Are people really doing 8800 RPM with the flashpro? I thought it was more like 8500. 8500 is not too bad. I did the calculations. Here are my notes:

AP1 @ stock cutoff 9000 RPM
Max Piston Speed ft/s: 8331
Max Piston acceleration positive/negative (g): 2906 / -5019

AP2 @ stock cutoff 8200 RPM
Max Piston Speed ft/s: 8016
Max Piston acceleration positive/negative (g): 2504 / -4446

AP2 @ 8500 RPM
Max Piston Speed ft/s: 8310
Max Piston acceleration positive/negative (g): 2690 / -4777

AP2 @ 8800 RPM
Max Piston Speed ft/s: 8603
Max Piston acceleration positive/negative (g): 2883 / -5120

So at 8500 RPM, I feel moderately OK with it, since the max piston speed is about the same and the max piston acceleration is actually less. But at 8800 RPM, you're upping maximum speed by 3-3.5% compared to the AP1 - which was already a very high speed. Plus it worries me that they gave themselves so much extra wiggle room on the AP2 - I'm not sure why they did that? Can it not handle the same forces?

Also, none of this takes into account floating valves or anything like that, since that would depend on the camshaft profile. Anyone have any idea if the camshaft profile is significantly different between AP1 and AP2?

I'm really, really hoping this class doesn't get to the point where it's either engine reliability or competitiveness.

 

AP1s are 9000 RPM rev limiter.

 

I think this is a matter of the grass is greener on the other side. FWIW, my dyno numbers I posted up were measured on a dynopak at the hubs, which reads substantially higher than at the tires. Peak power was 224hp (227 with the hood left open, but I’m not interested in autocrossing with the hood open), which is 26hp down on the 06+ AP2s on the same dyno with similar mods and a flashed ecu. I used 1st gear once on each course, and I assume the AP2 guys did too. Maybe Nick or Matt can chime in, but with the raised limiter, I don’t believe 3rd gear was a big issue for the reflashed cars.

Honestly I think my nationals results were mainly a function of how well my car was handling at that site. I run A LOT of front bar, really low, the rear wing helped, and the hankooks worked great. I didn’t drive out-of-my-mind, I just setup the car to where it’s boarderline boring and easy to drive fast.

Clearly I think the AP1s are competitive and will continue to run mine because I’m not interested in making car payments at pretty much any point in my life. So if you’re shopping for an STR S2000 and have a tight budget, get any AP1 (02-03 will be a little heavier but so what). But if you want to spend lots of money get an 06+ or a CR. Until the ECU rules change the main ones I’d stay away from are the 04-05, but the AP1 ECU trick may work there.

 

Good to hear. Any chance you could post a dyno plot?

Also, is the 02-03 AP1 that much heavier? I thought it was like 25 lbs?

 

Jon, Interested numbers with the piston velocity and accelerations. Either way, 8800 rpm scares the crap out of me in an AP2. The stock AP1 piston velocities are actually above an F1 engine, iirc.

If I ran a reflashed AP2 I'd probably get in the habbit of changing rod bearings once a season just for peace of mind. They're cheap and it's really really easy (especially after you know what sizes you need). Like... $50 or so from HPD.

 

[QUOTE=IntegraR0064,Sep 21 2010, 03:45 PM] Good to hear.

 

oops! Yeah I must have been at work. Work blocks most images, and it doesn't even show broken links or anything to signify that there is an image I should check out when I get home.

Thanks!

 

[QUOTE=Aristoi,Sep 21 2010, 04:00 PM] If you do not benefit from the AFR, do you still benefit for increased redline/fuel cutoff point?

 

Never touched 1st or 3rd. Went straight to 2nd and the car was never out of the powerband on either course.

 

What do you have your rev limiter set to?