Lets Talk Flowmaster Exhaust

t_ruth · July 1, 2009

So i finally decided its time to louden the truck up a bit over stock. Im looking for something thats not gonna wake the nieghbors up like a super 44, but not as quite as stock. I believe ive got it down to the 50 series. Im between the SUV/Performance and the Delta Flow. Anybody with some experience??

I've got the CAI bringing more air in, can i cut out the cats to help evacuate the exhaust? Its a 2000 model with the 4.8, so its OBDII. Can a tuner disable the check engine light for the rear o2 sensors, or should i get dummy 02 sensors?

x pipe with 2 mufflers or y pipe with a single in dual out?

thanks for any help

rmarkey · July 1, 2009

So i finally decided its time to louden the truck up a bit over stock. Im looking for something thats not gonna wake the nieghbors up like a super 44, but not as quite as stock. I believe ive got it down to the 50 series. Im between the SUV/Performance and the Delta Flow. Anybody with some experience?? I've got the CAI bringing more air in, can i cut out the cats to help evacuate the exhaust? Its a 2000 model with the 4.8, so its OBDII. Can a tuner disable the check engine light for the rear o2 sensors, or should i get dummy 02 sensors? x pipe with 2 mufflers or y pipe with a single in dual out? thanks for any help

I've used numerous flows and loved them all. For the 50 series, I'd go with the 50 HD or the 50 delta, they'll be a little louder than the 50 suv. Personally I'd leave the cats. I used to be that guy that got rid of them right off the bat on everything, and now that I've lived and learned, I leave them. Unless you are planning some huge power increases, you are better off leaving them. As far as going true dual or the y pipe, it depends on the sound and money. True duals will cost you more and give you a rougher, more like an old carb'd truck sound, whereas the y pipe will be cheaper and give you a deep rumble tone all the way through the rpms. It's all up to your preferance of sound, and what you want to spend.

For the first round, and I say that because everything I own has gotten a few variations of flows, you could go with a cat back y pipe setup so you'll have a good deep/clean sound and a lower cost and less work. You won't have to worry about 2 mufflers, twice the pipe, and throwing engine codes. Also, if you like it but want a little deeper/more sound out of it after you run it for a while(they do break in and sound better) Try going with a longer(if possible) and larger exhaust tip(s). Larger tips will deepen your sound and reverb a little more.

There are many variations you could try and they will all sound different. Beware if you go to extreme though on it, if you lose to much backpressure you'll lose some power and mpg, trust me I've done it before.

Hope that helps a little, I tried not to right a book, but there is so much that could be said.

DBVille · July 1, 2009

Leave the cats. They will trip CELs that you will have to address somehow, and won't gain much (0-5 hp). In addition, it is illegal, and very easy to spot - a simple look under the truck will catch it. Why bother for no real gain?

Bostonsfavson · July 1, 2009

So i finally decided its time to louden the truck up a bit over stock. Im looking for something thats not gonna wake the nieghbors up like a super 44, but not as quite as stock. I believe ive got it down to the 50 series. Im between the SUV/Performance and the Delta Flow. Anybody with some experience??

I've got the CAI bringing more air in, can i cut out the cats to help evacuate the exhaust? Its a 2000 model with the 4.8, so its OBDII. Can a tuner disable the check engine light for the rear o2 sensors, or should i get dummy 02 sensors?

x pipe with 2 mufflers or y pipe with a single in dual out?

thanks for any help

Yea, ruin the air a little more and do something illegal so your pickup truck will be a couple decibels louder. Good thinking.

t_ruth · July 1, 2009

Yea, ruin the air a little more and do something illegal so your pickup truck will be a couple decibels louder. Good thinking.

Well. Rude much?

In KY, we dont have emission testing. There's quite a few ol boys around here that run open cats for several reasons. Some like the sound, and others are just too tight to spend the money to replace them. I dont want a real loud truck, and that wouldnt be the reason for removing them. The reason for getting rid of them would be for more HP. But of course, as mentioned above, i dont want to remove too much backpressure. I know the check engine light will come on, thats why i'd asked if it could be programmed out with a tuner, such as Justin at blackbear, or if anyone knew where to get 02 simulators.

66nova · July 1, 2009

Well. Rude much?

In KY, we dont have emission testing. There's quite a few ol boys around here that run open cats for several reasons. Some like the sound, and others are just too tight to spend the money to replace them. I dont want a real loud truck, and that wouldnt be the reason for removing them. The reason for getting rid of them would be for more HP. But of course, as mentioned above, i dont want to remove too much backpressure. I know the check engine light will come on, thats why i'd asked if it could be programmed out with a tuner, such as Justin at blackbear, or if anyone knew where to get 02 simulators.

Leave them. You will not gain any horsepower taking them off. Yes a tuner can turn off the CEL, but again it's bad for the environment, illegal (even if you don't have emissions test), and you won't be gaining anything. I have took them off before. I gained some noise, but there were no performance gains (and yes I tested with 1/4 mile times). I let someone talk me into it because of all this hp I was going unleash. Hah. I have since done a ton of research on exhaust and built quite a few different sytems.

Anyone that tells you they picked up power by removing the cats is filling the placebo effects of more sound. There are 1000+hp cars running cats.

Unless you just want the sound of true duals there is no real performance to gain from them (until you start making big power). I am happy to see that you are talking about using an X-pipe, but seriously unless you just want the sound stick with a single muffler with single or dual out, depends on the look you want.

One last thing. I absolutely love the Flowmaster sound. But if your main concern is power, I would look into Magnaflow, Corsa, Borla, Dynomax, etc. Flowmasters are not flow masters at all. But they sound great.

After you are done, absolutely hit Justin at Black Bear up. You will be AMAZED at the power and drivability he uncorks.

t_ruth · July 1, 2009

yeah ive always kinda doubted how cutting out the cats would help power. Thats why i came here before i did a thing. haha. im not doing anything serious. its a 9 year old 4.8L, no need to dump too much money into it.

I was really planning on getting a tune from Justin, but he didnt seem as he's been described on here. It took him about a week to answer my email, and when i told him iwanted to be on the scan cable wait list, he never sent me back a confirmation email to say i was on the list. I understand he's a busy man tho. I still may go with him. Especially if i get a cable within the next few weeks. If not, im going to hit up a local guy here. He has a degree in computer programming with a dyno in his garage. All about 60 miles from me. Can it get much better than that? haha. Either way, its getting tuned after the exhaust, but ill probably tune up before i do the tune. 118,000 miles on original plugs and wires.

66nova · July 1, 2009

yeah ive always kinda doubted how cutting out the cats would help power. Thats why i came here before i did a thing. haha. im not doing anything serious. its a 9 year old 4.8L, no need to dump too much money into it.

I was really planning on getting a tune from Justin, but he didnt seem as he's been described on here. It took him about a week to answer my email, and when i told him iwanted to be on the scan cable wait list, he never sent me back a confirmation email to say i was on the list. I understand he's a busy man tho. I still may go with him. Especially if i get a cable within the next few weeks. If not, im going to hit up a local guy here. He has a degree in computer programming with a dyno in his garage. All about 60 miles from me. Can it get much better than that? haha. Either way, its getting tuned after the exhaust, but ill probably tune up before i do the tune. 118,000 miles on original plugs and wires.

Send Jenna (Jennabear) a PM. Justin has been gone so much he is having a hard time keeping up. Jenna will make sure you are on the list. You would not believe the number of emails he gets per day.

Where are you from? More than likely he has a live tune coming up somewhere near you.