Maximum Boost for a 951

[arnebret]

Hiya,

Anybody got any ideas about the maximum boost a 951 can handle. Of course, pushing it up to crazy values like 3 bar will certainly kill the engine. But how about upgrading from the standard 1.8 tot 2.2 or so. Of course, those high values must only be used small periods of time (like a race). For normal street use 1.8 is enough.

With a special headgasket values of about 2.2-2.5 bar must be do-able... but does this increase HP that much that it's worth it?

[Scott R]

O-ring the head. That will get 2.2 to 2.5. Couple that with a widefire headgasket and you should be ok. You should ask Wolfpri his old 951 had major boost, with the modifications to make it work.

[Lawrence Coppari]

Just got finished with a small upgrade. I increased the size of the boost tubes and reamed throttle body. Acceleration from 70-100 (full boost) dropped from 4.51 seconds to 4.35.

Then I installed the new boost metering jet that changed boost from 1.0 bar to 1.1 bar. Same test improved acceleration from 4.35 to 4.15 seconds.

Your test may vary depending on tire size, etc, etc. All testing was done at nearly 50 F. So you can see what 0.1 bar does on my car.