9K AP2
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From: Mt. Pleasant, SC
Originally Posted by vishnus11,Oct 10 2006, 10:38 AM
Although, I agree with the fact that Honda had to drop the fuel cutoff from 9200 to 8200 due to the increased stroke, the drop didn't have to be that significant. There's a thread floating around on acurazine.com which details the production cars with the highest piston speeds. Of course the AP1 S2000 is at the top with something like 4795 ft/sec. However, the AP2 exhibits a lower piston speed, and I don't see why it does. If anything, it should have a similar piston speed to the AP1, which would put the fuel cutoff somewhere between 8200 and 9200rpm.
I believe that this is one of the reasons why Hondata felt confident in bumping up the fuel cutoff of the AP2 from 8200 to 8500rpm. 8500rpm on the 2.2 would probably produce similar piston speeds to 9200rpm on the AP1.
My advice would be to figure out what rpm in the AP2, gives the same piston speeds as in the AP1, and then bump the redline up to or around this area, and then adjust the fuel/air maps to compensate.
Or just get Hondata.
I believe that this is one of the reasons why Hondata felt confident in bumping up the fuel cutoff of the AP2 from 8200 to 8500rpm. 8500rpm on the 2.2 would probably produce similar piston speeds to 9200rpm on the AP1.
My advice would be to figure out what rpm in the AP2, gives the same piston speeds as in the AP1, and then bump the redline up to or around this area, and then adjust the fuel/air maps to compensate.
Or just get Hondata.
as others has said it is due to increased stroke. I would feel comfortable taking it a tad higher but certainly not to 9k.
The hondata however is not made for his MY but he could use a standalone...
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From: Charlotte, NC
Originally Posted by Mulder ATO,Oct 10 2006, 10:50 AM
If you wanted to rev to 9K, you should have bought an Ap1.
suprfunguy, do you not think the blower would have changed the result of the power dropping?
All in all, sounds like its not worth it without doing significant mods to make it worth while, but not necessarily reliable.
Thanks again everyone for chiming in.
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From: Myrtle Beach, SC
I've been running an ap1 ecu for over a year now. You can probably do a search as I posted both dynos of my stock ecu and the ap1. Basically the stock ecu showed greater peak of 220/155 while the ap1ecu did 215/153 but there's more power under the curve when you take into shift points and what not. I had a table with the diff equations I had done and I think it was a 7-8% better than the stock ecu, but I can't remember exactly off hand. Also, I only rev to 8500
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From: Dry Branch
I could be wrong, but I believe a few members are running AP1 ECU's in their AP2's, and reving to 9,100 (the AP1 rev limiter kicks in at 9.1k, not 9.2k). I did some calculations back when I first got my AP1 (right after the AP2 came out), and on paper the piston speed of the AP1 exceeds the theoretical limit at which the cylinders can be lubricated by any conventional means. Honda was able to make it work by using a number of tricks (mostly straight from F1 cars) including abbreviated piston skirts and their chioice of block alloy (among other things) to make the high piston speeds reliable in long-term use. Reving an AP2 to 9,100 yields even higher piston speeds, becaues of the longer stroke, but there is probably enough of a margin in the engine design to get away with it. Maybe. 
If I had an AP2 I wouldn't rev it higher to make a little more power, beause there are cheaper, proven ways to make more power.
If I had an AP2 I wouldn't rev it higher to make a little more power, beause there are cheaper, proven ways to make more power.
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From: SIN CITY - Las Vegas
Originally Posted by RED MX5,Oct 10 2006, 11:16 AM
I could be wrong, but I believe a few members are running AP1 ECU's in their AP2's, and reving to 9,100 (the AP1 rev limiter kicks in at 9.1k, not 9.2k). I did some calculations back when I first got my AP1 (right after the AP2 came out), and on paper the piston speed of the AP1 exceeds the theoretical limit at which the cylinders can be lubricated by any conventional means. Honda was able to make it work by using a number of tricks (mostly straight from F1 cars) including abbreviated piston skirts and their chioice of block alloy (among other things) to make the high piston speeds reliable in long-term use. Reving an AP2 to 9,100 yields even higher piston speeds, becaues of the longer stroke, but there is probably enough of a margin in the engine design to get away with it. Maybe. If I had an AP2 I wouldn't rev it higher to make a little more power, beause there are cheaper, proven ways to make more power.
If I had an AP2 I wouldn't rev it higher to make a little more power, beause there are cheaper, proven ways to make more power.
also, the side loads of the pistons on the cylinder walls might be too much already at 9100 RPM.
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From: Myrtle Beach, SC
it's an my01 ecu and I have the modifry shift beeper set at 8500. I have not thrown a cel. From the dyno, it's a little lean at vtec, settles, and then dumps crazy rich at 7600+. Interesting note though, vtec appears to come in at 5800 on the ap1 while the ap2ecu is 6k
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From: Potomac Falls, VA
Putting the MY02-03 ECU in the AP2 would probably be a bad idea. It was recommended that AP2 owners doing this swap use the 00-01 ECU because it ran richer which was good to prevent detonation on a larger displacement engine.
As far as revving above 8200rpms, the car does seem to make more power with Hondata revving up to 8500rpms with some light bolt-on mods, so I don't think you necessarily lose power by adding rpms. I'm not sure if 9000rpms would gain you more power.
Hondata Dyno Graphs
8500rpms is what had been calculated as a "safe" level for piston speeds in the AP2, so it wouldn't exceed the piston speeds of the AP1.
As far as revving above 8200rpms, the car does seem to make more power with Hondata revving up to 8500rpms with some light bolt-on mods, so I don't think you necessarily lose power by adding rpms. I'm not sure if 9000rpms would gain you more power.
Hondata Dyno Graphs
8500rpms is what had been calculated as a "safe" level for piston speeds in the AP2, so it wouldn't exceed the piston speeds of the AP1.