Microtech Area is for discussing Microtech systems

Microtech heavy electrical load stumble

Old 07-29-08, 09:59 PM
  #1  
Senior Member
5 Year Member
Thread Starter
iTrader: (5)
 
pistones's Avatar
 
Join Date: Oct 2005
Location: nyc
Posts: 721
Likes: 0
Received 0 Likes on 0 Posts
heavy electrical load stumble

basically i have a stock port with an LT10s. the problem is i have a lincoln 18" fan running off of a spal PWM controller. when the fan kicks on the engine bogs down and goes lean to the point where it wants to stall. i have compensated for the bog by adding fuel in the next load cell, which works ok but not the way i want. i am also not running a BAC.
i have to mention that i have had the same fan running the same way off the stock computer and it never bogged. is it just the maps that need to be adjusted? is there a way to compensate it in the microtech without running the BAC?
pistones is offline  
Old 07-29-08, 10:44 PM
  #2  
Back at it again!!
iTrader: (3)
 
2Lucky2tha7's Avatar
 
Join Date: Jun 2003
Location: Western Colorado
Posts: 1,318
Likes: 0
Received 0 Likes on 0 Posts
I'm assuming that the fan has it's own powersource of course and is being driven by a relay. My suggestion? You need a bigger alternator. I'd use an s5 alt (80 amps) or a s6 alt (100 amps). I also add a 4 gauge wire from the alt 12v+ to the (+) terminal on the battery.
2Lucky2tha7 is offline  
Old 07-30-08, 09:20 AM
  #3  
Engine, Not Motor
iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,671
Likes: 0
Received 23 Likes on 22 Posts
The Microtech has poor resolution on the Matrix table and isn't very good and interpolating between values. This is what causes the issue. About the most you can do without a BAC is tweak all the surrounding load cells until you find a point where it's rich enough to keep the idle from drooping too much but not excessively rich. FANADD can be used to add a bit more fuel.

Best bet is to run a BAC, but unfortunately this means sending the unit back to Microtech.

A bigger alternator won't help. As mentioned, the FAN is on a FAN-PWM unit.
Aaron Cake is offline  
Old 07-30-08, 06:36 PM
  #4  
Rotary Freak
iTrader: (8)
 
rx72c's Avatar
 
Join Date: Jun 2003
Location: Australia
Posts: 2,608
Likes: 0
Received 0 Likes on 0 Posts
get rid of the controller.use the microtech to triggr the fan. and then youll be able to add fuel everytime the fan kicks in.
done.
rx72c is offline  
Old 07-30-08, 07:16 PM
  #5  
Senior Member
5 Year Member
Thread Starter
iTrader: (5)
 
pistones's Avatar
 
Join Date: Oct 2005
Location: nyc
Posts: 721
Likes: 0
Received 0 Likes on 0 Posts
i forgot to mention that i already have an S6 alternator, i think aaron is right with the map being low resolution. i already have the load cells around idle tuned so that when the fan kicks on it doesn't completely stall out, it idles normally around 12.8 to 13.1 afr. when the fan kicks on it dips sometimes to 14.x and leaner, to the point where it almost stalls.
why would i have to send the microtech back to control a BAC?
can i still utilize the PWM controller and compensate with fanadd?
i currently don't have the fan controller wired with a relay, should i do so? i was told that the PWM itself is a relay. and that it would make it redundant.
i guess i could just use the microtech to control the fan but i kinda didn't like the whole on/off thing. i like how the fan speed ramps up.
i think i am going to have to run the bac since i also want to run a/c.
i am thankful for all input, if you have any other suggestions please fill me in
pistones is offline  
Old 07-30-08, 07:19 PM
  #6  
Senior Member
5 Year Member
Thread Starter
iTrader: (5)
 
pistones's Avatar
 
Join Date: Oct 2005
Location: nyc
Posts: 721
Likes: 0
Received 0 Likes on 0 Posts
this is the culprit

i have this run by a 60 amp fuse in the fuse box with heavy gauge wire, and switched power to the PWM by a check connector, is this not the best way? input please
Attached Thumbnails heavy electrical load stumble-dsc00766.jpg  
pistones is offline  
Old 07-31-08, 08:40 AM
  #7  
Engine, Not Motor
iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,671
Likes: 0
Received 23 Likes on 22 Posts
Originally Posted by rx72c View Post
get rid of the controller.use the microtech to triggr the fan. and then youll be able to add fuel everytime the fan kicks in.
done.
I don't quite agree. The Microtech's fan control is simply abysmal compared to the FAN-PWM. The aux output on the Microtech is a good stop gap if you just need to control a fan and can't afford much more then a relay. But the FAN-PWM is a variable speed PWM controller that makes the electric fan act much more like a clutch fan with a speed proportional to engine temp.

I have the FAN-PWM on my car and it's resulted in much more steady temperatures and a more consistent load on the engine. It's made the idle area easier to tune because I'm not constantly fighting the inconsistent load of a relay triggered fan.

Originally Posted by pistones View Post
i forgot to mention that i already have an S6 alternator, i think aaron is right with the map being low resolution. i already have the load cells around idle tuned so that when the fan kicks on it doesn't completely stall out, it idles normally around 12.8 to 13.1 afr. when the fan kicks on it dips sometimes to 14.x and leaner, to the point where it almost stalls.
Do you have the FAN-PWM set correctly? Sounds like you have the fan speed set too high. The fan should not really "kick" unless the temperature of the car is at the high setting. There will be a kick as the fan initially starts but this should be a few degrees below thermostat temp anyway so you will still be running a tad rich as the warmup enrich finishes off.

If it's dipping to 14:1 and leaner, it's a tuning issue for sure. Check surrounding cells and I bet you'll find one too low.

why would i have to send the microtech back to control a BAC?
I'm assuming the LT10 is the same as the LT8. If it is, and you did not order the BAC option, you need to send it back to Microtech to have it installed. Very, very stupid.

can i still utilize the PWM controller and compensate with fanadd?
Sort of. If you set the fan temp on the Microtech to the temp at which your fan draws the engine down too much, you can then use FANADD to add a bit of fuel. But the aux output is still unconnected. I've not found this unnecessary.

i currently don't have the fan controller wired with a relay, should i do so? i was told that the PWM itself is a relay. and that it would make it redundant.
You're half correct. The PWM itself removes the need for a relay (I don't even know how you would rig both of them up?) but is not a "relay" per say.

i guess i could just use the microtech to control the fan but i kinda didn't like the whole on/off thing. i like how the fan speed ramps up.
I agree. On/off fan control is far from ideal, and damn annoying as well.

i think i am going to have to run the bac since i also want to run a/c.
i am thankful for all input, if you have any other suggestions please fill me in
You'll need a BAC for A/C unless...

But it sounds like you have two issues here:

1. FAN-PWM set to aggressively. What is your high and low point?
2. Still some tuning to be done.
Aaron Cake is offline  
Old 07-31-08, 11:42 AM
  #8  
Senior Member
5 Year Member
Thread Starter
iTrader: (5)
 
pistones's Avatar
 
Join Date: Oct 2005
Location: nyc
Posts: 721
Likes: 0
Received 0 Likes on 0 Posts
Hey Aaron, thanks for replying. I do have the load cells tuned a bit odd. But that is so I am not idling unnecessarily rich at idle. I will take a pic of my matrix table and you will probably see better. I have the low speed on the pwm set at 90'C and high at 105'C, maybe a lower setting will just keep the fan on but stop it from cycling excessively.
pistones is offline  
Old 08-01-08, 02:41 AM
  #9  
Rotary Freak
iTrader: (8)
 
rx72c's Avatar
 
Join Date: Jun 2003
Location: Australia
Posts: 2,608
Likes: 0
Received 0 Likes on 0 Posts
Never had a problem using the microtech to switch fans on and off. look at most proper factory cars. fan on for a good 10/20 seconds then off again.

having variable speed fans is a luxury not required, bit of a waste of time, but this is my opinion.
rx72c is offline  
Old 08-01-08, 09:13 AM
  #10  
Engine, Not Motor
iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,671
Likes: 0
Received 23 Likes on 22 Posts
Originally Posted by pistones View Post
Hey Aaron, thanks for replying. I do have the load cells tuned a bit odd. But that is so I am not idling unnecessarily rich at idle. I will take a pic of my matrix table and you will probably see better. I have the low speed on the pwm set at 90'C and high at 105'C, maybe a lower setting will just keep the fan on but stop it from cycling excessively.
Whoa...I think you will have overheating problems with those settings.

I have my low set to 80 degrees, and my high set to 92 degrees. Of course it depends on your fan. One thing you want to make sure is that your fan is on low speed at thermostat temps. This will keep the electrical draw very low, and keep temperatures very consistent.

Another benefit of the FAN-PWM is that it works very well to prevent intercooler heat soak in traffic. Even with the fan at low you will get enough airflow to keep it cool.
Aaron Cake is offline  
Old 08-01-08, 01:57 PM
  #11  
Senior Member
5 Year Member
Thread Starter
iTrader: (5)
 
pistones's Avatar
 
Join Date: Oct 2005
Location: nyc
Posts: 721
Likes: 0
Received 0 Likes on 0 Posts
I have never had overheating problems with this fan. It is 18" yes "18" and I don't have specific flow ratings but it was claimed to pull 4800 cfm at 14v static. I have never had the temps even pass 95C. But I think I will lower the low setting, the fan will be running at 50 percent all the time but at least it won't keep cycling.
I figured since the fan is so powerful I could have the low setting higher. I happen to like the fan controller so it will stay in. Has anyone used the microtech to run a fan that draws as high current as mine? My fan supposed to have a 60 amp fuse from the Lincoln mark VII.
pistones is offline  
Old 08-01-08, 02:17 PM
  #12  
Engine, Not Motor
iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,671
Likes: 0
Received 23 Likes on 22 Posts
The amount of current the fan draws is immaterial to the Microtech as it's just providing a low level signal to switch a relay.

Setting your low point to just below or just at thermostat makes it mimic the clutch fan, which is what the FAN-PWM is designed for. You'll find it will keep your temperatures very stable.
Aaron Cake is offline  
Old 08-01-08, 02:22 PM
  #13  
Back at it again!!
iTrader: (3)
 
2Lucky2tha7's Avatar
 
Join Date: Jun 2003
Location: Western Colorado
Posts: 1,318
Likes: 0
Received 0 Likes on 0 Posts
I agree, those settings are too high (well, atleast for me). I have mine set at 185 F (85 C), and it doesn't turn off until 165 F (74 C). Although I'm using a relay, I'm giving an example of temps. You have your low set at 203 F and your high at 221 F !! The boiling point of straight water is 212 F (100 C). Granted, a mix of glycol and water raises the boiling point, but still!!
Consider this.
2Lucky2tha7 is offline  
Old 08-01-08, 06:58 PM
  #14  
Senior Member
5 Year Member
Thread Starter
iTrader: (5)
 
pistones's Avatar
 
Join Date: Oct 2005
Location: nyc
Posts: 721
Likes: 0
Received 0 Likes on 0 Posts
i have just changed the settings today to see how it will run. i have my low turn on temp set to 82/84 degrees and the high at 92/94C. so far on the ride home the temps never went above 86*C. the thing is that the fan cools too rapidly( not that i'm complaining). Since i have set the turn o temp lower it will still cycle on and off while idling. when i'm driving it remains more consistent.
i have also added another m/s of fuel in the 15"hg idle cell to compensate for the dip. it now dips the afr's to high 13's sometimes 14.0, which is livable. i just want to get as much driveability issues sorted before i go baseline on the dyno next week. then i put in the 35R!
pistones is offline  
Old 08-02-08, 09:48 AM
  #15  
Engine, Not Motor
iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,671
Likes: 0
Received 23 Likes on 22 Posts
The fan shouldn't cool too rapidly. The thermostat will keep the engine at a constant temp.

You can try raising your high point. Sounds like you fan is very large and can stand less speed at low temps. Bring your high point to 98 or something.

Tuning the fan controller is a bit like tuning the fuel curve. It takes some time to find settings that work well.
Aaron Cake is offline  
Old 08-02-08, 10:26 AM
  #16  
Senior Member
5 Year Member
Thread Starter
iTrader: (5)
 
pistones's Avatar
 
Join Date: Oct 2005
Location: nyc
Posts: 721
Likes: 0
Received 0 Likes on 0 Posts
I agree that the fan needs "tuning". The fan's low setting is cooling the engine too rapidly. It cools to beyond the turn on temp and has to heat up again. I have tried the new settings and now the fan is not cycling as much, the temp is regulating at 84-86C.
pistones is offline  
Old 08-03-08, 09:33 AM
  #17  
Engine, Not Motor
iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,671
Likes: 0
Received 23 Likes on 22 Posts
Sounds like you're not running a thermostat, or it's stuck open.
Aaron Cake is offline  
Old 08-03-08, 12:19 PM
  #18  
Senior Member
5 Year Member
Thread Starter
iTrader: (5)
 
pistones's Avatar
 
Join Date: Oct 2005
Location: nyc
Posts: 721
Likes: 0
Received 0 Likes on 0 Posts
no i am running an oem new thermostat, the new setting seems to do the trick.
pistones is offline  
Old 08-03-08, 10:38 PM
  #19  
Senior Member
5 Year Member
Thread Starter
iTrader: (5)
 
pistones's Avatar
 
Join Date: Oct 2005
Location: nyc
Posts: 721
Likes: 0
Received 0 Likes on 0 Posts
doesn't the LT10s have BAC controls? i see that it can control pwm output.
pistones is offline  
Old 08-04-08, 03:12 PM
  #20  
Engine, Not Motor
iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,671
Likes: 0
Received 23 Likes on 22 Posts
I'm not sure if the BAC control is enabled or not when you purchase the unit. Someone who has used an LT10 can probably answer this. I stopped using Microtech except under specific circumstances due to the limitations of the unit...
Aaron Cake is offline  
Old 08-04-08, 04:47 PM
  #21  
Rotary Freak
iTrader: (8)
 
rx72c's Avatar
 
Join Date: Jun 2003
Location: Australia
Posts: 2,608
Likes: 0
Received 0 Likes on 0 Posts
on the lt10 it is enabled.
rx72c is offline  
Old 08-05-08, 06:03 AM
  #22  
Junior Member
10 Year Member
 
KalliR's Avatar
 
Join Date: May 2006
Location: Salzburg / Austria
Posts: 41
Likes: 0
Received 0 Likes on 0 Posts
Yes I use it and it works fine. (LT10s)
KalliR is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
spokanerxdude
Megasquirt Forum
3
10-06-15 12:28 PM
musker
New Member RX-7 Technical
1
10-01-15 05:58 PM
Smokeyfb33
Old School and Other Rotary
10
10-01-15 12:10 PM


Thread Tools
Search this Thread
Quick Reply: Microtech heavy electrical load stumble


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: