Just curious if its a nitrous motor any of you guys seen gains from running open header?

 

You'll just have to experiment.

I have seen quite a few motors make more power with mufflers in place than full open. A good muffler can actually help performance.

May want to invest in some cutouts, take it to the track and see what it likes.

-Mindgame

 

With SLP single cats/ypipe mine did 340rwhp/337rwtq through the full exhaust (Borla with the small opening plate), then it did 355/350 through a cutout in my ORP right at the end of the ypipe, that was on the same dyno, back to back runs. Not quite "open header" but pretty close to it.

 

Wuuuuh? Open headers will always outperform a full exhaust.

 

How much money you want to place on "always"?

I can think of quite a few that improved numbers with xr1 collector mufflers (race cars)... a number that never dynoed but did run quicker at the track... and at least one example that made better peak HP numbers. I can throw you a link if ya think I'm bluffing.

It'll cost you $20 to see my hand.

Paypal works fine for me.

Not trying to make a blanket statement here.... just saying that everything is worth a little experimentation.

-Mindgame

 

I also ran my car with a flowmaster muffler vs cutout and gained a SOLID 1.5tenths and 1mph. I really would like to hear how a muffler could create more hp than without one. I know that you gain torque with a muffler in general, but I dunno about hp. I'm not trying to bash your opinion, Mindgame. If my thinking is wrong please teach me.....Exhaustology 101.

 

I'm not trying to add to the confusion Tair... just trying to get a point across in Always feel free to experiment. There are some general gearhead rules, but some things will really surprise you if you take the time to try it.

How, theoretically, could a muffler make more hp than open headers?
I think people get confused with the term "backpressure". If you'll just think of it as a pressure differential seen at the cylinder it makes things less confusing. Take an open header and a full exhaust for instance. In the open header, you have a strong return pulse seen at the cylinder. The pulse is high energy because it has traveled a very short distance and was generated at the pipe end. It is possible that the depression seen at the cylinder could draw intake charge out the exhaust during overlap. If the intake port is low velocity it compounds the potential of overscavenge. If you have less air in the cylinder, you make less torque and volumetric efficiency suffers.

Answers the question of "how a full exhaust, or at least a short one" might help in some situations. It's the exception... not the rule. So I don't want to come across that way.

-Mindgame

 

Here is a car that I know very well and got dynoed at his shop.
He is a very well known tuner.

B&B Tri Flow Car dynoed 435
Open Headers 480
Just bullets right off the headers 476

The motor as you can tell is not stock at all.

Just like Mindgame said every car is different, you have to experiment with it. I'm getting ready to change out my X-Pipe system to another type of setup just to see if I can get more out of mine.