[E-Type] 3.07 invite

E-Type
1

Now that my car is back on the road, if there is anyone in the Seattle area
who wants to go for a ride to see what the difference is between a 3.07 rear
end and the stock 3.54, I’d be happy to do so.

I still need to either get a new speedo or re-gear my current one. Is the
latter a feasible option?

R.

Roger Los Design
Seattle, Washington

“Everyone’s a designer, not everyone’s good at it.”
http://www.los.com

2

Roger Los wrote:

Now that my car is back on the road, if there is anyone in the Seattle area
who wants to go for a ride to see what the difference is between a 3.07 rear
end and the stock 3.54, I’d be happy to do so.

I still need to either get a new speedo or re-gear my current one. Is the
latter a feasible option?

R.

Roger Los Design
Seattle, Washington

“Everyone’s a designer, not everyone’s good at it.”
http://www.los.com
Yes, the latter is most definitely an option, and in the interests of
originality, more desirable I think. I had my conversion to the 3.07
done a few months ago and it makes a HELL of a difference!! Can’t think
why any U.S e-types are cruising around on the 3.54. When my conversion
was done, the guy that did it sent the speedo away and got the
re-gearing taken care of. If no-one responds with supplier info’ to you,
I’ll check out where my guy got it done and let you know.

3

Roger:

Call Nisonger Instrument Service
and ask the man…he can answer
your questions…does good work too!
914-381-1952
He did one for me!
Maynard Fisher-----Original Message-----
From: Roger Los roger@los.com
To: e-type@jag-lovers.org e-type@jag-lovers.org
Date: Thursday, May 07, 1998 2:26 AM
Subject: [E-Type] 3.07 invite

I still need to either get a new speedo or re-gear my current one. Is the
latter a feasible option?

R.

Roger Los Design
Seattle, Washington

“Everyone’s a designer, not everyone’s good at it.”
http://www.los.com

4

In a message dated 98-05-07 03:17:51 EDT, you write:

Now that my car is back on the road, if there is anyone in the Seattle area
who wants to go for a ride to see what the difference is between a 3.07
rear
end and the stock 3.54, I’d be happy to do so.

I still need to either get a new speedo or re-gear my current one. Is the
latter a feasible option?

Roger-

I am very interested in trying your car regarding this swap - My rear diff is
at Gerard’s now for seals
Doug

5

Doug, I will be gone Friday night and all day Sunday, but any other time
this weekend or early next week would be fine. Give me a ring, 206 522 3698.

Roger> -----Original Message-----

From: owner-e-type@jag-lovers.org [mailto:owner-e-type@jag-lovers.org]On
Behalf Of DHarr13177
Sent: Thursday, May 07, 1998 6:41 PM
To: e-type@jag-lovers.org
Subject: Re: [E-Type] 3.07 invite

In a message dated 98-05-07 03:17:51 EDT, you write:

Now that my car is back on the road, if there is anyone in the
Seattle area
who wants to go for a ride to see what the difference is between a 3.07
rear
end and the stock 3.54, I’d be happy to do so.

I still need to either get a new speedo or re-gear my current
one. Is the
latter a feasible option?

Roger-

I am very interested in trying your car regarding this swap - My
rear diff is
at Gerard’s now for seals
Doug

6

I am under the impression the gear ratio for the speedo is controlled by the
90 degree adaptor at the transmission. different gears are available. Is this
correct?

Don

7

Please say it isn’t so. My desire to take off the tranny cover is extremely
limited!

Roger Los> -----Original Message-----

From: owner-e-type@jag-lovers.org [mailto:owner-e-type@jag-lovers.org]On
Behalf Of DPowell126
Sent: Sunday, May 10, 1998 7:52 PM
To: e-type@jag-lovers.org
Subject: Re: [E-Type] 3.07 invite

I am under the impression the gear ratio for the speedo is
controlled by the
90 degree adaptor at the transmission. different gears are
available. Is this
correct?

Don

8

At 10:52 PM 10/05/98 EDT, DPowell126 wrote:

I am under the impression the gear ratio for the speedo is controlled by the
90 degree adaptor at the transmission. different gears are available. Is this
correct?

No, I don’t think it is correct for the e-type (but is correct for an
XJ-S). There were 2 schools of thought for speedo calibration: Those
manufacturers who used the same transmission gear for all diff ratios (most
UK manufacturers until the 1970s) and those manufacturers who used the same
speedo head for all rear axle ratios (most US manufacturers, UK Ford, and
Jaguar from the 1970s).

Cars which vary the transmission gear (e.g. my XJ-S) typically have 1000
rev per mile speedos, my S3 e-type (3.31 diff) has a 1216 rev per mile speedo.

That is why Jaguar speedos have a 4 digit number somewhere on the face, to
itentify which axle ratio the particular speedo head is for. The number is
the number of revolutions per mile of the speedo cable. You could achieve
the same result by changing the transmission gear, but it is not how the
factory did it.

regards,

Mike Morrin
S3 2+2
XJ-S
XK150

9

In a message dated 98-05-11 03:40:29 EDT, you write:

Please say it isn’t so. My desire to take off the tranny cover is extremely
limited!

It isn’t so. I’ve done this. The gear change is in the speedo. You can do it
yourself, with some patience, Nisonger sold me just the gear - we figured out
which one I needed over the phone by counting gear teeth on my old one.

Doug

10

Don:

No this is not correct. The speedo head must be recalibrated by changing
it’s internal gearing to adjust the reading.

Mike Frank
1969E-Type 2+2

At 10:52 PM 5/10/98 EDT, you wrote:>I am under the impression the gear ratio for the speedo is controlled by the

90 degree adaptor at the transmission. different gears are available. Is this
correct?

Don

11

Hi Roger,

I ran across your post on JagLovers re your 3.54 to 3.07 diff conversion.

I’m looking to do the same on my SII FHC.

So… How do you like it?
I’d like to meet up next time Im in Seattle.

Dave
San Francisco
415 559 1832

13

Talk about a zombie thread!

Roger sold his car, quite some time ago (AFAIK), and I have not seen him on JL for quite some time.

@paul_spurlock might know how to contact him…

I can say this, for the 3.07: to my mind, it was the best fit for the car: it worked well on the highway, keeping revs to ~2900 rpm/75 mph, and doesn’t take away all that much low-end grunt.

14

Oops; ancient Thread. Irrelevant Post deleted by me.

Regards,

Bill

1 Like
15

Dave, one of the two best changes I’ve made to the car (3.07). The other being an S1 spec distributor.
The car was actually quicker with the taller gear.
Cake AND ice cream.

2 Likes
16

Am I missing something? Changing from 3.54 to 3.07 swaps lower rpm at high speeds and less acceleration. I have a 5sp and when I’m in 5th gear my acceleration really suffers.

17

I think David’s point was that the advance curve on the ‘S1 spec distributor’ he went with more than offset the effect of the taller diff.

I did something similar but just tweaked the springs on the S2 distributor ti get a steeper curve.

18

Got it and agree. I went to a mallory dual point 30+ years ago and really noticed a power upgrade. I’m now running Ray’s EDIS and couldn’t be happier.

1 Like
19

That’s it exactly Mike and George. I know I sound like a broken record regarding advance curves. A properly running E can easily pull a 3.07.
Originally, I had put 60 series tires on with th OE 3.54. It was geared like a short track racer. And with the original distributor it still wasn’t quick. A truly miserable combo.

1 Like