Boost Behaviour

[AlfaJack]

Hi, I was doing some "boost testing" last night and I noticed the following readings.

1st Gear - 0.7 Bar
2nd Gear - 0.7 Bar
3rd Gear - 0.9 Bar
4th Gear - 1.1 Bar
5th Gear - 1.3 Bar

My car is a standard engine and turbo, with K&N panel filter and a Squadra chip.

I was testing by running the engine at 2000RPM in each of the above gears - not changing up or down to get more speed - just let it run from 2000 to 6500RPM - throttle fully open.

Then I did another test of running it fast as possible through gears 2, 3 and 4 - I did not get more than 0.7 on any - even on the longer run all the way through 3 then up to 4.

I believe its how the car is intended and not any fault, but why wouldnt it deliver the full boost that I know is possible in that gear?


EDIT - Perhaps I am answering my own question (just read the "ignition cut " thread more carefully) - maybe I get higher boost when going from slow to fast in one gear because the ECU can sense a higher load on the engine...

[cuore_sportivo_155]

if you go fast through the gears, the turbo speed and thus pressure is always catching up with engine rpm.

In a high gear and from low rpm it takes quite a while for the engine to reach redline, and thus the turbo can keep up.

Smaller turbo's would perform better in the first case, large turbo's in the second...