ALFAGTV6.COM

So, with my stock ECU the rev limiter would kick-in around an indicatd 5400 rpm... (I heard that this wasn't a real number though, but it's actually higher?)

Some guys tell me that a Verde's limiter kicks in at more like 6200 rpm. Could the error be that huge? Is there a fix?

With the GoTech now last night, the engine would pull to an indicated 6K and still not cut off! We know what is safe with these engines, but how do I know what is safe on my stock tach?

It still feels like it had more by the seat of the pants tach...

Can't you just use another tach or a multimeter with a tach function? Usually ignition timing lights have a tach function...

JJ,

5400 rev limiter - sounds like your tachometer reads too low.

I'm trying to recall, so this is with some uncertainty, but at 85 MPH I think the verde tachometer reads something like 3500 RPM (in 5th). I had my tachometer reconditioned some 5 years ago, and it has worked flawlessly since. The tachometer is notoriously for failing with time and show too low. Anyway, the above point should give you a reference (with stock rear-end).

I'll double check the point above next time I take it out.

Jes

JJ, You can adjust your own tach, if you take the dash pod off and take it apart, get the tach out, you will see a screw on the top back side of the tach, drill a hole big enough for a small screw driver to fit through directly above the screw in the dash casing (you can always put a little tape over the hole in the future) and then put the tach back in and plug everthing in, use a multi meter with a tach function and adjust yours to match, I think it should read 500 rpm with the engine off, this is it's starting position...

hhmm... Thanks guys

The 3.7 gets all custom guages, but I wanted to keep the street Verde pretty well stock. So these suggestions may work well...

JJ,

Checked tonight: At 160 MPH the tach reads 6800 RPM
At your kind of speeds it would be 80 MPH at 3400 RPM. So my memory was off

Anyway, you can use the above point to check your verde gauges. It is with stock tranny and 205/45-16 tires. Though, you wouldn't know if it is the tach or spedo that is off, if you don't have the above reading, I suppose.

Jes

Well, all bets are off, I mean, what's stock now any way, with tire and wheel changes and then wear on those tires etc etc and like you said - the tach is bound to be off too... See below:

- Should have done a 160mph run on the dyno yesterday just to see while I was there, but we only had time to map up to like 5200-5300 rpm…

Any way, I just ended up driving with the laptop plugged in a bit today and found this:

At an indicated 1000 rpm idle, the computer jumps around 880-895-905 rpm....

At an indicated 5800 rpm in 1st second and 3rd I a running against the GoTech rev-limiter set to 7225 rpm, but the computer is only showing about 7050 at that point (couldn't tell with traffic and crap and gears and watching the damn computer and listening for the rods and watching the tack and watching my temp gauge and watching the damn laptop....)

John,Have found Gotech to be off at the higher rpm`s by some 200 odd rpm...

The other thing to look at is signal strenght to the tach. At higher revs it might be falling off and the tach starts slowing down and not reading correctly-maybe a pull up resistor on the signal line??

The tach output from the ecu is directly related to the input signal. To check the accuracy of the tach output you can use a ossiloscope to check the input signal and the tach signal. I'm sure that you will find these signals to be the same.