A6 Mani Plus turbo porting Q's

[F22AboostIT]

ok i have a A1 91 Dx coupe i am putting a DSM turbo setup on soon i have the A6 intake mani and TB and the cam also and finding a p06 to chip for tuning with wideband O2 and with the IAB setup would it be worth turning the 8 runners into 4 at the butteryflies like bore them into 4 oval openings for the flow with the boost or should i stay with the IAB setup sorry bout the horrible mess this is lol

[ikayto]

i believe most ppl remove the iab all together with turbo, but i know nothing.

[F22AboostIT]

would running the spacer help down low tho since it lengthens the runners but with having it opened up and bored it would increase the flow rate a ton right?

[F22AboostIT]

o and to add the h23 and 22 TBs arent any bigger than f22ax's are they are all 60mm except the type R's they are 62mm

[MRX]

I could tell a difference driving normally from down low with the IAB's. It just made it easier to get up to speed under partial throttle. Didn't matter under full throttle. All felt the same then.

[F22AboostIT]

thanks i think im gunna bore it out nothing bad with better flow lol

[deevergote]

It's not necessarily "better flow". turning it into one big oval can cause turbulence, which is a bad thing if it becomes extreme. You want flow velocity, and evenly distributed airflow in the intake. Personally, I'd leave the IABs and add a Blacktrax spacer.

[F22AboostIT]

thanks deev thats why your top dog so you think it will cause turbulence or that it is possible?

[deevergote]

There is such a thing as making things too open. Many amateur head porters hog out the ports, and end up with less power.

Doing this is a bit of a tossup. You are technically decreasing the length of the intake runners, as well as increasing the volume of the plenum. The IAB plate becomes more like a part of the plenum than the runners. However, the shape is very angular... I don't see how it couldn't create turbulence. An extremely turbulent condition in the intake manifold could result in uneven distribution of air throughout the cylinders.

This is merely speculation, as I am not an expert on this, nor have I ever tried it myself...

[F22AboostIT]

yeah i kinda understand the fact that quantity is only good when coupled with velocity and smoot flow instead of creating pockets for build up right?

[wed3k]

for a big turbo setup, hogging out the ports can be somewhat beneficial. remmeber you have forced induction.