Miata Legacy Build
#64
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Coppied from a different thread. I should be just fine in terms of amp draw and for startup if i have an issue with idle dip i can always wire in a soft start feature.
This guy piled on aftermarket stuff weighing in ~94 amps when everything was cranked up.
Quote:Originally Posted by aseer
I was driving home the other night in the rain (so everything was on) and when I got home I noticed my battery was running down (MSPNP log was at 10.5V)....
Here are the numbers; I used a clamp-on DC ammeter and measured at the alternator and turned on one component at a time and recorded the reading (rechecking the base current each time too). Listed is the excess current above the baseline when that component is turned on (I also continually checked the logged voltage which stayed at 14V during the measurements).
All measurements are done at idle.
Baseline current: 13A
Fans (FM dual Spal package) 27.6A (18A for the big fan, 9.6A for the small fan)
PIAA Headlights (Xtreme white) 18.6A
Blower 15.9A
PIAA Foglights 11.4A
Aftermarket sound system on full 7.4A
Radar 0.3A
Any thoughts would be great (and if this post belongs in a different section, please feel free to point me in the right direction). The car is a 91 with a turbo, MSPNP, big injectors and other stuff...
vs. a stock system drawing ~57 amps
Quote:Originally Posted by aseer
In case anyone is interested, I borrowed a stock 91 and did the same measurements, same conditions (though this time I measured the voltage at the battery for each measurement rather than reading my MSPNP since this car is stock, battery voltage barely moved once steady state was established).
Baseline ~11A (remeasured each time)
Excess above baseline.
Blower + Fans (AC on) 28.1A
Hi-Beams on 16.5A
Blower alone 15.5A
Headlights (hi-beams off) 12.7A
Drivers side fan 7.3A
Radio ~ 1A (it was moving around though)
From there you can infer the total fan draw is 12.6A
and the AC fan is 5.3A.
Again, if anyone was curious... (and I only checked one car besides mine)
This guy piled on aftermarket stuff weighing in ~94 amps when everything was cranked up.
Quote:Originally Posted by aseer
I was driving home the other night in the rain (so everything was on) and when I got home I noticed my battery was running down (MSPNP log was at 10.5V)....
Here are the numbers; I used a clamp-on DC ammeter and measured at the alternator and turned on one component at a time and recorded the reading (rechecking the base current each time too). Listed is the excess current above the baseline when that component is turned on (I also continually checked the logged voltage which stayed at 14V during the measurements).
All measurements are done at idle.
Baseline current: 13A
Fans (FM dual Spal package) 27.6A (18A for the big fan, 9.6A for the small fan)
PIAA Headlights (Xtreme white) 18.6A
Blower 15.9A
PIAA Foglights 11.4A
Aftermarket sound system on full 7.4A
Radar 0.3A
Any thoughts would be great (and if this post belongs in a different section, please feel free to point me in the right direction). The car is a 91 with a turbo, MSPNP, big injectors and other stuff...
vs. a stock system drawing ~57 amps
Quote:Originally Posted by aseer
In case anyone is interested, I borrowed a stock 91 and did the same measurements, same conditions (though this time I measured the voltage at the battery for each measurement rather than reading my MSPNP since this car is stock, battery voltage barely moved once steady state was established).
Baseline ~11A (remeasured each time)
Excess above baseline.
Blower + Fans (AC on) 28.1A
Hi-Beams on 16.5A
Blower alone 15.5A
Headlights (hi-beams off) 12.7A
Drivers side fan 7.3A
Radio ~ 1A (it was moving around though)
From there you can infer the total fan draw is 12.6A
and the AC fan is 5.3A.
Again, if anyone was curious... (and I only checked one car besides mine)
#72
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Was under the car straightening the frame rails and found one of my mystery clunks. The rear of the PPF is hitting the trans tunnel. Ill post a picture in a little bit but does anyone know what would cause the ppf to move enough to hit the unibody. Theres delrin diff bushings and the motor mounts are good with the engine damper support thingy.
#74
Originally Posted by matrussel122
did a mild roll and pull
Looks like a good build going. Did you ever find out why the PPF was hitting the tunnel?
Are you sure that's going to be enough fan?
Nice toys, too. I'd be lucky to ride a sled with half that power.
#75
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Dude I have no idea why its hitting the tunnel I'll dive into that more this summer now that I know where it's coming from. The fan is going to be overkill but when I get around to wiring it I'll use the megasquirt pwm control so I can bring it on slowly
#76
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From: Seattle
Got my block back from the machine shop wasn't at all happy with the communication and service from the guy. He ended up just doing a bore and hone and decked the top.
Had the rotating assembly balanced last week by a new shop that has great service and is super knowledgeable. I'm having him line bore the block this week and need to verify oil clearances to tell him. The below is what I have found and the Robello Racing spec is what I am leaning towards but i don't know anything about anything. Can someone verify one of the oil clearances I've found or suggest a new one.
Also the new machine shop is Auburn Auto Machine
Robello Racing
Main .0020-.0022
Rod .0018-.0020
FSM
Main .0008-0014 .0040 max
Rod .0008-.0027 .0039 max
Soviets Miata
Main .0020
Rod .0018
Had the rotating assembly balanced last week by a new shop that has great service and is super knowledgeable. I'm having him line bore the block this week and need to verify oil clearances to tell him. The below is what I have found and the Robello Racing spec is what I am leaning towards but i don't know anything about anything. Can someone verify one of the oil clearances I've found or suggest a new one.
Also the new machine shop is Auburn Auto Machine
Robello Racing
Main .0020-.0022
Rod .0018-.0020
FSM
Main .0008-0014 .0040 max
Rod .0008-.0027 .0039 max
Soviets Miata
Main .0020
Rod .0018
#77
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So Really having a brain fart on how to wire my big *** fan. It is a Volvo 850 fan with a high and low speed. The easy way to wire it is with the dual relay setup below. But if i do that wont i need to run a separate temp sensor instead of using MS or can I somehow use the MS for a temp signal still.
-I would relay prefer to have a pwm control to control the fan so the speed slowly ramps up based on a temp table in the MS but i have no idea how to go about that.
-The only other option i thin i could do is use a derale pwm fan control and use the temp sensor for a signal to control the fan controller.
Maybe im just over thinking it but any help wrapping my around this is greatly appreciated.
-I would relay prefer to have a pwm control to control the fan so the speed slowly ramps up based on a temp table in the MS but i have no idea how to go about that.
-The only other option i thin i could do is use a derale pwm fan control and use the temp sensor for a signal to control the fan controller.
Maybe im just over thinking it but any help wrapping my around this is greatly appreciated.
#78
You can use the relay diagram you have above, but instead of the low/hi temp switches, they would be MS outputs. Say you use Injector E for low temp and Injector F for hi temp, you would setup in Tunerstudio that Injector E is for fan control, then Injector F is in Programmable Outputs. The way these relays are setup, when none of the outputs are active, the fan is not on. When the low temp output is active and hi temp output is not active, the fan is on low speed. When the hi temp output is active and low temp output is not active, the fan is on high speed. When both inputs are active, the fan is on high speed. The Fan Control portion (low temp activation) works with a temp on and temp off setting. So you could set that to go on at 190 and off at 185. The programmable output portion (hi speed activation) works with a trigger temp and hysteresis. So you could set that to go on at 210 with a 5 degree hysteresis (basically meas 210 on, 205 off). As the car heats up, the fan will be on low at 190, then the high will be on at 210, then the fan will go back to low at 205, then the fan will shut off at 185.
I'll make sure to report back when I test out my MS controlled PWM control setup. It's about $100 in electronics, but isn't ideal for a standard MS. Savington has mentioned that a PWM'd fuel pump was extremely noisy, I can just imaging how that'd be with a big fan. My JBPerf CAN expansion board can PWM up to 20kHz, which should smooth everything out.
I'll make sure to report back when I test out my MS controlled PWM control setup. It's about $100 in electronics, but isn't ideal for a standard MS. Savington has mentioned that a PWM'd fuel pump was extremely noisy, I can just imaging how that'd be with a big fan. My JBPerf CAN expansion board can PWM up to 20kHz, which should smooth everything out.
#80
You would need a controller for that. When you shut off the car, MS loses power, and so does your outputs. You'd need a controller that knows how to detect an engine shutdown, and keep the fan active for 5 minutes, then kill power. I wouldn't know what type of controller or how to do that though. It reminds me of how to safe shutdown a Raspberry Pi computer. There is a separate micro-controller that has constant power and switched power. When switched power is gone (aka you pull the key), it issues a computer shutdown, waits until the computer is shut down, then kills constant power. The idea would be the same for this.