Hey guys i'm building my n/a engine with a bp onthe aux. port do you guys have any idea how this is going to react when aux. port opens up is it going to feel rough or is it going to feel normal?All the mods were done to the engine the rest is stock.Istill have not put the engine together, any suggestions would be greatly appreciated. https://www.nopistons.com/forums/pub...1047683561.gif

Don't use a stock ECU/FI computer, and I would stay away from the stock intake manifolds.



Mazdaspeed7 did this and said he wasn't too pleased with all the limitations stock equipment gave him.

So there is problably not much power to gain with a stock ecu/fi computer? that sucks ! https://www.nopistons.com/forums/pub...1047683358.gif

I think I remember him saying that it was with the S5, and that the S4 would do better with a bridged aux. But I could be wrong.

Not only not much power, but not much driveability. It moves enough air to max out the AFM and make it run like crap (On stock componentry).

Maybe i should use the stock sleeve in the port until i can upgrade the ecu and change the manifolds.that way the bp won't be activated when open.

That's probably a good idea. The porting itself is a great way to keep low end and then have good power up top... the problem is trying to use the stock stuff with it. It maxes everything out, and the port timing is all wrong for the length of the intake runners. You need to separate the aux port runner from the other ones, it needs to be much longer.

Good luck

Dear god...I hate to sound like RX7club, but those FAQ's are there for a reason. I have gone very in-depth on my aux bridge experiment, and really dont feel like typing it again. Search my username and "aux bridge" and you should come up with 2 threads in thie forum(or the FAQ's) that have all of my results/thoughts on it.

I hate to sound like a dick, but maybe you should take care the manifold and ECU first. The stock sleeve will only close about half of the eyebrow. You will have an engine that barely runs on the stock ecu, and youll hate it. The S4 AFM has a lot more range than the S5 ones, but you will still never make good power with it, but more importantly, you will lose TONS of low end and midrange.



Im much happier with my SP engine than I ever was with the Aux bridge.

Hey i don't mind you sounding like a dick as long as it is to help me out , https://www.nopistons.com/forums/pub...#>/biggrin.png But seriously guys thanks for all your opinions and share of knowledge.I can tell you one thing my 89-vert will not be styling an aux. bp(thanks)