TheSamba.com :: View topic - First time bus owner, and sunpro tach question

Sun Feb 15, 2004 12:23 pm

Hey all,
My lady and I became first time bus owners a couple months ago (third owner, 76 westy), :D and we're loving it. So far we haven't done a whole lot other than make the occasional trip across town, but we plan on doing a lot of camping come spring, and taking it cross country in the summer (Eugene, OR to upstate NY) :!:

Mechanically, she pretty much rocks, the previous owners converted from auto to 4 speed and did a really good job of maintenance and staying on top of rust, so she purrs like a kitten when you turn the key over.
Although I think we've pretty much gotten used to the transmission and got the hang of knowing when to shift, I want to put in a tachometer to make it a little easier to see what's going on back there, especially since the engine is so far away compared to our other car and it can be hard to get it right when the stereo is going.

I bought a sunpro tach (Sun Super Tach II Mini - CP7906) after getting sticker shock on a VDO tach, and getting a recommendation from somebody online, and was wondering if anybody had any experience doing an installation like this and could offer any advice/instructions/help to a bus newbie. :?:

peace,
L+L

Sun Feb 15, 2004 6:51 pm

I put in a tach in 1980 using the rear window defroster circuit to run my coil #1 lead to the tach. I have a jumper from the instrument lamps to the tach illumination lamp. 12 vts power from a switched fuse terminal. Ground to the big terminus on the plenum where all those brown wires congregate.

Best rev range is 2,000 to 4,000 rpm under load, when puttering around without load on the engine, you can drop it down to 1,750 without shifting.
If you are getting onto the New York State Thruway with a big eighteen wheeler bearing down on you, you can wind it out to 4,800-5,000 rpm in third gear before shifting into fourth. Highway cruising sweet spot seems to be between 3,500-4,000 rpm, about 63-70 mph depending on your transmission. What is the model # on your transmission? It is under and to the front of the fill plug.
Colin

Sun Feb 15, 2004 7:24 pm

No disrespect intended at all, but if you get the chance do try to drive your bus a few times sans stereo while you are still getting to know it. Even with the motor that far away, its sound and feel is, to me at least, incredibly communicative to the driver.

My bus is bone stock so I have no tach, but within the first hour of ownership I got a very good idea of the best up & down shift points and highway cruising speed. The sound of the engine, the rate of its response and the feel of the pedal will tell you an awful lot. Even after you get the tach installed it will be nice not to have to consult it constantly. :)

And BTW, I'm jealous that you have a stereo good enough to make this an issue. My Blaupunkt AM still works perfectly, but loses pretty handily to the type IV engine in the decibel level battle. :scatter:

Welcome and enjoy your "new" bus!

Sun Feb 15, 2004 7:41 pm

Well here is mine.

http://images.thesamba.com/vw/gallery/pix/138156.jpg

I suppose if your tach is a 3 3/8" it could use the same busboys mount ring I used for my VDO where the clock goes. I just did a search and I think your might be 2 5/8". :(

I used a wiring loom from the back to the front and ran all 4 of the sending unit wires in it.