Under Battery Pipes

[Stazza_Brendan]

Looks like one of my brothers is buying me an under battery pipe for christmas.. Not the intake pipe. But the one that has the boost sensor attached.

I have an intercooler setup that replaces all the factory pipes aside from the ubp so there's no other restriction. What improvements will I notice? I've seen a pic of a stock pipe cut in half to show how small it gets so I'm guessing better response..Currently running stock tune but hope to get a custom soon.

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[Yoshi]

Did this as one of my first mods, yes the car feels a bit more responsive. Could just be imagining things but I think slightly louder induction and flutter/dose out of my BOV.

[FAST-XR]

I also did this mod, waste of time.... the boost gauge still read 5psi after it was installed, not any noticable gains, didnt free up anything....

I actually cut open the standard UB pipe and measured the internal area. even though the shape changes its a smooth transition and the area is exactly the same as the inlets of the pipe.... so no its not a restriction.

your better off putting your money towards a set of injectors to compliment your flash tune....

[Stazza_Brendan]

Wasnt expecting boost to go up any. Compared to rest of my piping its the smallest piece though. Hopefully theres a difference.

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[our06t]

I also did this mod, waste of time.... the boost gauge still read 5psi after it was installed, not any noticable gains, didnt free up anything....

I actually cut open the standard UB pipe and measured the internal area. even though the shape changes its a smooth transition and the area is exactly the same as the inlets of the pipe.... so no its not a restriction.

your better off putting your money towards a set of injectors to compliment your flash tune....

which one did you buy the process west one is BIGGER than the stock one ,Kev doesn't waste time making things that are of no benefit.

to the O/P you might be able too prove this one way or another if when you have both out of the car fill them with liquid and see wich one holds more volume.

Edited 09/11/10 09:28 AM by our06t

[Stazza_Brendan]

That wouldn't work unless both followed exactly the same path.. Which none of the aftermarket ones do from looking at pics.

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[Smoke them tyres]

The Process West one (or any UBP) won't increase the full boost level...that's the job of the wastegate to limit maximum boost.

But it will help reduce the additional "load" the turbo has to generate to push airflow through to the engine. It may only be a 5-6psi maximum, but what does the turbo have to generate with all those std restrictions? Extra load on the turbo = more backpressure = slower response and less power.

The boost level is only half the story. If you can get more airflow for the same boost level, it stands to reason that the engine will make more power with that increased airflow.

I chose the PW one and have to say it is the biggest that can physically fit in there. Kev makes well engineered top notch stuff and this is the one I would buy again. The engine response was better and made slightly more full throttle power for the same boost.

The PW one just plain works (and other good ones will also).

[Redback]

Under standard boost on the road you will feel no difference what so ever!

[FAST-XR]

which one did you buy the process west one is BIGGER than the stock one ,Kev doesn't waste time making things that are of no benefit.

to the O/P you might be able too prove this one way or another if when you have both out of the car fill them with liquid and see wich one holds more volume.

whats the point of increasing the pipe size when all of the std pipe work after the UBP is still 2.25"? the one I used was 2.25", not 2.5" like process west...

its not about volume, its about restrictions in diametre, and there are none in the standard pipe, cut one up and measure for yourself. it may Look bad from the outside, but its not a problem... internally its a smooth shape transition

if you already have a cooler and are looking to get a tune, your better off throwing that cash at a high flow cat ( now that will help you make more power off less boost, compared to an UBP which is a marginal gain at best)

[Stazza_Brendan]

Hmmm im gonna go with getting one, was going to do cat and injectors anyway and hell, my brother is buying the pipe not me . I will do some back to back on the road testing. Wont expect huge gains as only stock tune but ill see if I can get a difference in 0-100 times using my OBD2 logger.