Can't wait to get home and get some install therapy....

I praying for a whopping 7rwhp gain with these badboys....

No dyno time slotted, but I will let you know about SOTP gains when done...

 

Sweet! I felt a tiny boost in power with just my plenum so you should definately feel some gains! Plus it looks much nicer under the hood.

 

I'm giddy as a schoolgirl over this crap. I've been denied my install therapy for too dang long!!!!

 

what other mods do you have?

 

if you have a bunch of other mods you might want to at least get your A/F checked cause I'm convinced the plenum and 75mm TB I had on my previous stang leaned me out big time.

 

Well, I'm friggin' pissed... I got the damn' TB and I'm like Where the Hell is my Plenum?! I check the friggin' invoice and it says the plenum is on backorder. Why the hell didn't they mention that when I ordered the crap.... Not happy with BOI right now. Not happy at all.

But at least it was on the friggin' invoice.

 

CAI
Pulleys
(75MM TB and Plenum)
HandHeld Tuner
Catback...
4.10s

 

Hate to burst your bubble but I just installed a 70mm Accufab TB/Plenum on my 03 GT stock with the exception of Magnaflow catback and KN drop in, and it sucked.....
Lost all midrange 2000-3000 power and had the classic RPM hang... Do a google.......

Mine went back after a day, and yes I did a TPS adjust to .98v and a PCM reset... I've been working on cars for 30 years......
This mod was a total waste of money and thank goodness the place I purchased from took it back.

Maybe it makes power way up in the RPM range, but for me with an auto it sucked....
BTW I had a 70mm version.


Personal opinion: dont' waste your money.

 

Steve... Did you adjust the tune or just reset the ECU? In any case, yeah 7hp at the top and nothing down low is what to expect. You'd think with 30 years of wrenching you'd have expected that. In any case, you may or may not need some tinkering done to the tune afterward to take care of the IAC duty cycle and the WOT point for TPS and with the upper plenum, some work better with a small adjustment to the plenum volume value in the tune.

Sounds like steve just installed it and didn't update a tune for it. While you can run such parts without any tune adjustments, you should adjust the tune to take care of it. Otherwise you'll be unhappy. Steve didn't have any supporting mods to take advantage of the added TB flow so he had unsatisfactory results... well duh.

Most aftermarket TB's come without a breath hole in the butterfly. Stock TB's have that and the IAC tuning is set to take advantage of it (it lowers the required duty cycle of the IAC which allows it to close sooner farther, dropping RPM's faster at 0 throttle).

In any case, caballo... check your AF ratio once you're all installed. I'll bet it's leaned out a quarter to half point. Depending on where you started that can be important.

 

1. ECU was reset after the TPS adjustment.

2. Only mod on the car is a Magnaflow catback.

3. Aside from the hanging RPM problem, the car felt like it was running lean. No detonation or any other signs, but it just lost midrange (2000-3000) power and it was noticeable SOP.

4. I agree, a tune probably would have solved at least the power problem, but again I was only using a 70mm, which should still be well within the limts of the MAF etc.

I've come to the conclusion that either:

1. I needed a tune to check / adjust A/F because the car felt lean.

2. The TB/Plenum was defective or the setscrew was not adjusted correctly at the factory. I had no binds and the trhottle plate snapped closed (slight opening of course) fine.

or both......

I sent it back because at this point I'm not interested in going for a tune on the car. I put the stock units back on, adjusted the TPS
and the car has all it's midrange power back. It was THAT noticeable. The RPM hang is also gone.

Puzzling...

 

One more thing, I could expect that a tune might be needed to get the FULL benefit of the MOD, but I don't think I should LOSE performance by installing just a TB/Plenum. Most people don't get tunes when they install these things AFAIK.
Maybe it has to do with how rich/lean the particular car is running prior to installing the unit, although I would think the ECU would be able to compensate, especially for normal driving because this isn't a major change to things as the HP gains generally show.

 

In my experience with EFI cars, you almost always lose something in the mix if you don't make sure the tune is understanding the changes.

I routinely saw cars lose tq and sometimes hp on a bolt-on mod, then we'd tinker to get the fuel and timing trims to come back to where they used to be (assuming we'd tuned the car before). EFI's like the Ford EEC-IV and V take so many different values into account that it's nearly impossible to sauce it out by looking around. You really have to get them up on a dyno and let an experienced tuner at it to make the most.

Tb's are one of those twitchy things though. I've had horrid results from one brand and perfect from others. I prefer accufab as they've got the best quality controls that I've seen (other than FRPP 70's which are pimpin).

FWIW... if you ever pick up a FRPP 70mm, you'll probably have better luck. They come with the TPS already calibrated and the idle hole in the blade is correctly sized to keep the idle and RPM issues from popping up.

Totally understand not liking them as a mod... unless you really need it you shouldn't have it. I have it cuz I got it free, the one before that I already had... so I've at least never spent any money on such things. I also advocate making those your absolute last purchase. it's just not worth it in hp:$$.

 

Thanks guys!!
A lot of great information in this thread and I apologize if I was a little harsh in my first reply. I was just frustrated

Steve

 

No biggy as far as I'm concerned... I know people have all kinds of different experiences with all kinds of different experience. I take it for what it's worth and make my own choice from there.

As far as all this stuff goes...I'm gonna wait until I finish up the exhaust (LT's and Catted X. Then I'll get over to MileHiDyno in Denver and get a tune... Until then I'll do what I can with the Diablo and go from there...

 

Oh R3d... Ever think about doin' a write up on TPS adjustment or do you know of a place on the net to find one?

I decided to do the TB/Plenum thing after the article in MM/FF on 2V basics and that was the only part of the mods I didn't have... (that was excuse enough for me)

 

Interesting because it was 5.0 Mustang's 4.6l 2v bolt on article that made me give it a try. I think it was in last months issue.

They did a catback exhaust first (which I have), then the TB/Plenum and got about 10RWHP from the TB/Plenum I believe.

Then they did pullies and finally a tune. The tune gave them 1hp.

I dunno, my automatic was awful with the Accufab TB/Plenum compared to stock. For $400 I can see not getting the *full* benefit from it without a tune, but it just killed my low/midrange power so back it went.
The lazy idle return was just the icing on the cake.

 

It's pretty easy so I elected to leave that to the gods of the quickie doc. The gist is:

3 wires go into the TPS, 1 is 5v+, 1 is v -, the other is the sensor wire which has a 0-5v range IIRC. Stick a straight pin into the sensor wire, turn the key on leave the engine off and the throttle closed and read the sensor voltage with a VOM. It should be between .95 and .99v. If it's not, loosen the screws and twitch it around till you get the right voltage. If you CAN'T get the right voltage, then you'll have to oblong the holes or replace the sensor or reinstall it correctly if you find you actually did it wrong (if you use that last option hit yourself in the head with a hammer for being a dumbass cuz it's really hard to **** up the install).

Please see the following procedure... it works for modulars too but the pictures become invalid. Remember that the fox's and modulars used almost identical sensor packages in the MAF cars... SD cars are a different story.

http://www.muscularmustangs.com/tps.php

EDIT: Once you've nailed the closed throttle voltage, please do yourself a favor and see if you get near the full 5v for WOT. A little off is fine but you may want to consider replace the sensor if it's more than trivially off.

 

Finally got the plenum today....

So I installed them both tonight with little fanfare. I ran a 1/4" drill bit through the hole for the throttle cable. Seemed like it had a burr or something in it so the cable wouldn't go. I didn't enlarge it or anything, just maybe a "hone".

I reinstalled the stock tune and disconnected the battery. RnRd the plenum/intake combo by removing everything off the old assembly. pre assembled the new and reinstalled everything else after torquing the plenum down. I then reconnected the battery and fired her up. idled until warm. turned it off. hooked up the Diablo. Installed the tune. took her for a drive.

At first I just let her idle then I did an easy drive down to the highway. moderate acceration up to 65 and then pulled over to check the log. cursory glance showed everything ok. Turned around. punched it. Engine let go around 5500 rpm....


Just kiddin'.


everything was smooth and silky and the main difference I noticed is the exhaust not smoothed out a little bit. I did 3 WOT runs to 65 and no problems at all.

When I reviewed the log nothing really stuck out as abnormal, but I guess we'll find out when I get a tune in the next few months...

 

This morning I did my usual 0-65 acceration run when I got on the "highway". from what I can tell I'm a bit quicker than before. Lemme esplain.

From where I turn on to the highway to a certain road sign I get to 65. Today I was at 65 about 2 car lengths before the sign. At least the width of the crossroad before the sign... I don't what that translates to in HP or secs to 65 but there you go...

 

refreshin' everyones mind about my "performance" mods...

 

yea those gains should be nasssty

 

hahahahahahahaha-what?!

 

Okay... after running around a few days it would seem like the computer is better using the new found air flow. Now on my acceleration runs I've gain a few more car lengths. Before it seemed like it was alright with a couple of car lengths (about the width of the 2 lane road on the short side of the run) now I'm up to about 3 times longer distance improvement. (about 1/2 to 2/3 of a block)

No detonation problems or drivability problems up to this point. I've ordered a slp catted xpipe that should be here next week and at that time I'll do the Jmod on my tranny. I think I'll see another noticeable jump then...

I'll keep you posted.