I am looking into inreaseing the puenny *** stock greddy downpipe but someone told me that was a bad idea and that I would probably cause problems with either spiking or lag. Is this true? It is only a sohc kit and I think the stock diameter is 2 inch. Any info would be great.

 

The only time I've heard of problems with boost creep with a larger dp is the drag3 kit because of their manifold design. It would definately help upgrading your downpipe. Faster spool up, more power.

 

I went from the stock GReddy toothpick. . . I mean downpipe, to a 2.5 inch downpipe and 2.5 inch test pipe. I noticed a difference in spool, but I did get spiking occasionally (even with my profec ). I, for some odd reason, couldnt see below 9 psi. I dunno if this helps any.

 

spiking might be a concern since you already have 3"exh
if quicker spool is what you want you can turn the wastegate actuator arm a couple
of turns clockwise and you will see a signifigant gain
capping off the turbo vacuum line to the wastegate,and running a vacuum line from the intake manifold to the wastegate instead will also increase spool and help
control boost "honda-tech" tip
if you are still considering a downpipe after these mods you can buy one from
http://testpipes.com/htmlsite/testpipe.asp?item=Honda
omar

 

I noticed some nice boost reponse when I went from stock DP and stock exahust to a 2.5" DP right to a 3" catback, and yes there is definatley some spiking, for me it was anything over 9-10psi and spiking got pretty crazy, even with the AVC-R.