m42 with m3 tach swap - advice

[robrez]

I bought an m3 tach. I was planning on keeping my original tach and just swapping my gas economy gauge for the M3 tach's oil temp gauge. Now I'm wondering if I should use the m3 tach too?

I have a MarkD chip, which raises the M42 redline to 7100, but is the m3 tach's upper rev end realistic? And would I need to re-calibrate it too?



Not mine below, but the same, minus the red needles.

[KenC]

Bump, same question.

I have a MarkD chip, too. I want the redline on my tach to be realistic...

What is involved with installing an M3 tach?

[Kershaw]

holy shit. i thought all m42s redlined at 7500rpm. thats why everyone calls it a "rev happy engine."

6500rpm.. you might as well use an m20.. im disappointed to find this out. big fail for an m42.

s42b20 ftw.

[e304me]

the gauge will not display right. When you are at 7000 the gauge will say 8k

[KenC]

the gauge will not display right. When you are at 7000 the gauge will say 8k

Exactly what I wanting to know how to change. It has to be some sort of electronic module.

[e30lyf]

you need e30 M3 coding plug to work accurate.

[M-technik-3]

the gauge will not display right. When you are at 7000 the gauge will say 8k

Why? If it has an M42 and it's a 4 cylinder engine then they should be compatible. Especially if it has the right codec plug.

[xwill112x]

use the right coding plug and the rpms will display correctly.