Taking the venerable v6 cat to the ler shop December 07, 2005, 07:02:21 PM :flip: Finally on Friday I will take the cougar to the ler shop to put the dual system, I decided that the ler guy built everything and will not use any h pipe so any suggestions guys, :flame: Quote Selected
Taking the venerable v6 cat to the ler shop Reply #1 – December 08, 2005, 01:41:28 PM I would suggest a 2-1/4 system with a crossover pipe(H) Quote Selected
Taking the venerable v6 cat to the ler shop Reply #2 – December 08, 2005, 09:17:37 PM I will go with 2 1/4 but will go with direct tubes from each manifold to the each ler instead of using an h pipe Quote Selected
Taking the venerable v6 cat to the ler shop Reply #3 – December 08, 2005, 11:56:03 PM Quote from: cougarpower51I will go with 2 1/4 but will go with direct tubes from each manifold to the each ler instead of using an h pipesounds good.. an h would just help tone it down some and usually give about 7-12 h/p. ive had several shops add one for 15-20 bucks extra when doing a custom exhaust job. Quote Selected
Taking the venerable v6 cat to the ler shop Reply #4 – December 09, 2005, 12:37:39 AM h-pipes do nothing to the 3.8L, theyre an even fire V6, no pulses that need equalizing Quote Selected
Taking the venerable v6 cat to the ler shop Reply #5 – December 09, 2005, 09:11:55 AM yeah, if shawn says it it must be true.Do you have headers for it? Quote Selected
Taking the venerable v6 cat to the ler shop Reply #6 – December 09, 2005, 10:46:03 AM Quote from: Tbird232cih-pipes do nothing to the 3.8L, theyre an even fire V6, no pulses that need equalizingThats not a correct statement, and H or X pipe equals out engine pulses. No combustion engine is pulse free. as far as ising why waste time with an H use an XX-pipes create more power and torque than an H-pipe or procharmber because they merge your exhaust pulses at the X. Traditional H-pipes loose this ability above 3000RPM and the H becomes non-functional Quote Selected
Taking the venerable v6 cat to the ler shop Reply #7 – December 09, 2005, 11:22:28 AM Once again, not true. They equal out exhaust pulses from two cylinders firing very closely in time on the same bank. On a 3.8L, they are even fire engines, never once does a cylinder fire at almost the same time, meaning an H-pipe is useless. V6 mustang guys only use h-pipes because they mellow out the sound a little bit, because the sound vibrations will travel back and forth and do a little bit of cancelling. Quote Selected
Taking the venerable v6 cat to the ler shop Reply #8 – December 09, 2005, 11:26:18 AM Quote from: KTBug at 3.8mustang.comFirst off, our V6 firing order is 1-4-2-5-3-6. Cylinders 1, 2 and 3 are on one side of the engine while cylinders 4, 5 and 6 are on the other. Follow the firing order and you will see that the engine fires a cylinder on one side and then the other and then back to the 1st side again. What that means is that the exhaust pulses in the pipes are evenly staggered. No two cylinders on one side of the engine fire in sequence. It's always one side and then the other. This keeps the exhaust pressure even in both pipes (if you have dual exhaust). One pipe doesn't carry more pressure than the other.Better explaination than what i could say. Quote Selected
Taking the venerable v6 cat to the ler shop Reply #9 – December 10, 2005, 01:59:59 PM QuoteI will go with 2 1/4 but will go with direct tubes from each manifold to the each ler instead of using an h pipeExactly what I did on my old V6. What are you using for manifolds/headers? Quote Selected
Taking the venerable v6 cat to the ler shop Reply #10 – December 11, 2005, 10:57:17 PM Will stay with the manifolds for now Quote Selected
Taking the venerable v6 cat to the ler shop Reply #11 – December 12, 2005, 07:50:17 AM A crossover pipe (either and X or and H) does far more than just cancel out uneven engine exhaust pulses. The higher pressure from each exhaust pulse creates a corresponding low pressure area in the exhaust system in between each pulse. The leading low pressure area helps to draw the following higher pressure pulse out of the exhaust system. This even helps to scavenge the cylinder on the exhaust stroke, leading to a higher V.E. What scavenging pressure may be lost from each extended high/low pressure area is made up for by the correspondingly opposite pressure present on the opposite side of the exhaust system. This helps low-end torque considerably, doesn't do much for low-end horsepower. At higher engine speeds, the crossover is of minimal value. A properly located crossover will help any dual-bank engine to some degree. For the head pipes, 2" would be the best, and the 'H' should be located failrly closely to the end of the manifolds. Chamber volume, cam design and V.E. have a lot to do with where exactly the 'H' should be, but a good guess is better than nothing. Basically, whatever volume there is in the exhaust manifold, from the exhaust port on the head to wherever that section of manifold meets up with the other runners on the same bank is the volume in question. Ideally, you would want to have about the same amount of volume leading from that point to wherever the 'H' is installed. just take a good visual guess, but remember, the I.D. of the manifold is probably smaller than you think. After the lers, 2 1/4" would be best. This would help to create the needed venturii effect, which in turn would speed up the exhaust exiting the pipes, drawing out the exhaust pulses behind them, further increasing the scavenging effect. Too big of a pipe diameter is the rookiest of all rookie mistakes, exceeded only by an older car's owner who would forever saddle thier engine with way too big of a carburetor. The factory exhasut system uses small pipes for a reason. Quote Selected
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