We all know that a slammed Y pipe (where the individual pipes are welded into each other) makes much more rasp than a merged Y (where the individual pipes go in whole to a collector). Is there any data that indicates a power difference between the two?

 

A friend of mine has QTP lts and a QTP y pipe (which has a collector) and it's raspy.

 

PM Patrick G.

 

yeah go with a y-collector it allows gasses to flow more evenly isntead of just slamming into each other which leads to more rasp and robs you of a few ponies

 

pat g says go 4in y into 4in collector and I pipe.

 

And I have a tsp "slam" y-pipe with zero rasp. Must be another one of those internet myths.

 

rasp also depends on your catback and header combo etc.

 

What the heck is a "slammed" y-pipe?

 

yup, and I chose wisely

 

the cats cut it out.. you'd have rasp if you removed them

 

I have the TSP catted y, he has off-road. And that is why I have cats.

 

I'm actually using a TSP y too and it's also alot less raspy then my old Mac set up.

 

Proof?

Ive heard true duals with rasp, Ive heard the "badass" QTP Y with rasp, etc..

 

The 4" Y is compete overkill and you will only need a 4" catback if you are over 550 rwhp.

What good is a 4" Y if the colector is only 3". You can only flow as much air as your smallest pipe. Id like to see the clearence of a 4" Y too

 

I think the y merge in question is a dual 3" inlet and single 4" outlet.

 

Rasp is also a matter of opnion

 

not only that, i have not heard a ls1 that doesnt rasp .... alot of people dont know what rasp is, maybe i dont know what rasp is but i know that all ls1's make a sound around 3000 rpm's when under a load that i dont like

The way to mask the sound is to dump the exhaust because when pointed at the ground it kinda gets cancelled out.

 

I had rasp once, doctor said to use gold bond ;0P oh wait....wrong forum

 

Well, my question really wasn't about rasp ... (I guess I took it for granted that a slammed Y was more raspy) - it was about any power difference between a true merged Y (Flowmaster merge) vs. one where the the pipes are simply welded together - due to better flow, less turbulence, etc.

 

4" at the y is what he meant. which mine tucks up well above my subframes. and it can be benificial to help scavenge the gases if built properly. but u will loose most of the benifit if there isnt a cutout directly behind it and u push it back into a 3" muffler.