Well maybe cuz it was a Cattman 3" y-pipe...
But that shouldnt really matter much because it still had a cat and 2.5" piping + a non-straight-thru Remus muffler...
Anyway...
I sold my Cattman 3" y-pipe last week and put the stock one back on.
Now, my car feels about the same...
BUT last week (same temperature) I was running 6.5-6.6 0-60mph on the GTech...
Today I ran 6.2-6.3 0-60mph every time...
I expected my car to be slower and it's actually faster...

Before everyone comments on the accuracy of the Gtech let me say this.
(1) it may not be completely accurate, but it IS very consistent (which is what really matters when comparing before/after mods)
(2) i ran on the same stretch of flat highway in similar temperature, +/- 5 degrees.
(3) the ONLY thing i changed was the y-pipe, everything else is the same.
(4) i am comparing the averages of 6 runs on each occasion...

Now I know the y-pipe has been proven with dyno/quarter mile times, but does anyone have an explanation of this on my car?

PS: I had a check engine light with the Cattman, and i still have it with the stock y-pipe, even had the code cleared after installing the stock y-pipe and the C.E. light came right back on... The code is 3 bad O2 sensors...which should have nothing to do with full throttle acceleration anyway...

Thoughts/Comments?

 

My exhaust mechanic told me that 3" piping is way too big for a N/A car with an engine the size of the Maxima's. He said my 2.5" Y and piping he thought was still a little big but better.

I think you suffered low end loss with your Y-pipe becuase of it's diameter...but still it shouldn't be THAT bad...

Damn...I REALLY don't know what to tell you...I mean I could feel my pipe pulling me hard...you didnt' feel any of that ?

 

you auto or stick? i think an auto would maybe see some 0-60 gains from a stock y pipe cuz ur not into the high end as much, and y takes a lil away from the low end especially a 3 inch. i duno dude, whats ur transmission

 

No autotrajic for me.
I am a man.

 

I could understand that if i had all 3"...
But the only part that's 3" is the y-pipe collector!
everything else is 2.5"...
and i even have a Remus muffler (not strait-thru)...
so i dont see how i could have had too little back pressure...

 

3" was probably too big. But was each "downpipe" larger dia. also? If the pipes were too large, it would possibly cause a loss of exhaust velocity that wouldn't start resonating until high in the rpm range.

 

the downpipes are the same diameter as all cattman y-pipes...
the *ONLY* difference is in the collector...

 

That might do it too. But that piece is pretty short though.

 

My max keeps getting slower and slower as I put more and more mods on it. If it was not for the improvements made on the dyno I would yank all my mods off. I think my biggest problem now is the full second peel out on my 1-2 shift, when I was stock it was about half as long.

 

Wait...so actually you are getting MORE power to the wheels, since you are spinning twice as long right? This is a good thing..you need some heavier wheels to deal with that extra power..wanna trade??

 

my only comment is..

wow.. after months and months of searching.. you finally got a stock y pipe

 

The spinning is what kills me, when I go from first to second I get a violent tire spin session. BTW I don't really want to trade my rims I just went out the door and did 6.13 0-60, when I was stock I did 5.96. My 1/4 mile times are a little better though and the trap speeds are up 2-3 MPH.

I think my new tires need to break in a bit more too.

 

DAMN!
I can't even chirp 1st!

 

sure

 

Ethan Hmm...you have intake and that's it performance wise, right? Possibly it's human error, but how come your slower than your stock times? Shouldn't sticky tires help your 0-60 with more grip

BTW, I thought your best time was a 5.7 ?

 

Stock was 5.96
With a intake I did 5.76
Check out my sig I have a RT cat and Greddy exhaust. Low profile high performance tires are not the best for launching a car hard. Low profile tires are good at taking corners but bad in aceleration. The stiff side walls do not alow the tires to flex during a hard launch, instead they tend to just spin. Cold NE weather makes summer tires not able to grip well too.

 

Makes sense...so my less expensive H-rated will be better for launchin....save money and be faster...sweetness.

 

Your tires might grip better in the cold but summer tires offer the most grip in the summer .

 

Bro here in Florida it is ALWAYS summer .. it's friggen 80 degrees and humid as a **** right now..i'm already gettin my tan on..

My tires are soo soft they practically melt into the road

Hell...I could probubly even beat JOO off the line if you came down here to race me.

 

Don't push your luck .