rico05

I am getting a free one on Saturday, and I want to see if this can be done? Will it help at all? It is a complete S5. Also, I am getting 2 n/a s5 ECU (also free) and can I do anything w/ these? 1 works, one is fried.

mazdaspeed7

Porting the manifold has a more noticable increase than full true dual exhaust on S5 n/a's. Me and PP13Bnos have the true dual exhaust and ported manifolds, and we agreed that the manifold made a more noticable increase in power. Sounds cool too.

von

Hey mazdaspeed7... how do we port deep inside the runners on the lower intake. Did u use a hone or something. Where can I buy the necessary tools.

rico05

Do I also need to port the upper manifold as well?

pp13bnos

iTrader: (1)

Ohh the intake made a much bigger difference. I first ported the TB, upper, and mid intake. Felt like a +10hp difference easily. Then i did the lower. Felt like anouther +10hp. I also noticed a +4 mpg on the freeway. CJ

rico05

So I can just port the lower intake? Then I am planning on doing the TB mod. Would this help at all, or should I buy a upper manifold and do that as well?

Green

The throttle body mod shouldn't raise HP at all, Just a little better throttle response... Might make yer idle a tiny bit more bumpy.. but I think it's nice..

Just take out the back 2 butterfly valves, and JbWeld the holes.. Make sure the inside is smooth..

rico05

Got it. But my main question is still unanswered. Can I port the lower intake w/o doing the upper? I really don not want to have my car down while the job is getting done!!! I am planning on getting it done professionally, so I will have to ship all the parts, and wait for them to get back!!!!!!!!!!!!!

mazdaspeed7

I use a high speed mini die grinder. Spins at 58K rpm, and takes dremel bits. Works great.

Heres a few pics of mine, some of the pics didnt turn out very well though

http://home.sprintmail.com/~dja4near...s/manifold.jpg
http://home.sprintmail.com/~dja4near...ymanifold1.jpg
http://home.sprintmail.com/~dja4near...ymanifold2.jpg
http://home.sprintmail.com/~dja4near...ymanifold3.jpg

SureShot

The pics of the upper in & out look great. You got me thinking, I may do this. I presume you are doing more smoothing than carving?

mazdaspeed7

Basically. Its just pretty much a match port job, plus some extra on some of the ports, like the secondaries where the lower and middle manifold bolt together.

tweaked

iTrader: (4)

If you really want to port your intake. then send it to extrude hone.
I don't have their number here, I am at work. but they have a web page with prices for our cars.
If you don't know what Extrude Hone does... They take a putty like substance with abrasive material in it. they force it through your intake at high velocity. this cuts away places where air is going to meet resistance. it is increadable. I did it to my celica when I was racing them. Gained about 15 horses. RAcing beat did a Neon and gained 13 horses on just the manifold.
You will get hit with sticker shock. They may have lowered the prices since the last I checked was two years ago. $500 for the entire intake at once. this port matches and everything you need. in about an hour of "bench time" instead of the 12 hours it would take to do the exact thing by hand. I know it is high dollars but it is really worth it!

pp13bnos

iTrader: (1)

Dang it!! I just trashed all my old porting pictures! Anyways...let me look around...

Where the secondary injecoters fit into the manifold, you want to take out the bump, as much as possiable....or smooth it out atleast. This will make less turbuleance, because air not only goes down the intake, but back up it. (The VDI just changes how far it travels) So, you will increase the speed the charge travels bolth directions.

yeah...i trashed em all.

But if you do a search with some words like "My thoughts and opinions on porting the intake" or something like that....it has alot of helpfull pictures and thoughts. CJ

TonyTurboII

I wonder if I should do this to my TII?

mazdaspeed7

Probably good for a few hp at least. I say why not.

TonyTurboII

Well, I wouldnt do it myself, Id ask my friend too. He seems to have some expierence at it. Like it was said before, how do you do the runners?

Also I checked into Extrude Honing, there is no way it justifies its price.

pp13bnos

iTrader: (1)

I know what you mean! Thats just insane!

CJ

mazdaspeed7

The runners arent the real problem. The problem is that all of the runners narrow at each of the flanges where 2 parts bolt together. All I did was even those parts out to the size of the rest of the runners. the only way to get into the manifold runners is cut the manifold and weld it back together,

Rattaan

Hey mazdaspeed7, about how long did it take to port and match the intake? It does seem like a good idea, but I can't take my car apart for several days at a time since it's my daily driver. Would this be something one could do in say, a whole Saturday, or little more during a weekend? I've love the idea of cheap hp, only requiring a little elbow grease! Is it an easy weekend mod?

von

YYYEEEEEEESSSSSSSSSSSSSSSSs.... I have been asking that ? for like 6 months or something in posts here and thier... THanx mazdaspeed7 for finally ansewering. I thought thier would be small size personal hone or somthng. I used one to port or hone a small engine from a lawnmower. 10hp I think it was. The hone had three stones on it that revolved really fast and would retract wider the faster they went...

U also ansewered another ? that saved me and im sure alot of other people lots of time...THE RUNNERS ARE BIG ENOUGH NOT TO PORT.....

But the last time u told me I remember u saying that the middle manifold was the one were the runners were 50percent larger than the flange. That the lower intake to the engine was the one with the small runners that needed to be ported but I guess I misread somehting unless u can tell me otherwise in THIS POST...?

mazdaspeed7

That is correct, but the middle piece needs to be ported to match. Its in one of the pics above, but I dont remember which one it is. Its really fuzzy and had a red line under the ported ports, only half are ported.

You could do it in a weekend, but be prepared to spend 10+ hours to do it right. It is a lot of work, but this is the best thing I have done to my car yet. Made a bigger difference than any other mod.

This applied ONLY to the VDI manifolds, but when you port the secondary runners in the middle and lower manif0olds like I did in the pic, it shortens the effective radius of the turn at the flange between those 2 parts(dont make me explain how), which shortens the effective runner length. Shorter runners make for a higher powerband, and more power. This is one of the reasons why it makes so much power, and I can rev freely to the rev limiter. I wont know for sure, but Im pretty sure my power peak is at or above the rev limiter. My engine is still pulling like crazy when I hit the rev limiter. Ive hit it unintentionally quite a few times.

Rattaan

Dude. If ten hours will help that much, I'm there. I want to do more mods without spending huge amounts of $$$, or porting the engine itself and voiding the warranty I got on it. Looks like I'll have something to do one of these weekends soon!

von

Thats so sick I im going to do it as soon as I can.