Low Compression Pistons

[Mountaintech]

The stock Yamaha gaskets are about .025" thick. The thick Cometic gasket is.067" thick and the thinner Cometic gasket supplied with the Wiseco piston kit SK1334 is .027" thick.

 

[spray25]

I thought someone said that Wiseco was no longer including a gasket in there kit?

 

[Mountaintech]

That was me that you heard that from because that is exactly what Wiseco told me about a month ago. So I ordered my piston kit and guess what shows up with them? A .027" Cometic gasket!

 

[Buckeye]

I measured the Commetic gasket I put in mine and I am pretty sure it was .057" thick.

 

[spray25]

Uncle Buck I think you have an extra 0 in there. 57/10,000 would be awefully thin.

 

[Buckeye]

You are right! It should be .057 :shock:

 

[joerocket107]

lets c now

what do I need to do, to run around 300 hp? 10 to 1 pistons? and which gasket should I use. I would still like to run on pump gas if at all possible.

MC told me I could run pump gas with the low compression pistons.

They also told me that the rods are good for 300 + HP.

Does this sound correct?

 

[Buckeye]

If you are looking to make 300 hp, you should install the stronger rods. I don't think you should be using pump gas at that boost level. If you install the thicker gasket with low compression pistons, you will be able to run more boost on pump gas than with the stock gasket. The combo of pistons and thicker gasket should put you about 9 to 1. I have not talked to anyone that has run this combo yet. This is basically the second year of RX-1 turbos, so I am sure alot more info will be available after this winter.
My plan is to run both the .057 gasket with the 10 to 1 pistons and Carillo rods. I like the ability to be able run 18 pounds of boost.

 

[joerocket107]

Thanks

 

[ken_climb]

Joe rocket,I personally would wait a year try it with the thicker gasket .At 10-11lb's boost I think you will be more than impressed! These rear mounts have some lag already and I know of one guy who installed low compression pistons with a rear mount and the lag effect seemed to get significantly worse,mind you when it did kick in it was still the fastest sled in the west.You could always add a little race fuel for some extra boost!

 

[Buckeye]

I don't believe dropping the compression ratio 1 point would have any impact on lag. Lag is a result of building boost pressure, not compression ratio.

 

[joerocket107]

pistons and rods

Buckeye have u installed your pistons and rods yet? How big of a job was it? How long did it take. Thanks Just waiting for my 05 sled to come in.

 

[Buckeye]

No I have not. I will be starting that project after Columbus Day. It is a major Project. There is alot to take apart and put back together.

 

[joerocket107]

Yes there is. I will be starting mine when I receive my 05 sled if they ever get here.

 

[ken_climb]

I don't believe dropping the compression ratio 1 point would have any impact on lag. Lag is a result of building boost pressure, not compression ratio.

OK don't call it extra lag then call it "extra doggy"off the start.