Lowering Shift Points

[SRT82ECOBOOST]

I have seen a lot of dyno graphs showing that the Ecoboost engine tends to fall off as the RPM's climb towards to the stock shift point. Has anyone manipulated the shift points down to 5,000-5,500 rpms at the track? Would this cause for any extra shift through the 1/4 mile that would hurt ET?

 

[jomc111]

I thought I had seen on atleast livernois tunes they changed there tunes to hold boost till redline which cured the fall off

 

[4DRHTRD]

I hold boost to redline but I still fall off massively above 5200 RPM.

I just did some calculations I'm going to modify my shift points to these:
1st-2nd        5540    32
2nd-3rd        5539    51
3rd-4th        5146    73
4th-5th        5318    99
5th-6th        5224    137

Just need to figure out the slope/intercept of the 3 bar map so we can tune first.

 

[SRT82ECOBOOST]

I hold boost to redline but I still fall off massively above 5200 RPM.

So would you be better off shifting at 5,200rpms?

 

[4DRHTRD]

I edited my previous comment but according to a couple of shift point calculators here's where I should be shifting with my torque curve:
                    RPM    MPH     
1st-2nd      5540  32
2nd-3rd      5539  51
3rd-4th      5146  73
4th-5th      5318  99
5th-6th      5224  137

 

[SRT82ECOBOOST]

And where does the car shift now?

 

[4DRHTRD]

And where does the car shift now?

6500ish, I've seen almost 7K a couple of times on the tach.
I'll make huge gains dropping to those RPM according to what I'm calculating as I'm shifting to above the torque max.

 

[SRT82ECOBOOST]

Are the shift points accessible to change?

 

[SRT82ECOBOOST]

Another aspect to take into consideration is what rpm do you fall back into following the shift if you lower the rpms on the shift point.

 

[4DRHTRD]

Are the shift points accessible to change?

Yes via tuning

Another aspect to take into consideration is what rpm do you fall back into following the shift if you lower the rpms on the shift point.

That's what a shift point calculator does for you. As stated my current shift points drops me down into the gear ABOVE my max torque yet I'm still running mid 12's. By dropping down 1200 RPM I'll be dropped right into the torque curve as it rises to peak.

 

[SRT82ECOBOOST]

Damn, I should have kept this little nugget to myself to post up some faster times and then let the cat out of the bag.

 

[steve142857]

The way I understood it is that the torque is good for initial acceleration but at one point (in the power zone), it is the hp that takes over. So, ideally you would like a lot of torque in the low rpm, but from let's say 4000 to 6500, you want to have the most hp possible.
Surely in the first 2 gears, it is already optimal (with my current setup LMS tune, meth downpipes, etc.). After that, in gear 3-4... it is already shifting at around 6200 and dropping at 4500... It wouldn't make sense to have gears from 4500-5000 and shifts... And I seriously doubt that shifting at 5000 and going down to low 3000's would be better...
Finally, with all the work that Dan Millen from Livernois and with the 3000+ Ecoboost vehicles that have been tuned (many of them on the Dyno), I would doubt that he hasn't tried it before.
If LMS tuned the car to shift from 4500 to 6200, I trust it to be optimal... No?

 

[4DRHTRD]

If you look at dynograph shifting over 5500 RPM doesn't make a ton of sense on my car due to the HUGE HP and torque drop off.
Here's my evaluation of the current vs future shift points I am going to try.
Current:
Shift Points (rpm)   
                                  TQ at shift                                  TQ at next gear
1st-2nd    6500    38    500    RPM in 2nd      4164    582   
2nd-3rd    6500    59    500    RPM in 3rd      4167    582   
3rd-4th    6500    93      500    RPM in 4th      4981    635   
4th-5th    6500    121    500    RPM in 5th      4610    635   
5th-6th    6500    170    500    RPM in 6th      4810    640   



Suggested:
Shift Points (rpm)   
                                      TQ at shift                              TQ at next gear
1st-2nd    5540    32      600      RPM in 2nd    3549    510
2nd-3rd    5539    51      600      RPM in 3rd    3551    510
3rd-4th    5146    73      624      RPM in 4th    3943    558
4th-5th    5318    99      612      RPM in 5th    3772    534
5th-6th    5224    137    618    RPM in 6th    3866    546

New shift points puts us into the torque curve as it builds and shifts just after, current shifts well after torque max and shifts into the max.

 

[SRT82ECOBOOST]

I agree that you may want to plan your shift strategy on the HP curve instead of the torque curve.

 

[4DRHTRD]

Here's the dyno with proposed vs suggested shift points. Much more power under the curve with the proposed shift points.

 

[4DRHTRD]

The way I understood it is that the torque is good for initial acceleration but at one point (in the power zone), it is the hp that takes over. So, ideally you would like a lot of torque in the low rpm, but from let's say 4000 to 6500, you want to have the most hp possible.
Surely in the first 2 gears, it is already optimal (with my current setup LMS tune, meth downpipes, etc.). After that, in gear 3-4... it is already shifting at around 6200 and dropping at 4500... It wouldn't make sense to have gears from 4500-5000 and shifts... And I seriously doubt that shifting at 5000 and going down to low 3000's would be better...
Finally, with all the work that Dan Millen from Livernois and with the 3000+ Ecoboost vehicles that have been tuned (many of them on the Dyno), I would doubt that he hasn't tried it before.
If LMS tuned the car to shift from 4500 to 6200, I trust it to be optimal... No?

If I trusted Livernois to be gospel I wouldn't be running E85 because they won't tune for it and according to them it's unsafe, I wouldn't be making 600WHP because I was told by them motor would blow at 450HP. Sorry I can't trust anybody but myself for what's best via experimentation and hard work.

 

[05yellowgt]

Horsepower is just a calculation based upon the torque and RPM.  Torque is what moves the car period.  Basing your gearing and shift points on the torque curve is the way to go.  The Ecoboosts have a broad and long torque curve.  Once the torque starts falling off, you are better to setup shift points just as 4DRHTRD is doing.           

 

[Needmoreboost]

I have brought this up before to a few members and it usually just blows over.  On the SHO's much past 5500 the hp is dropping fast.  I did not get to test this at the track, but my opinion for optimizing the torque curve would look something like this.  They shift stock usually 6000-6200 range.

1-2 leave stock
2-3 5700 rpm
3-4 5500 rpm
4-5 5500
5-6 5500

SCT does not have this option yet available to change the shift points.  So manually it's hard to do.  Dont know about Mycal??

 

[Josephm]

Believing in someone else's hearsay is just as bad as gossip, when someone else is willing to try it... Thanks 4DR for all the experimenting.

 

[steve142857]

Believing in someone else's hearsay is just as bad as gossip, when someone else is willing to try it... Thanks 4DR for all the experimenting.

Believing in someone else that knows more than you do is also called trust. I have trust with Livernois with all their experience. But at the same time, I admire 4DR that knows a lot about cars, which I don't, for taking it to another level.
That said, I can't blame Livernois for not wanting to go on the E85 route. Maybe one day, but they have a reputation to maintain and cannot afford to ruin it with experimentation. I guess they prefer to stick with what they know and are comfortable with.
So me too I want to say thanks to Mike 4DR for pushing it and thank you to Livernois that have so far been able to provide me with a powerful vehicle that is reliable with no bad surprises.
Cheers guys!