AP2 vs. AP1
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From: Flintstone GA
Originally Posted by ralper,Aug 20 2006, 08:46 AM
I have exactlly the same problem with my Si. My S (AP1) revs to 9,000. My Si revs to 8,000. While I never redline the S, I am always bouncing the Si off of the redline.
But then again I usually have an extra rev limiter on board asking "What are you doing to my car?".
Joined: Jun 2005
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From: 407 Miles E of the Dragon
Originally Posted by ralper,Aug 20 2006, 08:46 AM
I have exactlly the same problem with my Si. My S (AP1) revs to 9,000. My Si revs to 8,000. While I never redline the S, I am always bouncing the Si off of the redline. This makes me feel that I too would have trouble making the adjustment to the AP2.
I've often wondered if the reason for the lower revs in the AP2 has less to do with the capability of the engine and more to do with the warrenty claims for bent valves made by people who overrreved the engine. The simplest way to prevent overreving is to lower the redline by 1,000 rpm. Set the rev limiter to 8,000 and you decrease the likelyhood that people will downshift at a speed that will put the engine much above 9,000 rpm.
Since the AP2 there seems to be a significant decrease in the number of threads about damage caused by overreving. I have no doubt that people still downshift at too high a speed, but now the rpms stays (while over the redline) in the safe range of the engine.
I think the biggest difference in the two engines is the chip controlling the revs. Bore the engine a little for more displacement and more torque, lower the rev limit and you have and AP2.
I've often wondered if the reason for the lower revs in the AP2 has less to do with the capability of the engine and more to do with the warrenty claims for bent valves made by people who overrreved the engine. The simplest way to prevent overreving is to lower the redline by 1,000 rpm. Set the rev limiter to 8,000 and you decrease the likelyhood that people will downshift at a speed that will put the engine much above 9,000 rpm.
Since the AP2 there seems to be a significant decrease in the number of threads about damage caused by overreving. I have no doubt that people still downshift at too high a speed, but now the rpms stays (while over the redline) in the safe range of the engine.
I think the biggest difference in the two engines is the chip controlling the revs. Bore the engine a little for more displacement and more torque, lower the rev limit and you have and AP2.
Joined: Oct 2002
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From: Canton, MA
Originally Posted by ralper,Aug 20 2006, 08:46 AM
I have exactlly the same problem with my Si. My S (AP1) revs to 9,000. My Si revs to 8,000. While I never redline the S, I am always bouncing the Si off of the redline. This makes me feel that I too would have trouble making the adjustment to the AP2.
I've often wondered if the reason for the lower revs in the AP2 has less to do with the capability of the engine and more to do with the warrenty claims for bent valves made by people who overrreved the engine. The simplest way to prevent overreving is to lower the redline by 1,000 rpm. Set the rev limiter to 8,000 and you decrease the likelyhood that people will downshift at a speed that will put the engine much above 9,000 rpm.
Since the AP2 there seems to be a significant decrease in the number of threads about damage caused by overreving. I have no doubt that people still downshift at too high a speed, but now the rpms stays (while over the redline) in the safe range of the engine.
I think the biggest difference in the two engines is the chip controlling the revs. Bore the engine a little for more displacement and more torque, lower the rev limit and you have and AP2.
I've often wondered if the reason for the lower revs in the AP2 has less to do with the capability of the engine and more to do with the warrenty claims for bent valves made by people who overrreved the engine. The simplest way to prevent overreving is to lower the redline by 1,000 rpm. Set the rev limiter to 8,000 and you decrease the likelyhood that people will downshift at a speed that will put the engine much above 9,000 rpm.
Since the AP2 there seems to be a significant decrease in the number of threads about damage caused by overreving. I have no doubt that people still downshift at too high a speed, but now the rpms stays (while over the redline) in the safe range of the engine.
I think the biggest difference in the two engines is the chip controlling the revs. Bore the engine a little for more displacement and more torque, lower the rev limit and you have and AP2.
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From: The (S)Low Country
Originally Posted by Legal Bill,Aug 20 2006, 10:17 AM
Again, FWIW, the AP2 is not a bored out AP1 motor, it is stroked. This means the piston travels further in the bore. This means that at the same RPM, the pistons in the AP2 are traveling faster and further than the pistons in the AP1. Piston speed is a genuine concern with respect to engine failure. It effects the pistons, the rods and the crank.
Guess I'd better run out and buy that extended warranty I haven't decided about yet. Can't have my pistons, rod and crank in jeopardy. +1 feels the changes that Honda has made to the new engine are excellent changes, but he has similar sentiments to those that Matrix addressed earlier about rpms, etc. I am very conscious of over-revving ANY engine and watch those rpms. The AP2 sounds are more subdued than the AP1, so I've become more in tune with watching the tach than I was with the old one. Bear in mind I'd driven the 01 for almost five years, so I often felt I'd become "one with the car". Its going to take a little time to grab that feeling with the 06. I have NO REGRETS about making the switch and think it was the appropriate decision to make. I do feel kind of sad for all those folks who never had one of the AP1s and whose only experience with the S is the AP2. The AP1 gave a sensation of raw sports car driving that I really do not feel with the AP2. I'm not underestimating the AP2. It is FINE, but it is not as appealing to the purist heart as the AP1.
Joined: Nov 2002
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From: Arlington, VA
^ I agree...it's a different driving experience. I have no regrets, either. I got the extended warranty, like last time, although I barely had to use that one. It did cover the differential work I had done after the aborted OH trip, though.
my Suzuka baby!!
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From: Randolph, NJ
Originally Posted by Legal Bill,Aug 20 2006, 10:17 AM
Again, FWIW, the AP2 is not a bored out AP1 motor, it is stroked. This means the piston travels further in the bore. This means that at the same RPM, the pistons in the AP2 are traveling faster and further than the pistons in the AP1. Piston speed is a genuine concern with respect to engine failure. It effects the pistons, the rods and the crank.
I agree that the pistons are traveling faster and farther, but I think the engine could have stood 9,000 rpm. I think the 8,000 rpm redline is a result of American Honda and all of the bent valve warrenty claims.
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From: Randolph, NJ
Originally Posted by raymo19,Aug 20 2006, 08:43 AM
You really like tossing the Si around don't you? I've yet to hit the rev limiter so far in ours but have wound 2nd and 3rd pretty close to redline, especially on freeway on ramps.
I didn't think it was possible to find another car that is as much fun as my S, but my Si is. Both cars make me smile.