Exhaust wisdom for every tuner...

[myeverlovinsir]

I found this page quite interesting and seems to touch all
the bases when considering an exhaust setup. Hope to see
something similar to the H-VIX for an auto exhaust soon.

Backpressure (http://www.hondalife.com/articles/BackpressureandCrosssectional%20Area.htm)

[BlasTech]

We at ephatch should follow the good example hondalife/hondavision has set for the excellent tech info.

I hope our project pages fill up with lots of good info/how-tos just for EP tuners.

[JSIR]

only problem is these k20 engines break all the rules when it comes to tuning Honda engines, particularly exhaust tuning. That's why I am tempted to try a 2.0 inch mandrel midpipe, you can't predict what these engines may like better, you just have to try different setups.

[02blksi]

WOW, thats a very useful, yet confusing article, took me a couple times re reading everything to get things to sink in.... --Joe.

[BlasTech]

Someone should collect all the data collected so far from people/companies with various exhausts on the EP for comparison. That would be interesting.

[myeverlovinsir]

Two things that really stood out for me in this thread.

Quote:

Just changing back pressure is a bogus way of trying to create the "ideal" pressure in the system. The exhaust system should work like a correctly conceived header. It should extract the exhaust from the header, to minimize pumping pressures.

The only way to create a system that will serve as an extractor is to properly size the tubing to allow the flow velocity to create a sort of "vacuum" behind it.

Quote:

Building a system to divert the flow into a smaller system can help bolster lower rpm power, just as with todays dual runner intake manifolds, but you'll never find a dual runner intake on any engine that's targeting the greatest performance potential possible. I should also add that such systems are inefficient from a standpoint of weight and surface area.

This is the nemisis of the base rsx having dual smaller runners.
Low end torque at the sacrifice of larger flow in higher rpms.




Needless to say there is alot of valuable info in this thread. hth

[chunky]

tuan is awesome.

[CleanBlackSi02]

I'll have to read more thoroughly before I proceed to stick with my 2.5" piping. Again, dyno results will tell the most.

[myeverlovinsir]

CleanBlackSi02, Here is another nugget from that thread.

Quote:

2-1/4" for up to 200HP @ the crank, 2-1/2" for 275HP, 2-3/4 for 320HP...

[CleanBlackSi02]

Thank you for the nugget.

...I wonder why Thermal R&D as well as other companies make a 2.5" cathack exhaust then for mass use. The Thermal exhaust that I have is their "Stealth" model, for MILD applications. Hmm.

[myeverlovinsir]

Most exhaust manufacturers assume that if you are to buy an
aftermarket exhaust system you will also be installing the rest of the
goodies required to make it work at its full potential. An exhaust
alone will net you near nothing(except noise), unless you have added the increased
air flow from the front.

[JSIR]

it is important to understand that gains found on a dyno at WOT do not necessarily mean you have a better overall exhaust system. What happens at WOT conditions doesn't apply to part throttle acceleration. Thus you can bolt on a bigger exhaust system - big piping - go to a dyno and find a few hp gains during WOT dyno testing. But on the street during normal daily driving the car can actually feel slower because at part throttle driving you might be actually losing torque. Dynojet dyno's dont let you test part throttle acceleration, only WOT.

During daily driving you are using part throttle probably 98% of the time, compared to WOT. At part throttle application you have less exhaust gasses flowing through the exhaust system, and with a larger exhaust velocities drop and you lose torque. This loss of torque is very noticeable as you try to accelerate from a cruise condition.

That is why the stock exhaust feels so torquey in daily driving, it was made to maximize useable torque over various dirving conditions. The trick in choosing an exhaust system is to strike a balance between WOT hp and daily driving part throttle torque.

[Jpax]

When i added my coffie can exhaust tip to my 96 hb i noticed alot of things................" would you like some soy sauce with that RICE"

I got that alot..........

on the other hand......This info is great... keep up the modding .

[JSIR]

[QUOTE]Originally posted by PaXiE
[B]When i added my coffie can exhaust tip to my 96 hb i noticed alot of things................" would you like some soy sauce with that RICE"

I'm a big supporter of the stock muffler, I highly recommend keeping it and just upgrading the midpipe. Don't have to worry about it clogging up with rice either ;)

[B18CXr]

OEM, stock, flat black, look is nicey nice.


just need a front mount to paint black now.....:p