Thundermoose

What part made you think that you should lower your shift light SP? Do you have a dyno plot? unless your power were to really fall off before redline, you're still better to shift a hair before redline.

my car makes max hp at 7500, but is flat to redline (8200). I still shift at redline. This ensures that hp post shift is highest.

ProCoach

I don't recommend that drivers "game" shift lights. Set the lights so they all light up at the desired point of shifting. If you're timing is off, fix your timing.

In most cars without gear dependent shift lights (different splits between the lights in the lower gears, because revs climb quicker in lower gears), the split between the last few lights should get smaller and smaller.

Generally, no more than a 200 RPM split from next to last to last, 300 below that, 400, then 600, etc.

If you find yourself "slow" and bouncing off the limiter (the cardinal sin, it slows you down), then drop them 50-100 until you don't do that.

Arrange the lights so that if 7000 is the desired shift point, 6999 is one less light than you have.

NYoutftr

Now that is another fact, I didn't consider, the engine in climbing in revs much faster in lower gears, than in higher gears.
Thus, if there were .05 second shift duration, the rpm drop 2nd to 3rd is going to be much more than 4th to 5th.

That video was interesting, but circled all the way back to torque vs. HP.
My torque is almost the same (actually a little more) at 200 hp (4500 rpm) as at 290 hp (7000 rpm).
It stays constant from 4300 rpm to 7000 rpm.
That is what started me on this quest to find optimal shift points.

But now Pro Coach, brought the difference in rev acceleration in lower gears, which is absolutely a fact

Wild Weasel

ProCoach

Yep. That's the goal.

OP, don't get waylaid.

You're on the right track. You now have a good tool. Set it to the OEM redline and use it.

Thundermoose

Don't worry about torque, hp is what you want to focus on.

Where do you think this guy would shift?

mark kibort

the video was more for dave who really doesnt get it, but for you , i see you are thinking about it and thats good
you missed one very important point of the video. it's not about the engine torque values after the shift, its about the engine torque x engine speed (after a shift and through different gear ratios which changes rear wheel forces.), or in other words, HP..

Even though your torque is the same from 4500 to 7000rpm what is the HP level at 5800rpm. (after a 7000rpm shift) or at( 5000rpm after 2-3rd gear shift ) if the HP is as high or lower you shift at 7000rpm. this is because when you shift , you shift out of a higher numerical ratio (more mechanical advantage) vs the next gear that has a lower numerical ratio and less of a mechanical advantage. you can play with the gear ratios and engine torques and RPM, or you can just compare HP vs RPM for the gear spacing. its much easier that way

again, the entire point is to maximize HP. it never pays to shift at max HP, always a little after it, this brings the average HP up.. go back and look at the graphs i made so you can see it visually.

mark kibort

Thats a good one.... how about this one as well.



Or this one...BMW with HP limited by electronics to take advantage and opimize for Hp/weight rules.

rlm328

I take it you have never been in a rolling start at the beginning of a race. You can not hear anything but the noise coming from the cars surrounding you. Shift lights are needed.

winders

Wild Weasel

Veloce Raptor

Indeed. We had a nice long respite from his crap. I guess it's over.

LuigiVampa

At the start of my first ever race I was like "what's wrong with my car?"

Oh yeah - I gotta shift out of second!

I don't really use the shift lights but I like the fact that they are there.

mark kibort

I think you are agreing with me and others on this point, correct? Dave,do you understand????? what he is saying is exactly right. why would you shift before max HP when max HP is the greatest point of acceleration you will ever have at ANY speed. (yet again, the proof, acceleration = power/(mass x velocity) . Furthermore, past max HP is STILL greater than any "meat of the torque curve" that you will ever find.
the real and only question is, "how far past max HP do you go?" Not if, but when do you shift.

This was an informative thread until you chimed in with your nonsense and ingorance. please , stick to teaching the DE line... something you know about.
you are wrong dave and its sad you cant look in the mirror and with ALL the information here, figure it out.



Winders, you are going to stand around and let bozos spread complete falsehoods about one of the most basic concepts of racing. AND, dont forget , we are trying to help someone with an answer to a quesiton . when to shift.. had Dave not chimed in about something he has no clue about.... this wouldnt have gone sideways.

below, you are going to let someone in the race community spread this kind of misinformation? and you are ok with it and then send an insult my way? :confused"

You said this:


and then Dave says this and still stands by his "thoughs" and poor advice. ....................



that is a good reason..... a well as i know my car... at Autoclub speedway, that happened to me... i couldnt hear anything and forgot for a sec to shift and banged off the rev limiter.. droped a spot.

mark kibort

Thanks for that announcement . I'm sure we all are impressed. Dave, take a hint.. please learn about the subject before you go "advising" people on incorrect interpretations of reality and fact.
you made a statement and over the years, continue to not be able to understand, nor back it up, even after the list here has shown you the truth.

as soon as you find a HP /torque curve where it pays to shift at or before max HP , i will apologize to you, and never post on the racing board again! news flash...........that will never happen! so, STFU!!

the reason we have this conflict, is that we are helping a Lister understand the basic physics here and you chime in and make a mess of it. STOP! you should put anything relating to HP or torque on "ignore" .