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Boost taper over several gears


Old Sep 10, 2017, 10:44 AM
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Boost taper over several gears

Hi fellow RA owners! I have noticed something I find a little funny and strange... As I do a WOT pull, the boost pressure starts at 1.3 bar and tapers down to 0.8-0.9 bar at redline. The first explanation that comes to mind is that this happens as an effect of the turbo struggling to keep up with the engine, and is a normal thing.

What's strange is that keeping my foot down through 2-3 gears creates an effect where the boost never goes above the point to which it tapers to at redline. This is the same no matter if I change gear manually or automatically.

2nd gear = boost maxes at 1.3 bar and tapers to 1.0 bar.
3rd gear = boost hovers at 1.0. and tapers to 0.9.
4th gear = boost basically stuck at 0.9 bar.

What's funny is that if I were to do this changing gears manually and letting off the gas between gears, just like manual car, the behavior of boost building to 1.3 bar and tapering to 0.8 occurs on every gear.

Can someone explain this??

Bonus points to the one who can explain why the boost did not taper at all when I was using an AEM Cold Air Intake! :P

Last edited by robban87; Sep 15, 2017 at 02:56 AM.
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