I'm trying to hunt down some options for a replacement for the 2.8's stock plenum, I'd love to get a Trueleo but I'm not having any luck finding one. any advice would be great. I also tried westcostfiero but I can't get the website to work??
there's two, westcoastfiero.com and westcoastfieros.com, I just got it to work. I'd like to stick with something that would use the stock throttle body like the Trueleo intake.
Here is a mod I made to my intake with flow numbers. You can see how the under side was enlarged at the choke point. The throttle body and intake were milled out also for increased flow. The intake is installed on a 3.4pr. https://www.fiero.nl/forum/Forum2/HTML/118417.html
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------------------ Mark ' 85 2m6 3.4PR In the Great Northwest!
Perhaps I'll eventually start my own thread on this if it's a viable idea, but this thread has some relevant info in it, so...
From what I understand, the Fiero's stock intake has quite a restriction in the neck. The engine therefore runs out of steam at high RPMs. I use my 5-spd '88 Formula to autocross, so I'd like a few extra ponies without having to entertain an engine swap.
Various methods have been employed to deal with this flow restriction issue, such as enlarging the neck of the intake. I'm not interested in going that route.
I've relocated my battery to the front, and the old battery location is all cleaned out. Something needs to go there.
I'm interested in a installing a secondary throttle body, but one that's only employed for wide open throttle (WOT).
I'm not interested in having same-sized dual throttle bodies that are synched together. I feel that this complicates proper tuning. With my idea, the secondary throttle body (smaller in size/CFM) would be mounted over on the passenger side of the intake and wouldn't start to open at all until perhaps 3/4 full throttle. There's probably a "best" time for it to begin to open, and that's hopefully what can be determined here.
A few questions then.
1) With a stock (and/or mildly tweaked) 2.8, what flow/CFM is required at WOT?
2) And what does the stock throttle body/intake supply?
This info would allow me to choose an appropriate sized secondary throttle body or valve of sort sort. (Suggestions of what to use are welcome.)
3) I've heard that at some point, the ECM just basically dumps gas at WOT. When exactly does that occur...
4) And perhaps more importantly, what determines when the ECM dumps gas at WOT?
This info would allow me to hopefully configure when the secondary throttle body/valve should best be opened.
If I can get my buddy with a decent home shop interested in this idea, this is how I wanted to deal with the 2.8 intake issue...
[QUOTE]Originally posted by Patrick in This thread:
Perhaps I'll eventually start my own thread on this if it's a viable idea, but this thread has some relevant info in it, so...
From what I understand, the Fiero's stock intake has quite a restriction in the neck. The engine therefore runs out of steam at high RPMs. I use my 5-spd '88 Formula to autocross, so I'd like a few extra ponies without having to entertain an engine swap.
Various methods have been employed to deal with this flow restriction issue, such as enlarging the neck of the intake. I'm not interested in going that route.
I've relocated my battery to the front, and the old battery location is all cleaned out. Something needs to go there.
I'm interested in a installing a secondary throttle body, but one that's only employed for wide open throttle (WOT).
I'm not interested in having same-sized dual throttle bodies that are synched together. I feel that this complicates proper tuning. With my idea, the secondary throttle body (smaller in size/CFM) would be mounted over on the passenger side of the intake and wouldn't start to open at all until perhaps 3/4 full throttle. There's probably a "best" time for it to begin to open, and that's hopefully what can be determined here.
A few questions then.
1) With a stock (and/or mildly tweaked) 2.8, what flow/CFM is required at WOT?
2) And what does the stock throttle body/intake supply?
This info would allow me to choose an appropriate sized secondary throttle body or valve of sort sort. (Suggestions of what to use are welcome.)
3) I've heard that at some point, the ECM just basically dumps gas at WOT. When exactly does that occur...
4) And perhaps more importantly, what determines when the ECM dumps gas at WOT?
This info would allow me to hopefully configure when the secondary throttle body/valve should best be opened.
[/QUOTE]
that seems really familiar for some reason, maybe I've read it before. I was looking for something like a Trueleo for when I do a lot of my engine rebuilding. the 2.8 is getting a new Crane 272 cam, 1.52:1 roller rockers, stronger Push-rods, new valve springs, roller timing chain. so a good intake would be essential, and ideally I'd like to get a Trueleo, but its my understanding they're still halted on new orders.
that seems really familiar for some reason, maybe I've read it before.
It's possible you read it in the original thread that I posted it in.
As far as I can recollect, no one else at PFF has ever suggested mounting a smaller secondary throttle body on a 2.8 factory intake which would only open at WOT. Maybe that's because it's a lame idea , but I'd sure love to try it and find out for myself.
[This message has been edited by Patrick (edited 12-01-2014).]
Here is a link to my post on a dual tb. I have been running it for 8 years and it works. I increased the fp regulator a few lbs with no other tuning. It runs good, has a good kick above 4000 rpm , gets 28+ mpg highway 20 around town. This is an auto and should be better with a stick. Sorry, no dyno or proof just a good seat of the pants feel. Wheelie
------------------ WHEELER'S PERFORMANCE MOTORCYCLE SHOP NEAR DEALS GAP check out TAILOFTHEDRAGON.COM 318 curves in 11 miles #1 RED 85 GT ... GONE still in the area and for sale, needs work # 2 white 86 gt fastback project. UPDATE 3/03 IT LIVES!! UPDATE 12/03 3.4 dohc is here,this winter's project 12/04 still this winter's project 12/05 still this winters project 01/06 96 3.4 dohc engine is in! full length headers built,al flywheel, 5 speed,konis,coilovers, n* throttle body this thing kicks *SS whoo hoo!! OBD2 ,HP tuner. magnaflow 2.5, ,400lb springs,88 cradle,245/17 rear, I AM NOT ADDICTED.... BUT Now # 2 formula project. runs but needs work(so what's new?) # 3 86 gt BLACK it's an auto I want a 5 speed used engine is in and runs, 2012. Been driving for 2 years, dual throttle bodies, roller rockers, 2 1/2 magnaflow... still auto. AND NOW for 2012/2013 a kitcar!! I found an 88 SCORPION.and it's red! I found a GREAT engine for this, 96 3800 sc NEW on the crate never been run, it now has a 4 speed, al flywheel,3.4 pully powerlog etc etc
Here is a link to my post on a dual tb. I have been running it for 8 years and it works. I increased the fp regulator a few lbs with no other tuning. It runs good, has a good kick above 4000 rpm , gets 28+ mpg highway 20 around town. This is an auto and should be better with a stick. Sorry, no dyno or proof just a good seat of the pants feel. Wheelie
Here is a link to my post on a dual tb. I have been running it for 8 years and it works. I increased the fp regulator a few lbs with no other tuning. It runs good, has a good kick above 4000 rpm , gets 28+ mpg highway 20 around town.
Ah yes, I remember that thread. It helped to inspire my goal of mounting a second (smaller) TB elsewhere on the 2.8 intake manifold, although for some reason I didn't currently realize you had still used the original TB as well. I thought you were running just the TB on the top. Thanks for clarifying that.
Instead of a mechanical linkage between TBs, did you ever consider controlling the secondary TB using some sort of vacuum device, like the vacuum operated secondaries on some 4-bbl carbs?
I don't want to have the decklid clearance issues that you face with your top mounted TB, hence my desire to add a second "neck" on the passenger side of the manifold to attach the secondary TB. Right now it's just a pipe dream (pardon the pun), but maybe some day...
[This message has been edited by Patrick (edited 12-02-2014).]
Francis Trueleo is prototyping a dual TB plenum intake that he hopes to sell as a kit that can be welded at home (or a local shop). I'm sure he will post a progress report as the work starts.
