Anyways i called up a muffler shop (boise muffler), to see how much it would cost them to do a new y-pipe on my truck. Price $240.00. They seem like decent guys, and while we were discussing Ford's crappy y-pipe he tells me that fords main reason for necking it down to about 1" 7/8's is that the 4r100 auto. tranny couldnt handle the extra power if the y-pipe wasnt necked down.
This doesnt make sense to me! why would ford make a big engine, and then neck it down? I've heard the reason is exhaust flutter, and i dont buy it. Looks like i'm going to buy the e-bay y-pipe and weld it myself, and see what happens.
What do you all think? Ive heard nothing but good stuff about the ebay y-pipe, and doesn't seem as if anyone is blowing their trannys due this upgrade.

 

Boy that's a new one. I think the 7.3 PSD can put more power to the tranny.

 

i agree

 

I don't agree.

The 7.3L didn't put much more tq. down than the V10 did.

BTW: the necked down pipe was a faulty fix for the "exhaust flutter" that was present in the V10.

 

The 4R100 is rated to handle about 525lb ft of input torque which is why the 7.3L never went above that from the factory and why hot-rodded diesels really strain it. Of course, they can be made very strong via the aftermarket.

Once you put a Y-pipe on and hear the "flutter" you'll understand why they did it. Well..."understand" is not the correct word as I have a Y-pipe and I don't understand why they put on a T-pipe.

 

spdperformance.com got the Ypipe in a week and just put it on with a flowmaster FM70. All I hear is the motor breathing better so I am still not sure what the whole "flutter" thing is all about. Definately a good mod IMHO.

 

The reason for the necked-down y-pipe was a simple one.

From late 1997 in the E-series, through 1999, the V10 was a nice-sounding non-PI headed engine with no complaints.

In 2000, Ford came out with the PI-headed (Performance Improved) V10 which added a bit of power, HOWEVER, customers started to complain about something called "exhaust flutter". It's a resonance in the exhaust that worried a lot of people, thinking their engine had a problem.

So, Ford came out with the necked-down Y-pipe for the 2001 model-year, and for customers that complained about the flutter on their 2000 models, they retro-fitted the necked-down Y-pipe, and possibly reflashed the PCM with a different tune to eliminate the flutter.

It didn't completely solve it for all people, but I think Ford gave up trying to fix it because, to me, it sounds just like a decent exhaust system would. It resonates at certain RPMs, and there's not much you can do about it.

Many people report that when they remove the necked-down portion of the stock Y-pipe, the flutter gets worse, or suddenly appears.

Me, I had headers on the truck before I did the y-pipe, and I notice no flutter, at least none as bad as my '74 highboy did with it's hi-po 390 and long-tube headers. That thing had a bad resonance that almost sounded like a bad engine knock - but wasn't.

Anyway, the idea that the tranny is going to blow-up because of the y-pipe is BULL****. Plain and simple bull pucks.

 

The Y-pipe mod flutter I had was on HARD acceleration at about 1800-2100 rpm's.

I had NO flutter stock, flutter at above mention situation with the Stan's y-pipe mod, and NO flutter after Thorley header install.

As far as inside cab noise, mine sounds like a transit bus powered by CNG. I don't mind it at all, much better than the flutter noise.

 

My 04' had no flutter in stock form. My attempt at replacing the restricted portion of the y-pipe with a magnaflow universal y-pipe was a failure. It worked fine and increased power but the flutter was so bad it drove me nuts so I ordered the Thorleys the same day. No flutter at all with the Thorleys, more power and the trans is still together. The ebay y produces some flutter. I still think the stock manifolds have something to do with the flutter. Once you remove the stock manifolds and hold one in your hand and look it over you will see just how poor they really are.

If you can swing the $600 price and install them yourself I'd get a set of thorley headers. They replace the manifolds and the entire y-pipe also.

 

well i ordered the spd y-pipe in hopes that i will get rid of my flutter, its really annoying at 2000rpm. That is the main reason i am changing it out, improved gas mileage would be nice too. i dont think that 30-40 more hp is realistic though. hopefully it all works great, and if not it was only 80 bucks. i will have to let you all know how the change over goes.

 

Check out 5startuning.com. Mike has a V10 and added the pipe and did dynos. Definately not 30 - 40 hp but what I noticed is better tip in on the throttle, but I am also tuned. Check out Mike for a tuner if you don't have one. That is the one best for the money mod ever. I have tried mine at all rpms and can not find the flutter. Maybe just lucky.

Antelope - what muffler are you running? I have no drone from my Y/fm70 combo at all and only slightly elevated breathing sound up front but I also added a CAI.

And yes, headers will come one day but hard to justify with the bolts and manifolds still in good shape.

 

I'm running a complete Magnaflow Cat-Back.

 

I have the factory muffler, nothing too crazy, my manifolds are in good shape, along with the studs. I dont have an air intake setup, or custom tune either, but wouldnt rule it out in the near future.