Anyone heard of this Tach?

[Northboundtrain]

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=129/category_id=287/home_id=59/mode=prod/prd129.htm

Seems like it would be very accurate and easy to calibrate.  I guess you could just pull a tack off of a gasser at the junk yard or buy one.

[bhtooefr]

Yes, it would be very accurate.

Note that the DSL-1 is much cheaper, although it's a W terminal-based tach adaptor, which has a little less accuracy (driven by a belt that can run slower than engine RPM if it slips somehow).

[zyewdall]

The DSL-1 adaptor is the one I bought for mine, that we were talking about how to calibrate.  Haven't gotten around to installing it yet.  The DSL-2 sure would be easier to calibrate though.

[mortskeg]

I'm also running the dsl-1 and it has been working flawlessly for over a year.  Dakota digital shipped it out real quick and the directions and everything were pretty easy. http://vwcaddyforum.com/showthread.php?t=4749

It looks like that flywheel pickup would be a neat deal too though, especially if you didn't already have a W-terminal alternator.

The DSL-1 adaptor is the one I bought for mine, that we were talking about how to calibrate.  Haven't gotten around to installing it yet.  The DSL-2 sure would be easier to calibrate though.

zyewdall- I took a look for this topic but couldn't find where you guys were talking about the calibration.  It wasn't too bad for me, I thought about hooking up a timing light to my wife's 4 cyl gas car, having her run it at x rpm, and then using the light on my pickup to get the engine to a cooresponding rpm and then calibrate the tach from there.  However, I decided to do the one-man calibration, I figured out what RPM my engine should be turning at 5th gear going 60mph given my transmission's 5th gear, final drive ratio, and my tire size.  Then, using a handheld gps (much more accurate than the 25 yr old speedo) I was able to maintain a constant 60mph and set the tach to the predetermined rpm.

The only problem with this method is I guess tire sizes are actually hypothetical, and apparently 195/60/14 of one manufactuer, is a slightly different diameter than that of a different manufacturer.  But I figured close enough for me.  I guess if someone wanted to be real precise they could wrap a tape measure around the tire, or just mark out a spot on the tire and do one revolution and then measure the distance traveled on the ground.  Anyhow, if your interested I can dig out the tire size- diameter and gear ratio/rpm - mph formulas, or they are pretty easy to find on the net IIRC.

Hope this helps, and sorry for the slight thread jack there, Northbound

[zyewdall]

Sorry Mortskeg.  Wasn't on this forum.  I was over his house last week discussing how to calibrate it.  He said that they make shop tachs that clamp onto the injector line and actually sense the pulse of fuel.  Wish I had access to one of those!

I like the the idea of the road speed/gear ratio test like you described.  Just have to find out what transmission I have in my car.  I would need to do the GPS speed measurement, because I'm fairly sure my speedometer is measuring a bit high too.  Either that or a 1.6NA really can easily reach 70mph.

[mortskeg]

Actually you may be going that quick. :shock:   At least with the one's I've had, the vw's seem to read the other way around- so that you're actually going faster then what's shown.  My pickup will do 70+, though I usually don't cruise much over the higher 60's.

I was thinking about renting that diesel pulse tool locally, but I can't remember how much they wanted for the day.

Anyhow, if you're looking for your trans code it's not too hard- you'll find it on the flat spot of the bell-housing under the car.  It will probably be 2 or 3 letters followed by 5 numbers IIRC.  Like ACH02025, which would indicate a ACH code transmission manufactured on the 2nd of feb, 1985.  FF FN FO are pretty common 5 speeds.  GC if you have a 4.
Hope this helps.

[bhtooefr]

My 1.6NA's got some pedal to go at 70MPH.

Now, whether the more pedal is SMOKE, or it's NOISE, or it's actually speed, who knows.

[RabbitJockey]

my car goes 85 easy.  i dunno if it goes any faster than that though

[DVST8R]

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=129/category_id=287/home_id=59/mode=prod/prd129.htm

Seems like it would be very accurate and easy to calibrate.  I guess you could just pull a tack off of a gasser at the junk yard or buy one.

I have one, and it runs an autometer tach, works great. I have it monted to read the cam teeth.

[Northboundtrain]

I think I'll get this flywheel tach adapter.  I remembered that I have a sunpro tach that I guess I'll just use.

DVST8R:

So you divided the number of cam teeth by two to get one revolution?  Did you mount it in the timing belt cover?

Thanks for the input

[DVST8R]

Yes i divided it by two. No I didn't mount it to the cover as it has too much flex and it moves around too much, I was afraid of contact. I made a custom bracket that mounted engine lift lug (or at least i think thats what the hoop is used for) And as such was removable by the allen key bolt. I dont have a picture handy, but mabey Porcshe 935Racer, or Malone might have one. A bracket should be easy enough to come up with, mine was made using a CNC plasma, cuz I had one where I was living at the time, and as such was fancier then it needed to be. If I did it agin I think I would mount it in the tranny check plug hole and have it count the flywheel teeth. I think it would be less finikey (sp?) that way.

[texaseric]

I can't see flywheel teeth directly through the check hole on my tranny (four speed). Are five speeds different?

[DVST8R]

it would be at a bit of an angle but yes you can see them.