Ditto what those last two guys have said about leaded fuel causing O2 sensor and catalytic converter death. I hope for your sake that you won't have to replace these (quite expensive) components.

I'm willing to bet that those bumps in your dyno curve are not the result of the ECU, but your Injen CAI. Both the Injen and AEM CAIs have those signature bumps, which are the result of their tuned pipe lengths. FWIW your dyno curves, in relation to stock, look exactly like what I've seen on CAI-equipped but otherwise stock cars.

Also, in my experience, high octane gas (even the proper unleaded stuff ) makes no difference on the S2000's output on a dyno. In a high heat situation it might preserve power longer, but won't really help you produce higher peak numbers.

Good luck getting everything sorted!

[QUOTE]Originally posted by 9906
[B]
...

So, it's clear the Mugen ECU does something.

 

[QUOTE]Originally posted by jzr
[B]Ditto what those last two guys have said about leaded fuel causing O2 sensor and catalytic converter death.

 

Wow! What jzr wrote is absolutely correct. I just got this from the Injen web site and there is the bump right where mine is. So, it's not the ECU at all but the intake. So the ECU is doing even less than I thought it was. Amazing.

 

[COLOR=darkblue]QUOTE: With the highest octane rating of any street legal fuel, Sunoco GT 100 (etc.) ...

Specific Gravity 0.760
Antiknock Index (R+M)/2 100
MON, Motor Octane 95

Just wanted to make one point. Motorsport 103, available from VP Racing ...has a higher octane than the above mentioned Sunoco GT 100; both fuels are street legal (VP Racing Fuels does not have service centers unlike Sunoco). Here is some information on Motorsport 103:

Motorsport 103 is VP's name for its street legal gasoline, designed for maximum power and throttle response. Motorsport 103 is an unleaded fuel of high octane that provides the power and protection equal to some leaded racing fuels. Meets California RFG Requirements. Recommended for: high performance street cars, boats, snowmobiles, personal water craft, motorcycles and high performance import cars.

 

I am not the super gear /motor head you guys are.......but i was told that the mugen ecu adds no horse power.....but improves drivability. To see no gains in curve from the mugen is no suprise........no gain from the header is what puzzels me......Hey MAybe the honda engineers dida great job! I would toss the mugen ecu and get a vafc.....there have been proven gains for top end power and midrange.Then i would really concentrate on making the car lighter......dyno's are great...for finding where the power is during the range...but your ultimate goal is to go faster.
Losing weight shows nothing on the dyno but it does show on your times! Driving with a full tank i can feel the differnence then when driving with only a quarter tank ....about 8 to 9 gallon difference is about 60 to 70 lbs. When i am at three bars of gas i still have about 4 gallons left wieght about 32 pounds.....full tank 13 gallons about 104 pounds. The weight reduction of the exhaust has made your car faster......Is the header lighter than stock..........if so more the better......My point.....always do a baseline dyno run and a baseline 1/4 mile run. You could be a faster car even with the loss of 3 or 4 horses.

 

[QUOTE]Originally posted by ItalianBucwheat
[B]....I would toss the mugen ecu and get a vafc.....Then i would really concentrate on making the car lighter......your ultimate goal is to go faster.

 

Make sure your car is relatively in the same state of tune for each dyno session. Iow, things like plugs not getting too worn, valve clearances within specifications, air filter not dirty for one of the runs, etc...

 

One thing that has not come up at all is what your impressions are of the car after all these mods. Do you feel any difference driving the car through the RPMs.
I totally understand that you are dissapointed in the numbers, but i was just curious as to what you thought about the car out on the street?

 

Someone brought up the point of heat soak. I am just wondering about that. On my car, when I make back-to-back runs, my car will consistently make more power. It just goes up each time. Then again, I do have the intake insulator from Hondata.

I'm sorry you didnt make the numbers you wanted. I would suggest taking the car back to stock configuration and then make dyno pulls with each mod by itself. It's expensive, but the only way to determine the true culprit. The intake can be changed out quickly and the header can be done quickly too. ECU of course is no problem at all.

I think you should run your stock box with a good filter. I've tried the AEM, Injen, and the RM, and the stock box with a good filter yields the smoothest powerband. But then again, that's on my car. I know other people have had great luck with their intakes. My car just seems to hate them with the stock ECU.

Keep the Mugen header bro. It's a good investment. I would tell you that a stock ECU and Vafc would be a better mod than the Mugen ECU, cheaper too.

The Toda cams are definately a worthy investment. I highly recommend them


Chris

 

This was made with HKS exhaust, DC Header, STOCK intake, and AEM PEMS. I think you paid about the same for your Mugen ECU that I paid for my EMS. Also, my baseline run was only 193. You made about 10 more rwhp than me!

Chris