The other day when I was on the dyno, I noticed my RPM’s would match for a bit and then got progressively less accurate. My cut on my dyno was around 5800 but on my gauge cluster it said at least 6500 if not more. Is this because I now have an inline 6 rather then the 4 banger? Anyways, I’m thinking about getting it recaliberated. Anyone know any shops in Calgary or close to?
Secondly, wouldn’t mind uping the speedo as well. Should I be using an Rb20 GTS-T speedo or S13 speedo? Anyone know where to find either the NISMO, or preferably the TOMEI for the correct model?
Just thought of it now, can I steal an Rb20 tach and swap it with my s13 tach?
you can get a diffrent tach… It will bolt in the cluster. The tachs from the RB20’s are also diffrent than the RB25’s and the SR20’s.
I will need to know what engine and tranie you have and what cluster you got for the origonal engine and transmision and it will help me tell you what ya need to do.
you can get a difftent speedo like the Nismo 320km but you have to get the right one. The SR20 tranie has an electric sender but the RB20 transmision has a cable but the RB25 has an electric but you can get the cable sender for it and bults right in.
If you tell me what you got I can prob help you out since I ghot about 15 clusters at home and I am ordering a couple RB25 tranie cable senders so I can order another one for you if thats even what you need.
I dunno, my speedo in my 92 S13 is pretty accurate. I drove by one of those signs that tells you your speed and my speedo dial was within 1 km/h of what the sign was reading.
Anyway, I remember reading a while back that yes, it’s off because of the engine. It was on 240sxforums.com I think. I can’t remember the specifics but basically the number of cylinders screws up the rev readings because the tach is calibrated for a four-cylinder engine. It has something to do with both engines being able to have the same amount of combustion strokes per minute but with the RB the revs are lower simply because of the 2 extra cylinders.
**Edit:
Figured out a good way to explain it. I’m not satisfied with the way I stated it above. I’m working this out for my own benefit mostly :lol: Now think of it this way:
We’ll use 12 power strokes as our proverbial yard stick for this one. And we’ll define one “cycle” as the amount of time it takes for each cylinder to fire once before starting the sequence over again.
The RB has six cylinders, so to complete 12 power strokes would require 2 complete cycles.
The KA has four cylinders, so to complete 12 power strokes would require 3 complete cycles.
Now if each engine performed a power stroke at exactly the same time the KA would have completed 1 extra cycle in the same amount of time. Thus its revs were higher!
Yeah, but the KA and SR both have larger pistons then the RB and therfore don’t have to complete them same number of revolutions to create the same amount of power or go an equal distance. That’s where the trannys gearing comes into play! So I am afraid it’s not as cut and dried as that…there are many more variables!
If you had a 6cylinder engine and a 4cylinder engine that are the exact same size and power then the pistons are going to be aranged on the crank so that the same thing is acomplished in one full revolution of the engine.
I dunno, my speedo in my 92 S13 is pretty accurate. I drove by one of those signs that tells you your speed and my speedo dial was within 1 km/h of what the sign was reading.
Anyway, I remember reading a while back that yes, it’s off because of the engine. It was on 240sxforums.com I think. I can’t remember the specifics but basically the number of cylinders screws up the rev readings because the tach is calibrated for a four-cylinder engine. It has something to do with both engines being able to have the same amount of combustion strokes per minute but with the RB the revs are lower simply because of the 2 extra cylinders.
**Edit:
Figured out a good way to explain it. I’m not satisfied with the way I stated it above. I’m working this out for my own benefit mostly :lol: Now think of it this way:
We’ll use 12 power strokes as our proverbial yard stick for this one. And we’ll define one “cycle” as the amount of time it takes for each cylinder to fire once before starting the sequence over again.
The RB has six cylinders, so to complete 12 power strokes would require 2 complete cycles.
The KA has four cylinders, so to complete 12 power strokes would require 3 complete cycles.
Now if each engine performed a power stroke at exactly the same time the KA would have completed 1 extra cycle in the same amount of time. Thus its revs were higher!
Yay for me! I did it
B-Wurm :D[/quote]
You might have an accurate speedo. But that doesn’t change the statistical fact I printed. Was your check below 80 km/h or over 180km/h. The faster you drive the higher the inaccuracy.
