Hi, I have a 98 H22a5 98 prelude and I have recently change my exhaust system. I installed an OBX Header (the only one available here at a reasonable price) and a custom 2.5inch exhaust with no cat, 2 resonators (to make it quite) and OBX titanium muffler (this this is actually really light).
I also have a short ram intake, and for now thats it.
Here is the link to my dyno sheet: http://www.pilt.ee/view/518125/ - click on the picture to make it bigger. (that site does not allow to link images directly).
The dotted line is my car, and the solid line is97 prelude with just aem short ram intake we used for baseline.
The dyno is supposed to read crank HP, therefore the numbers seem really low (considering factory spec for H22a5 is 185 crank HP) for wich I guess there are two reasons: the dyno is set up incorrecly (S2000 with mugen header, buddy club exhaust and aem ems showed only 203 crank HP on that dyno) and also shitty gasoline we have here. However, it is still fairly good for comparison.
So, my impressions from the set up really good, considering we used the cheapest parts possible. Most of all I like that good amout of torque I picked up at low RPMs, the car is much more fun to drive now. The next thing I plan is upgrading to 2.5in collector to pick up some high RPM HP.
I do have one concern though, the guy doing the dyno test told me that the car is running really rich - somewhere around 12:1 AF (unfortunately they cannot print the AF graph). Do you guys have any idea what is causing that?
Also, I have a greddy e-manage ready to install, but my tuner says it is not reasonable to do that before we install something more, like new cams or IM, as it can not give more that 3-5 hp. What do you guys think, should I tune? And approx. how much HP can I gain from a good tune considering my set up?

Thank you in advance. (and sorry for so much text )

 

Bump for some answers.

 

You want to be around a 13:1 air fuel ratio. You'll probably pick up another 4-8whp by leaning it out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrecisionH23a &raquo;</TD></TR><TR><TD CLASS="quote">You want to be around a 13:1 air fuel ratio. You'll probably pick up another 4-8whp by leaning it out.</TD></TR></TABLE>

Thanks Precision. One more question then: can I lean it out (at least to some degree) by installing a fuel pressure regulator and lowering the fuel pressure? Or is installing and tuning my e-manage the only way to lean it out?
Thanks.

 

E-manage is a better solution for you. You can re-tune it after you add some more mods. Fuel pressure regulator is not needed at all.