Vg30e build... Z32 TT pistons?

[Guest cypres]

Im going to be building my vg30e eventually and have read several times that the TT pistons can be used along with the TT rods. If I used these rods and pistons what type of compression ratio would it yeild? Im planning on turbo'ing this engine. First Im going to have some fun with the stock block and see what I can turn out from that.

 

Thanks,

 

Kirt

[260DET]

http://www.nissanperformancemag.com/february05/pathfinder/ and

http://www.z31.com/

 

Z31.com has some useful links too, let us know what you end up doing.

[mtcookson]

You can use the rods but the pistons would likely hurt you more than help out. The combustion chamber of the VG30E(T) is quite a bit larger than the VG30DE(TT). 55 for the E(T) vs. ~44 for the DE(TT).

 

The VG30DE pistons would probably do a bit better than the TT as they would come out to roughly 9:1 however they're designed for an engine with 4 valves and therefore has 4 reliefs for the valves. Since the sohc VG has 2 it normally has 2 reliefs (turbo models use a dish). I'm not sure... but there may or may not be interference with the reliefs.

 

You can actually get some custom pistons made by BRC (http://www.brcperformance.com) for very reasonable prices. Being that they've made some for the Z31 guys in the past there's a good chance they already have all the specs to make them pretty quickly. That would likely be your best alternative.

[Guest Jason84NA-T]

There is absolutely no point in swapping out your pistons and rods for Z32 units. The pistons are about the same except for the CR difference mtcookson noted based on the cc size. The Z32 rods are speculated to be slightly stronger, but the main reason people use them is for the larger (full floating) pin diameter. You can use stock rods and pistons at 400+rwhp with no problems if you don't let it detonate. This is what I have been doing for a long time...

 

It would be dumb to swap out parts for something equally as good (or bad). BRC does have the specs for SOHC VG pistons and they will make them in any CR and pin diameter you need for around $700 shipped. They come highly recommended from everyone I know who has done business with them.

[Guest cypres]

OK... all the talk on the z31 site is about using the z32 pistons because they are forged and all the internals swap. Stronger set up that yielded a lower compression ratio, exactly how low is not exactly known. Im thinking that the stock N/a internals will be good enough for awile until the rest of the car is done. I know that there are few cam options, but what do you guys like. I know I've seen like four or so... one was a "race only" setup supposedly because of streatablity issues. Thanks,

 

 

Kirt

[Guest Jason84NA-T]

Z32 and Z31 VG rods are both forged (DETT and ET respectively)

Z32 crank is forged, Z31 crank is cast.

The pistons in both are cast.

 

Hence, it would be a complete waste of time and money to swap the pistons and rods. The stock NA internals have been run at 400-500rwhp my quite a few people (myself included). Let it detonate AT ALL and you'll lose ring lands in a hurry though (ask me how I know). Much over 500whp and the same thing is reported to happen. You won't make that much power without at least light head work and cams though.

 

I have used schneider regrinds for my last 2 VG's and have liked the results. They have some pretty good grinds to select from, there is also other VG cam info on my website.

[mtcookson]

i made a mistake on the DE(TT) combustion chamber cc's. i believe its actually closer to 49.5 cc.

 

i believe you'd see roughly a .7 decrease in the compression ratio if you used a DE(TT) piston in a E(T). i'm not possitive but from what i've been able to add up that's roughly the difference.