FI s2k= Transmission upgrade?

**AusS2000** · 08-09-2011 12:25 AM

Hmm, you want me to tell you my story yet you don't want to be talked out of an SC? :P

I bought a stock Comptech kit but quickly upgraded to 440cc injectors, AEM ECU and downsized my pulley. I also installed the aftercooler kit. i was then running 8.4psi. That's about 5psi at VTEC changeover point. I dyno'd at 217kw.

I then went turbo. At first I was running off the wastegate spring so 7psi. I dyno'd at 214Kw.

But that doesn't tell the whole story. With the turbo I was at 7psi by about 3000rpm. The midrange was there on tap whenever I wanted it. The area under the curve is much fatter.

PS> I'm now running 22psi. Not sure when it hits max boost. I'm too busy watching the road.

**chriis2k** · 08-09-2011 07:31 AM

Hahahaha that's mad, 22psi!? Have you rebuilt your engine!? I thought the stock block can only handle 14psi..

**AusS2000** · 08-09-2011 09:14 AM

That 14psi limit is because of the high compression ratio, not the strength of other components. I have a decompression head gasket but apart from that my engine is stock.

**chriis2k** · 08-09-2011 11:20 AM

Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhkay lol The amount of questions i have in my head right now is endless :P
One more question but !! (please don't hit me lol)
what's the negatives involved in lowering the compression??

**AusS2000** · 08-09-2011 11:30 AM

The proper way to lower compression is with low compression pistons, but this is a lot of work. Basically an engine rebuild.

You can lower compression with a thicker head gasket. Opinions vary about their reliability. I went through a few of them but that was a tuning issue. Now that the tuning is right the current 2.4mm SCE copper gasket is holding fine.

**VeYzZii** · 08-09-2011 07:49 PM

Originally Posted by AusS2000

The proper way to lower compression is with low compression pistons, but this is a lot of work. Basically an engine rebuild.

You can lower compression with a thicker head gasket. Opinions vary about their reliability. I went through a few of them but that was a tuning issue. Now that the tuning is right the current 2.4mm SCE copper gasket is holding fine.

Ya. Low comp. pistons would be expensive, but AUS with 22 PSI why dont you get the pistons and do a rebuild at the same time, for peace of mind? Arent you scared something may go wrong?

**AusS2000** · 08-09-2011 08:20 PM

I have all the parts for a low comp engine (bored and honed block, crank, rods and Woessner low comp pistons) in my workshop. Just haven't got around, and haven't had a need, to put it together.

With a good tune it's surprising how much the F20C can take.

**VeYzZii** · 08-09-2011 09:44 PM

Originally Posted by AusS2000

I have all the parts for a low comp engine (bored and honed block, crank, rods and Woessner low comp pistons) in my workshop. Just haven't got around, and haven't had a need, to put it together.

With a good tune it's surprising how much the F20C can take.

For sale...?

**AusS2000** · 08-09-2011 09:58 PM

Afraid not.

**chriis2k** · 08-09-2011 10:01 PM

If it is.. SHOTTY !

**ludecrs** · 09-09-2011 01:30 PM

Originally Posted by AusS2000

You can downsize pulleys for more boost but will eventually go outside the efficiency envelope of the blower and then you're just producing heat. You then have to upsize the SC. Then after you upsize the SC again and it still isn't producing any more power you do a slow part out.

Don't make me ban you...