Here is a side by side comparison of Ap1 and Ap2 mean piston speeds and max accelerations.

Mean Piston Speed(m/s) Max Acceleration(m/s^2)

RPM Ap1 Ap2 Ap1 Ap2
8200 23.1 24.8 39,699 43,573
8300 23.4 25.1 40,673 44,642
8400 23.6 25.4 41,659 45,724
8500 23.9 25.7 42,657 46,819
8600 24.2 26.0 43,667 47,928
8700 24.5 26.3 44,688 49,049
8800 24.8 26.6 45,721 50,183
8900 25.0 26.9 46,766 51,330
9000 25.3 27.2 47,823 52,490
9100 25.6 27.5 48,892 53,662
9200 25.9 27.8 49,972 54,848
9300 26.2 28.1 51,065 56,047
9400 26.4 28.4 52,169 57,259
9500 26.7 28.7 53,284 58,484
9600 27.0 29.0 54,412 59,721
9700 27.3 29.3 55,552 60,972
9800 27.6 29.6 56,703 62,236
9900 27.9 29.9 57,866 63,512
10k 28.1 30.2 59,041 64,802

 

noone can prove your point because your point is completely wrong. You made no sense whatsoever, and wrist pin wear...where did you come up with that? You need to do some reading on how engines work I think.

 

bro im tellin you this from doin it 8500 its your limit unless you like blowin money and motors

 

I dont see why you cant rev F22 same as F20 as long as head is sufficient. Most of the time failure is in the head from over revving.

 

read everything in this thread and then youll know, reading owned you badly.

 

I did read the whole thread. I came from high HP B series. I never messed around F series. I just dont see how bottom end would be effected much by 9K revs. you would have more of a failure with retainer letting go.

 

u did not comprehend the whole thread then. especially the piston speed chart.

if u rev an ap2 to 9k consistently it will = fail.

 

If you read the whole thread, you would see the piston speed chart above...and realize that revving an ap2 engine too much sends the piston speed VERY high which leads to your rod cap ends being stressed beyond belief, and lots of piston loading.

 

Let me add some food for thought. My car is not FI in anyway, but I'm currently running my 04 Ap2 with a 01 ECU. Now, one must understand that even that I have an 01 ECU that >>DOES NOT << mean I have to rev to 9K all the time. Anyway, the table I provided above is some what hard to read, considering all of the numbers. I tried to make a picture of the excel table but then figured out that I don't know how to upload it here.

Anyway, below are my observations from the calculations.

Case 1) At 8500 rpm, the Ap2 piston speed and acceleration are roughly the same as the Ap1 at 9000. If we use the Ap1 as our safe indicator, then yes this is how high (8500) the Ap2 should rev to maintain reliability.

Case 2) I read on this board that Sideways(?) has his supercharged Ap1 running to 9400 rpm, I think that his internals are not stock (can someone help me verify and fill me in on this?). I also don't know if he revs his to 9400 rpm on the daily basis or was it just for dyno purposes. Anyway, according to my calculations the Ap2 reaches roughly the same mean piston speed and max piston acceleration at 8700 rpm and 9000 rpm respectively. So if the Ap1 can handle this much piston acceleration why can't be Ap2?

My opinion: I don't think it really matters if the car is N/A or FI, whether is it being pulled or pushed, speed and acceleration are still speed and acceleration. If you want to play safe and have a piece of mind, set it at 8500 rpm.

If you think that you must have that other extra 500 rpm and feel that the reduction in engine life is worth it, then by all mean do it. I don't think you will blow your engine at 1,000 miles or 5,000 miles. If I have to GUESS, I would say the engine life would be reduced say ~30%?. FYI, there has been only one reported Ap2 failure with an 01 ecu, it failed at 8800 rpm. I understand that there are other means of getting higher rpm without using the 00-03 ecu's. To conclude, I think if you really want to play with 9k on the daily basis, you gotta be willing to pay.

Note: If you look at the table, you'll notice that the Ap2 reaches the mean piston speed at a much lower rpm than the max piston acceleration when compared to the Ap1 numbers.

 

Ok so I will ask this, has anyone built a custom AP2 block with longer rods and pushed the wrist pin up into the ring pack and used buttons for the rings to get the right rod to stroke ratio to run there motor higher (I did this on a B series motor to increase it to 2.0L but with a better rod/stroke ration than than the original stoke B18C1 Motor had).

This would help reduce the sideloading on the pistons. Also the AP1 and AP2 both have the smaller side skirts if I am correct on the pistons right? (to obviously reduce the amount of area that would cause wear on sideloading)

I had the rods center laser cut to give additional wristpin oiling as well.

Food for thought and would like to hear the points/counterpoints on doing this with a new built motor.

Lucky7s