MAP hookup....
Thread Starter
Joined: Aug 2001
Posts: 2,515
Likes: 1
From: MISSISSAUGA, ONT. CAN
MAP hookup....
Ok, i've seen conflicting reviews of where to acutally hook up a Standalone MAP sensor. Currently i've got a Boost gauge running off the UIM where the factory Boost sensor was. I hooked up my MAP source on the UIM aswell, but on the last of the 3 nipples facing the ALT. I notice a bit of difference between these readings. If it makes a difference, its a J-Spec motor. Any input is reallly appreciated.
I'm a boost creep...
Joined: Jan 2002
Posts: 15,608
Likes: 8
From: Auckland, New Zealand
Originally Posted by JIMMY54
Currently i've got a Boost gauge running off the UIM where the factory Boost sensor was.
I hooked up my MAP source on the UIM aswell, but on the last of the 3 nipples facing the ALT. I notice a bit of difference between these readings.
If it makes a difference, its a J-Spec motor.
Thread Starter
Joined: Aug 2001
Posts: 2,515
Likes: 1
From: MISSISSAUGA, ONT. CAN
Thanks for the replies... Acutally when i said the UIM, i wasnt thinking. You are correct, it is hooked up to where the acv was. So everything seems to be hooked up in the correct places. Basically what i notice is roughly a 5" hg difference between my standalone and gauge in vaccum. I havent been boosting yet, worried that maybe something was hooked up wrong.
Now could it be that i am using too long of a silcone hose to the ECU? I've considered the possiblity that since it is a long distance that the tubing itself may flex giving readings that are slightly off?
Now could it be that i am using too long of a silcone hose to the ECU? I've considered the possiblity that since it is a long distance that the tubing itself may flex giving readings that are slightly off?
Lives on the Forum
Joined: Feb 2001
Posts: 26,664
Likes: 22
From: n
That fitting off either the UIM flange or ACV is only pulled from one port.
When you do this, you get huge pulsation due to the dynamics of the motor.
This is really easy to see when you get a graphic datalog of the MAP sensor signal.
I got to see this off a Haltech E11V2.
So depending on how fast the MAP signal is sampled, you can get rather eratic readings.
Thus, going to the either the fittings off the "front" or the "rear" of the front-end of the UIM is a better placement, cause the readings are from the "plenum".
It's a much more stable signal due to the plenum and doesn't fluctuate as much versus taking it from one of the runners.
Note, of the front 3, top and bottom reads vacuum.
Of the rear 4, only the bottom reads vacuum.
All of these 3 fittings are *after* the TB.
If you hook-up to a vacuum fitting prior to the TB, you will never see vacuum - only boost or "0".
-Ted
When you do this, you get huge pulsation due to the dynamics of the motor.
This is really easy to see when you get a graphic datalog of the MAP sensor signal.
I got to see this off a Haltech E11V2.
So depending on how fast the MAP signal is sampled, you can get rather eratic readings.
Thus, going to the either the fittings off the "front" or the "rear" of the front-end of the UIM is a better placement, cause the readings are from the "plenum".
It's a much more stable signal due to the plenum and doesn't fluctuate as much versus taking it from one of the runners.
Note, of the front 3, top and bottom reads vacuum.
Of the rear 4, only the bottom reads vacuum.
All of these 3 fittings are *after* the TB.
If you hook-up to a vacuum fitting prior to the TB, you will never see vacuum - only boost or "0".
-Ted
BOOSTED Vert
Joined: Sep 2002
Posts: 2,307
Likes: 0
From: Miami
Originally Posted by RETed
That fitting off either the UIM flange or ACV is only pulled from one port.
When you do this, you get huge pulsation due to the dynamics of the motor.
This is really easy to see when you get a graphic datalog of the MAP sensor signal.
I got to see this off a Haltech E11V2.
So depending on how fast the MAP signal is sampled, you can get rather eratic readings.
Thus, going to the either the fittings off the "front" or the "rear" of the front-end of the UIM is a better placement, cause the readings are from the "plenum".
It's a much more stable signal due to the plenum and doesn't fluctuate as much versus taking it from one of the runners.
Note, of the front 3, top and bottom reads vacuum.
Of the rear 4, only the bottom reads vacuum.
All of these 3 fittings are *after* the TB.
If you hook-up to a vacuum fitting prior to the TB, you will never see vacuum - only boost or "0".
-Ted
When you do this, you get huge pulsation due to the dynamics of the motor.
This is really easy to see when you get a graphic datalog of the MAP sensor signal.
I got to see this off a Haltech E11V2.
So depending on how fast the MAP signal is sampled, you can get rather eratic readings.
Thus, going to the either the fittings off the "front" or the "rear" of the front-end of the UIM is a better placement, cause the readings are from the "plenum".
It's a much more stable signal due to the plenum and doesn't fluctuate as much versus taking it from one of the runners.
Note, of the front 3, top and bottom reads vacuum.
Of the rear 4, only the bottom reads vacuum.
All of these 3 fittings are *after* the TB.
If you hook-up to a vacuum fitting prior to the TB, you will never see vacuum - only boost or "0".
-Ted
Trending Topics
^^ Would you mind posting a picture of exactly what nipples you're talking about? I've got an s4 n/a and I'm on the waiting list for the Zeal Megasquirt and I've been thinking about where to hook up the MAP sensor.
Lives on the Forum
Joined: Feb 2001
Posts: 26,664
Likes: 22
From: n
Originally Posted by arghx
^^ Would you mind posting a picture of exactly what nipples you're talking about? I've got an s4 n/a and I'm on the waiting list for the Zeal Megasquirt and I've been thinking about where to hook up the MAP sensor.
-Ted
Thread
Thread Starter
Forum
Replies
Last Post
killerrx710
Adaptronic Engine Mgmt - AUS
5
Sep 28, 2015 09:13 AM
killerrx710
2nd Generation Specific (1986-1992)
1
Sep 24, 2015 10:57 PM