Just how accurate are the mazda orinal equpment tachometers? +-3% +-5%? Cause if you can safely rev to 8500rpm on steel apex seals, if your tach happens to be reading 5% on the high side, and you decide to take it to 8000, you are really at 8400! Sounds a little dangerous to me. Are these gauges accurate at high rpm? I dont wanna have to go put and buy an ugly, gigantic autometer tach (no offence to those who have them) just to make sure I'm not over revving wthout knowing it.

 

Steel starts to shatter at 6200 RPM. Just letting you know.

 

Not shatter... CHATTER....

I tested my '85 tach. It reads a little high. 2500rpm on my known-good tach read about 2700 on the RX-7 tach.

 

Sorry my english is pretty bad.

 

so that time i revved to 8000rpm could very well have been 8500? Are aftermarket tachs any better? I dont want the aftermarket tach look, but better safe than sorry. How hard would it be to put an aftermarket tach in the stock location?

 

Realistically you couldn't. The circuit board behind the guage pod covers the entire back of the cluster, there would be no way to replace the tach in the stock location.

cheers'

 

you could do it.. it would just take a little work getting the two wires that you need to go through one of the holes in the circut board.. once i get around to doing it, i will let you know.

 

good luck re-routing all the connections on the circuit board.

cheers'

 

i think that you could do it without re-routing anything.. there is that hole in the middle of the connector.. just run it through there..

 

I am wondering about the clearence behind the aftermarket tack in relation to the circuit board.

cheers'

 

that i do not know.. possible that it would have to stick out a little. but even that should not look that bad, since it is in the stock location...
guess i will find out when ever i get around to getting a new tac

 

The stock seals are not steel, they're iron.

 

no, he said the guage read over, so if you were reving to 8000 you were probably only do 7600....i'm pretty sure mazda would stick to the side of safety with this one.....

 

I hope so man Cause just a coulpe % off and your motor is toast.

 

Lol... its not an exact science you know... You might rev to 9500rpm someday with no obvious damage to your engine. You could also just as easily blow up your motor on a 6000rpm rip...

 

Now you are making me paranoid man.

 

..........its a ticking timebomb.................duh don duh don..............

 

If it makes you feel any better, the tach doesn't go that high anyway... even if the tach was accurate, once you go past about 8200rpm you're flying blind anyway.

 

Or idleing as mine did, sitting there running perfect, and presto sounds like gravel in there rolling around. Been there and knew what that was