anteater guys advice/thoughts wanted

T-MAN

T-MAN

misunderstood
Anteater / valvebody question.

Is anybody having a problem with the commanded shift not actually hitting the mark?

I was finally able to make a few consistent passes the other night and noticed im shifting late in the rpm. (4200) my RPM in the shift schedule should be around 3300 and overdrive about 81mph.

when I had this last valvebody built it was set to shift at 4200 on the valvebody dyno.

I guess my question would be, if shift mph is based off of governor pressure, and a stock valvebody has a shift spring that strokes the valve at about 3200 rpm (full throttle) the anteater could control the flow or governor pressure to increase shift MPH. So im wondering if there is to stiff of a spring on the shift valve will the anteater be able to overcome that spring and valve and complete a shift earlier ?

I think if I can loose a few RPM on my shifts I may be able to pick up some time, Has anybody run into this issue? Thanks in advance
 
Is every gear late, or just OD?

I had to turn my Governor Pressure Modifier up to 60 for my 1-2 shift timing, but OD is controlled by electronics so the Anteater should be the only thing controlling it.
 
Tailor the tune to compensate for the mechanical delay.

Lower the MPH set points just a few MPH lower at your WOT table and see if it does what you want.

I forwarded to Joe farmer, he may have other insight to add.

Sent from my XT1575 using Tapatalk
 
Correct, the mechanical delay of the solenoid being activated, the time it takes for the circuit to fill and apply the clutch keeps you from being able to calculated your speed vs rpm 100% accurately. The Anteater will command it at the exact MPH you request but the shift is a slight delay. I always look at my datalog and adjust down 3-5mph until i get to my desired rpm shift point.

Lavon
 
Thank you for the replies. they are all coming in late except lockup. I launch in manual first and when I get straightened out I slap the stick to drive. My tach dances and I don't have a speedo so im going by video and time slips. Im hitting overdrive at the 1/8 im running about 107 and I want od at 81.

heres my anteater schedule
1-2 30 mph
2-3 58 mph
3-4 81 mph
lockup 14 mph
gov psi modifier @ 45
I launch at 2700 and im sure it rips past 4k before it can lock the converter. then I feel it lock and I smack the stick to drive, it hits second but its around 4k then 3rd around the same, I have to wait for overdrive and I get that at the 1/8 around 107.

here is mph vs rpm from a gear calculator

1-2 locked 30 mph = 3000rpm drop to 1700 in second
2-3 58 mph 3400rpm drop to 2300 in third
3-4 81 mph 3200rpm drop to 2200 in fourth

what has me thinking is that 107 mph in third is around 4300rpm how much lower should I adjust? Its off by almost 1100 rpm..I understand if it overshoots each shift it may take a second to figure out where it needs to be and that's causing the delay... Would it be easier to change the shift springs?
One other thing is im around 90% tv it will hang the shift from 2-3 and lay right over on the governor, im set at about 75% now..Here's 2 passes you can hear it wound up and see the smoke fade on the shifts 5000 gsk.

IMG 5123 - YouTube
IMG 5124 - YouTube

Thanks for the info...
 
Lavon and Kyle have the right answer and the experience to back it up - the mechanical portion of the VB takes a little to catch up with the command. Issue the command at a lower speed to accommodate the VB mechanical parts.
 
joefarmer said:
Lavon has the right answer and the experience to back it up - the mechanical portion of the VB takes a little to catch up with the command. Issue the command at a lower speed to accommodate the VB mechanical parts.
Click to expand...
Is an 1100 rpm difference normal??
 
That depends on VB setup, temp, pressure, age, leakage, etc. Nothing you're describing sounds abnormal in a race application.
 
Im not doubting lavon has the knowledge, is there a point where the valvebody will have a greater mechanical advantage that the anteater can electronically compensate for?
 
This is a screen shot of the datalog off Rick Fox's truck running a 5.92@123mph in the 1/8th along with a screenshot of the tune. It honestly sounds like you may have a transmission issue with delayed shifts and 14mph lockup is way too soon for any of our vehicles. Our best times have always been with lockup between 33 and 38mph. The attached screenshot is a truck with 3.55 gears and 30in tires for reference.

Lavon

view
 
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Looks like your commanding about what I am , also getting later shifts then me. I guess ill drop the shift mph way down. im running 30" tire with 3.55 gears. locking at 14mph picked me up a few tenths. thank you for the reply.
 
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ramthiscummins said:
https://www.blocklayer.com/rpm-geareng.aspx

Would this help at all?
Click to expand...

That is way cooler then what I use thanks. The basic answer for my original question is, the anteater cant anticipate the way my trans shifts hydraulically, it can only ask for it electronically.so keep dropping mph to achieve the desired shift. looks like in a drag race application may be as much as 1500 rpm...going to build 3 tunes for this weekend and see how it works. thanks for the cool link..

Request Rejected

above is the calculator I use
 
@joefarmer, when the Anteater commands a shift based off the shift curve, is the modified governor pressure on a curve as well? Or is it stepped to like a middle to middle high end of the actual pressure needed to actuate and hold each valve? Does that question make sense? lol

So I guess for example if normally the 1-2 spool valve requires 15psi of governor pressure to overcome only the spring and actuate it and the 2-3 shift valve requires 30psi to overcome only the spring and actuate it. Are you supplying 10psi for 1st gear, 25psi for 2nd gear, and 50psi for 3rd?

Either way. I could imagine that the shift timing could get slow or sloppy since it sounds like you still have the TV pressure acting on the opposite side of each shift valve as well? How do you combat that?

Im wondering if the OP is experiencing the TV pressure holding the shift valve closed even after the shift is initiated? Is that a possibility? Or simply maybe a sticky spool valve or leak in the governor pressure circuit.
 
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With my build, not using anteater but the hydraulic circuits still work similarly; my shift is initiated and I only have a delay of about 5mph at WOT max. Hydraulically the shift from 2-3 for example, the pressure in the governor circuit overcomes the spring on shift spool valve and possibly whatever TV pressure is on the back side of that valve (that should be pretty instantaneous) and then the circuit fills to actuate the front band servo and direct drum piston. There may be a slight delay here, but I really don't think it should be anything like you are seeing.
 
Redrider2911 said:
@joefarmer, when the Anteater commands a shift based off the shift curve, is the modified governor pressure on a curve as well? Or is it stepped to like a middle to middle high end of the actual pressure needed to actuate and hold each valve? Does that question make sense? lol

So I guess for example if normally the 1-2 spool valve requires 15psi of governor pressure to overcome only the spring and actuate it and the 2-3 shift valve requires 30psi to overcome only the spring and actuate it. Are you supplying 10psi for 1st gear, 25psi for 2nd gear, and 50psi for 3rd?

Either way. I could imagine that the shift timing could get slow or sloppy since it sounds like you still have the TV pressure acting on the opposite side of each shift valve as well? How do you combat that?

Im wondering if the OP is experiencing the TV pressure holding the shift valve closed even after the shift is initiated? Is that a possibility? Or simply maybe a sticky spool valve or leak in the governor pressure circuit.
Click to expand...
In testing, there is more accuracy across the board with a fixed TV (80%). I ran mine both ways, and never really had an issue at 5-600hp.
For simplicity, I suggest fixed TV.

Sent from my XT1575 using Tapatalk
 
biggy238 said:
In testing, there is more accuracy across the board with a fixed TV (80%). I ran mine both ways, and never really had an issue at 5-600hp.
For simplicity, I suggest fixed TV.

Sent from my XT1575 using Tapatalk
Click to expand...

Ok cool. That confirms some of my thoughts then. That’s why i plugged the holes in the valvebody that supplies TV pressure to the shift valves. Now my TV only controls a ramp up in line pressure with no effect on shift timing. ?
 
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