I thought you all might like to see some results from a dyno session last week. This was a couple days after the big Evo gathering at Altered Atmosphere...I showed up a couple days late, but the dyno is the same, so results should be somewhat consistent.



The plot shows two baseline runs, then a later one done on the same day, after we added a Buschur Racing intake and full Buschur Racing 3" no-cat exhaust. Weather was about 70 and rainy the whole day.

Sorry it's not in color, and it's kind of small. (I didn't want to make it too huge here.) The peak HP on the first two baseline runs is 221.3 and 223.6 (I think), and torque is 240.9 and 240.3. Peak on the last run is 247.4 hp and 254.9 torque.

The car is otherwise stock; no fuel tuning or boost control added.

I did an intake-only run, too. Haven't scanned that in yet.

--Dan
Mach V Motorsports
MachEVO.com

P.S. Moderators, if this post is out of line or in the wrong place, let me know...

 

Did you happen to log the A/F ratios during the pulls?

 

Yeah. They were typical "plummet past 10:1 in the upper rpm ranges" in all cases. I didn't notice much of a difference at lower rpms, either, but I don't have printouts of the AF trace right now, so I don't know for sure if the mixture leaned out to any appreciable extent.

--Dan
Mach V

 

Thanks. Just wondering if the those 2 mods adversly affected the ratio into the danger zone without any additional fuel adding mods under stock boost of course.

 

Great comparison! With some fuel tuning you will be in the 270's.

 

amazing gains for an exhaust system. i luv this FI stuff. soo many gains to be easily made.

 

I am assuming these results are with a full turbo-back, cat-less exhaust system?

 

Yeah, he said he had no cat. What was the HP difference for just the intake alone?

 

whats the difference if you have the stock cat in there instead of the test pipe??

 

i mean how much hp do you think the stock cat is robbing

 

the Full 3" Exhaust, Test Pipe, etc.. Did you throw a CEL? And did the Buschur system have bungs welded for both front and rear O2 sensors? Its not documented on their site.

 

What gains did you see with the intake only?

 

n00dle- Adding an intake/air cleaner and exhaust is not going to adversely affect the A/F ratio.The boost levels might increase marginally due to the free flowing exhaust, to create a slightly leaner mix.However, if Dans dyno runs showed the A/F still dropping under 10:1 at higher rpms then it is likely that the lower RPM A/F ratios are still fat, safe and happy as well.

Certainly these mods alone are not going to push this engine into the danger zone. The purpose of the fuel management piggybacks like the SAFC is not to add fuel, at least not on the EVO, which needs fuel pulled away to lean-out the mixture for a cleaner more efficient burn.

This is obviously the right path to more power, but also an easy way to grenade an engine if you don't use caution and lean things out too far.

BTW- Thanks for posting the dyno info Dan, 24-25whp improvement with just a 3" turbo back/test pipe and intake is nice and confirms what we might expect.

Other tests have shown about 8-10 whp with a cat-back, 4whp for a cone filter, and a DP and test pipe are usually worth 15-20 whp. Again those are gain numbers for specific parts, and the cumulative of the combo will always be less.

Seeing what the combos do together though really tells a story and your dyno indicates a pretty nice picture with excellent broad low rpm torque and hp improvement, flattening a bit in mid range, then a nice improvement again tracking from 4800 through redline. Thats the kind of power that really adds-up, as opposed to short duration peak power gains!

 

Thanks, good info. I wanted to know what to expect from some of the basic mods with safety in mind. I'm going to get a wideband monitor to play it safe, cause the list of mods will certainly grow and not knowing wether or not it's going to blow sucks...

 

About 4-5 hp, although no change in maximum torque.

--Dan
Mach V