Help!

I've recently replaced the standard up pipe for a 2.5 inch bore on my 1995 RA. Will this effect the boost and power, should go back to a 2 inch bore?

Can anyone dispel this myth for me,

Thanks - adb2227

 

For any given volume of gas, if travelling through a smaller bore than a larger one, then it would travel faster (think of what happens to the speed of the water when clamping the end of a hosepipe with your fingers a bit...). So this means the turbo's turbine will spool quicker, thus making boost quicker.

Only unless your engine is flowing really massive amounts of air, then a smaller diameter up-pipe could back-up the gases, thus stalling the turbine.

So I'm sure for most 'street' levels of tune, the 2" up-pipe will give you quicker spool than a 2.5" one(?)...

 

Makes sense!

That's great, thanks for your help.