my 66' impala hardtop :)

[rch-13z]

This last page has made my brain hurt..... but I'm excited it's at this point - seriously, this is the only thread I come back for.

 

[ari666]

i like it when you comment too. was just reading the first few pages and sure enough, there you were.

glad to have you

 

[Not_An_Abba_Fan]

I only read this thread to see what ari has ####ed up now....

 

[wwilde]

interesting... if you go off the 1000 cable rotations per mile, and take the above number, then its 2.3 to 1... looks like ive found the magic number.

Are you saying the driven gear is brown? like the site I linked to previously it has 39 teeth:

From here: Speedometer calibration with a 700R4 Trans - The 1947 - Present Chevrolet & GMC Truck Message Board Network
Then I get:

Input Parameters Are the Following:
Speedometer Revolutions/mile = 1000
Rear Tire Diameter (Inches) = 28.94
Differential Gear Ratio = 3.36
Driven Gear Teeth Number = 39
Computation Results:
Computed Drive Gear is 17
Ratio of Driven Over Drive Gear is 2.3

Can you not have a look at the number on the back of the housing as pictured above?

Sooo I think your on the money, that makes your olive " drive gear " 17 teeth.

My head hurts...

 

[Deuce]

interesting... if you go off the 1000 cable rotations per mile, and take the above number, then its 2.3 to 1... looks like ive found the magic number.

a song to celebrate your discovery:
[video=youtube_share;aU4pyiB-kq0]http://youtu.be/aU4pyiB-kq0[/video]

 

[ari666]

so ephect came round last night to help me confirm a few figures as we drove.

the VSS is reading the same as the dash, so thats a win, but the gear shifts up and down are not happening at the same time IRL as they are on the computer.

i love these scales. you just select a point ad there is a line thatll show exactly what each thing was up to. here is an example. in the above pics, you can see the line i have highlighted has
3% TPS
15mph
gear 3 (just 2-3 upshifted)

so then look at the tables for gear changes

3% tps (under 6% so the first column)
2-3 upshift
22MPH

so now if you take 22 (the number its supposed to shift at) and divide it by 15 (the ERR number it is shifting at) youll get 1.466666 error margin.

whats cool is as i go over the whole chart and check upshifts and downshifts in relation to actual spped, i find that the whole map is out by around 1.5...

now this is where it gets weird as:

if you take 2.3 and remove a 1.5% error margin... well... unless we did math wrong (which wouldnt surprise me) ... the magic number is 2

and i now have no idea why.

 

[Heron SSV]

I understand everything you've said

 

[ari666]

if you wanna tune your LS powered VK, its good to know how its done

 

[ephect]

that torque is rediculous, and that idle lump is to die for.

 

[VRSenator065]

No way of hooking up the gear switch to the shift lever itself? Pretty sure that's how the VR was before I put the VY box in there with the unit on the side of the trans?