Registry 8x Series V8 Swaps (29 Viewers)

[TLC94LS]

Shifting gears, literally. Using the Overland bound app as a speedometer check. My speedo is off about 6mph. On the slow side. Indicates 6mph slow. That’s with a gm4L80 and stock LC gearing on 35s. I took some videos of speed and eng rpms to see if I’m in an appropriate power band or cruising rpm. I think I’m over revving for current speed. Burning extra fuel.
Onscreen shots of videos. Realize, this is 5-6mph slow. So it’s closer to 65 and 75. For an rpm comparison.
65mph- 2150/2200 RPMs
75/76 mph- 2400 RPMs

Does anyone have any insight or comparisons?? I think I’m really hurting in fuel economy at highway speeds. Now I know it ain’t a Prius. But I want to make sure I’m not wasting fuel economy, thinking about longer trips and fuel efficiency for off road destinations.

 

[RivMan]

Shifting gears, literally. Using the Overland bound app as a speedometer check. My speedo is off about 6mph. On the slow side. Indicates 6mph slow. That’s with a gm4L80 and stock LC gearing on 35s. I took some videos of speed and eng rpms to see if I’m in an appropriate power band or cruising rpm. I think I’m over revving for current speed. Burning extra fuel.
Onscreen shots of videos. Realize, this is 5-6mph slow. So it’s closer to 65 and 75. For an rpm comparison.
65mph- 2150/2200 RPMs
75/76 mph- 2400 RPMs

Does anyone have any insight or comparisons?? I think I’m really hurting in fuel economy at highway speeds. Now I know it ain’t a Prius. But I want to make sure I’m not wasting fuel economy, thinking about longer trips and fuel efficiency for off road destinations.

View attachment 3514412

View attachment 3514413

The 4L80e has a 0.75 overdrive ratio which isn’t ideal for that setup. Here’s what the calculator kicks out for your configuration.

The 4L60e has a higher overdrive at 0.70 which drops the RPM to a better point.

A 6L80e drops is even further:

-Rob

 

[PIP]

Shifting gears, literally. Using the Overland bound app as a speedometer check. My speedo is off about 6mph. On the slow side. Indicates 6mph slow. That’s with a gm4L80 and stock LC gearing on 35s. I took some videos of speed and eng rpms to see if I’m in an appropriate power band or cruising rpm. I think I’m over revving for current speed. Burning extra fuel.
Onscreen shots of videos. Realize, this is 5-6mph slow. So it’s closer to 65 and 75. For an rpm comparison.
65mph- 2150/2200 RPMs
75/76 mph- 2400 RPMs

Does anyone have any insight or comparisons?? I think I’m really hurting in fuel economy at highway speeds. Now I know it ain’t a Prius. But I want to make sure I’m not wasting fuel economy, thinking about longer trips and fuel efficiency for off road destinations.

View attachment 3514412

View attachment 3514413

Something is wrong. Your math doesn't math.

Is the converter locked? Do you have underdrive gearing in the transfercase?

 

[TLC94LS]

Something is wrong. Your math doesn't math.

Is the converter locked? Do you have underdrive gearing in the transfercase?

Not sure what you mean my math is incorrect. I didn’t do any yet, The Toyota gear train is stock. It has a stock 4L80e in it. I “believe” the torque converter is locking. It is shifting smoothly and the pedal to engine feel seems to becorrect for a locked torque converter. Meaning I don’t feel I’m riding on the rpm’s, there is a lag when you ease into the pedal to pass then a down shift. But I could be wrong. I could drive it with a tuner to verify trans operation.

 

[TLC94LS]

For the Toyota drive train. I should clarify, I didn’t do anything to it. Now I bought it at 310k. It was a grocery getter, so I doubt anything was done.

 

[TLC94LS]

The 4L80e has a 0.75 overdrive ratio which isn’t ideal for that setup. Here’s what the calculator kicks out for your configuration.

View attachment 3514418

The 4L60e has a higher overdrive at 0.70 which drops the RPM to a better point.

View attachment 3514421

A 6L80e drops is even further:

View attachment 3514423

-Rob

What calculator did you use?? According to that sheet. It says I should be closer to 2200 rpm’s at 75. I’m at 2400. So high but not crazy. Was it online that you put in some other data? Thank you for the post.

 

[PIP]

Not sure what you mean my math is incorrect. I didn’t do any yet, The Toyota gear train is stock. It has a stock 4L80e in it. I “believe” the torque converter is locking. It is shifting smoothly and the pedal to engine feel seems to becorrect for a locked torque converter. Meaning I don’t feel I’m riding on the rpm’s, there is a lag when you ease into the pedal to pass then a down shift. But I could be wrong. I could drive it with a tuner to verify trans operation.

The specs you've given don't match the numbers you have. Something you have stated is not accurate if you have 2400@75.

I was involved with a similar 80 series situation and it turned out it had 4.56 gears installed. Nobody knew.

 

[RivMan]

What calculator did you use?? According to that sheet. It says I should be closer to 2200 rpm’s at 75. I’m at 2400. So high but not crazy. Was it online that you put in some other data? Thank you for the post.

Gear Ratio Calculator

 

[TLC94LS]

The specs you've given don't match the numbers you have. Something you have stated is not accurate if you have 2400@75.

I was involved with a similar 80 series situation and it turned out it had 4.56 gears installed. Nobody knew.

Ok, So either my speed is off for my estimate, or the rpms are off? Or based on your calculations, tire size or gear ration is throwing off your calculations. When I opened the transfercase, it seemed as if it had never been opened, so if something is different it would be in the differentials would be my guess.

To be specific, tire size is 315/75/R16.. so not quiet 35s I suppose

What is the gear ratio for the 94? Im messing around with that calculator now. I put in 4:10. I think that is correct. Pet that calculator I should be doing about 200 rpms less. Could be tolerance stacking errors, error int he RPM gauge, inaccurate speed etc.

 

[NeverFinis]

Ok, So either my speed is off for my estimate, or the rpms are off? Or based on your calculations, tire size or gear ration is throwing off your calculations. When I opened the transfercase, it seemed as if it had never been opened, so if something is different it would be in the differentials would be my guess.

To be specific, tire size is 315/75/R16.. so not quiet 35s I suppose

Seems to work if you have 4.56 axle gears rather than 4.10

 

[tmxmotorsports]

Who did the tune on the ecm?

 

[TLC94LS]

Who did the tune on the ecm?

Local guy. When we did, the RPMs matched up pretty close from HP tuner info to what was being displayed, but now I may want to look at it more closely.

 

[tmxmotorsports]

Local guy. When we did, the RPMs matched up pretty close from HP tuner info to what was being displayed, but now I may want to look at it more closely.

So your tire size was put into the tune?

 

[tmxmotorsports]

Also how are you getting second vss do you have a reluctor ring installed in the back half of the 4l80e? With a speed sensor?

 

[TLC94LS]

Can't recall exactly, not sure it would matter in the tune, since, its not controlling speedo or tach on the toyota cluster. But I will verify. It was several months ago, and I was driving trying to look at the laptop at the same time.

Yes, I added the second reluctant ring gear during the transmission rebuild.

Academically speaking, lets say, its inaccurate data by a bit or its the 4.56 gears. Is it safe to say that I could consider a re-gear to bring down the engine rpms? I also put 'none' in the under drive selection. And TOYOTA default for transfer case, of 1.00 ratio in high.

What would be a better target RPM for cruising 65-70? That's more of my question.

Thanks for all the inputs. I will have to drive it more, and hook up the laptop again, to get some ECM data to verify, ECM/tach read outs, transmission lock up, (if i can) and some different phone apps to get accurate MPH.

 

[tmxmotorsports]

What is overland app?

 

[TLC94LS]

What is overland app?

Overland Bound community. Guy has a pretty cool YouTube channel online community.

 

[tmxmotorsports]

Sorry should have asked this question with the other does ot plug into the obd port or is it GPS driven

 

[TLC94LS]

Sorry should have asked this question with the other does ot plug into the obd port or is it GPS driven

just on the phone, so however a phone can get it, not sure if its just gps based or some cell information somehow.

 

[PIP]

What would be a better target RPM for cruising 65-70? That's more of my question.

2000 @ 65 is a good safe target for electronic V8. You can gear to lower RPM a little from that, but you can lose driveability quickly with a 4 speed auto if you lug it too far. There's a big gap between 3 and 4. You want to gear so you're not hunting between 3-4 or unlocking the converter frequently.

Another consideration is you have a 4L80E which has a tall 1st gear. I've had a few GM pickups with 4L80E's and used several more in conversions. They have this uncomfortably high take off gearing, you noticeably have to lay into it to get them moving, especially towing and starting out uphill. If you go to tall with the axle gearing you can hurt the low speed takeoff performance in high range.