jkm1987

ive got a trick flow plenum on my car and i love it it really pulls harder past 4k or so and it makes the exhuast sound a little throatier also definently worth the money

BCisme

what kind of supercharger are you planning on using? with a twin screw, you wouldn't need a TB either as they use a dual blade style like the cobra TB. with a centrifugal, like a vortech or ati or novi, a plenum can give you a 15-20 rwhp gain with a TB.

Martinrulz

Any guesses as to my RWHP with mods listed? 240 maybe?

Obselite

roots style ones...

i know, i plan to get the twin screw...and then i can sell my TB

DIVER8374

Yeah You might be getting close, my guess would be around there, but probley closer to 235rwhp or so. And don't beat yourself up because you have a auto, throw a good shift kit in it, add the diablo predator tune and adjust your shift points and your car will shift harder than a 5 speed. I love driveing mine even more now that I have my shift kit installed, it chrips second gear almost everytime I start from a stop, even when I am not getting on it that much. Get a shift kit and some gears (which are one of the next mods I am going to get) and you will be happy your drive a auto!!!

kubball2005

It sounds like that shift kid would be hard on your transmission but I don't know a whole lot about autos

DIVER8374

^^^ It is actually better on the trans because the shifts are shorter/faster which mean less slippage/wear. That with the trans. cooler will make it last longer, because of less wear and lower temps in the trans.

Deannostang

I first installed a Ford Racing 70mm throttle body on my engine and a K&N filter. More recently I added the Accufab plenum and took out my wind silencer. What a difference with the plenum installed. It made the throttle body come alive and smoothed my acceleration right out. Accufab, by the way, proved to test highest at increased cfm than any other competitive brand. Really a quality made piece too. Accufab also found that the 75mm throttle body really does next to nothing more over the 70mm TB unless other mods are made on the engine.

Taking the wind silencer out actually created essentially the same thing as most CAI's on the market. Now the entire right side of the K&N is exposed for increased air flow. I was going to add my Densecharger but didn't really see the need unless I was also adding a blower. They seem to test the best on the 390 HP blown Cobras. With just a SOHC 4.6L, what I did seemed to make about as much sense and much easier to maintain. If anyone is interested in a MAF forward Densecharge that has never been used, I have one you can buy at a savings.

One other thing I did at the time of installing the new plenum was replace my IAC valve with a new Ford part ($99) since my other IAC had over 40,000 miles on it. The IAC is one of the known items that can cause idling and acceleration problems with your engine. Why not change it and start out with a whole fresh system? You have to transfer the IAC from your stock plenum anyway, why not just use a new IAC instead.

Anyone holding off on installing their new plenum, don't. It really does help the engine breathe better and will definitely smooth you entire system out. As far as rough idling is concerned, it may be due to your installation procedures. First, whenever modifying your engine's mechanics in any way, you should disconnect your positive battery cable. This will essentially zero out your computer so it will immediately start making the necessary adjustments after firing your car up again with the new mods. If you do not do this, nothing bad will happen. It just gives the computer a headstart on smoothing out the proper settings for your newly modified engine. Without disconnecting the positive battery cable first, the newly modified engine will struggle for up to 10 days to make the proper adjustments to once again allow your engine to operate at its optimum settings. Simply take your Mustang on a 100+ mile trip and all once again should be fine. You need the contant running at highway speed to really let the computer do its thing if you haven't zeroed it out. The same results will come without the trip but just take longer to accomplish. This will definitely give you the illusion that your car is idling rough, which it its. If your car still is idling rough as a result of your install after an extended period of time, I suspect you do not have a tight vacuum seal on the work you have just completed. You may want to loosen, re-adjust the seating of parts and tighten all again to specs. Do your self a favor. When working around your intake area, ie throttle body and plenum, only us a 1/4" drive rachet and not a larger drive. These small parts seat very easily and utilize quite small bolt heads. Furthermore, you are dealing with alumimum parts that can distort and/or crack if over torqued. And that, over torquing, can also cause your engine to run rough if it resulted in distorting any of the seats or the parts.

Whole job, throttle body, plenum w/new IAC and air silencer removal didn't take much more than 30 to 40 minutes. When you remove the air silencer and/or install any CAI, it is always a good idea to spray your MAF sensor wires with electrical contact cleaner to remove any contaminants. Contaminants on these sensors will cause all kinds of running problems. And, be very careful when re-oiling your K&N filters. Over oiling can contaminate your entire intake system resulting in everything from MAF failure to multiple 02 sensor failings. Less is more. And let it stand a good long while to allow for maximum absorption prior to reinstalling the K&N into your air intake system.

Thought I would pass along what I have learned with these Stangs in the past. Hope I haven't been too long winded. Good luck with your modifications.

Martinrulz

Great Info for N00bs like me ^^^^ One question though. You say disconnect the positive battery connection, It said in my directions and from other people here that you should disconnect the negative cable?

Deannostang

Heck, disconnect both. The positive is what I always do to deaden the battery. Leaving the ground on won't hurt anything. With the positive connected and the negative off, the battery may have a tendency to try and ground itself if you touch the wrong thing. Be safe, disconnect both and the battery will be 100% benign. The big thing is to disconnect the battery in some form for sure before starting your work. And don't forget to clean the contact areas of your cables before reconnecting them to be sure you have good conductivity. Ford may say to disconnect the negative cable because it may not zero out your clock and radio settings that way. I really don't care because it only takes a heartbeat to reprogram those settings anyway. Disconnect it all and you can't have any unforeseen mishaps.