Speedo Calibration for 4.08 gearing

[jamesmost]

Is there an easy way?? the yellow box did not work for Rob.

[rsiwicki]

do the math in your head.....

100=8560=51135=115

etc....

besides you can really freak out your friends and tell them you cruising at 100mph when you are really only going 85mph...they will never know the difference when there are not many other cars on the road

[elwesso]

must..... read..... posts

zerothread?id=167471

[Rex]

Wes, what's in those posts that answers the 4.08 any better than the yellow box, whcih hasn't worked and actually be tried??

Gonna use a GPS to figure what real speeds are until the yellow box thing can be figure out.

[jamesmost]

did

must..... read..... posts

zerothread?id=167471

yes i did did that yo

[jamesmost]

do the math in your head.....

100=8560=51135=115

etc....

besides you can really freak out your friends and tell them you cruising at 100mph when you are really only going 85mph...they will never know the difference when there are not many other cars on the road

being that u are a mathamatical genious mabe u could set upan excel spread sheet for me

[jamesmost]

Wes, what's in those posts that answers the 4.08 any better than the yellow box, whcih hasn't worked and actually be tried??

Gonna use a GPS to figure what real speeds are until the yellow box thing can be figure out.

I have my GPS

[elwesso]

just take your as read speed times 85%.. 4.08 is about 15% taller than the 3.54, so for every 10 MPH you go, youll only be going 8.5MPH... You could do a simple formula in excel..... no problem, do it every 5 MPH

Wes, what's in those posts that answers the 4.08 any better than the yellow box, whcih hasn't worked and actually be tried??

Gonna use a GPS to figure what real speeds are until the yellow box thing can be figure out.

As far as the speedo calibration for the 4.08, I am using the plastic gear for a 3.9 ratio. Once you get past this size, the plastic gear will no longer fit on the VSS of our cars.

So I just went with the 3.9 VSS gear. The speedo reads a bit optimistic, less than 5%.

If you run taller tires in the rear, then this would work out perfect.

if you ran a 245-45-18 in the rear, the difference would be perfect, within 1%

(26.7/26.1=1.02)

with that speedo sensor it reads about % faster... so for every 10MPH you go, your only going about 9.4 MPH (4.083/3.961= 1.0308, or about 3% faster

[elwesso]

just for kicks and giggles i put together a spreadsheet of all the values between 0 and 221MPH as read by the speedo with their actual values.

[jamesmost]

just for kicks and giggles i put together a spreadsheet of all the values between 0 and 221MPH as read by the speedo with their actual values.

Damn Wes you my Nismo

[elwesso]

i aim to please.

[jamesmost]

heard that sjoko put the J30 speedo gear in and only 5% off me bee cool wit dat

[elwesso]

yeah you heard it from me 5 posts up.

[redmanfx]

Think Z

red

[elwesso]

the 4.08 speedo sensor wont fit in there.....

[redmanfx]

bet the farm on that?

red

[maxnix]

bet the farm on that?

red

I think Azhitman would.

[FarFetched]

In any case it (4.08 diff) will keep you out of trouble with pin-heads in uniform becuase you travel slower that actual speed. I had 4.08 diff swapped and loved it because actual speed was lower and I was always in a safe zone - Cheers!Now I ride my HO and if you go too slow people look at you like on an idiot!So, I keep up avarage speed of 80-90 MPH. Cops just look at your sorry a$$ and make you slow down! I like that! Cheers!

[elwesso]

bet the farm on that?

red

SIJOKO just mentioned it in that thread, 3.9 is the biggest one you can fit in there!!!!! Im not just pulling this out of a hat!

[jamesmost]

yeah you heard it from me 5 posts up.

thats pretty funny ^ u funnywhat year j30 SHOULD I GET THE VSS GEAR FROM ??

[elwesso]

93-97.

[jamesmost]

Cool just ordered speedo gear $22.00I will have it on Friday, I will also have my NICO ECU w/ switcher by friday.Just need headers and SC

[elwesso]

superb..... cant wait to see how it works!!!!!

[jamesmost]

superb..... cant wait to see how it works!!!!!

yes I am feeling quite giddy