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-   -   new intake shudder at 3300-4000 rmp (https://www.ft86club.com/forums/showthread.php?t=90489)

tcroft91 06-22-2015 11:41 PM

new intake shudder at 3300-4000 rmp
 
i just installed a fabbed 3''intake sets the filter in the bumper it was designed off of the perrin my problem is it stutters when accelerating with driving it has about 80%gone away but you can still feel it a hair in 4th an in 5th an 6th a little more is the just the ecu learning or is it getting too much air maf was placed 8 inches from the t/b an there is a vacuum spot also mounted

Turdinator 06-22-2015 11:44 PM

What do you mean by shudder? Is it a vibration through the car or a noise?

DJCarbine 06-22-2015 11:58 PM

Pictures of intake specifically where the MAF is installed?
Is the MAF in a different diameter tube?

tcroft91 06-23-2015 12:11 AM

like a lack of power

i don't have anyway of putting pictures up

tcroft91 06-23-2015 12:11 AM

it is all 3in tubing

steve99 06-23-2015 12:42 AM

Quote:

Originally Posted by tcroft91 (Post 2296323)
it is all 3in tubing

A maf sensor does not measure the total air passing, it measures a sample and that reading is used to estimate the air flow in total.

As you have increased the diameter of the tube the maf sits in you have thrown this calculation way off.

You may also have turbulance issues

you wil definitely have to rescale you maf sensor . its a major sensor used to calculate engine load as well which the ecu uses extensivly for fueling timing and camm timing

you may be able to use the perrin 3" scaling a a rough starting point.

see maf scaling links below

KoolBRZ 06-23-2015 12:49 AM

Quote:

Originally Posted by tcroft91 (Post 2296291)
i just installed a fabbed 3''intake sets the filter in the bumper it was designed off of the perrin my problem is it stutters when accelerating with driving it has about 80%gone away but you can still feel it a hair in 4th an in 5th an 6th a little more is the just the ecu learning or is it getting too much air maf was placed 8 inches from the t/b an there is a vacuum spot also mounted

If you haven't scaled the MAF that's a problem. Your fuel trims are going to be way off. In closed loop mode, (cruising, moderate acceleration, etc.) the ECU corrects the fuel mixture automatically, but this gets much worse in open loop mode, since the ECU can't use the same feedback to moderate fuel to air ratios, so don't floor it until you have the MAF scaled. A 3" intake is 125 to 150 % higher that the stock MAF multiplier. The airflow in this intake is also slower and so the torque dip is going to be more severe.

tcroft91 06-23-2015 01:59 PM

Quote:

Originally Posted by steve99 (Post 2296366)
A maf sensor does not measure the total air passing, it measures a sample and that reading is used to estimate the air flow in total.

As you have increased the diameter of the tube the maf sits in you have thrown this calculation way off.

You may also have turbulance issues

you wil definitely have to rescale you maf sensor . its a major sensor used to calculate engine load as well which the ecu uses extensivly for fueling timing and camm timing

you may be able to use the perrin 3" scaling a a rough starting point.

see maf scaling links below

how do I use romraider on my car?

Sent from my HTC One using Tapatalk

steve99 06-23-2015 07:04 PM

Quote:

Originally Posted by tcroft91 (Post 2296866)
how do I use romraider on my car?

Sent from my HTC One using Tapatalk

you will have to do a bit of reading, see links below, romraider tips and also at romraider.com .

romraider allows you to edit the tables in the ecu rom then you can flash the edited rom


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