Need Speed to RPM Comparison

[Fierofool]

Anyone who might be out driving their V6 5-speed, I need a speed to rpm comparison.  Since my 7730 conversion, it seems that I redline very easily in the first three gears.  Even so, the engine just just doesn't sound as if it's reaching its full potential.  I have also noticed that I'm turning 3300 rpm at 70 mph.  I think before the conversion I was only turning about 2700 rpm at 70 mph. 

I had the chip programmed that the rev limiter was set at 5700 but I can very easily go over 6500.  So, if you're out tooling around, would you look at your tach to see how speed and rpm compare at 70 mph?  Thanks. 

[Raydar]

Anyone who might be out driving their V6 5-speed, I need a speed to rpm comparison.  Since my 7730 conversion, it seems that I redline very easily in the first three gears.  Even so, the engine just just doesn't sound as if it's reaching its full potential.  I have also noticed that I'm turning 3300 rpm at 70 mph.  I think before the conversion I was only turning about 2700 rpm at 70 mph. 

I had the chip programmed that the rev limiter was set at 5700 but I can very easily go over 6500.  So, if you're out tooling around, would you look at your tach to see how speed and rpm compare at 70 mph?  Thanks.

My GT was like that, but I just attributed it to the Quad 4 transaxle. But then I realized that my tach was off, too. I added a variable resistor to the circuit, so that I can adjust it to match my scan tool.

To directly answer your question... http://gafiero.org/speedcalc.shtml  Says you should be at 2431 RPM at 70 MPH.

[Fierofool]

Thank you, Steve.  I'll contact Ryan and see if the chip is programmable.  On my technical order sheet, it did ask what size rear tires I had, but I believe that was to calibrate the speedometer.  By GPS it had been showing 95% of my true speed.  Now, speedo and GPS match at 70. 

I've noticed that the tach filter is removed on the 7730 application, so maybe that could have some effect?   

[Raydar]

The chip is programmable for tire size, which works out to revolutions per mile, and pulses per mile. Probably just a bit of math involved, entered into a couple of fields.
The tach should not be programmable in the tune. RPMs are RPMs.
Is it off by a factor of "twice what it should be reading"? Your DIS might be set up as a "wasted spark" system. (I think they all are?) If so, it's possibly reading a pulse on the exhaust stroke, too. Depends upon where the tach gets its feed. If it's just randomly off (which mine was) it's not a terribly ugly fix. Cut one trace on the tach board. Solder in two wires to the board, and a 1 Megohm variable resistor to the other end of the wires. The capacitor in your tach has probably changed value. Will probably continue to change. 

[Fierofool]

It is wasted spark but both cylinders on the same coil fire as 1 so I think the ECM would only 'see' 1 spark.  It definitely isn't reading twice the rpm, At first I thought the 5700 rev limit set point had not been programmed or had failed. 

I guess I'll have to go back to driving old school method for RFTH.  Seat of the pants and sound of the engine.