[Tim Zenger]

Has anyone tried it? Did you get the tach to work?

 

[Ranger50TT]

Provided you are using a non CAN bus GM harness, you can fish out the tach wire and hook it up like factory to the tach input wire. but using the factory tach is about as accurate as a yardstick measuring a cylinder bore.

Brian

 

[Tim Zenger]

I understand the accuracy of the OEM tach, but I just wanted to know if anyoune got the GM harness/computer will drive the tach.

 

[DillRacing87gt]

painless will be releasing a gauge converter box in roughly 2 months that taps into the obd2 port and allows one to use aftermarket gauges. I'm planning on getting one since i've already rewired the whole car. also from what i understand, the factory tach output on the GM ecu is set to run in 4cyl mode

 

[bikewiz]

The GM performance parts standalone LS wiring harness & ECM setups have a special connector wired for gauge outputs. Pretty sure its designed to drive aftermarket gauges. Eliminates the need for redundant sensors.

http://static.summitracing.com/global/images/instructions/ls_engine_control_system.pdf

start reading page 3 under "system features" and it goes until page 5.

 

[racin lsc]

all my stock gauges work, except speedo. need new trans shaft for that

 

[allovers]

once i work out all the wiring I expect all my the facotry gauges to work.
Got to figrue out the speedo but I really dont think that's going to be too tuff.
the issue with having something connected to the OBDII port is what do you do when tuning on the street/track, cant use both connections.

 

[DillRacing87gt]

from what i read about the painless setup is that it splices into the obd2 port. I'm waiting for its release to decide if thats the route i really want to go.

 

[96gt4.6]

As stated above, if you're talking older Mustang's (pre '99), you should have no issue getting every gauge to work just fine, speedo included.

Here's my Fox. TH400 transmission:

My friend's '96 GT with Heads/Cam 6.0L and 4L60E. In the video the tach appears slow, it's just the video for some reason:

And yes, Factory tach's are very innacurate. I was shifting my Fox at 6k, but looks like nearly 7 in the video.

 

[ManicMike]

As stated above, if you're talking older Mustang's (pre '99), you should have no issue getting every gauge to work just fine, speedo included.

Here's my Fox. TH400 transmission:

'83 Mustang, 5.3L Turbo, 9psi Pump Gas, 0-132 on Drag Radials - YouTube

My friend's '96 GT with Heads/Cam 6.0L and 4L60E. In the video the tach appears slow, it's just the video for some reason:

96 6.0L Mustang Idle tuning - YouTube


And yes, Factory tach's are very innacurate. I was shifting my Fox at 6k, but looks like nearly 7 in the video.

Can you explain how you got each gauge to work? I'd really like to know, I'm going 5.3T/TH400 in my car very soon.

 

[96gt4.6]

It's very simple really. Just use all the stock 5.0L Senders on the LS motor for the water/oil. There is a plug in the RH rear head on the LS motor, remove the plug and drill/tap the head for the Pipe Thread Water sender on the Mustang. Autometer makes an adapter for the oil psi sender threads on the LS motor to take it to pipe thread as well, then just use your 5.0L Oil Sender.

The speedo cable is equally as simple with a cable from these guys:

Speedometer Gear, Speedometer Gears, Ford, GM, Dodge 700R4

It will have a Ford end and a GM end, works great. The Ford and GM speedo heads of that era use the same rev/mile so you then calibrate the speedo by the driven gear just as you would normally.

 

[ManicMike]

It's very simple really. Just use all the stock 5.0L Senders on the LS motor for the water/oil. There is a plug in the RH rear head on the LS motor, remove the plug and drill/tap the head for the Pipe Thread Water sender on the Mustang. Autometer makes an adapter for the oil psi sender threads on the LS motor to take it to pipe thread as well, then just use your 5.0L Oil Sender.

The speedo cable is equally as simple with a cable from these guys:

Speedometer Gear, Speedometer Gears, Ford, GM, Dodge 700R4

It will have a Ford end and a GM end, works great. The Ford and GM speedo heads of that era use the same rev/mile so you then calibrate the speedo by the driven gear just as you would normally.

Ah that's simple enough.. what about the tach though? I know it'll be off (as it is in your video's), I'd just like it to work.

 

[96gt4.6]

Ah that's simple enough.. what about the tach though? I know it'll be off (as it is in your video's), I'd just like it to work.

Mike i'm sorry about not seeing this post sooner, or responding to your PM. I'm rarely on Corral.net, I sent you a PM with my contact details.

In short, the way you get this to work with the LS computer is use a 'Pull Up' resistor in the tach signal circuit. A quick Yahoo! search will get you what you need.

Also, you need to change the LS computers tach output pulses from 6 to 3 in the tune if using a stock V8 tach.

I'll try to keep an eye on this thread from now on and get to questions a little quicker.

Hey, while i'm here, check out my new project:

lol, Yes, I know I have a sick sense of humor....but how cool is this granny car right! Just got her done recently.

Here's the 1st track video, rushed it together just to make the last race. 7lbs, ultra rich AFR and pump gas. 4150lbs race weight. 15PSI, Race gas times coming Spring 2013:

 

[cambo42390]

the guy that does all my harness and tuning work he made mine to where it would register its a v8 problem solved