IAC Restrictor Gasket Trick Guide - MustangForums.com


V6 (1994-2004) Mustangs Technical discussions on the 3.8L and 3.9L V6 torque monsters

Reply
 
 
 
Thread Tools Search this Thread
Old 05-16-2007, 12:11 PM   #1
Jefferson
Moderator
Thread Starter
 
Join Date: Jun 2005
Posts: 3,557
Default IAC Restrictor Gasket Trick Guide

This step by step tech article was provided by Cmpfreak88.
Thank you.
[sm=smiley20.gif]

This is a free mod intended to lower the RPM's at idle to give your stang's exhaust a slightly throatier idle sound while also increasing the engine braking effect. This is achieved by limiting the air going to the IAC (Idle Air Control) module, which in turn maintains a lower idle RPM. This mod works on both single and split port and on both auto and manual. The mod is more noticeable on a manual though as RPM's will drop faster in between shifts meaning you'll have to get used to the timing.

This was suggested by NeoTokyo and v6stang07 seemed to get the right hole sizes for out v6. All I did was follow what they said and take pics!

Original Thread

Materials Needed:
Felt gasket material ($5/roll at Autozone)
Socket wrench w/ 10mm Socket
Razor
Ruler/Measuring Tape
Fine point pen
About 30 minutes time
Possibly Gloves

Step 1: Park your car open the hood and prop it up. If the car was just running you're probably going to need gloves because the IAC gets a little hot.


Step 2: Take the socket wrench and loosen the two bolts on the IAC module, if you're looking at the car from the front it's on the left side of the upper intake and has one bolt on top and one on bottom. (Shown below) You may not be able to see the second bolt, but it's right underneath the middle of the IAC, fish around for it! And don't drop the bolts! I loosened both bolts with the wrench, then ended up taking off the wrench and just using the socket to take it off because it wouldn't rachet anymore!


Step 3: Pull off the stock gasket and take out the bolts. Set the IAC module on top of the upper intake and take the gasket to the bench.

Note: Your gasket will have much bigger holes, mine already had my modified one on and you can see here that it ripped!

Step 4: Open up your gasket material and cut out a small section about as big as the gasket, if you want, you can trace it out with the pen and then cut it or just lay it on top of the material and then cut around it, I did the latter. Since I was doing this for the second time for the writeup, I saw that my first gasket had ripped, so I recommend cutting out two!

Step 5: Place the stock gasket on top of the new gasket material and trace out the bolt holes, then cut them out.


Step 6: Measure a 5/8" hole on the center of the left side and a 3/16" hole on the center of the right side. Make sure your 5/8" hole is actually going to be all the way open by making sure it fits in the space of the stock gasket. I just drew lines from my center point and made it into a circle. Then cut these holes out. Do this for both gaskets! A razor would probably have been real nice, but I used regular scissors. My holes weren't perfect, but it worked!


Step 7: I left out my stock gasket and then put both of the gaskets on for strength since the last one ripped. Simply place the gaskets on the IAC with the bigger hole on the left side, nearest the fender and the smaller hole nearer the engine. Put the bolts back in and tighten down snug.


Step 8:
Make sure all tools are out of the way and go ahead and start the car! Right away you should notice that the rpm's at idle have dropped and it almost sounds like the car is going to stall, but it's just the lower idle speed. Go ahead and rev it up and listen to the new tone! In a 5spd you really notice the difference and will have to shift faster or possibly double clutch it to keep the rpm's up. Nice and easy mod that worked pretty good! Makes my little 6er sound like it has a decent exhaust note! Once you decide you like it, go ahead and make the same thing out of sheet metal and make sure to put gaskets on both sides to keep the seal!

Idle RPM and Exhaust Note Video

Click here for the Active thread
Jefferson is offline   Reply With Quote
Old 06-15-2010, 12:40 AM   #2
jaysun99stang
 
Join Date: Jun 2010
Location: Florida
Posts: 1
Default

Sweet ima do this to my 99 soon!
jaysun99stang is offline   Reply With Quote
Old 06-15-2010, 10:57 AM   #3
RyansQuick6
Reverse Gear Member
 
RyansQuick6's Avatar
 
Join Date: Dec 2006
Location: Baton Rouge, LA
Posts: 8,130
Default

Woo for the no-power mod!!!!
RyansQuick6 is offline   Reply With Quote
Old 06-15-2010, 02:48 PM   #4
neo8222
4th Gear Member
 
neo8222's Avatar
 
Join Date: Nov 2007
Location: Florida
Posts: 1,700
Default

Quote:
Originally Posted by RyansQuick6 View Post
Woo for the no-power mod!!!!
i did this not to lower idle but it makes the engine rev down faster when i let off the gas so i can perform a clutchless shift faster. also makes the engine match closer to the correct rpm for the next gear under a high RPM shift like in racing. so it does have SOME use lol not everyone can be like you and have a "cobra intake"
neo8222 is offline   Reply With Quote
Old 06-15-2010, 10:51 PM   #5
RyansQuick6
Reverse Gear Member
 
RyansQuick6's Avatar
 
Join Date: Dec 2006
Location: Baton Rouge, LA
Posts: 8,130
Default

I auto-x so this mod is the enemy to rpm matching, but I also have an aluminum flywheel! lol

It's amazing how much power a plastic tube can add lol
RyansQuick6 is offline   Reply With Quote
Old 02-06-2011, 10:17 PM   #6
NeoTokyo
6th Gear Member
 
NeoTokyo's Avatar
 
Join Date: Dec 2003
Location: Sacramento, CA
Posts: 6,521
Default

I remember when I started that thread. :P

Guess I will be doing this here with the 01', its RPM's hang like a fried squirrel on power lines!
NeoTokyo is offline   Reply With Quote
Old 02-06-2011, 11:42 PM   #7
v6stang07
6th Gear Member
 
Join Date: Jan 2006
Location: Alabama
Posts: 5,173
Default

Yea I did this mod a while ago but it hasn't been on my car in 4 years or so
v6stang07 is offline   Reply With Quote
Old 02-07-2011, 12:21 AM   #8
NeoTokyo
6th Gear Member
 
NeoTokyo's Avatar
 
Join Date: Dec 2003
Location: Sacramento, CA
Posts: 6,521
Default

Crap, I didnt think this would pop up if I replied to it. Thought it would stay in the sticky.
whoops for two old threads. :P
NeoTokyo is offline   Reply With Quote
Old 02-07-2011, 09:30 AM   #9
v6stang07
6th Gear Member
 
Join Date: Jan 2006
Location: Alabama
Posts: 5,173
Default

hahaha...Whats a sticky? I don't think we have/use those anymore.
v6stang07 is offline   Reply With Quote
Old 02-07-2011, 10:54 AM   #10
NeoTokyo
6th Gear Member
 
NeoTokyo's Avatar
 
Join Date: Dec 2003
Location: Sacramento, CA
Posts: 6,521
Default

Its under the tech sticky.
NeoTokyo is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Bad cylinder? Dathan V6 (1994-2004) Mustangs 4 10-05-2015 06:52 AM
Need to rebuild the automatic transmission 1996 GT wraith777 General Tech 1 09-28-2015 11:49 AM
How To: Ford Mustang GT 1994 to 2014 Buying Guide MustangForums Editor Mustang News, Concepts, Rumors & Discussion 0 09-25-2015 07:30 PM
Slight surge at 1500ish rpm lmurf60 4.6L (1996-2004 Modular) Mustang 1 09-24-2015 11:07 PM
Taillight Guide SilverStallion05 General Tech 0 09-05-2015 11:48 AM


Tags
50, air, control, fox, gasket, hole, holes, home, iac, idle, made, material, mod, mustang, restricter, restrictor, size, v6

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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

Forum Jump


All times are GMT -5. The time now is 08:03 AM.