i did a run and hit the limiter. when do you guys shift?

 

The beep is probably the best time, i trust in the tech in this car - however since I've only had it a month i still shift ~200 rpm early since I'm not used to have fast this tranny is yet

 

any one know where the speaker is for the beep and if it is used for anything else? i would like to hook up a relay and a shift light to it. i cant hear the beep with the windows down lol

 

I usually keep hammering it slightly after the blip,

Since I've gotten used to the car I pretty much rape it daily

 

Same Here your shifts are spot on since you're not hitting the limiter where it's bouncing off. Now you're ready for the 1/4 mile runs and do exact shifts have fun and enjoy

 

Yup!, I do the same, slightly right after the beep! I'm wondering now too, where the beep is coming from?...

 

always touch the limiter. don't shift at the beep. this has been covered many of times in this thread:

https://www.clublexus.com/forums/is-...ce-thread.html

 

I would think even grazing the limiter in the ISF will negatively impact 1/4 mile times and MPH. In every car I've owned, grazing the limiter doesn't do you any favors in the 1/4 mile.


Also, has anyone actually calculated the appropriate shifts points seeing that peak power occurs well before the limiter? Just because you can rev that high doesn't mean it's the ideal shift point. Also, ideal shift points can be vary from gear to gear.

 

If someone has torque numbers for the 2UR-GSE in a table format, you can use this spreadsheet to help calculate best shift points. This spreadsheet was originally built by Dan Masters. I have made many edits to it, but he provided the basic functionality. It can be modified to work with any vehicle by changing the blue numbers.

 

What will this chart establish ? It definitely won't establish a better 1/4 mile run if you follow peak tq number at certain Rpm to shift at. It's just a mathematical equation that won't work in real life

 

Why would you do that? You shift at the points providing the most area under the hp curve. Torque has nothing to do with shift points because you want power, not torque.

 

I know I said it won't help anything if you go by tq even if you follow hp figure it's still under the actual rev limit . I've tried before shifting at both peak power or peak tq as some one had suggested before and it doesn't work. Best time come in at riding it out to the throttle limitter 1st blip where at that point the peak hp already drops off on the 2ur . Unless I'm misunderstanding what you're trying to say.

 

Completely. Peak torque shifts are wrong and peak power shifts are wrong. You shift past the power peak to drop back to the same power level you were at when you shifted. If power is flat (torque is dropping) then you stay in it to the rev limit then shift. The idea is you are doing work. Maximum work occurs with the largest area under the power curve, so you set your shift points to ensure you are getting maximum area. The gearing chart helps you calculate this by showing the rpm drop between gears.

If you read the HP vs. Torque document you would also realize if you had an infinitely variable CVT, your engine would run at peak power for the entire run and out accelerate anything with fixed gears.

 

Based on review of a handful of ISF dynos, it appears the peak HP occurs at ~6200rpms with much of the power holding until around ~6400rpms. Fuel cut is at 6800rpms, but has dropped off hard after 6500rpms.


I haven't run the calculations, but my guess would be the ideal shift points would be:


1-2: Just before fuel cut
2-3: 6400-6500rpms
3-4: 6400rpms
4-5: 6200rpms

 

On paper is one thing, but I've found hitting the limiter just a tad works best.