I put a Honda Civic tach in my 240

[daijoubanai]

So my 240 tach stopped working, and instead of spending the money on another one, I'm cheap and spent even less on one from a honda civic since its about the same size.

I figured with some minor trimming it should fit, and hooking it up should be easy. I used the power and ground from the cluster, and the tach signal I'm getting from MS.

Was it worth it? Probably not. It took my a couple hours, and I could have just paid a bit more for an actual 240 tach. But this was cheap, and a learning experience.

Comparison.


after some dremel work


had to modify the cluster a bit for the tach circuit board.


All wired up


back plate on


installed and working


checking it with tuner studio at different rpm, to make sure its accurate. And it is.

[LeedomtoFreedom]

Nice job, I like little things like this. Notice any difference between the two, maybe the honda tack keeps up with the revs quicker than the 240 one.

[DrHutch]

That's pretty awesome. Was this out of an EK civic?

[daijoubanai]

Originally Posted by DrHutch

That's pretty awesome. Was this out of an EK civic?

It was. It was one of the cheapest on ebay, so its what I went with. I think the EG tachs are pretty much the same size, and would have also worked.

Originally Posted by LeedomtoFreedom

Nice job, I like little things like this. Notice any difference between the two, maybe the honda tack keeps up with the revs quicker than the 240 one.

Don't know to be honest. My 240 tach hasn't worked in so long I don't even remember.

[Broke4speed]

Ok, now THIS is the **** I like.
Good job!

[cwdodson88]

Pic of installed and operating shows 900 rpm, tuner studio shows 1773, so are the pics lying? Or were the two pics at different times?

[brian smith]

Does it exhibit the better damped needle of a more contemporary tachometer, or simply a functioning replacement?
I disliked the Volvo tach so much I put the darned clock back in and used a 2 1/16" Spek in the 3-hole spot.

[tryingbe]

Good job!

[daijoubanai]

Originally Posted by brian smith

Does it exhibit the better damped needle of a more contemporary tachometer, or simply a functioning replacement?
I disliked the Volvo tach so much I put the darned clock back in and used a 2 1/16" Spek in the 3-hole spot.

honestly I don't remember the original tach really having a problem. I haven't really driven around yet with this in so I'll update how it is.

Originally Posted by cwdodson88

Pic of installed and operating shows 900 rpm, tuner studio shows 1773, so are the pics lying? Or were the two pics at different times?

I was wondering if someone was going to mention that. But yes it was different times, I just didn't bother uploading the other image. It was more to say that I checked it at a range of different rpm to check for accuracy. Just to make sure I didn't have to mess with the tach calibration or anything.

Here it is though.

[propav8r]

That's a pretty cool look. Looks like the finish on the gauge face is a good match too. A little orange paint on the needle, and it would almost be unnoticeable!

[cwdodson88]

Now swap the speedometer face.

[ZVOLV]

Thumbs up.

[Ursan]

[J_Jones]

Very neat. What did you use to hold the tach to the cluster?

[Mueller]

Looks good, I like.

Looks good, now swap engine

[daijoubanai]

Originally Posted by J_Jones

Very neat. What did you use to hold the tach to the cluster?

Well, when I trimmed it, it just so happened to stay mostly in place by itself. Though I realized with vibration it could pop out. Between the back of the gauge circuit board and the black back cover, I just put a small piece of foam which adds just enough pressure for it to not move.

Originally Posted by 240240

Looks good, now swap engine

too much work/money. Though I'd be totally down with it.

[dl242gt]

So what type of rpm signal does this tach use? Would it use the same signal as the VDO original tach?

[tryingbe]

Originally Posted by dl242gt

So what type of rpm signal does this tach use?

Signal from Microsquirt.

[Broke4speed]

Originally Posted by dl242gt

So what type of rpm signal does this tach use? Would it use the same signal as the VDO original tach?

It uses a square wave, 5 or 12v. The original tach used a flyback voltage spike from the coil. At least I think that's what it's called. Most modern cars have been using a square wave for decades, so their tachs integrate nicely with aftermarket engine management.

[daijoubanai]

Originally Posted by tryingbe

Signal from Microsquirt.

This. I figured I could get the signal I needed anyway because of MS, but as you can see in the picture of the laptop it was pretty straight forward.

The original signal on the civic comes from the distributor, as well as most honda's since at least the late 80's, so if you don't have MS, it probably wouldn't be difficult to do this.

Originally Posted by Broke4speed

It uses a square wave, 5 or 12v. The original tach used a flyback voltage spike from the coil. At least I think that's what it's called. Most modern cars have been using a square wave for decades, so their tachs integrate nicely with aftermarket engine management.

or this I guess.

Trying to get the signal from the coil like the 240 originally does probably wouldn't work, which is why I didn't try it.

[dl242gt]

Thanks I was wondering about that signal. That may be something to do when some type of the squirt family of injection is installed on my turbo. Looks great in there. My interior is blue in my turbo so it would be a nice little blue touch.

[M.H. Yount]

Is there a switch of some sort that allows the choice between a 5V or 12V signal?

[Broke4speed]

No, I just don't know the exact voltage used, lol. It's either 5 or 12.

[M.H. Yount]

If it went in without a 'resistor' adjustment, it's likely set up for a 12V signal just as the VDO tach was. When I hooked up the LS ecu output (5V) to the stock Volvo/VDO tach without any adjustment, it read WAY low. Had to "T" in another 12V connection through a 1000 ohm resistor.

Don't know my Civic nomenclature -- what year did the tach come out of?