do i need custom tunes after muffler change

[Shorse]

I am really tight on money right now, but after i installed my magnaflow 14" muffler today, it smells like i am running really rich. I'm not sure if it's because i am looking for it now or not, but it is STRONG smelling. I have 275-55-17's, and a little extra weight in my truck tool box( ~200 lbs). Other then that i am stock. I usually run level 2 with the gears and tire sizes adjusted.

If i get a custom tune, i am torn between a 87 fuel saving tune, or a 87 performance tune. My gas millege sucks, 12-14 mpg mostly highway, and if that can be improved with a tune and not effect my perfomance too much, then i'll go with that.

I live in a hilly place out in the country, and rarely go into the city... but i tow my boat every other week (4000 lbs), and a quad on a heavy trailer every once and a while (2000 lbs)... so i need to tow on this same tune also...

what do you guys recommend i do, and can the muffler make a difference at all?

[cleatus12r]

There will be a lot of help here shortly. I'm no Gryphon expert so hang tight!

[white eagle]

I think the muffler will only effect how you feel about your truck I really don't think it needs a special tune
you may be smelling you muffler burning out should get louder tooo

[Jackpine]

I doubt the muffler will make any difference to your tune at all. Towing weights of 2000-4000 tells me a custom tow tune would be worthwhile, optimized for the 4000# load. The 2000# load could be towed with either the tow tune or a standard performance/economy tune.

I do think Bill can write tunes that can both save you on gas and still perform well. He did that for me.

- Jack

[Jon82387]

The smell is probably just the new muffler burning off some of the oil that is on it from being new i had a smell after installing my flowmaster kit it will prolly go away after a week or so.

[Shorse]

i did not know mufflers had to break in... good to know.

so he can make me a tune aimed at fuel savings and performance, what form do i fill out?

[88Racing]

Originally Posted by Shorse

i did not know mufflers had to break in... good to know.

so he can make me a tune aimed at fuel savings and performance, what form do i fill out?

Goto powerhungryperformance.com click on order forms.

One note on exhaust mods. A muffler will never require a new tune. It's what goes on before that and what you have changed.

Please fill out your user info with hex/calibration code and serial number.

Lars

[Power Hungry]

The biggest difference in exhaust that would require tuning is for headers, crossovers (X and H pipes) and high-flow cats. These have a more dramatic effect on backpressure and subsequently can affect air fuel ratio.