dual flowmasters

[Bad2000v6]

anyone have 2 flowmasters on their 3.8? how does it sound compared to a single? thanks

[triad]

Hmmm. Dual Flowmasters probably aren't possible on our cars unless a dual converter setup is achieved...which again...I havent seen.

Don't think its possible bro.

[GrdLock]

Well I've seen people run custom setups with two dynomax's and other mufflers so a dual flowmaster setup would be possible, just fairly expensive for the custom job. Just buy two single in/single out flow mufflers and go to a muffler shop and ask em.

[pgriffith]

I would think it would be possible but you would lose too much back pressure so the car would underperform compared to a split cat back.

[pvtschultz]

You know, the problem with backpressure really isn't a concern. The biggest change with lowering backpressure is that an engine will run leaner. Well, that is where that computer comes in. But you will shift you power peak, but then again, it is only a 3.8 and it isn't going to go very far. When you start talking about 400+ hp, then yes, it does alot, ask my Impala. But I just got off the subject. There is a reason that there is only one muffler in the rear of our cars. They are aports cars that sit quite low to the ground and the only place that GM could find was at the rear of the car. Ever wonder why there is that big hump in the floor pan in the passengers seat? Go for the dual mufflers, but you'll be much happier with just the one cross flow in the rear.

[pgriffith]

Engine will run leaner with a free flowing exhaust? Explain this to me please. I have never heard of this before.

[scottblack]

<blockquote>quote:</font><hr>Originally posted by pvtschultz:
You know, the problem with backpressure really isn't a concern. The biggest change with lowering backpressure is that an engine will run leaner. <hr></blockquote>

That is the most bass ackwards thing I have ever heard. How does a loss in backpressure make the PCM run leaner??? The PCM will run leaner if you have more airflow coming IN to the engine and your fuel level is not compensated accordingly. I could be uninformed, but PLEASE explain this to me???

Scott

[John_D.]

In the olden days of carbs, the air flowed past a jet in the carb, and the air flow drew the fuel out of the jet. Kind of a suction effect. It was drawn from a bowl of gas that was not under any pressure other than a little gravity. If you made the air flow easier, there was less of the suction effect, to oversimplify it just a bit.

Headers make the air flow easier due to a bunch of complicated stuff related to exhaust scavenging which helps the cylinder draw intake air more effectively. You usually had to go to a bigger jet in a car or motorcycle if you significantly improved the exhaust. Check the aftermarket muffler systems for carb'd bikes. They are selling bigger jet kits on the same page usually.

That's where a lot of the old backpressure discussions originated too. Less backpressure, more flow, stock jets did not match up, required complicated rejetting (complicated to figure out the correct jet sizes that is....)

With fuel injection it is not nearly as much of a problem. A sensor (MAF in our case) figures out how much air is flowing and tells an injector to shoot fuel under pressure into the airstream. Increased flow is not too much of a problem, since the computer just says "more fuel", and the fuel is under plenty of pressure.

Until you increase the flow to the point that the fuel system can't keep up anymore. Exceeding the capacity of the injector, or the fuel pump, or the pressure required to feed 6 or 8 hungrier than ever injectors.

And that is why the first gauge (and only gauge, if I could only get one) for my supercharger will be a fuel pressure gauge... Since too lean is a very bad thing.

[SuprSpdDB7]

i have heard that on our cars, it have no benefit. it's just really a PITA to do or even both with... (well, that's what i heard)