WOT Shift RPM's for drag racing?

metroplex

New member
Has anyone found the optimal RPMs for WOT shifts to get the best 1/4 mile ET and trap speeds? Stock seems to shift around 6100 RPM. I've experimented with 6500 RPM but it seems I am losing momentum. I don't have the 3.16s from the Perf Package and I have the stock 255/45R19 tires, so I shift into 4th gear right before the end of the 1/4 mile, putting me into the 4700 RPM range.
 
metroplex said:
Has anyone found the optimal RPMs for WOT shifts to get the best 1/4 mile ET and trap speeds? Stock seems to shift around 6100 RPM. I've experimented with 6500 RPM but it seems I am losing momentum. I don't have the 3.16s from the Perf Package and I have the stock 255/45R19 tires, so I shift into 4th gear right before the end of the 1/4 mile, putting me into the 4700 RPM range.
Your butt dyno is correct.

At 6500 with non-PP, you don't benefit from gear multiplication like PP does.

This might help...

http://www.ecoboostperformanceforum.com/index.php/topic,5796.0.html
 
So what's the recommended shift RPMs? There was a better discussion on the F-150 forums but they have a very different torque curve and vehicle. They were discussing shifting into 4th a bit earlier but tweaking the 1-2 and 2-3 as well (lower RPMs).

What are your shift RPMs at the track?
 
Just put the car in D or S.  Let the car do its thing.  You are losing time trying to shift the car yourself.  Car should be shifting around 6200.  Did full season of bracket racing, never shifted the car myself.
 
bamsho said:
Just put the car in D or S.  Let the car do its thing.  You are losing time trying to shift the car yourself.  Car should be shifting around 6200.  Did full season of bracket racing, never shifted the car myself.

I just leave it in S, and hammer it from the launch, and my car is pretty consistent. This is spot on. I gain/lose time based on how carefully I launch it. If anything, I would adjust shift points within the tune, rather than add the extra variable of shifting myself.
 
bamsho said:
Just put the car in D or S.  Let the car do its thing.  You are losing time trying to shift the car yourself.  Car should be shifting around 6200.  Did full season of bracket racing, never shifted the car myself.

Who said anything about manual shifting? I'm asking to see if there's any merit to changing the WOT shift points in the tune. Mine is shifting at around 6100 RPM at WOT in Sport mode. Factory settings are 6200 RPM in the WOT table, but I'm sure the anticipation logic is doing its thing. The F-150 owners found shifting earlier in some of the gears or the 3-4 helped produce better 1/4 mile timeslips. I'm not concerned about bracket racing, it's very consistent as-is because it's an automatic.
 
metroplex said:
So what's the recommended shift RPMs? There was a better discussion on the F-150 forums but they have a very different torque curve and vehicle. They were discussing shifting into 4th a bit earlier but tweaking the 1-2 and 2-3 as well (lower RPMs).

What are your shift RPMs at the track?
I find it irrelevant to bring up the F150 owners if they indeed have a vastly different torque curve and being in a different platform. Z
 
I felt that the Explorer was falling off in 3rd before it shifted to 4th so I asked AJP to just pull it in a little.  It shifts at 6000rpm now instead of 6150 from 3rd to 4th.  Haven't raced it with that tune.  I am sure the difference will be tiny, but it was shifting too close to the finish line as well so I wanted to get it into 4th a little sooner.
 
16MagSport: Thanks. That's kind of what I'm going with regarding my question.

ZSHO: I only brought up the F-150 platform because those EcoBoost owners are at least experimenting and sharing, while getting better 1/4 mile ETs and respectable trap speeds.
 
metroplex said:
So what's the recommended shift RPMs? There was a better discussion on the F-150 forums but they have a very different torque curve and vehicle. They were discussing shifting into 4th a bit earlier but tweaking the 1-2 and 2-3 as well (lower RPMs).

What are your shift RPMs at the track?
I'm confused, the spreadsheets I linked to had shift points for PP and non-PP based on rpm/torque/gear multiplication.

The optimum shift points for PP are much higher that non due to gear multiplication.

IIRC non PP starts at 5900 in 1st. PP is like 7150 for first and second.

I would shift at 6750 if I could but my tranny doesn't like to cooperate.
 
The stock WOT shift tables are 6200 RPM for 1-2, 2-3, and 3-4 - but actual WOT shift RPM was like 6000 for 1-2, and 6100 for 2-3 and 3-4 probably due to shift anticipation logic. I have datalogs at the track and on the street.

Are you actually seeing 7150 RPM for your shift points? Can you post some logs?
The final drive shouldn't require this high of a shift point.
 
I don't think these cars respond well with RPM.  They fall on their face after 6000.  After that RPM the engine is just reving but not really doing much.

Obviously bigger turbo's would extend that greatly.
 
And at high boost wgdc becomes really high to maintain boost and that leads to high iat2 and with high wgdc that has to kill volumetric efficiency because more of the exhaust is exiting through the tiny 38mm turbine...with lower boost the gate is open so its an easier exit for the gasses
 
Cool tests! Do you have any STFT data? The amount of boost you're running also has an impact because you can see it heat up the manifold charge temps (IAT2).

The transverse 3.5L EB doesn't seem to like it above 6k RPM very much. I guess the 2.7L EB reacts better at higher RPMs.
 
LMS 4+x tunes don't shift until close to 7K rpms... The boost starts to dive after 6500 rpms.. and the tune runs really rich in the higher RPMs... They advance the timing pretty good through the whole rpm range...

The LMS tunes keep the IAT down significantly though... They are not pushing the turbos outside of their effeciency to start pushing hot air...

Sent from my Nexus 6P using Tapatalk

 
I stand corrected (Maybe).... I datalogged all my LMS tunes... which shows that the shift is happening around 6350 RPMS.. HOWEVER.. I know the tach swings very close to 7K... and the resolution of the SCTx4 does not capture the RPMS very well at the high end...  so... I suspect that the shift happens between 6400 - 6600 maybe? I highly doubt LMS will chime in.... would be nice!
 
StealBlueSho said:
I stand corrected (Maybe).... I datalogged all my LMS tunes... which shows that the shift is happening around 6350 RPMS.. HOWEVER.. I know the tach swings very close to 7K... and the resolution of the SCTx4 does not capture the RPMS very well at the high end...  so... I suspect that the shift happens between 6400 - 6600 maybe? I highly doubt LMS will chime in.... would be nice!

is there a minimum number of things you can configure to log? maybe build a config that only logs rpm so you get the best resolution possible.
 
BOT_ROCKET said:
StealBlueSho said:
I stand corrected (Maybe).... I datalogged all my LMS tunes... which shows that the shift is happening around 6350 RPMS.. HOWEVER.. I know the tach swings very close to 7K... and the resolution of the SCTx4 does not capture the RPMS very well at the high end...  so... I suspect that the shift happens between 6400 - 6600 maybe? I highly doubt LMS will chime in.... would be nice!

is there a minimum number of things you can configure to log? maybe build a config that only logs rpm so you get the best resolution possible.
Yup, you could log one thing at a time. I no longer have my SCTx4 so I can't log anything at the moment...

Would provide marginally better resolution...

It is funny though... at the higher RPMs the boost dips and the fuel mixture richens up quite a bit..They also don't drop the spark as much during the shift as other tuners.. but their overall approach is much different..

Sent from my Nexus 6P using Tapatalk

 
Back
Top