The MK4 manifold flows tons better over the mk3 manifold day in, day out.
The runners are larger, smoother, and there is less of an extreme transition from the upper to the lower manifolds.
It's been tested to give more horsepower by just bolting it on, I've gasket matched the lower manifold and checked them so they are all identical.
So If they give more horsepower on a stock N/A, then there is absolutely no reason it's not going to with FI.
At the end of the day, Flow is Flow, no matter what it's application. Didn't even know why this needed to be explained..
Oh, and this.
Last edited by AJmustDIE; 03-31-2011 at 02:13 PM.
1: Flow is subjective. Port velocity is just as, and in some cases more important then flow. Just because it is larger, doesn't make it "better."
2: Gasket matching the halves will create a varying port cross section through the runners. This will create turbulance, and cause the velocity to drop in areas which is not only bad for "flow", but causes turbulence in the port. Bad idea all around. "Gasket matching" causes WAY more cons the pros.
3: Comparing NA intake design to FI intake design is useless. In na, you Big long runners+ small plenum=terrible combo for FI.
4:At the end of the day, "flow" is not "flow."
In FI, "PSI" on the intake side, is a measure of the restriction in your intake tract. Increase VE, and your PSI of boost will drop per power figures. This is commonly looked at wrong. People "brag" all the time about how much "boost" they run, like its a measure of performance. The irony, is that by bragging that you ran say 25psi on a stock ABA, you are basically saying that you had a VERY inefficient setup, and componsated by cranking the boost. TQ (and RPM fatigue) kills internals, not "how many pounds of boost" you run. If a Rod can withstand 250ft/lbs of TQ before being compromised, it doesn't care if it comes from 20 PSI through a Gt20, or 10 PSI through a Gt30, or 15 PSI through a Gt20, with a large plenum, short runner, ported head, and suitable cam.Oh, and this.
PSI, or Pounds per Square Inch, actually is a measure of pressure, and measuring strength of components. Like compressor tanks, tires, among other things. lol.
I'd go on the explain the role of PSI on the exhaust side, and intake/exhaust pressure ratios, but honestly, with the replies already seen, I'm wasting my time.
Good luck with the build, I suggest you research ALOT more. Preferably outside of this community, as everyone here likes to repeat bad practices. Hence why built NA Vr6's are making less power then bolt on Single cam, 2.0 neon motors, and NA 2.0 8v ABA's "fully built" are making as much as stock SOHC engines of smaller displacement from many other manufacturers.
Small update here guys.
Seeing as how I had to torch some of the nuts to get the exhaust manifold, I had to go out and get some new exhaust studs.
I went to go put them in and I realized they weren't gonna go all the way in, the studs were too long.
So the mighty dremel comes to the rescue again!
From top to bottom: Shortened new stud, old stud, out of the box new stud.
Got them all shortened.
That's all I was able to do because of the rain again today here in Florida.
BUT, tomorrow I should have the turbo mounted so I can start mocking up charge piping and such.
Take care until the next update
Micro sized update here,
The battle to get the remaining exhaust studs out is on-going.
I have them all removed but 1, it's almost broken off at the head so I'm curious as to how I'm gonna tackle that. But tomorrow I should have it out so I can bolt up the turbo so we can get back to actual progress.
This is been SO aggravating.
IF all goes as planned, and all the shipping goes off without a hitch. I should be able to turn this thing over soon.
List of things I still need:
Autotech Plug Wires
2 10" Slim Radiator Fans (stock setup has GOT to go)
Misc. Silicone Couplers and Clamps.
Btw, I also forgot to mention I will be using a Forge Splitter (recirc. & blowoff hybrid).
You guys should get some pics tomorrow after I get back from the lake.
I got the turbo "mounted" today.
It's just temporarily bolted up right now as to give me what I need to move on to the rest of the project. Forgive the cell phone pics, I wasn't near my d5000.
I unfortunately, and I will probably regret my decision to post this because I'm a novice at turbocharging, but wresting the turbo behind the motor took a LONG time, even though it's a tiny thing. Not one thought about rotating the compressor housing even came into my mind until I tried to unbolt my rear motor mount and snapped the bolt in half.
Anybody got any advice on replacing the bolt? Something I can order or do I have to go to a local store and seek through the rows of bolts myself. I don't think they include the bolts in the BFI motor mount kits.
get bfi mounts they come with the botls and everything.
you will need a new top to the mount so it threads in. if you want send me a pic of the bolt i got one laying around here somewhere
I want to see somebody hang a billet 5756 on the back of an aba, and set up the right peripheral parts.
stock obd1 block with arp bolts
ported obd1 head
management other than c2
The project looks like its headed in the right direction!
Last edited by root beer; 04-06-2011 at 01:12 PM.
So I ordered the VF Engineering rear mount off ECS as it's a whole piece I believe.
Now moving on to some updates.
Pulled the core support off the car so I can shave what needs to be shaved when I mount the Air/Water heat exchanger. Also looked at where I'm going to be mounting the radiator an inch or two back.
Then pulled some goodies out the box and just played around in my head for awhile trying to think out where everything is going to be.
Then I went to the trunk and pulled up the carpet and took out this thing.
So I could look at the nastyness that can be seen below.
Just threw in the Ice Box for the Air/Water to see my clearances and what not, I assure you when it's in there for good it will look very very nice.
Ordered the rest of my parts today as well,
That's all for today, gotta go work on the fiance's Jeep.
Last edited by AJmustDIE; 04-07-2011 at 04:26 AM.
keep it up man. Aptuning is having a sale on there forced induction chips and i am thinkin about joining the boosted ranks. keep up the inspiration
does your ac still work?
Yeah my AC is fine, I live in Florida so that **** staying put! lol.
But thanks, this project is making me learn a lot and I do a little bit everyday so it doesn't burn me out when I run into problems.