: Recalibrate Coolant Tables
tj1930vik Aug 20th, 07, 10:29 AM In the thread about cutting a 2" hole, JimM mentioned recalibrating the C950 tables to match the gauge reading. Since I'm thinking about installing a temp gauge, would you mind giving more details about adjusting the tables? I've read (on Chevy Talk) that a gauge & C950 don't always match up very well. So, if there's a way to make them read the same, I would like to learn some more about it.
JimM Aug 20th, 07, 10:48 AM They don't need to read the same, and I don't know a way to make that happen, but...
Let's say you gauge is accurate, and your "normal operating temp" is 180.
Lets further say that once the coolant temp reaches 150, your engine is "warm" and no longer needs the "choke" on.
Then let's go comepletely crazy and say that when your gauge says 150, the c950 says 220!
And let's say that your motor wants 25% enrichment @ 50 degrees, and 10% at 100.
So you go into the c950's temp enrichment table and set 220 and up to be ZERO.
Then you determine by watching that 50 on the gauge is 80 in the c950, so you set that cel to 25%.
Ditto at 100 degrees, then just enter the rest of the numbers to smooth the curve out.
It doesn't really matter what the computer thinks, as long as you know how far it's off and you set it to do the right thing at the right point.
tj1930vik Aug 20th, 07, 02:46 PM Thanks Jim, I think that will work. Since my '67 Camaro has the original console gauge package, I've been reluctant to make changes. HOWEVER, an Autometer 270 degree gauge makes me a lot more comfortable than the needle on the gauge package. I'll try your set-up advice (still wishing there was a way to recalibrate the C950 read-out). Thanks again, Todd
camcojb Aug 20th, 07, 06:46 PM I've never run the Holley system, but of all the others I've used I've never seen one far enough off to matter. Realize that if the computers coolant sensor is in the head and your gauge sensor is in the intake or water pump there is a heat difference, so because they don't match up does not mean the computer one is wrong. In fact, I consider the computers sensor the accurate one.
However, in the above case that Jim set up, you would want to do as he said. I just would not assume the computers reading is incorrect, you need to verify first.
Jody
JimM Aug 20th, 07, 08:10 PM If you missed the first post Jody, what I'm gonna try to do is simply tap the c950's coolant temp wire right into the autometer gauge sender line. Only one sender involved, one less wire messing up my motor, connection will be in the console.
The same thing would work using the factory sender too, with the original gauge.
The ONLY wires from my EFI will come off the throttle body in the smallest bundle I can make, under the air cleaner, around the distributor, and thru the firewall right behind the motor. I want "invisible"!
I wonder if it's safe to clip out all but one ground and power wire, and splice those together as they come off the sender connections? TPS... AIC...inlet air temp... I could lose 3 wires?
I'm even gonna put the MAP under the dash, as I all ready have a vacuum guage there.
camcojb Aug 20th, 07, 08:56 PM If you missed the first post Jody, what I'm gonna try to do is simply tap the c950's coolant temp wire right into the autometer gauge sender line. Only one sender involved, one less wire messing up my motor, connection will be in the console.
The same thing would work using the factory sender too, with the original gauge.
The ONLY wires from my EFI will come off the throttle body in the smallest bundle I can make, under the air cleaner, around the distributor, and thru the firewall right behind the motor. I want "invisible"!
I wonder if it's safe to clip out all but one ground and power wire, and splice those together as they come off the sender connections? TPS... AIC...inlet air temp... I could lose 3 wires?
I'm even gonna put the MAP under the dash, as I all ready have a vacuum guage there.
Jim,
on the map sensor I'd advise keeping it in the engine compartment; actually you want it as close to the intake source as possible, so if it is hooked by a vacuum line keep it as short as possible. The longer line seems to affect the reaction of the sensor, at least every pro tuner I've spoken with says it does.
Jody
tj1930vik Aug 21st, 07, 08:48 AM Jim - the next time you're out in Or-e-gone, would you stop by & clean up my wires, too? Something like a 14-gauge common ground wire should be just fine - especially if you solder in your splice points. Sounds like a good idea. It wouldn't hurt to try the MAP sensor under the dash after you've established a short-tube calibration. If nothing is changed or affected by the longer tube under the dash, then you should be O.K.
JimM Aug 22nd, 07, 06:00 AM I really can't wait for winter so I can start tearing into this...lol!
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