Have had my y pipe on now for about a week, 04 f350 cc sb 4x4 3.73 gears with hypertech tuner, k&n fipk and fm70 muffler. Did one on my brother in laws bone stock 01 f350 cc, lb 4x4 3.73 gears at the same time. We both notice better throttle response, less throttle needed to maintain speeds and to get the truck moving, no dyno runs though but seat of the pants feels good. Deffinetly worth the 90 bucks spent. Neither one of us have towed anything since the install. The pipe removed from the truck is a joke the way it is choked down, couldn't be good for power or mpg.

 

Guess what I'm saying is that I have a $39 Flowmaster Y-pipe. Y250300 (Was less when I bought it, I think.)




$90 plus the outlandish claims by that guy make me want to not give him any kudos.

I do I think anything is better than the factory piece.

 

That one looks real good, sure can't beat that price!

 

To touch base on the choppy data numbers on the dyno, I spent about 4 hrs at a NED in Mass and they found it to be in the loop on how the motor is reading air/fuel. They guy that did my tune was a master programmer and wrote Ford code. He fixed it and I am looking for my dyno sheets to scan. It was communication between the MAF and what the O2 sensors were reading. I had a back fire and a lean condition at the higher end of the RPM range. Choopoy like what you saw. Now, all good, the tune I have is a custom tune, wiped out a chip and reprogrammed it. I think when it was all said and done, I picked up almost 50 hp and much more torque. Let me find my sheets so ya'll don't call me a fibber...

 

Actually, 33HP at the flywheel is believable, if you're using "corrected" rear-wheel dyno results. Of course, we all know how accurate rear-wheel dynos are. Great for comparisons between mods on the SAME VEHICLE like fordmdb is doing, but overall not a completely accurate portrayal of what's happening at the flywheel. (Rear-wheel-dynos show more HP when you remove rotating weight like lighten the driveshaft or rear wheels/tires or remove the mechanical fan and replace it with an electrical fan. In reality, you haven't done anything to the actual amount of torque at the flywheel available at any one RPM. HP=Torque*RPM/5252. HP at the flywheel has nothing to do with engine acceleration).

I suspect what the restricted Y-pipe does is limit the acceleration of the crankshaft. Which is not really "flywheel HP".

 

They don't claim flywheel HP & TRQ gains. SPDs site says

Doubt they pulled the engine to test it.

I'm not even seeing a 33HP with a custom tune.

While its a great mod, I think the performance gain claims are crap, that's all.

 

Of course they are. And I can safely bet that they are "adjusted flywheel" numbers. Did you get your tuned X dynoed?

 

It's the same with every CAI, catback exhaust and TB spacer "power gain" claim.
JL

 

^^^^ The Y-pipe from flowmaster may cost around $40 but to have an exhaust shop bend up the pipes and install everything its going to cost a bit more than $100 at most places. Then in most cases you end up with collapsed bends like in the picture that hurts flow. The stock Y pipe is mandrel bent and just replacing the restricted section works well and is easily doable with no bending.

I can believe the 33hp 35tq claims for the 01-04 pipe isn't impossible especially if they calculate flywheel numbers. Remember where the claims come from however. They advertise the best gain at any one point on the entire hp and torque curve not at the peaks. For example the 30 hp gain could be at 1200rpm and the 35tq gain could be at 5000rpm. Not at the peak of either curve but at one given point. Thats how Banks gets there claimed numbers. Its marketing.

 

Yes, that's absolutely right... I was amazed that Superchips, for my 4.6L '96 t-bird, only advertised like a 12ft/lbs PEAK increase in torque.

The fun was the 32ft/lbs increase at lower and higher RPMs that was obvious on their dyno chart. Calculated "flywheel" numbers, but the increase was very noticeable at other parts of the curve.

Maybe their marketing people didn't know what they were doing

Anyway, back the dyno thread - this stuff is way

 

When I bought my ebay pipe, the 99/00 did not have the same claims as the 01-04 pipe, & thats what this dyno run was all about, the 99/00 yrs without the choked down pipe that was supposed to remove flutter. I just checked the ebay site & did not even see the 99 pipe any more. Any how, I was impressed with these results, tuned & not tuned , it confirmed what I had felt in the drivers seat. It's all good !

 

oops, I now see the claim for 99-00 pipe...sorry Monsta !!

http://www.spdperformance.com/

 

Hey Mike. I forgot to ask you when I called earlier... I was thinking about getting a new valve body. How well would a good tune be compared to a valve body or would both be a great thing to do?

 

Do the tune first , if you feel you need the valve body then do it.
I did a valve body on our 7.3 and was not completely happy with it

Mike

 

Forget the valve body unless your willing to get the truck on a dyno for custom tuning or have the software and knowhow to tweak it yourself. Been there with the VB and its a PITA to get it dialed in right or at least to my liking. Thats why I pulled it off. Anyone who is interested in a FT VB PM me. You can however leave the trans stock and still run the accumulator upgrade but the converter still locks slow then. You would have to get a lockup valve kit to get the TQ to lock quicker.