My tach is fine till 5500 RPM but after that it goes to 9000 RPM and sits there till I let off. Car runs fine and has no problems, is there a fix for the tach or is it a 20B compatibilty issue?

On start up the car has to be reved for about 15 secs, is this normal?

Please advise...

 

Is the tach accurate when it's under 5500?

As for the revving part, try adjusting your water temperature maps.

Brandon
BR7 Racing

 

yeah i have the dash display and the tach is accurate till about 5500

plz elaborate on why adjusting water temp maps would help cold starts

 

you running premix or the oil metering pump?
still no word from anyone if the microtech will run the
20b's metering pump...
matt

 

premix ofcourse

 

gohorns: Fuelling requirements change with water temperature. If the maps are off, the car will stall when cold.

Are you running the tach off the trailing coil like stock or from the Microtech itself?

now: No, the LT will not run the 20B-REW's MOP.

Brandon
BR7 Racing

 

theoretically the e11 can output the right tach signal, hopefully in a few weeks i'll know fer sher

mike

 

And that has what, exactly, to do with the topic at hand?

Brandon

 

that the stock tach will work with the 20b

 

No7yet: the tach is hooked up stock like it should be.

 

good to see the forum up and running again...so does anyone have a working tach using the LTX-12 on a 20B?

 

if you have the tach hooked to the coils thats your problem. 20b = v6, 13b = 4cyl.

mike

 

what should the tach be hooked up to for it to work correctly? I had a professional mechanic with microtech exp do the install and he is telling me its a cmpatibility issue with the 20B.

anyone here have working tack up to 8000 rpm on a 20B using the LTX-12?

 

Doesn't that LTX have an aux out to configure a tach output?
I know the Haltech could do it.


-Ted

 

if you have the tach hooked to the coils thats your problem. 20b = v6, 13b = 4cyl.

mike


I've always heard that the 13b =v6, and 20b = v8, but even that sounds odd to me, I don't think you can really compare pistons to rotors, it's like apples and oranges

 

no, you can compare them, at least here. the 13b fires once every 180degrees just like a 4 cylinder. the 20b fires once every 120 degress just like a v6. so you have a v6 with a 4 cylinder tach hence the tach reading "fast"

mike

 

yes it does, but the signal is not the same format as the stock tach

 

Hmmm...that's interesting.&nbso Most tach signals are pull-down square waves.&nbsp What exactly does the Microtech output as a tach signal?



-Ted

 

I've not had one on a scope, so I can't say for sure. The interesting bit is that the tach's accurate until 5500 whereupon it pegs and stops. This isn't your typical 20B-swap scaling error. I'll see if I can't dig up any info.

Brandon
BR7 Racing

 

Typicaly a rotory will need aprox 20-25% more fuel when the engine is around 30'c and about 10-15% more fuel at 45-55'c, and about 3-5% more fuel at 65-70'c, after that you can go to the normal map. This will vary depending on what kind of port you have, back pressure on the ex side etc....

This has nothing to do with your Tac problem, but I thought i'd throw it in there... I plan on just putting in a Apexi' 360' tac and pretty much not using any of the stock guages other than the fuel level and if I can find what I need from summit racing that will be discarded as well..

 

micortech's tacho output is a square wave output, the problem is your factory tacho is for basically a 4cyl, the microtech running the 20b will be set as a 6cyl, dont think there is much you can do about it,

Dale

 

http://members.tripod.com/~grannys/rx7tachrecal.html

 

Thanks for the link Evil! I knew the RX-7 Manglers were good for something

 

LOL

Like my friend says, "Even blind squirrels find nuts once in a while".

Seriously though, there are a few good things on that site, and although I much prefer the rotary engine, I am not opposed to the V8 conversion like many other people. I also like this Capri hood scoop idea as an alternative to buying a TII hood for your NA.
http://members.tripod.com/~grannys/mazdarx8.html
However, don't look at any of the other scoops on that site if you have eaten within the last 3 hours, lol.

 

Not a problem for an FC...

There is a "calibration" screw on the FC circuit board that you can adjust so the revs should match.&nbsp We normally calibrate the instrument cluster with a simple stand-alone uP to handle such adjustments.&nbsp You probably can do this by looking at the RPM display off your Microtech and adjust the needle until the RPM's correspond correctly.&nbsp I can't confirm if this works on an FD3S intrument cluster...



-Ted