94bajakid

iTrader: (1)

After seeing what Turblown did with the stock port engine, it got me thinking about leaving stock ports for my next build. Who here is running stock ports and making good power? Also would it be stupid to port the exhaust and not the intake?

rx72c

iTrader: (8)

I have made 550rwhp on stock ports on normal pump fuel and that was almost 5 years ago now.
Could easily make more with the right turbo and enough boost.

94bajakid

iTrader: (1)

how much boost were you running? Thats awesome!

rx72c

iTrader: (8)

28psi at that particular time.

Kanho

iTrader: (3)

^ how long (miles) did your motor last at 28 psi? What kind if turbo you were runing? Was that car a daily driver or a weekend car? And do you always run it at 28 psi? I beleive you had some sort of auxiliary injection, you were injecting a lot of water (I may be wrong)?

On stock parts 550 WHP is pretty impressive! Good job!

Andrew

rx72c

iTrader: (8)

Water injection. Car got driven every few days (mainly got belted)
Motor never died.
that setup was like that for around 18 months before the block was sold to a customer which is still going.

arghx

iTrader: (3)

Larger intake ports shift the powerband and do increase volumetric efficiency at high speed, while costing some low end. With stock ports you can use the turbo to make up for that, if you have the right set up.

2RotorsNaDream

iTrader: (7)

Guy out here made I think 731whp on stock ports with a BW S475 and e98 I think.

94bajakid

iTrader: (1)

holy ****. REW or t2?

lOOkatme

iTrader: (19)

I think the stock ports for a street car is good. My engine has a small street port from the owner before me, but I don't think it makes that much of a difference. if I had the choice, I would leave the port alone, that is just me.

2RotorsNaDream

iTrader: (7)

REW

Same here, I did a BW S366 setup with stock ports purposely to get better response and driveability. Should still make upwards of 500whp and that's enough power for me.

cewrx7r1

iTrader: (2)

There are 100% stock ports then there are the more efficient blue printed stock ports which I have.

Do the same for the stock ports that most do with the larger ports:
(1) port matching of all intake manifolds to each other and to the engine block
(2) grinding off/smoothing out all rough edges and corners inside the ports, polishing is the extreme of this
(3) removing the exhaust ports extended edges from the exhaust stream.

None of this affects timing of the ports but reduces turbulence and this increases flow.

94bajakid

iTrader: (1)

this is what I want, but closer to 350-400 daily, and 450-500 track. Build thread or anything to go with this?

arghx

iTrader: (3)

yup, you are mostly addressing imperfections in the manufacturing process while not getting into the tradeoffs of changing port timing.

94bajakid

iTrader: (1)

any reading material on how to do this? Or is it pretty obvious when the engine is apart?

Mps_hell

Have not finshed my build yet but I will be running stock intakes that have been polished with a bw s366. I have however enlarged the exhaust ports. Hoping to hit 500

j9fd3s

iTrader: (3)

pretty simple, open engine, look for big casting boogers. the rotary port is cast, and then the final port shape is machined into the face, and this doesn't always line up like it should.

then you can put the gasket on the engine, and then the intake, and match them to each other

rx7jocke

407rwhp @ 16psi stock port s4 T-II, unleaded gasoline and ball bearing t04s p-trim

94bajakid

iTrader: (1)

that's right around what I want. When does boost come online?

rx7jocke

full boost by 4000rpm to 7500+, i could have it a bit earlier but my ebc is set to delay full boost a little (we are talking a few hundred rpms only).
at 4000rpm i do have over 200rwhp