Tut just curious, but have you looked into an electronic boost controller that reduces boost at higher rpms or are you trying to this with just the throttle plate? I guess not having one more thing to screw with is good..

One thing I never quite understood with all these classes is how they can clearly enforce HP limits/etc without cheating.. These days it'd be easy at the flick of a switch to easily change your boos/fuel/timing maps. I guess there's some level of honesty required..

 

There are rules against that, and I like to think they will have smart people there to enforce things. I might be the only turbo car in TT3 anyways as most are going to be DBW BMWs and Corvettes. I know they tape over the OBDII port, so I can't leave my FlashPro plugged in like I do for every session to datalog. They obviously don't allow any map switching unless you mention it in the dyno form and have dyno sheets for each map (cars like EcuTek BRZ/FR-S that switch maps with the cruise control). Original plan was to send my ECU to Hondata and have the boost control added, and then use DBW as a secondary restriction. I really don't want the down time or additional cost and complexity of switching to an electronic boost controller. I'd rather ramp the boost with a manual boost controller and then limit it with the throttle plate. Heck if I was confident a tuner could do it properly, I might just let them do it instead of buying a day or two of dyno time and doing it myself.

 

After thinking about Tut's issue some more, I really think that the throttle mapping will be pretty simple. I don't think it's going to require a finely tuned "curve" in the throttle plate mapping at all. I think it's just going to require a flat / constant restriction starting around 3K RPMs. Basically, you need to create a restriction that limits air flow to some fixed number of liters per minute, regardless of RPM. You just need to determine how much throttle restriction is required to do that.

 

That will maximize mid RPM horsepower and limit top RPM horsepower? I really want the motor on full song until it nears 322 whp at which point I start limiting the power. That point will be somewhere between 5000 and 6000 RPM.

 

I believe it should, since the throttle plate has very little impact on flow once it's opened enough to allow "full load". Opening the plate more than that amount mainly impacts acoustics / resonance, which don't matter much in FI applications. I think that once you find the magic throttle position that limits peak power to what you need, I think that same throttle level may not reduce midrange much at all, if any.

I think I mentioned it earlier in the thread, but my approach would be to restrict the throttle to something like 20% max, then do some WOT datalogs in 3rd gear. If you want to email the datalogs to me, I'll run them through my software dyno.

 

That would be great. I will do some datalogs starting at 20% and going up to say 50% every 5% and see how the car responds.

 

Try to find a flat road where you can do repeatable pulls in the same direction from the same spot without attracting too much attention to yourself. If you can do 3-4 pulls with each throttle setting, that would be good. Also, record the datalog on the FlashPro itself, so that it has the highest possible sample rate.

 

Yup I think this is the answer. Of course it takes some physics to do the calculations. Merely dropping the throttle % steadily is a much more brute force/non intellectual approach that also should work.

 

I have a perfect road for this. I always datalog on the FlashPro itself. I will bring my laptop just to flash the throttle change calibrations.

 

I struggled in Physics I and II in college, so if you could just do those calculations that would be great mmmkay.