as far as in terms of HP gains and performance, is there a difference between the two? I know having a catback will only gain about 7 hp if lucky, but would i get the same hp gains with an axle back system or would i need the complete system for better flow? let me know im interested

 

catback is better for obvious reasons.

 

+1!

If you're looking for better gains, definately a catback will be better than just the axleback. Larger piping diameters will allow for more flow in the exhaust giving more gains.

If you're looking for maximum gains I'd recommend possibly even a full headerback system.

T1R offers the header, test pipe, b-pipe, and also axleback for the Fit GD3 and currently the b-pipe and axleback for the Fit GE8.

Let me know if you'd like more information on these parts, you can PM me or give me a shout at 604.279.0329.

Cheers.

Regards,

Jason @ AJR

 

run a full j's or spoon exhaust if your looking for just performance.

 

Would anyone have an idea of how loud a 2.25 cat back wit an ap1 exhaust will be? Looking for a bit more balls than stock and plan to boost next summer. Just dont want the drowning/fart noise....

 

Be careful of full or cat back systems on stock Fits. They may give you more HP than stock but it may occur at 5,000 rpm. LOOK for dyno results if possible.
If you are planing to modify with boost than a full system would be warranted. If staying stock You should do fine with just an axle back system.

 

+1

This is from Neons.org! (Ok i know, i know... But i've owned and tuned 4 Neons so almost all my knowledge comes from them!)



These are general guidelines I calculated from David Vizard's formulas.

1. For avoiding significant restriction from back pressure, the pipe should flow at least 2.2CFM per horsepower produced.
2. A straight pipe will flow ~115CFM per square inch of area (using inside diameter of the pipe)
3) I used the formula: (115*pi(diameter/2))/2.2
4) The pipe size will become more restrictive the further you go above the zero loss horsepower.
5) Similarly, try not to go too big on piping for your set up. I think Vitor dynoed 2.5 vs 2.25 on a 160whp set up and had very minimal gain. Putting a 3in pipe on your stock Neon will be very loud for no good reason!
6) Add length as a factor.
7) Each 90° bend will reduce air flow by 8%!

Exhaust Diameter (inches): 2
Zero loss Horsepower 164.22

Exhaust Diameter (inches): 2.25
Zero loss Horsepower 207.84

Exhaust Diameter (inches): 2.5
Zero loss Horsepower 256.59

Exhaust Diameter (inches): 3
Zero loss Horsepower 369.49

Exhaust Diameter (inches): 3.5
Zero loss Horsepower 502.92

Exhaust Diameter (inches): 4
Zero loss Horsepower 656.88





So a catback sure would gain some high rpm power on a fit, but just not that much... I would start with a Header + Axleback combo and put a catback only if i were to add boost or Nitrous in the equation!! Stock 1st gen Neons have a 2¼ mandrel bent catback from factory and those are proven to flow enough up to something like 190 - 200HP with just a muffler and cat change... So a stock 47 or 48mm catback on a fit sure is sufficient enough for ''near stock'' power level! Too big of a pipe will add noise and reduce much wanted low RPM torque for no reason!

...still not understand that ''Bigger is always better'' idea that is common practice in the Honda community when speaking about exhaust! We're speaking about exhaust pals, not Penis!

My 2¢!

Marko!