Well..... I think if you get a tach that can read a 1 cyl (maybe 2) engine it'll work fine with the 4cyl without a tach adapter.

quicklilcav - I'm gonna take a wild guess here, but i'm assuming that the speedometer works on the same process as the tach does? I'm getting 2 clusters, so I have one to "play" with. If I can do any sort of wicked modification to adjust the tach needle position I might as well try to play with the speedo too right?

Yes, but seeing as how we now have 6 cylinders it doesnt work that way. My tach has a switch for 4,6,8 cylinders. Im not sure why it doesnt read. But actually I made a discovery. I tapped my signal wire from the tach into the same wire that goes to the megasquirt for the tach reading, without any power to the Megasquirt the tach works! But with the megasquirt powered and running no reading from my tachometer. I know this because I was working on it the other day and had unplugged the harness at the megasquirt and tried cranking it without hooking it back up first and was reading around 300ish which is my crank speed.

Any opinions on this? Is megasquirt just a tach signal hog?

SHOoff wrote:I am worried about this since aftermarket tach's don't work properly without an adapter on the J-bodies...

But you're not using a J-body engine.
The ICM on the 3X00 engines has a dedicated tach output (the second white wire). That will run an aftermarket tach directly. That's how my DD cluster is set up, and it works perfectly.

SHOoff wrote:quicklilcav - I'm gonna take a wild guess here, but i'm assuming that the speedometer works on the same process as the tach does? I'm getting 2 clusters, so I have one to "play" with. If I can do any sort of wicked modification to adjust the tach needle position I might as well try to play with the speedo too right?

Yes, they work the same. There is a dedicated microproccesor that converts the signal to the sine/cosine PWM signals for the motor. I think the easiest way to modify the speedo readout would be before the cluster. If you could get a circuit that could effectively slow the pulse down (dividing it by half, maybe), then the cluster would simply think the car was going slower, and you'd just have to make a custom gauge face. If you know someone good with electronics, it's probably not too complex of a circuit to design and build.

Z24 Speed wrote:

Michael Antle wrote:My buddy bought an aftermarket tach for his civic and couldn't get to work. I popped the hood on my car and got it working in a couple minutes, without using an adapter.

Mind sharing how?

I just popped the hood, installed the clamp thing around one of the plug wires, held the power wire and ground wire onto the battery terminals with the tach layed on the battery and got my buddy to get in and fire the car up. It gave the same reading as what was showing on the factory tach.

Best run:
171 HP @ 4800 RPM
193 ft--lbs @ 4000 RPM



I'm running scary lean hense the drop to 160, so while it was fun to drive her, time to pull her off the road.

The 145 was a 4th gear pull



Edited 1 time(s). Last edited Sunday, January 13, 2008 8:28 PM

Kardain what are you running for exhaust?

Kardain wrote:Best run:
171 HP @ 4800 RPM
193 ft--lbs @ 4000 RPM



I'm running scary lean hense the drop to 160, so while it was fun to drive her, time to pull her off the road.

The 145 was a 4th gear pull

That's really weird. You have 171, 145, and 160. Did you get a datalog or anything while the dyno was running. Something's got to be going on that needs to be looked at. I can see the numbers being off a bit on each run, but at least closer to consistent.

Michael Antle wrote:Kardain what are you running for exhaust?

see my profile.

SHOoff -- I'm more surprised at the 171. The wheels I have aren't exactly light, so the 160 seems about right given rotating mass and whatnot.
I should have the datalog later today.

As for the 145, that was from a dig in 4th (2500 rpm part throttle)

I'm planning on making a custom cat back, in 2.5". Though, I'd much rather buy the monza cat-back and throw a resonator on it but I'm not sure if the 2.25 will be enough, what do you guys think?

Kardian just looked at your profile it said you were running 2.25, so I should be good with that. I also saw that your dream car was an 84 Monte Carlo Aerocoupe. The aerocoupe wasn't made until 86 and there were 200 made, in 1987 they made 6000 IIRC.

^^ in the 5 years that's been there you are the first to correct me on it.

I went w/ 2.25 since that was already there from when I had the exhaust done on my 2.2


Edited 1 time(s). Last edited Monday, January 14, 2008 12:20 PM

Sorry, lol I'm just a fan of those cars as well.

Its all good.

very true. My dream has been to build one with a built and blown 427 and a richmond 6 speed. Sorry, off topic, lol

If I use a 2nd gen pcm and harness, I'll still have trouble with the vats or passlock correct? what are my options on going around this, without using a bcm?

second gen doesn't use VATS as far as I know

Never seen a 2nd gen theft system, you could get a CLUB on them instead of VATS though.



01 cav w/01 3400 gam gt 4t45e

joe malechowski wrote:Never seen a 2nd gen theft system, you could get a CLUB on them instead of VATS though.

Gold, lol. Sorry, wasn't thinking straight at that hour...

Kardain, if you had all your tuning and shifting issues fixed, what would you figure you could pull of in the 1/4 mile? mid 14's?

I did 15.100 @ 92.79 with a not so good 60' time. So mid to high 14's sounds reasonable.
2nd Gen cars can pull well into the 14's with the swap, and the weight is close enough on the 3rd gen in comparison to the 2nd gen to make it sound more reasonable.

My speed on the top end plugged into one of those online calculators says I should be able to get a best of 14.28. But that was also calculating a 1.9 60' time. Which, will take a good setup to achieve on a FWD car. Dunno how possible it would be without slicks.

I saw those vids I think, with a good set of tires I think mid 14's are possible. I've got just about everything figured out now about wiring. I'm going with the 2nd gen harness and pcm. Other than the obvious stuff, (wiring, chip to run 3400 injectors, lower dogbone, upper mount, tach) is there any other trouble that I should run into while doing the swap? I know there are gonna be things that'll pop up, as any swap. But anything else you guys should have me watch out for?

IIRC the 2nd gen's came factory with an oil psi gauge, so I could easily wire it into the 3.1 harness, instead of installing it as an aftermarket setup is that correct?

Michael Antle wrote:IIRC the 2nd gen's came factory with an oil psi gauge, so I could easily wire it into the 3.1 harness, instead of installing it as an aftermarket setup is that correct?

Are you running an aftermarket gauge? If so, most of them use a different type sending unit than the factory one. Our cars have an oil pressure sensor, but the signal just isn't transmitted to the cluster, only the on/off indicator for the warning light.

Yeah I knew about the light. I think I'm going with a complete aftermarket set-up like kardains, only it's all going to be analog gauges. Also, the speedo and tach will be slightly smaller than kardains, and between them up top will be on oil psi gauges.

I had to put a T fitting on the factory oil sender to run the sender that came with my guage or else it would nt work.


01 cav w/01 3400 gam gt 4t45e