Shifting points

[spinixguy]

Sorry if this has been asked before. I did a search and did not really come up with the answers I was after. Anyway, sometimes I run the car through the gears shifting around 7500 - 8500 RPM. Is this hurting the car in any way? I have had several people tell me that I am over revving the car. I was under the impression that it was kind of made for that.

[kevos2k]

i rev mine to 9k regularly hasnt blown up yet (almost 100k of abuse)... im guessing the people u are getting comments from have 4k redlines in their cars

[spinixguy]

Yeah, kevos2k. I kind of figured that too. Figured I would ask just to be sure.

[Tx_Phantom]

What is the purpose of shifting that high? Unless you're racing, why not shift at 4-5k?

TxP

[dfws2k]

What is the purpose of shifting that high? Unless you're racing, why not shift at 4-5k?

TxP

Brings more enjoyment :)

[kevos2k]

its all in your driving style i suppose... i dont sit in 1st at 8k but i do like to run it through the gears or downshift while passing hit redline getting on the highway etc...

i mean if u shift at 4-5k you dont even get into the cars powerband... may as well be driving a 90hp fit everywhere imo (i know a bit of an exaggeration)

[spinixguy]

Normally I do shift at 4-5K, but sometime I want to play a little ;).

[Tx_Phantom]

Thats what I do... 4-5k usually...

whats fun is to see how many miles i can get out of a single tank... my record is 319 city...

[BuzzKillington]

Thats what I do... 4-5k usually...

whats fun is to see how many miles i can get out of a single tank... my record is 319 city...
I started doing this too...

4th tank of gas and was able to hit 301.2, 1/4 highway, 3/4 city :thumbup:

[dfws2k]

Thats what I do... 4-5k usually...

whats fun is to see how many miles i can get out of a single tank... my record is 319 city...

i guess our definitions of fun are a little different :rofl:

[spinixguy]

I have to agree with dfws2k on this one. Most of the time I drive it like I stole it. But again, I thought that was what it was built for ;)

[mlc]

What is the purpose of shifting that high? Unless you're racing, why not shift at 4-5k?

TxP

The eternal question...WHY??


Hell...because it's there and you can :rockon: . Because the people that designed it would be disappointed if you didn't. Because your breathing. Because your alive.... Should I go on??

Kevin

[Tx_Phantom]

i guess our definitions of fun are a little different :rofl:

Not too far apart based on other common interests....

:LOL:

[JonBoy]

Thats what I do... 4-5k usually...

whats fun is to see how many miles i can get out of a single tank... my record is 319 city...

Towing it with your Tacoma isn't a valid representation of your gas mileage. :D

[dfws2k]

Lol..

[Tx_Phantom]

Towing it with your Tacoma isn't a valid representation of your gas mileage. :D

LMAO @ Jon - how ya doin man? I think I sent you a pic that day I hit the 319...

Long time no see - you ever get out to DFW?

TxP

[JonBoy]

LMAO @ Jon - how ya doin man? I think I sent you a pic that day I hit the 319...

Long time no see - you ever get out to DFW?

TxP

Doing pretty good. Sold the S2000 on July 4th (rocking a Ford pickup for now - yay) but looking forward to getting another sports car in the near future.

The day you hit the 319? What's the 319? I don't remember a pic...

I might be coming up to DFW this month or early September, possibly over Labor Day or something. Not sure yet.

[Tx_Phantom]

Doing pretty good. Sold the S2000 on July 4th (rocking a Ford pickup for now - yay) but looking forward to getting another sports car in the near future.

The day you hit the 319? What's the 319? I don't remember a pic...

I might be coming up to DFW this month or early September, possibly over Labor Day or something. Not sure yet.

I got 319 on a single tank in the S, thought I CCd u on the pic... Sad your S is gone... :(

hit me up when u are here, lets get out for a brew-ha-ha

[speedracer]

On the road 3000 - 4000. On the track 8500. Going to 9000 does not give you any more power.

[JonBoy]

I got 319 on a single tank in the S, thought I CCd u on the pic... Sad your S is gone... :(

hit me up when u are here, lets get out for a brew-ha-ha

:thumbup: How 'bout a ski lesson? :D

[JonBoy]

On the road 3000 - 4000. On the track 8500. Going to 9000 does not give you any more power.

Power under the curve combined with gearing means you're probably losing a bit of time if you don't shift at redline. ;)

[speedracer]

Power under the curve combined with gearing means you're probably losing a bit of time if you don't shift at redline. ;)

That's because the S2000's engine only starts doing its best work after most car engines have stopped doing theirs, namely over 6000rpm, with maximum performance requiring the sort of revs that would blow most car engines to bits, peak torque (208Nm) being delivered at 7500rpm and peak power at 8300! And maximum performance in the S2000's case equates to 0-60 in 6.2 seconds and 150mph.

So according to this after 8300 you are losing both power and torque.

[repiv]

So according to this after 8300 you are losing both power and torque.
But you've still got more power and torque above 8300 than you would at the rpm you end up at after the shift. By shifting at redline, you are taking advantage of this extra power for just a bit longer. No drag racer or even a professional car racer will short shift, not even a little bit. They take advantage of every little rpm they can before shifting. If you look at power curves, if you run the remaining rpm to redline, you will end up at a part of the rpm band that will also be higher up on the power band than if you short shifted.
Let's say you lose 10% hp above 8300, so you're down to about 180 whp. You're propelling the car with 180 whp for almost another 1000 rpm. What's your whp at 6000 rpm after the shift? Mathematically speaking (and I'm sure in reality as well), you are motivating the car with a lot less whp after the shift.

[repiv]

OK, I just took a peak at an AP1 dyno chart. I won't post it here because it's not my property and I don't have permission anyway. But the gist of it is as follows:

Peak hp was reached at about 8500 and it was 203. From 8500 to 9000, the hp dropped to about 200.
Peak tq was reached at about 6800 and it was 137. From 6800 to 9000, the tq dropped to about 117.
Power doesn't drop that much after it peaks and tq does drop quite a bit but not to the point as what it will be after the shift. After a shift, depending on the gear, you would end up around 6000 rpm. At this rpm, your hp would be about 130 and the tq about 110. So, would you rather propel the car for another 1000 rpm with 200 hp and 117 tq or shift and go that next 1000 rpm at 130 hp and 110 tq? The advantage is clearly going to redline.

[SpitfireS]

No drag racer or even a professional car racer will short shift, not even a little bit.
:)
First: I'm no professional, not even an experienced enthausiast when it comes to racing.
Second: I think the comment is true for drag racing.

But.... during road coarse racing it can sometimes, depending on the track, be better to short shift, or IOW not take it to redline.
I do have an example I've experienced myself at a track day.

Pit straight, followed by a 90º right hander, a short straight, followed by a 45º right hander going into a sweeping & tightning (yes again) righthander.
At first (on S-02's) I took the 90º RH in 3rd, accell to redline but not getting to redline, brake for the 45º (still in 3rd) and then go into the sweeper.
Last time (on A048 R-compounds) I found that I didn't have to brake that hard for the 90º RH so I carried more speed into the short straight leaving me in the 45º turn at redline so I had to shift in the turn = :nono:
Still taking the 90º in 3rd, short shifing into 4th (way before redline still going straight) before the 45º RH was quicker.

:cool:

[JonBoy]

I think he was probably talking about where it makes sense to keep your foot down (ie, on a straight or where you aren't hitting redline mid-corner). You're talking about a strategic short shift, which is a completely different animal.

Good point, though. :thumbup:

[Tx_Phantom]

Power under the curve combined with gearing means you're probably losing a bit of time if you don't shift at redline. ;)

If you have that kinda time on your hands - ABSOLUTELY - I'll get you on the lake - the boat is running great this year.

You got my # still don't you?

[JonBoy]

Yeah, I still have your number. :thumbup:

[repiv]

I think he was probably talking about where it makes sense to keep your foot down (ie, on a straight or where you aren't hitting redline mid-corner). You're talking about a strategic short shift, which is a completely different animal.

Good point, though. :thumbup:
I agree. Spitfire does have a good point but like you said, that kind of short shift is more of a strategic technique where it may not be efficient to maximize power delivery and to perhaps set up for the entrance to a particular section or to exit a particular section. My previous dissertation was primarily to explain that if you want to maximize power delivery, you shift at redline or just before the fuel cut. In the case like Spitfire's, one may not want to "maximize" power delivery but to more "optimize" power deliver with a future plan in mind.
Speedracer's premise what that you lose power going beyond the peak hp rpm point, but you don't lose nearly as much as if you were to shift early and take the power loss hit much further down the rpm band. It's like the Fram guy says ..................... "Pay me now or pay me later". Take a slight power deficit and keep accelerating with more power or take a big power deficit and play catch up.

[spinixguy]

So if you did not shift at red line, would you still make max power in 6th? In other words, would the car reach its top speed?

[repiv]

So if you did not shift at red line, would you still make max power in 6th? In other words, would the car reach its top speed?
It depends on if you're talking about AP1 or AP2. With both having an average of 200 whp, both are able to overcome drag to the point of getting to about 150 mph top speed. The AP2 could reach it's top speed. The AP1 will not.
Note: We're talking about strictly stock cars and I'm talking about "geared" top speed. The geared top speed of both models are different.

[NFR_AP1]

It depends on if you're talking about AP1 or AP2. With both having an average of 200 whp, both are able to overcome drag to the point of getting to about 150 mph top speed. The AP2 could reach it's top speed. The AP1 will not.
Note: We're talking about strictly stock cars and I'm talking about "geared" top speed. The geared top speed of both models are different.

What does that mean? Is the AP2 geared to 170 like the AP1? Or does the AP2's extra 9lbs of torque allow it to go a little faster? Please elborate AP1 owner on the end of his seat here!

[repiv]

What does that mean? Is the AP2 geared to 170 like the AP1? Or does the AP2's extra 9lbs of torque allow it to go a little faster? Please elborate AP1 owner on the end of his seat here!

No, AP2 is geared for a max speed of ~150 mph due to the lower redline. AP1 is geared for max speed of ~166 mph. It doesn't have the power to get there. It's achievable drag limited top speed is ~ 150 mph, the same as the AP2. The "extra" bit of torque the AP2 has doesn't really help much for top speed due to the slight difference in gear ratio of 5th and 6th.

[NFR_AP1]

No, AP2 is geared for a max speed of ~150 mph due to the lower redline. AP1 is geared for max speed of ~166 mph. It doesn't have the power to get there. It's achievable drag limited top speed is ~ 150 mph, the same as the AP2. The "extra" bit of torque the AP2 has doesn't really help much for top speed due to the slight difference in gear ratio of 5th and 6th.

Thank you for the clarification.