Benefits of TT pistons - NA-T

A question to all you NA-T'ers. What would be the advantage of replacing the NA pistons with TT ones? what would this achieve? I know it means i can run more boost...anything else? also what else would i need to change them over?

Thanks

There are two basic ways to reduce the compression on a 2JZGE engine when you go NA-T. Either you can change the headgasket for the thicker TT version (reduces CR from 10.0:1 to 9.2:1. Or you can change the pistons as you describe, reduces CR from 10.0:1 to 9.0:1.

AFAIK the advantage of changing pistons is that the squish in the area around the top of the piston stays at the stock distance (stock is 1.14mm). If you change the head gasket instead of the pistons then the squish distance increases to 2.15mm. The squish area forces the mixture into the centre of the combustion chamber and towards the plug so (within reason) the smaller the squish distance the better and more complete the combustion.

There is a counter argument which says that you will get slightly better response with the slightly higher compression when just using the TT gasket.

There's not that much difference in the amount of boost the two options will take with good road fuel. 1.8 bar if you change the gasket as against 2.0 bar if you change the pistons and both of these will give you 650+HP capabilities.

Of course it's a lot cheaper to change the headgasket so ultimately you pays your money and you takes your choice.

Brilliant, thanks for the reply dude. If i change the pistons, do i have to change to a TT headgasket too?

Brilliant, thanks for the reply dude. If i change the pistons, do i have to change to a TT headgasket too?

No if you fit tt pistons then you fit a n/a head gasket

No if you fit tt pistons then you fit a n/a head gasket

Ah i see, so its one or the other. What would you go for? any particular reason?

Brilliant, thanks for the reply dude. If i change the pistons, do i have to change to a TT headgasket too?

If you change both you will drop the CR down to 8.1:1 which will give a huge power capacity (more than the bottom end can take) but will increase lag.

Dont want lag now do we! Are you doing an NA-T as well?

Ah i see, so its one or the other. What would you go for? any particular reason?

If it was me I would go for TT pistons over the head gasket as have stronger block and the squish effect

Dont want lag now do we! Are you doing an NA-T as well?

Yes, I'm going NA-T on a 2JZGE but the engine is in a Soarer. My turbo is a Borg Warner S360 configured for the NA-T by Whifbitz and (at least to begin with) I'm going at stock 10:1 compression. After a bit of fun with that I'll decide whether to change the headgasket or the pistons.

TT pistons keep the squish band, which certainly helps guard against detonation. If you run an N/A gasket you keep a very nice compression ratio. I have 2 N/A gaskets and one TT one at the price I mentioned.