SPANKY LS1

iTrader: (24)

My new heads and cam are coming, and the cam supplier says that true duals will give me more TQ than a 3" single exhaust system, but I kinda like my car quiet when I'm cruising around. My question is this, if I put dual cutouts in my y-pipe directly after my headers, would that produce the same amt of TQ as a dual exhaust system? That way, when cruising around, I could cap them, and run it through the full exhaust, the best of both worlds. Any thoughts? Thanks, Shawn

PS Current exhaust consists of Hooker LTs, Hooker ORP, Hooker catback.

MyLS1Hauls

iTrader: (2)

No, it wont be the same. An X pipe offers much better scavanging than a Y pipe does. If you have dual cutouts open, then there wont be any scavenging at all. I've still got a Y pipe with plenty of torque. I've just got a single cutout in the I pipe.

hugger427

iTrader: (9)

I'm doing a custom dual 3" pipe (side by side)to about 12" prior to the axle with twin cutouts/QTP's with the duals merging into a single 3" (post cutouts)to my Hooker Cat. I will also have a "H" pipe about 12" prior to the cutouts.

This design should give me a great sound around town (not too loud) but if the cops take notice...just hit the switch and both QTP's will shut concurrently.

This going in next monday...I will see what the #'s looks like RWHP/TQ ASAP.

Jorday

Yah, the crossover pipe helps produce more torque.

Jordan

LIL SS

iTrader: (9)

So are you saying you will have more HP with an X-pipe than open dual cut outs do to scavanging?

Are you also saying you'll still produce more torque through a y-pipe than open dual cut out right be hind the header?

You will pick up torque across the board with open dual cut outs over a y-pipe. I have proven it..

Blue is through the exhaust, pink is open dual cut outs right behind the headers.

web page

MyLS1Hauls

iTrader: (2)

But how much more power did you make by having dual cutouts vs. just one in the intermediate pipe? Probably none with a stock motor. Dual cutouts in a Y pipe are not at all like an X pipe.

Nine Ball

iTrader: (38)

Don't do dual cutouts for a 346ci setup. On my old heads/cam setup I tried that (dual 2.5" cutouts where cats normally would be on an offroad Y-pipe) and I lost a TON of torque. Only gained about 2 rwhp peak vs a single 3" midpipe cutout. Ran slower at the track too

Needless to say, that setup was ditched after a week. Went back to the single setup and got my ET/MPH back.

One of the biggest LS1 mistakes I've made to date

Tony

LIL SS

iTrader: (9)

Never said dual cut outs were like an X-pipe.

Tony, I'm willing to bet I would lose power using a single 3" cut out in the Y-pipe vrs the dual cut out set up I have.. If you look at the dyno, I picked up 12lbs of tq @ peak and 7hp at peak with out any other changes. Not to mention the tq increase starting @ 2500 RPM and the HP increase starting at 3200 RPM all the way up. When I have more time (After the Cam and bottle install) I'll put a single 3inch cut out in the Y-pipe and remove the cats and see what happens. Whats another $50 in the search of HP? What do you say a 6 pack of Bass?