redline/peak H.P/ & H.P curve-When to shift?? :) intresting???

Mitco39 · 09-05-2013, 12:42 PM

I spent quite a bit of time putting this all together last fall. It falls into this topic pretty well I think.

Yes I am a bit of a nerd, lol. But if you care to look through it all you can actually determine through math and physics where you need to shift and how it affects your accelerations.

** Mitco's Acceleration and Gearing Spreadsheet

Chuck33079 · 09-05-2013, 12:48 PM

Quote:

Originally Posted by andre12031948

according to this chart, which stops at 7.5 rpm, I would shift(power) at apx. 8k.

Actually, this chart shows me that it could use 4:08 gears or maybe shifting above 8k. My tune/chart has a long flat line from 6k to 7.5k.

Raising the rev limiter to 8k has a nasty habit of grenading the oil pump.

DEpointfive0 · 09-05-2013, 12:53 PM

Sooooo... For the 370Z, I was pretty right, shift at the dead last second you can, right? Lol

Chuck33079 · 09-05-2013, 12:56 PM

Quote:

Originally Posted by DEpointfive0

Sooooo... For the 370Z, I was pretty right, shift at the dead last second you can, right? Lol

Pretty much. Peak HP is right about at redline, so shift there.

phunk · 09-05-2013, 02:23 PM

In any car, you will probably find that you should shift at the absolute highest RPM you safely can for maximum acceleration. Those of you looking at the dyno chart are not seeing the factor of gearing.

Even if the engine power at your high redline falls below the power you would land at in the next gear, the car will still accelerate faster in the lower gear.

You see.. these chassis dynos that we all use, despite what most understand, are actually measuring the *engine power* AT the wheels... not the *wheel power*. If you were to measure ACTUAL wheel power, you would see how ridiculously more power there is in lower gears then there is at higher gears... but since we are measuring engine power AT the wheels, we see little to no difference from one gear to another on the dyno minus the effects of altered engine load and driveline friction losses.

Shift as high as you can without hurting your engine and within logical reason. Do not skimp on the R's unless there is a solid mechanical or tuning related issue

Chuck33079 · 09-05-2013, 02:28 PM

Quote:

Originally Posted by phunk

In any car, you will probably find that you should shift at the absolute highest RPM you safely can for maximum acceleration. Those of you looking at the dyno chart are not seeing the factor of gearing.

Even if the engine power at your high redline falls below the power you would land at in the next gear, the car will still accelerate faster in the lower gear.

Well, yeah. What the hell do you know about any of this anyway?

Mitco39 · 09-05-2013, 02:44 PM

Quote:

Originally Posted by phunk

In any car, you will probably find that you should shift at the absolute highest RPM you safely can for maximum acceleration. Those of you looking at the dyno chart are not seeing the factor of gearing.

Even if the engine power at your high redline falls below the power you would land at in the next gear, the car will still accelerate faster in the lower gear.

You see.. these chassis dynos that we all use, despite what most understand, are actually measuring the *engine power* AT the wheels... not the *wheel power*. If you were to measure ACTUAL wheel power, you would see how ridiculously more power there is in lower gears then there is at higher gears... but since we are measuring engine power AT the wheels, we see little to no difference from one gear to another on the dyno minus the effects of altered engine load and driveline friction losses.

Shift as high as you can without hurting your engine and within logical reason. Do not skimp on the R's unless there is a solid mechanical or tuning related issue

You're right, technically you would take a dyno chart and multiply it by the gear ratios for every gear. If you do that you will see that in 1st gear a car that peaks at 300hp on a dyno (assuming a 5th gear pull) will actually put down 1477hp (300*4.924). So you want to ride every gear for what its got to get the best acceleration. Because the next gear your now only at a peak power of 958, and so on and so forth.

chrischhorn · 09-05-2013, 02:52 PM

I'll just leave this here........

Car felt amazing with the 4.08 gears too.....

phunk · 09-05-2013, 02:54 PM

I stumbled on a post like 10 years ago, and I was able to locate it just now. I remembered this post because this guys method of explanation is able to clearly isolate the required facts to communicate the idea efficiently and is very easy to read. I would recommend reading all the posts from the OP in this thread, but at least read the very first post.

Gear ratios, final drives, and torque - Team Integra Forums - Team Integra

then after that, if you dont read the whole thread, look at just this one post on the following pages:

Team Integra Forums - Team Integra - View Single Post - Gear ratios, final drives, and torque

notice that at not a single point on the entire graph will you find a gear that is able to put more torque to the ground than a lower gear number, at any rpm/speed at all.

phunk · 09-05-2013, 03:01 PM

and for anyone surprised... YES stock hondas generate over 1500lb fts of torque in first gear. Guess what a stock 370z does!

Mitco39 · 09-05-2013, 03:34 PM

Quote:

Originally Posted by phunk

and for anyone surprised... YES stock hondas generate over 1500lb fts of torque in first gear. Guess what a stock 370z does!

Mechanical Advantage

Sh0velMan · 09-05-2013, 03:42 PM

So this thread has determined what everyone should have already known.

Rev to red line before you shift.

chrischhorn · 09-05-2013, 03:53 PM

Quote:

Originally Posted by Sh0velMan

So this thread has determined what everyone should have already known.

Rev to red line before you shift.

Geez, it has already been determined no......

Sh0velMan · 09-05-2013, 03:56 PM

Quote:

Originally Posted by chrischhorn

Geez, it has already been determined no......

I don't...

I don't understand what you're saying?

DEpointfive0 · 09-05-2013, 04:23 PM

Quote:

Originally Posted by Sh0velMan

So this thread has determined what everyone should have already known.

Rev to red line before you shift.

I said it first!!! Lol

09-05-2013, 12:42 PM	#16 (permalink)
Mitco39 A True Z Fanatic Join Date: Aug 2012 Location: Edmonton Alberta Canada Posts: 2,089 Drives: 40th 370z Rep Power: 131	I spent quite a bit of time putting this all together last fall. It falls into this topic pretty well I think. Yes I am a bit of a nerd, lol. But if you care to look through it all you can actually determine through math and physics where you need to shift and how it affects your accelerations. ** Mitco's Acceleration and Gearing Spreadsheet __________________ 2007 Chevy Duramax - EFILive Tuned By Me 2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her My Build --> http://www.the370z.com/members-370z-...39s-build.html

09-05-2013, 12:53 PM	#18 (permalink)
DEpointfive0 Premium Member Bitches Join Date: Jan 2012 Location: SoCal Posts: 14,824 Drives: a lot Rep Power: 17151	Sooooo... For the 370Z, I was pretty right, shift at the dead last second you can, right? Lol __________________ Do YOU want to know what/where I got my username from? ( Click to show/hide ) NSFW due to language:

09-05-2013, 02:23 PM	#20 (permalink)
phunk A True Z Fanatic Join Date: Mar 2009 Location: Chicago Posts: 3,655 Drives: 370 Rep Power: 944523	In any car, you will probably find that you should shift at the absolute highest RPM you safely can for maximum acceleration. Those of you looking at the dyno chart are not seeing the factor of gearing. Even if the engine power at your high redline falls below the power you would land at in the next gear, the car will still accelerate faster in the lower gear. You see.. these chassis dynos that we all use, despite what most understand, are actually measuring the engine power AT the wheels... not the wheel power. If you were to measure ACTUAL wheel power, you would see how ridiculously more power there is in lower gears then there is at higher gears... but since we are measuring engine power AT the wheels, we see little to no difference from one gear to another on the dyno minus the effects of altered engine load and driveline friction losses. Shift as high as you can without hurting your engine and within logical reason. Do not skimp on the R's unless there is a solid mechanical or tuning related issue Mitco39 likes this. __________________ Charles @ CJ Motorsports : Website \| Facebook \| Instagram \| YouTube Home of the 9 second, stock longblock, stock drivetrain 6MT 370z. 9.91 @ 142mph Last edited by phunk; 09-05-2013 at 02:26 PM.

09-05-2013, 02:52 PM	#23 (permalink)
chrischhorn A True Z Fanatic Join Date: Jan 2012 Location: Mililani, HI Posts: 1,566 Drives: 2014 Juke Nismo RS Rep Power: 16	I'll just leave this here........ Car felt amazing with the 4.08 gears too..... __________________ R.I.P. 8/01/13 1SlowZ One day I'll have another.... Last edited by chrischhorn; 09-05-2013 at 02:54 PM.

09-05-2013, 02:54 PM	#24 (permalink)
phunk A True Z Fanatic Join Date: Mar 2009 Location: Chicago Posts: 3,655 Drives: 370 Rep Power: 944523	I stumbled on a post like 10 years ago, and I was able to locate it just now. I remembered this post because this guys method of explanation is able to clearly isolate the required facts to communicate the idea efficiently and is very easy to read. I would recommend reading all the posts from the OP in this thread, but at least read the very first post. Gear ratios, final drives, and torque - Team Integra Forums - Team Integra then after that, if you dont read the whole thread, look at just this one post on the following pages: Team Integra Forums - Team Integra - View Single Post - Gear ratios, final drives, and torque notice that at not a single point on the entire graph will you find a gear that is able to put more torque to the ground than a lower gear number, at any rpm/speed at all. chrischhorn likes this. __________________ Charles @ CJ Motorsports : Website \| Facebook \| Instagram \| YouTube Home of the 9 second, stock longblock, stock drivetrain 6MT 370z. 9.91 @ 142mph

09-05-2013, 03:01 PM	#25 (permalink)
phunk A True Z Fanatic Join Date: Mar 2009 Location: Chicago Posts: 3,655 Drives: 370 Rep Power: 944523	and for anyone surprised... YES stock hondas generate over 1500lb fts of torque in first gear. Guess what a stock 370z does! __________________ Charles @ CJ Motorsports : Website \| Facebook \| Instagram \| YouTube Home of the 9 second, stock longblock, stock drivetrain 6MT 370z. 9.91 @ 142mph

09-05-2013, 03:42 PM	#27 (permalink)
Sh0velMan A True Z Fanatic Join Date: Jan 2012 Location: Dallas/Ft.Worth Posts: 3,349 Drives: Noisily. Rep Power: 20	So this thread has determined what everyone should have already known. Rev to red line before you shift. phunk, DEpointfive0 and Mitco39 like this. __________________ Buy My Car! \| Build Thread

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