cats. We never did figure out why. Those are resonators that your looking at though on my truck.

Yeah, that thread never did come up with an explanantion. LOL - So you've left our resonators club and gone over to the dark side! Look at those poor little resonators just lying there breathless like big fish hauled out of the ocean and displayed on the dock. Go bury those before they start to smell.

JetTech · 08-20-2004, 07:59 AM

Good news and bad news.....The good news is I'm off to the dyno, the bad news is it's a different dyno. The one I've been using is going to be tied up until next week and I really wanted to get this done today. More good news is the guy is very anxious to dyno my truck because he said he hasn't done one before.

Will post the results later....

GETSOMZ28 · 08-20-2004, 08:04 AM

A couple questions: What gear are you dynoing (4th is 1:1, though you will prob bang the limiter)? Can you post your AF ratio with the hp/tq curve? They can split it into two charts, or you can get the dyno files from them (bring a floppy disk) and download the runviewer from dynojet (assuming you are going to a dynojet dyno, or I can email to you). If you are going to a Mustang dyno, it will dyno lower, but is closer to the load you will see on the streets.

JetTech · 08-20-2004, 11:19 AM

I'm back from the dyno, I'll start a new thread in the general section in a minute!!

mkirt · 08-20-2004, 03:51 PM

Quote:
Originally Posted by JetTech

There's actually been a lot of discussion about this lately on another thread because it appears some of the trucks have what mine does (resonators), and some have cats. We never did figure out why. Those are resonators that your looking at though on my truck.

I started that thread about CATs vs resonators and never was able to get an answer from the service guys at the dealer. Guess we have to chalk it up to Nissan wanting to keep us in the dark and under control.