Head gasket on RB25

[grepin]

OK I did a search to see what has been said before. I noticed a lot of people where going to fit a Head gasket. I am interested in the outcome. Is it really required if running 1.2 bar boost out of an upgraded turbo?

[Sydneykid]

Hi grepin, simply put, no it's not necessary. In fact I don't think it is ever necessary.

Hope that helps

[Guest Master of Disaster]

i hear this too - if your gonna run over 1 bar you need to drop the compression, if not need, then at least for a valuable safety measure.

Sydneykid, what boost levels have you seen reliably pumped into a 9:1 RB25 engine (Std pistons)? What can they handle? Would you say it just takes a good tuner to get it to run at over 1 bar without detonation? (with an upgrade non ceramic turbo of course)

Cheers, MASTER

[Sydneykid]

Hi Master of Disaster, we have run up to 1.5 bar on RB's with 9 to 1 compression ratios and standard pistons. The RB30/26 circuit race engine runs 9.1 to 1 with JE forged pistons and 1.8 bar is no problem.

Of course we don't have to run this much boost to make the power. The R34 with RB25DET makes 250 rwkw at 1.3 bar and 9 to 1 compresion ratio.

Boost is basically irrelevant when determining which turbo, it is the airflow that the turbo can support that makes the power. As I said before it is simply not necessary to run high boost levels with the current generation of turbos.

Hope that helps clarify.