Contour Enthusiasts Group Archives Forums Modifications Duratec Performance Cracked Secondaries Observations

After work today I am going back together with it. Any reason why to use both gaskets?

The Mustang (65mm) throttle body DOES have an air bypass. If your's does not. It is the wrong throttle body (I.E. not from a Mustang)

This screw (so to speak) has a rubber o-ring on it as well. It needs to be run down (turned clockwise) until it completely closes the air flow around the throttle plate. Otherwise you will have bad hang regardless of what ever else you do!!!

I personally filled in the air bypass & smoothed it to where it's flush with the throttle body walls (I.E. like it never was there)

I have zero hang. I also have the secondaries cracked just a bit (like 8-10 turns - maybe halfway)

My experience so far is...

Slight loss of power below 3k. Especially in 4th and 5th. (I really think this is from the secondaries being cracked - I plan to close them and see for sure)

Tremendous gain from 3000-5500rpm (very noticable!) I can easily break the tires free in 1st and 2nd by just stepping on the pedal. Had me worried the first couple times. I would tromped the pedal and it would hesitate and then just take off. Finally looked down at the tach and watched it jump up a good 500rpm before it caught and took off...

Nothing noticable above 5500rpm. Or atleast nothing I could tell by the seat of my pants. (G-Tech was within it's range of +/- 3HP - showing an average of 2HP more)

However currently I have the stock SVT cat-back with a custom Y-pipe so it's pretty corked-up up top anyway... We'll see here shortly on about that...

The T/B have diffrent bodies, put the contour gasket on manifold and mustang gasket on T/B. Use some RTV(HI-TEMP) for good measure.

Just closed the secondaries and the effect is a bit less. But not completely gone. I had the bolt (secondary stop) over halfway up.

I cracked them just slightly this time. Just enough to alow a little air to constantly pass.

Also I found out why the 65mm TB was not helping on the top end...

Go HERE for that...

so I got curious and looked at my car, this mod is pretty much impossible to do with everything "attached" right? I can't even reach in far enough to feel the bolt let alone turn a wrench

I can adjust mine with everthing attached. (just did for that little test)

The adjust nut can easily be seen looking just below and to the right of the TB. While standing on the drivers side

It will have a small thin cable right infront and above it.

BRB... I will try to get a good picture of it...

The adjustment bolt is dead center in the picture. Just to the right of the secondary rod stop and spring (kinda likes look the throttle body stop and spring)

The blury stuff on the left is my intake pipe

It's very easy to adjust with gear wrenches (I swear by gear wrenches! )

Adjusted mine one full turn, not sure how sure how much that opens it up exactly maybe .010-.020 i'm not in the mood to pull the upper intake, but has better response , releasing throttle I can feel engine braking. I've got ATX 98 Mystique LS.
I did reset the PCM after making the adjustment.
Paul

My guess is that you'll have to remove your upper intake manifold. :rolleyes: Takes a while but you get full access to it and may as well take the time to clean the secondaries as I did.

I put my car back together today and made several notes on the t.b. It has a "M" stamped on the butterfly. On the back of the tb it has the # 46 I am guesing its from a 4.6 something. Maybe not a mustang or some weird emissions car?