tach and ms way off?
#1
tach and ms way off?
I've always noticed that my tach was a little off at idle. about 200 rpm or so. No big deal right? so it idles at 850 rpm verified by snap on timing light with tach and that is what MS reads as well. but my tach reads 1k. I was just going to re time the needle so that it matched, but tonight I was doing some in boost tuning and noticed that the higher the revs the farther off it is. I have hard limit fuel cut set at 7200. anyway I do a third gear pull and look down to see my tach passing 8,200 and no sign of a rev limit at all. so I pull to the side of the road and verify the settings and then check my log. it read 7k. thing is when I was running the stock ecu it was dead on and fuel cut was right at 7200rpm.
so in short
idle 150-200 rpm high
7k 1200 rpm high
anybody come across this before? is it one of those things I need to fiddle and **** with a voltage range in mt config somewhere?
so in short
idle 150-200 rpm high
7k 1200 rpm high
anybody come across this before? is it one of those things I need to fiddle and **** with a voltage range in mt config somewhere?
#2
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,019
Total Cats: 6,587
Yes.
No.
The factory tach is a pretty simple analog instrument, and they're known to sometimes be inaccurate. I can't say that I've ever personally seen one as far off as what you're reporting, but it wouldn't surprize me. I would tend to trust the display from your megasquirt, as it's based on a fairly accurate crystal-driven reference.
is it one of those things I need to fiddle and **** with a voltage range in mt config somewhere?
The factory tach is a pretty simple analog instrument, and they're known to sometimes be inaccurate. I can't say that I've ever personally seen one as far off as what you're reporting, but it wouldn't surprize me. I would tend to trust the display from your megasquirt, as it's based on a fairly accurate crystal-driven reference.
Thread
Thread Starter
Forum
Replies
Last Post
JacksonRacingEngines
Engine Performance
10
09-10-2015 09:52 AM