Car loses power around 5,800rpms
Aug 7, 2011, 03:40 PM
#32
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I may be mistaken, but I don't think they touched the Mivec lobe.
I have spent the better part of the day trying to think of a solution...when it comes down to it the only solution I can think of is that this camshaft is WAY outside the normal operating scope of the factory and reflash map.
Given the complexities surrounding Mivec we are just pushing it. It took 24-36 months after the Evo IX came out before tuners could tune for Mivec correctly.
Lanzer I would be very interested to see your dyno sheets with AFRs if you have any. With you having a ported head I'm curious to see your power curve.
At about 5700 Rpms we achieve max hp, according to my AFR graph I was at 13.1:1 which is crazy lean. Preferably we'd need to be between 12 and 11.5 to maintain or gain any additional hp. My AFRs finally cracked the 12.0 mark at 6700 RPMS and at that juncture I'm so high in the power band I'm not sure we can expect anymore power.
Darewood log your AFRs if you can, I'd be very interested in seeing them.
I have spent the better part of the day trying to think of a solution...when it comes down to it the only solution I can think of is that this camshaft is WAY outside the normal operating scope of the factory and reflash map.
Given the complexities surrounding Mivec we are just pushing it. It took 24-36 months after the Evo IX came out before tuners could tune for Mivec correctly.
Lanzer I would be very interested to see your dyno sheets with AFRs if you have any. With you having a ported head I'm curious to see your power curve.
At about 5700 Rpms we achieve max hp, according to my AFR graph I was at 13.1:1 which is crazy lean. Preferably we'd need to be between 12 and 11.5 to maintain or gain any additional hp. My AFRs finally cracked the 12.0 mark at 6700 RPMS and at that juncture I'm so high in the power band I'm not sure we can expect anymore power.
Darewood log your AFRs if you can, I'd be very interested in seeing them.
Aug 14, 2011, 09:20 AM
#33
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I may be mistaken, but I don't think they touched the Mivec lobe.
I have spent the better part of the day trying to think of a solution...when it comes down to it the only solution I can think of is that this camshaft is WAY outside the normal operating scope of the factory and reflash map.
Given the complexities surrounding Mivec we are just pushing it. It took 24-36 months after the Evo IX came out before tuners could tune for Mivec correctly.
Lanzer I would be very interested to see your dyno sheets with AFRs if you have any. With you having a ported head I'm curious to see your power curve.
At about 5700 Rpms we achieve max hp, according to my AFR graph I was at 13.1:1 which is crazy lean. Preferably we'd need to be between 12 and 11.5 to maintain or gain any additional hp. My AFRs finally cracked the 12.0 mark at 6700 RPMS and at that juncture I'm so high in the power band I'm not sure we can expect anymore power.
Darewood log your AFRs if you can, I'd be very interested in seeing them.
I have spent the better part of the day trying to think of a solution...when it comes down to it the only solution I can think of is that this camshaft is WAY outside the normal operating scope of the factory and reflash map.
Given the complexities surrounding Mivec we are just pushing it. It took 24-36 months after the Evo IX came out before tuners could tune for Mivec correctly.
Lanzer I would be very interested to see your dyno sheets with AFRs if you have any. With you having a ported head I'm curious to see your power curve.
At about 5700 Rpms we achieve max hp, according to my AFR graph I was at 13.1:1 which is crazy lean. Preferably we'd need to be between 12 and 11.5 to maintain or gain any additional hp. My AFRs finally cracked the 12.0 mark at 6700 RPMS and at that juncture I'm so high in the power band I'm not sure we can expect anymore power.
Darewood log your AFRs if you can, I'd be very interested in seeing them.
Aug 15, 2011, 08:19 AM
#37
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At this point I have to believe either it's an A/F issue or timing is off. That's the only thing I can think off.
My understanding is that the factory timing is very good...but it could very well be that working with an aftermarket CAM it gets a little kooky. Could be that cam gear timing i needed.
My understanding is that the factory timing is very good...but it could very well be that working with an aftermarket CAM it gets a little kooky. Could be that cam gear timing i needed.
Aug 15, 2011, 07:39 PM
#39
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Nothing back fro Delta.
Here's my dyno graph with AFRS.
At the 150 HP side marker, the 4th intersection in is where I made peak torque...you can't see it here but I checked it against my other dyno graph. At peak torque I should be at around 12.5:1 for optimum performance, but if you notice I'm hovering around 14. CRAZY lean. As I get higher into the powerband I need to drop down to about 11:1 to avoid power drop off like we've all experienced.
Peak torque comes at 4K Rpms and I need to richen that point...so in summary I am leaving a lot of power on the table with my current tune.
One more thing, peak power normally comes in around 5900 rpms....that has shifted left and I now hit it at around 5300 rpms...powerband has shifted.
I hope this bring a little more clarity to the situation for those experiencing power loss.
If you have questions about this dyno chart please let me know.
Dacib or Darewood please log your AFRs if you can.
Here's my dyno graph with AFRS.
At the 150 HP side marker, the 4th intersection in is where I made peak torque...you can't see it here but I checked it against my other dyno graph. At peak torque I should be at around 12.5:1 for optimum performance, but if you notice I'm hovering around 14. CRAZY lean. As I get higher into the powerband I need to drop down to about 11:1 to avoid power drop off like we've all experienced.
Peak torque comes at 4K Rpms and I need to richen that point...so in summary I am leaving a lot of power on the table with my current tune.
One more thing, peak power normally comes in around 5900 rpms....that has shifted left and I now hit it at around 5300 rpms...powerband has shifted.
I hope this bring a little more clarity to the situation for those experiencing power loss.
If you have questions about this dyno chart please let me know.
Dacib or Darewood please log your AFRs if you can.
Aug 16, 2011, 06:29 PM
#43
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I thought you needed a wideband to get an accurate AFR measurement. The stock O2 sensor is just not accurate enough to get a real reading. Or is is only true for a AFR gauge?
Aug 21, 2011, 11:55 AM
#44
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I will try to get some readings, but sadly it wont happen for a while. Vacations and an anniversary steal a lot of money haha. Also I think Ralliartimus is correct, I thought the stock sensor isn't good enough for that?
