I'm new here... Wanted to say great information! I'm planning to pick up the SIDO Flowmaster 30 Standard based on many recommendations. I looked at the MagnaFlow, I bet its a great unit, but I was quoted $700.00 installed, felt it was a bit pricey for my needs...

 

I also had the 50 series SUV installed recently (04 F150 SCrew). Very qiuet inside the truck. Inside you can barely hear it idling and at highway speeds. Nice rumble when you get on the gas, but overall quiet and no drone or power loss. I stayed with smaller pipes to help ensure no power loss.

 

Why does smaller pipes save HP vs larger pipes? I thought the faster you could displace the exhaust the more HP you could gain... Without getting too techical, can someone explain this?

If im looking into FlowMasters, what size piping and tips should be used?

 

simple answer, backpressure

small pipe increase/maintain backpressure
large pipe decrease backpressure and rob low end torque

 

I just ordered a K&n cold air intake for my 2003 F150 Super crew, Lairat, FX4 5.4ltr, 4wd. Putting a 40 series FlowMaster on it thursday. Just put BFG's AllT Ko's 275's and it looks tight. I have a hard tonneau cover, westin chrome step bars and a full westin chrome brush guard on it now. It will be mostly done after the air intake and exhaust syst.

Hopeing to get alittle better gas mpg than 14 MPG of normal driving. Plus more power and better throttle response. I'll post some pic whe I 'm done.

 

I just put a Mac air intake on my 4.2L today. It works really well with my new dual exhaust. I felt more power and throttle response instantly. Hit the gas, and the power is there! Ha!

Just remember after you do any mod(s) to reset your computer by taking off your negative battery terminal, and turn on your headlight switch to drain any redidual memory out of your truck's ecu. Let it sit like that for 10 minutes, then turn your headlight switch off and reconnect your - battery terminal.

Turn your key to "on" but do not start it. A full gauge sweep indicates that your truck's computer is completley reset, and all sensors are fully recalibrated. Do this "computer reset" after you do any mods to your truck. It makes your truck's computer recognize your new mods instantly.

 

Thanks for all the posts guys. I actually ended up gettin the kit. I have had it for about 1 month and a half or so. give or take alittle. and i am happy with it i just want it to be alittle louder. will swapping out the flowmaster 50 series and goin to a super 40. I want to get as loud as possible with staying legal not loosing any back pressure and keeping a muffler. I want it as loud as if i was running a duped exhaust. Bowkil did u end up getting the flowmaster 40 if so how do u like it are u running 1 pipe in 2 pipe out? (i have some pics in my libary of the exaust in my gallery)
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