^^^ Yea im trying a slightly softer approach to the spring setup after reading about your experiences. Im starting out with 700 front and 600 rear... plus im trying to live with mine on the street too... down the line when I have another car I may step up the spring rate a little, We'll see how I like this setup

 

There seems to be two limiters - a soft one that the first scenario and a hard limiter like the latter. It appears to be related to how fast you approach the limiter so perhaps you're just at the point of being more experienced and able to induce the hard limiter easier.

I've only hit the hard limit once and it was certainly different...

 

Very interesting thought. I would not have ever thought my driving skills/experience would have been a variable. There is another AP1 driver locally that experienced the same situation where it did the soft limiter when with lower miles and as more miles clicked up (or more experience/skill), he got the hard limiter more frequently.

I was hoping that maybe prepping for STR might get rid of this, so it is semi on topic. LOL

-D

 

Dave, I know exactly what you're talking about and I think it has to do with how hard you are accelerating when you hit the rev limiter. Try this sometime and see how it works with your car - accelerate up to about 8,500 rpm and then ease off the throttle a bit so your at about 3/4 throttle (or even less maybe) when you reach 9,000 rpm. When the rev limiter activates, you should get the quick "bah bah bah bah". Try it again with full throttle and you'll get the more drawn out "buuuuuuuuuuuuuuuh bah bah", as you put it. At least that is how it behaved when I tried the above process with my 80k mile AP1.

I'm not very knowledgeable about the stock S2k ECU programming, but I wouldn't be surprised if it has two methods of rev limiting. Initially it will retard timing in an attempt to keep the rpm at 9,000. This is the softer rev limit with the "bah bah bah bah" sound. If you approach the rev limit under hard acceleration, you'll reach a greater rpm. The ECU will then cut the fuel to control the rpm, which results in the more drawn out rev limit characteristics. That's my theory of how it's set up from the factory.

 

Awesome stuff guys!! When the weather isn't so stupid cold outside, I'll take it out for a spin. I am betting you guys are dead on.

I'm a very easy going kinda guy, but this symptom, fuel starving and/or understeer in a run just infuriates me.

So... what is it going to take to have a legal ECU mod for those that have the "old" S2000's? I for sure would want to kill that hard limiter...

-D

 

basically they would have to allow piggybacks that only control what is currently allowed. This is actually up for membership comment, I sent in a letter myself

 

i have experienced the same thing with my ap2's.

 

A friend of mine has a MegaSquirt in the Miata ECU housing and is considered legal... or at least a couple of these Miatas competed (and trophied) at Nats last year without protest.

Maybe there is a similar solution that could be had for us?

-D

 

It was discussed briefly on page 5 of this thread...

https://www.s2ki.com/forums/index.php?showt...&#entry16912338

Not a valid solution at this point, unfortunately.

EDIT: Fixed link...

 

Crap... forgot about that... 29 pages ago. Maybe it didn't register with me with it being pointed out with different spellings/acronyms. Nah... My brain just doesn't remember worth a d@mn. Sorry!

-Dave