T&A Racing wrote:
AJ Hartman wrote:
I have no problem saying I submitted this one after my DQ at nationals for being 2tq over at 2300rpms.
RCR-AI-093016 dyno procedure change - ignore power below 3000
Recommended Changes: I would like to add a dyno procedure to the rule book for turbo charged cars in which the power prior to 3000 rpm is negated. Otherwise the dyno procedure will be performed the exact same way. This could also apply to NA cars so one dyno procedure covers all cars, but they don't have this issue.
Reasoning: Due to the turbos spooling up from such a low RPM, they will overshoot, or spike when the throttle is stabbed, and a false readout of Max TQ will occur only for a very brief moment. These spikes are followed by dips of a lower than normal readout, thus almost canceling out the spike. This undulation seems to happen prior to 3000 rpm as the computer and waste gates try to stabalize the system, and seems to steady out in the course of about 200-300 rpms. The readout from 3000 rpm to red line is more representative of true power when the car is on track as the turbos stay spooled up higher and have less of an over shoot, if any, since they are already loaded. Coupled with the fact any power prior to 3000 rpm is useless on track, these spikes before 3000 rpm should not be taken into account.
How I feel this will help the series: I feel it will open up the series to turbo cars. The 3.5 EcoBoost is a fairly easy swap gaining popularity, along with the 2.3 liter that is in the new Mustangs will eventually be coming into the series and both will face the same issue. I feel this will reduce costs associated with these engines as they wont need larger turbos that spool up slower to reduce spikes, wont need externally waste gated turbos as the factory units are internal waste gates, and won't need to pay a tuner tons of money to spend countless hours fine tuning the car for an RPM range that will never be used.
End RCR
Curious how people feel about this one as turbos are coming. I'm the only one at the moment, but we will have to figure something out sooner or later.
AJ, Two clarifying questions, the spike is real right, while maybe not at an RPM that is all that useful, the spike would propel the car forward based on that power. I just making sure we don't think it only happens on the dyno for some reason. Secondly how much higher is the spike than the next highest level of power and torque. I didn't feel that your car was under power as we raced together at WGI, also didn't feel like it was over either seemed pretty consistent with the rest of the group. If we are talking about a significant increase that might be an un-fair advantage to the rest of the field. I would guess it could be tuned out if need be.
Thanks
Makr
I wish I had a rock solid answer for you but I do not. I do not have access to, or the funds to pay someone with a dyno to just do some runs and pulls on a loaded dyno, from varying rpm's, and varying the speed of tip in to come up with a definite answer. I will say that Kevin Adolf (owns Flim Flam Speed and who tuned Steve Nichols car) was arguing FOR me at nationals. His rough take on it was that since its just an inertia dyno we get certified on, and such a low starting rpm, my turbos being so small that when they spool up, and even with the internal waste gate wide open, their inertia coming up will overshoot and cause the spike. Again, being unloaded, that spike is exaggerated. But in real world situations, being loaded and lets say even a low rpm of 3000-3500 rpm coming out of a slower corner, the turbos are already spinning much faster. So stuff happens a little slower so the waste gates can keep up when loaded, and since the turbos are spooled higher already, they don't overshoot as much, or if at all. The other argument I have is on starts this season. Al Watson can attest to this. I think any time I qualified in front of him, he would pass me by turn one. If the spike was real, why wouldn't I get a jump on him at the start?
I know turbos are coming to Ai eventually. Even the 2.3 in the new mustangs can easily make Ai power numbers. Aftermarket computers, or having to upgrade to different turbos with external waste gates, or extensive tuning to mitigate this unusable spike are all expensive options. This is club racing so am looking at it from a monetary standpoint. Hence why I'm just asking for any RPM prior to 3000 rpm to be negated. Otherwise, the dyno procedures will remain exactly the same.