Originally posted by Russ:
Does running up to 8500 RPM concern you at all? Have you upgraded your oil pump gears (as recommended on Dali's site) or done anything else to the motor to handle the extra revs?
Good question!
I cross my fingers figuring that if the engine can blow apart at 8300 then it can just as easily blow apart at 8000. That is, if one thinks an additional 200-300 rpm will toast their oil pump or engine then they should be crossing their fingers at 8000 too. Clearly we don’t have a problem with our engines or oil pump gears at 8000. Is the additional 250-300 rpm pushing things to their limit or over? I don’t know the answer to that question, what is obvious is that it is pushing things closer to their limit. Kent Shepley showed us a toasted NSX oil pump at the Laguna Seca NSXPO and indicated that indeed the gears were capable of shattering at severe RPMs. I’m not sure anyone knows what exact RPM those gears saw before giving up, but my bet is that the engine they were hooked to was at something well over 8300 rpm when they blew.
Just from my own opinion formed from reading these forums and email lists, it seems that valve/piston interference is more commonly associated with high RPM damage than oil pump failure. Over the years, my own engine has seen excess of 9000 RPM several times on screwed up downshifts when I was learning how to heal-toe at the track and occasionally sees 8300 with the dali chip mod. My engine has not blown yet. Am I lucky? Will my luck run out? Who knows?
When we mod our cars, we take a certain risk of overloading a designed feature of our vehicles. Whether it be taxing our electrical system with a new, more powerful head unit or headlamps, or taxing our suspension with wheel/strut/spring/sway bar mods or overheating our brakes with brake pad/rotor mods or playing with aerodynamics with body mods. Each mod can have (and in many cases has had) its own severe and catastrophic effect whether it be fire, break failure, suspension failure, unexpected handling characteristics or engine failure.
Some people are fine with suspension modifications (wheels/tires/struts/springs/sway bars) that change the designed handling characteristics in a way which may and in many cases, has contributed to loss of vehicle control and severe damage (both car and human). Some people who are fine with taking these risks are not fine with taking risks when it comes to damaging their engine, which is fine. I think it’s wise to understand the risks associated with every mod and manage them accordingly.
I’d be hesitant to use the chip with NOS, FI or IEM without first talking to Mark J. I don’t think there are any advantages to shifting at the higher RPM in terms of reducing 0-60 or ¼ mile times but there may be certain tracks where the extra 200 rpm is nice. If the car is going to see regular high rpm use (like in door-to-door racing) then I think it would be smart to change the oil pump gears regardless of any chip modification.
DanO
... One too many zeros. thanks Ken
