Mugen ECU dyno tested
07-21-2002, 01:25 PM
#1
Registered User
Thread Starter
Mugen ECU dyno tested
Folks, getting back to the discussion of Mugen parts, I just dyno'd a Mugen ECU equipped MY00 car this morning. The owner wishes to remain anonymous as to avoid becoming any part of the furor that has surrounded past Mugen discussions.
All tests were documented with engine coolant temps and intake air temps. The car also had an IDI intake snorkel which, on the dyno, was found to increase intake air restriction over a stock airbox (underway, it may develop positive pressure while providing cooler air). The intake manifold vacuum was up to 1" higher than on other stock airbox cars tested. If anything, this hurts power on the dyno (since the hood is open and cool air provided by fan).
We also datalogged A/F ratios for the Mugen equipped car.
With coolant temps between 185-190F, the Mugen ECU equipped car recorded peak hp numbers of 222 and 223.5 hp to the wheels. This compares to several 2000-2001 model cars which stock put down 210-213 hp on my dyno. This also compares to several cars tested yesterday which put down around 220 even with a CAI and exhaust (stock ECU). It also approaches the values we got for a slightly modded car with VAFC (227). While we weren't able to do back to back on the same car (since the ECU needs time to learn), I firmly believe that the Mugen ECU is responsible for the large differential. Here's why.
1. A/F ratios - The Mugen ECU runs dramatically leaner than the stock ECU. I used MarkS2K's healthy, but bone stock MY00 as a comparison. At idle, the typical stock S2K shows an A/F ratio of 14.7-15.5:1 measuring A/F after the cat (which tends to show a leaner ratio by a few tenths of a point). During our dyno runs, MarkS2K's car showed an A/F ratio between 12.1 and 12.6 from 3000 to 7000 rpm. From 7k-8k rpm the ratio clibed as high as 12.9 before dropping back. From 8k to the limiter, the ratio dropped from 12.6 to 11.7.
Now, the Mugen ECU car. At idle, the Mugen ECU ran very lean. At first I thought my A/F meter was malfunctioning - this is probably done to help avoid an off-idle stumble. Between 3000 and 6000 rpm, the Mugen car shows a ratio between 13.4 and 13.7, with a brief spike to 14:1 just before 4000 rpm. At 6000 rpm it goes richer, down to 12.9:1 by 7000 rpm (to supplement the VTEC transition?), before starting a steady climb back up to finish at 13.9:1 at 9000 rpm.
To me this is extremely important information. At its richest the Mugen ECU runs leaner than the stock ECU at its leanest. Compared to a VAFC tuned car, the values above 5000 rpm are similar, but hte Mugen ECU runs leaner down low, and is leaner near the limit (where it can be very difficult to get the stock ECU to run, even with a VAFC). Compared to cars equipped with CAI's, the Mugen car is leaner as well, except for a couple points where the CAI car gets a resonant peak and goes lean to levels near the Mugen ECU equipped car.
2. The shape of the torque curve is different than a stock car's . The power peak moves to 8500 rpm. I haven't really seen any bolt on mods that move the power peak around. Even with a VAFC its hard to do. The Mugen ECU olds power better after the power peak at 8300 rpm (like the VAFC does), but it also moves the power peak up. This is clear evidence to me that the timing is advanced along with a leaner mixture. I also observed more advanced timing on my OBDII scantool at lower rpm. As soon as my computer equipment arrives, we can actually datalog that and show it.
I'll post the graphs as soon as my laptop arrives (dell says it should be shipping tomorrow). Take what you will from this data. Ideally we'll be able to test one car with both stock and Mugen ECU's (Prolene is interested). But even though we are comparing two different cars here, perhaps discounting _some_ of the hp gains (throughout the rpm range!), you can't ignore the vastly different shape of the A/F curve. And as that curve does alot of what a properly tuned VAFC does (and then some), combined with more ignition advance, you have to think that the Mugen ECU puts out some significant power gains on its own.
For those who aren't seeing gains with the Mugen ECU, I suggest giving it time to learn your car. Even a day should be enough. Also, make sure that you control conditions such as coolant temperature. For those using the Mugen ECU with non_Mugen boltsons (like a header), observe carefully. IMO, the Mugen ECU is clearly designed to be very complimentary with their header setup (which normally loses a little power after 8300 rpm).
Reminder - I do not sell any parts. I am not in the employ of anyone from Mugen or its affiliates. I only observe, test and report. I do own a Mugen header, and I paid full retail for it 2 years ago.
:-)
UL
All tests were documented with engine coolant temps and intake air temps. The car also had an IDI intake snorkel which, on the dyno, was found to increase intake air restriction over a stock airbox (underway, it may develop positive pressure while providing cooler air). The intake manifold vacuum was up to 1" higher than on other stock airbox cars tested. If anything, this hurts power on the dyno (since the hood is open and cool air provided by fan).
We also datalogged A/F ratios for the Mugen equipped car.
With coolant temps between 185-190F, the Mugen ECU equipped car recorded peak hp numbers of 222 and 223.5 hp to the wheels. This compares to several 2000-2001 model cars which stock put down 210-213 hp on my dyno. This also compares to several cars tested yesterday which put down around 220 even with a CAI and exhaust (stock ECU). It also approaches the values we got for a slightly modded car with VAFC (227). While we weren't able to do back to back on the same car (since the ECU needs time to learn), I firmly believe that the Mugen ECU is responsible for the large differential. Here's why.
1. A/F ratios - The Mugen ECU runs dramatically leaner than the stock ECU. I used MarkS2K's healthy, but bone stock MY00 as a comparison. At idle, the typical stock S2K shows an A/F ratio of 14.7-15.5:1 measuring A/F after the cat (which tends to show a leaner ratio by a few tenths of a point). During our dyno runs, MarkS2K's car showed an A/F ratio between 12.1 and 12.6 from 3000 to 7000 rpm. From 7k-8k rpm the ratio clibed as high as 12.9 before dropping back. From 8k to the limiter, the ratio dropped from 12.6 to 11.7.
Now, the Mugen ECU car. At idle, the Mugen ECU ran very lean. At first I thought my A/F meter was malfunctioning - this is probably done to help avoid an off-idle stumble. Between 3000 and 6000 rpm, the Mugen car shows a ratio between 13.4 and 13.7, with a brief spike to 14:1 just before 4000 rpm. At 6000 rpm it goes richer, down to 12.9:1 by 7000 rpm (to supplement the VTEC transition?), before starting a steady climb back up to finish at 13.9:1 at 9000 rpm.
To me this is extremely important information. At its richest the Mugen ECU runs leaner than the stock ECU at its leanest. Compared to a VAFC tuned car, the values above 5000 rpm are similar, but hte Mugen ECU runs leaner down low, and is leaner near the limit (where it can be very difficult to get the stock ECU to run, even with a VAFC). Compared to cars equipped with CAI's, the Mugen car is leaner as well, except for a couple points where the CAI car gets a resonant peak and goes lean to levels near the Mugen ECU equipped car.
2. The shape of the torque curve is different than a stock car's . The power peak moves to 8500 rpm. I haven't really seen any bolt on mods that move the power peak around. Even with a VAFC its hard to do. The Mugen ECU olds power better after the power peak at 8300 rpm (like the VAFC does), but it also moves the power peak up. This is clear evidence to me that the timing is advanced along with a leaner mixture. I also observed more advanced timing on my OBDII scantool at lower rpm. As soon as my computer equipment arrives, we can actually datalog that and show it.
I'll post the graphs as soon as my laptop arrives (dell says it should be shipping tomorrow). Take what you will from this data. Ideally we'll be able to test one car with both stock and Mugen ECU's (Prolene is interested). But even though we are comparing two different cars here, perhaps discounting _some_ of the hp gains (throughout the rpm range!), you can't ignore the vastly different shape of the A/F curve. And as that curve does alot of what a properly tuned VAFC does (and then some), combined with more ignition advance, you have to think that the Mugen ECU puts out some significant power gains on its own.
For those who aren't seeing gains with the Mugen ECU, I suggest giving it time to learn your car. Even a day should be enough. Also, make sure that you control conditions such as coolant temperature. For those using the Mugen ECU with non_Mugen boltsons (like a header), observe carefully. IMO, the Mugen ECU is clearly designed to be very complimentary with their header setup (which normally loses a little power after 8300 rpm).
Reminder - I do not sell any parts. I am not in the employ of anyone from Mugen or its affiliates. I only observe, test and report. I do own a Mugen header, and I paid full retail for it 2 years ago.
:-)
UL
07-21-2002, 07:59 PM
#4
UL,
As always you bring incredible knowledge and experience to this board. Great to have you here. I remember reading somewhere that the Mugen ECU is not intended to be used in everyday driving. Is that because it doesnt have the ability to retard the timing? Would you recommend this ECU for s2000s in only certain climates? For example, New york Vs. Texas?
Thanks,
Bobby
As always you bring incredible knowledge and experience to this board. Great to have you here. I remember reading somewhere that the Mugen ECU is not intended to be used in everyday driving. Is that because it doesnt have the ability to retard the timing? Would you recommend this ECU for s2000s in only certain climates? For example, New york Vs. Texas?
Thanks,
Bobby
07-22-2002, 04:13 AM
#5
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Would testing be valid if you ran the baseline using the Mugen ECU first and then the stock ECU? If the vehicle has already been using the Mugen ECU for several days, the ECU has already learned and adapted. If you then plug in the stock ECU, wouldn't it give out a different reading?
07-22-2002, 04:48 AM
#6
Registered User
s2krob- the AEM EMS is fully programmable and appears to finally work.
UL- Maybe I just didn't see it, but was the "Mugen Equipped" car equipped with header and exhaust? Or just the snorkel?
UL- Maybe I just didn't see it, but was the "Mugen Equipped" car equipped with header and exhaust? Or just the snorkel?
07-22-2002, 06:50 AM
#7
Registered User
Thread Starter
Marcucci - the car was stock except for the ECU and snorkel
turbo-pwr - even with a stock ECU you need to ime to let adapt to your car. If you unplug it, it loses its fuel trim numbers.
HwangTKD - I don't sell the Mugen ECU, so I'm really not in any position to make recommendations on its suitability for daily driving. I do remember discussions about needing to be more cautious in hot climates. I think you'd be best off getting an official statement from Scott at King Motorsports.
S2kRob - Hondata has been using my dyno fro development work. They are working on a reprogrammable S2000 ECU. I have a baseline model in my office which I showed to a few people this weekend.
UL
turbo-pwr - even with a stock ECU you need to ime to let adapt to your car. If you unplug it, it loses its fuel trim numbers.
HwangTKD - I don't sell the Mugen ECU, so I'm really not in any position to make recommendations on its suitability for daily driving. I do remember discussions about needing to be more cautious in hot climates. I think you'd be best off getting an official statement from Scott at King Motorsports.
S2kRob - Hondata has been using my dyno fro development work. They are working on a reprogrammable S2000 ECU. I have a baseline model in my office which I showed to a few people this weekend.
UL
Trending Topics
07-22-2002, 09:48 AM
#9
On moving the power peak: UL, as you might recall, we saw the power peak on my car move from 8300 to 8550 with just VAFC tuning...
07-22-2002, 09:58 AM
#10
Community Organizer
Originally posted by ultimate lurker
Marcucci - the car was stock except for the ECU and snorkel
UL
Marcucci - the car was stock except for the ECU and snorkel
UL
I currently have the same one on my car and do like it. It keeps my air box damn cool. Just currious.
