MEGAsquirt A place to collectively sort out this megasquirt gizmo

joes spark output mod

Thread Tools
 
Search this Thread
 
Old 12-24-2010, 11:37 AM
  #1  
I'm Miserable!
Thread Starter
 
Techsalvager's Avatar
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,866
Total Cats: 0
Default joes spark output mod

Can I use 100 ohm instead of 270ohm without problem for spark out on ms2 build?
Techsalvager is offline  
Old 12-24-2010, 12:19 PM
  #2  
Senior Member
 
WestfieldMX5's Avatar
 
Join Date: Nov 2007
Location: Belgium
Posts: 999
Total Cats: 73
Default

Yes, but use a 1/2W resistor because you're pulling 50mA (=1/4W) through it.
WestfieldMX5 is offline  
Old 12-24-2010, 12:25 PM
  #3  
Elite Member
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,977
Total Cats: 356
Default

I wouldn't quite say that 50mW are 1/4W. More like 1/16W, a bit less even. So he's fine with 1/4W.
Reverant is offline  
Old 12-24-2010, 12:30 PM
  #4  
Senior Member
 
WestfieldMX5's Avatar
 
Join Date: Nov 2007
Location: Belgium
Posts: 999
Total Cats: 73
Default

50mA @ ~5V
WestfieldMX5 is offline  
Old 12-24-2010, 12:40 PM
  #5  
Elite Member
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,977
Total Cats: 356
Default

Reverant is offline  
Old 12-24-2010, 12:42 PM
  #6  
I'm Miserable!
Thread Starter
 
Techsalvager's Avatar
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,866
Total Cats: 0
Default

I used 1\2 watts anyways, cause its what I have on hand.
Techsalvager is offline  
Old 12-24-2010, 01:20 PM
  #7  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,026
Total Cats: 6,592
Default

Originally Posted by Techsalvager
Can I use 100 ohm instead of 270ohm without problem for spark out on ms2 build?
Yes.

5v through 100 ohms is 50ma, which is 0.25 watts. So a 1/4 watt resistor will do. It'll generate some heat, but it'll be fine. A 1/2 watt part won't even notice.
Joe Perez is offline  
Old 12-24-2010, 05:35 PM
  #8  
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,659
Total Cats: 134
Default

We use 100 ohm pullups in the PNPs. Some of the newer hotter coils prefer lots of pullup. Pretty sure they're all 1/4 watt.
__________________
Chief of Floor Sweeping, DIYAutoTune.com & AMP EFI
Crew Chief, Car Owner & Least Valuable Driver, HongNorrthRacing

91 Turbo | 10AE Turbo | 01 Track Rat | #323 Mazda Champcar

Originally Posted by concealer404
Buy an MSPNP Pro, you'll feel better.
Ben is offline  
Old 12-24-2010, 05:55 PM
  #9  
Elite Member
iTrader: (1)
 
richyvrlimited's Avatar
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,642
Total Cats: 42
Default

what's the advantage of more pullup?
richyvrlimited is offline  
Old 12-24-2010, 06:18 PM
  #10  
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,659
Total Cats: 134
Default

If your coils fire, then likely none.
__________________
Chief of Floor Sweeping, DIYAutoTune.com & AMP EFI
Crew Chief, Car Owner & Least Valuable Driver, HongNorrthRacing

91 Turbo | 10AE Turbo | 01 Track Rat | #323 Mazda Champcar

Originally Posted by concealer404
Buy an MSPNP Pro, you'll feel better.
Ben is offline  
Old 12-24-2010, 06:20 PM
  #11  
Elite Member
iTrader: (1)
 
richyvrlimited's Avatar
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,642
Total Cats: 42
Default

They don't when it's really cold out...
richyvrlimited is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
slomiata
MEGAsquirt
5
10-07-2015 01:11 PM
The Gleas
MEGAsquirt
3
10-01-2015 09:30 AM
FrankB
Miata parts for sale/trade
6
09-30-2015 11:48 AM



Quick Reply: joes spark output mod



All times are GMT -4. The time now is 07:31 AM.