kevin87turbot

iTrader: (2)

We upgraded all of our 2.10, 2.75, and 2.98 TH400 and 4L80E gearsets to the billet carrier design a few months ago. Since then, I've had one of our TH400s with the 2.10 planet in a 2000+ hp true 10.5 car. It was running 4.5x at 170+ mph. He was testing it versus a PG. He ran almost identical times with both transmissions. The PG was easier to hook on a slicker track though.

TrueBlueGTO

Kevin...Before anyone can compare the graphs they all have to be on the same scale. The 4L and 6x have 0-500 lbs (left side) set to a 0-7000 RPM scale (right side), where as the 6L80/90 graph is skewed with 0-500 lbs set to a 2000-7000 RPM scale.

And the ones on top are off too: 1.0 vs. 1.4.

poorhousenext

TB,

You may are may not have done this.

Right click on each picture and save it to your computer. Then you can either display 2 of them on screen next to each other and zoom in on area of common intrest to study them or print them out and compare.

If you look at say the "G's" 1.4 on 4l & 6X graph vs the 1.0 G you'll see the program did the scaling. Not saying scaling can't be forced to start the 6L at 1.4, but other than making it a little easier to see the 6L' gearing at launch vs 6x, has a G value of 0.9 and held G value drop to only 0.74 while the 6X strained due to it having less mecanical advantage and it pops up to 1.4 and then drops to a low of 0.65.

Same goes for the right side numbers. Values generated want change due to scalling, just makes you have to look closer to see whats going on. That can be good sometimes as you have to work a little harder to see the facts.

Looking at the FEET scaling at the shift points showed me what I was seeing with my MPH's gearing comparsions I did. 6L blows thru it's lower 1 & 2, while 6X stays in it's first gear a little longer, while the 6L has already shifted to 2nd and same thing happens in 2nd to 3rd. Part of the initial value of the 6L lower gearing advantage is negated by the 6X's time in it's 1st and 2nd gearing.

Bottom line, I was shocked by how my earlier comments in post 70 matched up with the models. Without being educated by thread about RPM retention & lost I wouldn't have made my Wild A$$ Guess that the 6X might just be able to hold it's on.

Didn't think it would come out on top, just close.

Old saying, "Even a Blind Hog can find a Acorn ever once in a while."

TrueBlueGTO

Believe me I hear what you're saying and am trying to make sense of it....but I don't see how anyone can make an accurate and fair assessment of these charts when one, the transmission in question, is scaled differently than the other two. The value of each individual box means something differently between the charts if they aren't scaled the same.The bottom line MUST start at the same value (zero) for all the charts....and have the same top values (1.4).

100 lb/ft of torque is at 1500 RPMS for the 4L70 & 6X's LS3, but at 3000 RPM's for the 6L's LS3???

Secondly, what stall speeds were used for the converters. I see the 4L70 stall is mentioned, but neither of the six speeds'.

TrueBlueGTO

Now I get how it shows that the 6X can get through 3 gears in 550 ft and how the 6L takes 600ft and how this loosely translates into elapsed time comparison. (i.e. How QUICKLY does the car make it to 550 or 600 ft compared to how little time does it take for the engine to sweep through its rev band.)

Assuming traction is not an issue and that we have full torque converter lock up, that means the engine and tires are positively connected during the run. So for every full sweep of the engine's RPM range, the tires do X numbers of revolutions. As the graph shows, the transmission with the greatest gear/revolution multiplication means is spinning the tires.... tire circumference converting into linear distance shows how the 6L80 is the 0-60 champ, as you said. The 6L has it in the 1st to 2nd, but the 6X's 3rd gear reels the 6L back in. So, based on the present unequal scaling, I see how the 6X just beats the 6L at the end. But again...the scalings have to be equal to get an accurate, fair, and more conclusive picture.

poorhousenext

TB,

First, I read Kevin's post on comparisons, and interpreted it differently from you.

To me he describes the engine, rear end ratio, and converter stall the same and constant on all 3 models. The weight of the vehicle is not constant. He changes the cars weight on the other two models due to both the 6L80 & TCI 6X being heavier than the 4L65.

I understand why just looking at the graphs, all doesn't seem kosher.

Re-scaling want change were the lines intersect with RPM.

RPM scale ends at 7000 RPM on both models. It steps down at 500 RPM increments, with 1000 increments being the major RPM identifiers. You should be able to see the values are not skewed. Should help if you have both model on you monitor at the same time. Zoom in on both where lines intersect with RPM scale. that makes it easier to see differences.

Hope this helps.

TrueBlueGTO

Thanks Poorhouse...but it doesn't help me grasp how you can have two graphs with different starting points and call them comparable. Maybe my physics professors were wrong when they admonished ups for comparing the 'same' data on two differently scaled charts.

How do you explain 100 lb/ft of torque is at 1500 RPMS for the 4L70 & 6X's LS3, but at 3000 RPM's for the 6L's LS3??? By that chart the 6L80 is making NO torque at 2000 RPMs.

Additionally, assuming your interpretation of the stall speeds is correct....with a 4.xx first gear in the 6L and 3.73 rears, am I the only one thinking that stall is a bit too high? I'm thinking a 3200 would be more appropriate.

poorhousenext

First I need for you to tell me what each color of line on the first gragh depicts/defines or displays. Then do the same for the second graph.

Once you do that, I'll try to explain the TQ problem.

By the way, I went to Sam Huston Institution of Technology. My BS is in Deception an I have a Masters in Misdirection.

On my final aptitude test, this fool had a near perfect score on being Offensive and Defensive in both of my degrees.....

PS:I'll let you figure out higher or lower with the 3200 vs 3000. The 4L could benefit form a higher Stall, to help with it's gear splits.

kevin87turbot

iTrader: (2)

TrueBlue,
Sorry about the scaling differences. I noticed that when I did the simulations. The software autoscales the graphs for you and doesn't have a manual override feature.
As far as the converter, I used the same 3000 rpm stall for all three models. I can change that in the software if you'd like for me to run a different stall speed. The only changes that I made were the transmission gear ratios and the vehicle weight. I also increased the Traction Coefficient from 2.7 to 3.0 for the 6L80E, because it indicated some tire spin.
The performance data is as follows:

4L60E
60' = 1.819
1/8 mile = 7.864
1/8 mile (mph) = 91.0
1/4 mile = 12.279
1/4 mile (mph) = 112.3
0-60 = 4.11 secs
0-100 = 9.81 secs

6L80E
60' = 1.816
1/8 mile = 7.725
1/8 mile (mph) = 93.0
1/4 mile = 11.99
1/4 mile (mph) = 115.4
0-60 = 3.77 secs
0-100 = 8.98 secs

6X
60' = 1.830
1/8 mile = 7.709
1/8 mile (mph) = 93.0
1/4 mile = 11.95
1/4 mile (mph) = 115.8
0-60 = 3.76 secs
0-100 = 8.90 secs

TrueBlueGTO

Ok Poorhouse...now you owe a ride in the Vettes AND a beer!!

Now THAT's a crowd-on-their-feet race I'd love to see, Kevin!

Can you repost the corrected graphs?

poorhousenext

I'll gladly give you a ride in the Vettes. We want be able to abuse Ms Scarlett (66 Vert), she's still a little weak in the knees for doing a hard run.

She does look ok between the Spread & Sheet, but don't want to have to come pick you up and give your a ride in the 6X to go pick up my 6L80E car at the Transmission Shop.

Now Ms Lydia (True Southern Belle with good looking curves), she can get down and Boogie, all day and night. She should be able to take you for a real ride.

Hope a PBR or Milwaukee's Beast will be OK. I'm more of a find wine man, myself, so I'll bring a bottle of Boon's Farm Strawberry Hill for myself. Man may need more than one bottle to watch you weld up the old armor...

Kevin, thank you for doing the 3 Models.

You may need to rethink which trans would come out on top in 0-60 time too. Looks like the 6X squeaked that one out too. It would be a no brainier if the 6L80E had a 4.10 rear gear. It would have to shift to 3rd to get to 60 MPH per my math if we hold engine to 6500RPM max..

kevin87turbot

iTrader: (2)

Poorhouse, I actually had said that the 6L80E would outperform the 6X in the 60', not 0-60. When I first modeled the transmissions, it showed that the 6L80E was the slowest in the sixty. That's when I tweaked the traction coefficient on the model for the 6L80E. That brought the performance numbers around to what I expected. I would also expect to see the gap between the three transmissions to be much closer with a higher stall converter.

True Blue,
There's actually no problems to be corrected with the graphs. They're all correct. It's just difficult to compare the three since the computer scaled them differently. If I have time this week, I'll export the data into a spreadsheet and graph the curves in Excel.

TrueBlueGTO

You are ON sir...anyone who has the same taste in women and alcoholic beverage is ok with me!! Keep the PBR and Beast and bring 3 bottles! I've recently been on a Riesling kick...the Vodka was hitting one of these organs a bit too hard! lol

TrueBlueGTO

Kevin...is it a 3000 or 3600 stall speed across the board?

Now that I relook at these charts and better understand the variables that go into it, beings the 6L80/90 has low g-forces off the line due to traction issues, and the race is so close....I'd be willing to bet a dollar to a donut that a lower stall speed 2800 (if 3000 originally) or 3200 (if 3600 originally) stall speed would help with hooking off the line and reel that .03-.05 1/8th and 1/4 time back in.

kevin87turbot

iTrader: (2)

Hey guys, Don't leave me out of the adult beverages. I'll take a cold one too! lol

I modeled the car with a 3000 stall for all three transmissions.
As you suspected, it does help the 6L80E when you change to a 2800 converter.
Here are the numbers.

4L60E 12.30 @ 112.3
6L80E 12.00 @ 115.4
6X 11.98 @ 115.7

Let me know when ya'll are ready to start the test drives!

Kevin

poorhousenext

Kevin,

If you work the NSRA Street Rod Nationals South show, we hope to have Ms Lydia on display there.

If we don't have it ready by then, the car is only about 4 miles away from Chilhowee Park and Exposition Center so you can come over and help us figure out how to get the transmission working...

I'll buy you one of those $5.00 COLD lemonades since you are working...

Maybe a test ride too if the shop will let me get it dirty.

SnIpEz

iTrader: (4)

Jesus this thread went way over my head

And to think it started with a simple question lol

poorhousenext

LOL.... Since I was one if not the number 1 Simpleton responder to what you call a simple question, I think this Foolish Simpleton should respond. After all I have the degrees from the Major University most in TX seem to have attended, Sam Huston Institution of Technology....

Lets break down your so call simple question(s)....LOL You tell me which ones you think weren't answered.

Read through the responses posted and tell me which of your questions weren't answered, and I'll see if I an my research assistant Hesus can't point you in the right direction to find that answer.

The answer to how curious people were and how many followed this tread, NOT MANY...LOL

TrueBlueGTO

The official answer to the OP's question will be known within 2-3 weeks when test fit a '97 T/A with a 6L80.

CarsandWomen

iTrader: (19)

excellent news