[aaron_bc]

Hey guys, dropping in from Canada and have a few questions.


I am currently heading up a rebuild on an R34 NUR block I built last year currently in an R32. I have located a few options when it comes to pistons and wanted some real first hand information.

Backstory on the block, is the N1 pump blew and pistons 1 and 6 melted.

Before the block blew, it was tuned reliably to 575AWHP at 1.8BAR with 700cc SARD injectors at 100% duty cycle. The tuning was done by Eric Hsu at XS Engineering in California.


Old block specs were

-Brand new R34 NUR block
-ARP head studs
-ATI race damper
-GT2860r-5's
-TOMEI con-rod bolts
-TOMEI 1.2MM HG
-TOMEI manifolds and dumps
-TOMEI Type B poncams
-PowerFC ECU


I will be using the following to rebuild the block.

-current NUR con-rods
-TOMEI con-rod bolts
-TOMEI oil pump
-TOMEI 1.2mm HG kit (with intake and exhst gaskets)
-ARP head studs
-SARD 1000cc injectors

Right now I am deciding the TOMEI pistons and the HKS pistons. The HKS pistons a fair bit cheaper. Also, what pros are there to get the titanium coated option (available on both Tomei and HKS).

I want to build this block to handle over 600AWHP reliably, which I don't see being a problem looking at the prior build specs and what it put out on the stock cast NUR pistons.

Thanks!

 

[aaron_bc]

I find it hard to belive that no one has experience with either?

Lets hear some numbers of what your engine achived along with what supporting internal parts/modifications you did!

 

[Thrust]

If you've got the money, go for the Tomei internals.

 

[aaron_bc]

Any reason in particular? I know TOMEI makes great products which is why I am using thier oil pump, gasket kit and rod bolts, but is there a reason they are better than the HKS?

Money is not really an issue... well it is but isn't. I have done a few builds in the past and "skimped" when it came to parts and it ended up costing me more in the end to redo it (take this for example, using the N1 pump that came with my NUR block instead of upgrading, and ended up melting two pistons and have to rebuild the whole thing).

 

[Chris Wilson]

If the budget allows, and we are talking off the shelf pistons, not bespoke, go for the Tomei oil gallery pistons, they take a lot of thermal stress from the rings and ring lands, and that is GOOD NEWS on any high power turbo engine. It's also quite a nice light forging. Ti coated rings have less friction, and wear better than a plain or chrome plated ring. They do demand a round bore with a decent cross hatch hone, with a plateau finish to bed properly though. At the cheap end of the spectrum I get good results from Wiseco pistons in many turbo engines. A meaningful assessment should take material spec, with expansion and strength paramount at elevated temperatures, weight (which is usually based on the piston coming from a sensible, and not just a generic, forging). It's hard to correlate all this, and for most it's adequate to follow a tested route. Given an unlimited budget the likes of Omega or Engine Developments can do bespoke pistons to die for, weight and performance wise, both from beautiful forgings, or from billet, but the gains in an engine that's probably got pretty unstable bores may be perceived rather than actual I can't get any Mugen MF-308 pistons for my F3000 engine, so ED are making some from billet. It's not something you want to get into unless forced by special needs or total lack of availability of something off the shelf, it's fearsomely expensive for one off or small batches, as well as slow.

 

[Irish GTR]

Wosner are a very good piston and a very good buy.Allways available too.

 

[james1067906]

both are good brands and make fantastic products, but if you own a nissan and tomei make the part, for me they are always the way to go if you are going for japanese brands

 

[AVUS Motorsport]

If money is no problem go for the Tomei Forged Pistons with Oil Cooling Channel.