quick question ( newb ) on megasquirt install - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members

MEGAsquirt A place to collectively sort out this megasquirt gizmo

LinkBack Thread Tools
Old 10-26-2008, 06:59 AM   #1
Thread Starter
Join Date: Apr 2008
Location: Honolulu
Posts: 29
Total Cats: 0
Default quick question ( newb ) on megasquirt install

Ok so I haven't bought megasquirt yet. I have not even bought a turbo kit yet. But I kind of want to buy the megasquirt and turbo kit the same time on begi. I was reading the manual and it says I need a timing gun. I don't have one. I am not really sure on why you need one I believe it said to make sure the CAS didn't slip. What is the CAS? Is this necessary? Is there any way to get around this? Thank you.
k4thomas is offline   Reply With Quote
Old 10-26-2008, 11:40 AM   #2
iTrader: (17)
Vashthestampede's Avatar
Join Date: Feb 2007
Location: Danbury, CT
Posts: 4,659
Total Cats: 54

CAS = Crank Angle Sensor. Located at the back of the head, turns to adjust the timing. Use the timing light to verify correct settings.

Read this - Miata Ignition

Vashthestampede is offline   Reply With Quote
Old 10-26-2008, 01:22 PM   #3
Senior Member
iTrader: (4)
Join Date: Jan 2008
Location: Falls Church, VA
Posts: 1,367
Total Cats: 16

Yes, a timing gun will be necessary when you install your Megasquirt for the first time. You will have to adjust a couple parameters in Megatune (MS software) to get the timing set, so what MS thinks it is agrees with what the engine is actually running. Once that's set though, you might not need the timing gun again. They're about $30-40. If you don't want to spend that, try to borrow one from somebody or find an auto parts store that will loan you one for the afternoon.
ScottFW is offline   Reply With Quote
Old 10-26-2008, 01:32 PM   #4
Boost Pope
iTrader: (8)
Joe Perez's Avatar
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,326
Total Cats: 1,926

First off, timing guns are inexpensive. You should be able to find one at a local auto parts store or Wal-Mart for perhaps $30 to $40. You don't need any fancy features like dialback. I'm still using a POS SunPro brand timing light that I think I paid about $15 at K-Mart eons ago.

As Vash pointed out, the CAS is what tells the ECU where the crankshaft is in its rotation. Specifically, it sends out a pulse every time a piston is about 60 BTDC (This is a hugely approximate number, and is adjustable.)

Now, it's that adjustability that's the problem. As you read The Documentation you'll see that in the Spark Settings page there is Trigger Angle (deg) field. This is where you calibrate the orientation of your CAS. To do this, you first lock down the ignition advance to 10 degrees BTDC, then you run the engine while observing the crank pulley with a timing light. If the notch in the pulley is not aligned with the "10" mark on the timing strip (and it won't be the first time) then you adjust the trigger angle number to bring it into alignment. Once that's done you set the Fixed Angle back to -10, and now your spark advance tables will be accurate.
Joe Perez is offline   Reply With Quote
Old 10-26-2008, 06:52 PM   #5
Thread Starter
Join Date: Apr 2008
Location: Honolulu
Posts: 29
Total Cats: 0

Ahh I see. Thank you that cleared it up for me very nicely. About how long did the install and setting up the megasquirt take on average?
k4thomas is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
15x10 - 15x11 6UL @ 949 Racing emilio700 Wheels and Tires 151 06-02-2017 03:36 PM
1994 Spec Miata Race Car SM/SM2/SSM For Sale Quinn Cars for sale/trade 6 10-23-2016 08:58 AM
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 04:00 PM
WTB MP62 (Hotside) (NB2) Rick02R WTB 3 01-03-2016 08:18 PM
Walbro 255lph Fuel Pump $50 lsc224 Miata parts for sale/trade 2 10-01-2015 10:17 AM

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 07:36 AM.