turbos and high compression??

**MRJDM** · 17-09-2004 11:28 AM

can some some tell me why turbos dont like high compression. cos isnt a turbo charged car essentially a bloody high compression motor??

**tinkerbell** · 17-09-2004 11:42 AM

yes, it is a bloody high compression motor, and therein is the answer! you are doubling the compression, which would be bad.

you have either one or the other, high compression with no turbo or low compression with turbo

this is the most simplistic way to look at it

(the compression ratio will determin how the car drives off boost...)

**tinkerbell** · 17-09-2004 11:43 AM

oh and the reason why is because high compression plus turbo is very hard to get good reliable power due to the amount of timing you have to take out to get it NOT to detonate or ping...

**pornstar** · 17-09-2004 01:21 PM

Originally Posted by tinkerbell

oh and the reason why is because high compression plus turbo is very hard to get good reliable power due to the amount of timing you have to take out to get it NOT to detonate or ping...

**tinkerbell** · 17-09-2004 01:35 PM

the higher the combined compression ratio:

the less timing you can run...

or,

the higher octane fuel you need...

otherwise there will be pinging, knock or detonation.

**tinkerbell** · 17-09-2004 01:41 PM

this is why ITR's with turbos rarely run more than 7-10psi on stock internals...

**vtml** · 17-09-2004 03:47 PM

Tuning window is smaller on a hi comp engine as compared to low comp engine.

**SiR JDM** · 20-09-2004 04:46 PM

very informative tinkerbell, ive learnt a bit

wat would u think about b16a then.. if i were to ever consider turboing it..
its got a compression of 10.4 ...?

**2ds** · 20-09-2004 05:10 PM

no problems, you just can't run too many psi on stock internals (as tink said before)

-2ds

**poid** · 20-09-2004 05:38 PM

Sir JDM you just have to be a little more careful with the tuning

**tinkerbell** · 20-09-2004 06:42 PM

Originally Posted by Sir JDM

very informative tinkerbell, ive learnt a bit

wat would u think about b16a then.. if i were to ever consider turboing it..
its got a compression of 10.4 ...?

yes - very good engine to turbo charge.

as long as boost is kept below about 8psi and you can tune it with aftermarket ECU (or piggyback if desperate)

you can get thicker headgaskets (eg 2mm) that reduce the compression to around 8 or 9:1 - or you could install lower compression pistons along with forged rods for extra strength - then boost it a LOT! (se BLKCRX's 400kw for example)

i have been informed that 130 - 150kw ATW is attainable on a stock B16A with turbo and proper engine management, probably able push it higher (but with greater risk of damage)

i have never done this so am only refering to discussions that i have had (when i was considering turboing my B16A)

i learnt lots from honda-tech.com boosted forums too