turbo 986?

[Jaxonalden]

I think the compression ratio is way too high for forced induction.

[Kenny Boxster]

Originally Posted by Jaxonalden

I think the compression ratio is way too high for forced induction.

Adds another challenge to forced induction. Most of the people that did any forced induction ran 4-6 psi.

[reiver]

Originally Posted by Kenny Boxster

Adds another challenge to forced induction. Most of the people that did any forced induction ran 4-6 psi.

Why not change compression ratio? I am not looking at it due to possible heat and space issues in the Boxster.

[BYprodriver]

Originally Posted by reiver

Why not change compression ratio? I am not looking at it due to possible heat and space issues in the Boxster.

The proper way to add forced induction is to 1STinstall cylinder sleeves & stronger pistons that also lower compression. This requires total engine disassembly, so basically you need to rebuild the engine, while you are "in there". This will cost $10,K+. Naturally you will want to start with a 3.2L+ engine for max power, so now you have 300+HP & 280+ ft/lbs torque with is plenty for any 3000lb street driven car.
Now if you want to add power,complexity,heat,cost & lower reliability to your car forced induction is the next step.

[JFP in PA]

Originally Posted by BYprodriver

The proper way to add forced induction is to 1STinstall cylinder sleeves & stronger pistons that also lower compression. This requires total engine disassembly, so basically you need to rebuild the engine, while you are "in there". This will cost $10,K+. Naturally you will want to start with a 3.2L+ engine for max power, so now you have 300+HP & 280+ ft/lbs torque with is plenty for any 3000lb street driven car.
Now if you want to add power,complexity,heat,cost & lower reliability to your car forced induction is the next step.

Plus you are going to need cams ground to a lobe profile designed for forced induction, and a reprogrammed DME for the same reasons.

The OEM engines are not designed for the kind of cylinder pressures that either a blower or a turbo create, even at low boost levels.

[Perfectlap]

Originally Posted by JFP in PA

The OEM engines are not designed for the kind of cylinder pressures that either a blower or a turbo create, even at low boost levels.

Is this true of all m96/97 non-GT3 engines?

[BYprodriver]

Yes all M96 are at least 11:1 & a engine designed for forced induction like a 996tt has 9.6:1 or less.

[reiver]

Originally Posted by BYprodriver

The proper way to add forced induction is to 1STinstall cylinder sleeves & stronger pistons that also lower compression. This requires total engine disassembly, so basically you need to rebuild the engine, while you are "in there". This will cost $10,K+. Naturally you will want to start with a 3.2L+ engine for max power, so now you have 300+HP & 280+ ft/lbs torque with is plenty for any 3000lb street driven car.
Now if you want to add power,complexity,heat,cost & lower reliability to your car forced induction is the next step.

It's not this complicated in the 350Z (needs forged/built internals for 500+ WHP) or BMW (up to 350WHP on a 325Ci). Neither requires internal work until that point. I am not familiar with the boxster enough to attempt it and worry enough about IMS failure as it is without pushing my luck. The engines for the other 2 are probably a lot cheaper to replace without going to a junk yard/part out resource. If I was going for pure power, I would have bought something else. The Boxster has the fun factor and I'm ok with the lower amount of power until I get used to having the engine behind me. I've only owned mine for a month and have little experience with Porsche, but have worked with the 4 cyl flat engines out of the Subbies that have lower compression.