Should I Go Forged Rods?

[stunnd]

hey guys, johns managed to find me an r34 crank from japan so there goes that problem (knock on wood) but now decidin whether or not i should stick with stock rods or forged 1's, he said he can get me forged 1's for bout another $1000, wat do u guys think? thanks, an sorry 2 keep askin q's but much appreciated...

[Bluprint]

Viet I wouldn't bother with changing the rods, GT-R rods are pretty bloody strong, yours will be fine providing John checks them for cracks & integrity, straightness and balancing and makes sure they're all ok. If they turn out to be cracked or bent then yeah you're going to have to replace them then you might as well upgrade them.

[stunnd]

hey mark, no worries....il get him 2 check 1st....

[Scooby]

depends on the power you want. correctly prepped rods will be good for significant power ie from memory around 350 awkw. i'm pretty sure a local GTR was making damn good power on prepped standard rods.

however, if your budget can stretch to it then by all means go forged.

[Imtorqing]

I went to Predator Motorsport before I undertook my rebuild and they had a skyline in the shop there that was running standard rods and pushing some series numbers. They used it for their track car and he said they flogg the crap out of it and despite what everyone had said they were going just fine.

Mind you I would take the advice that bluprint was saying have them tested and balanced right.

My 2cents

Cheers

Imtorqing

[Amaru]

As I said in your other thread I was making well over 300kw on standard prepped rods for quite some time (shot peened, balanced). They are a strong rod, the weakest point is the rod bolts. Put a set of ARP 2000 rod bolts in it and it will be good... just dont think of revving it over the standard 8250rpm limit. You can pick up a set of forged Eagle (H-beam rods I think) for well under $1000 now, so its cheap insurance (you have to keep in mind the standard rods were only intended to support the factory 180ish-rwkw while the Eagles are intended for much higher hp applications).

How much did you pay for the crank if you dont mind me asking? I personally wouldnt have gone for it, as it costs stuff all to get your current crank crack tested and reground if needed... you could then put the other few thousand $$'s you would have saved to some other stuff, like new turbos or camshafts or something. Just my opinion though

[Scooby]

As I said in your other thread I was making well over 300kw on standard prepped rods for quite some time (shot peened, balanced).

speak of the devil...

[stunnd]

hi amaru, im payin bout 1200ish for the crank...supposedly its brand new from japan....yeh he's usin arp bolts...

yeh ive got a couple of garrett gt2860r -5's to put on...

yeh i no its a smarter/cheaper move if i do the r32 crank but its jus the fact that its a new crank that gets me...but then again i should b listenin 2 u guys kos u guys no wat ur talkin bout an then il actually start saving some money...

[Amaru]

The cranks are hardened steel... you have to screw up in a big way to damage them. I would get your current crank checked before spending $1200 on a "new" one. The reason I say "new" is because they cost a hell of alot more than that from Nissan brand new... and as I have said, there is no stock in Australia or Japan availible from any official Nissan outlet.

If your current crank is ok, get it reground throw in some undersize bearings and spend the $1200 on a set of Tomei Poncams. I was running similar size turbos to yours (HKS GT2530's) and the poncams changed the whole car... best $$ I have ever spent on it.

My rebuild list for what you are after would consist of the following:

Standard crank crack tested, reground (if needed) with King bearings (dont use the Nismo/NDC bearings... they are a tri-metal bearing and the first layer started to delaminate on mine after a measy 10,000kms). Pro Engines JUN style crank collar fitted.

Eagle conrods with ARP 2000 rod bolts (they will only cost ~$300 more than getting your standard rods prepped)

Arias forged pistons (86.5mm so you can overbore and re-hone so its all nice and shiny and fresh)

Standard water pump, N1 oil pump, oil restrictor for oil feed to the head, enlargement of oil return galleries from the head, Pro Engines JUN style sump baffles, and a bit of a port/polish job just to clean up the head.

Thats just me though, and im sure your engine builder has probably reccomended along the same lines... I was just a bit shocked about the "crank might be cracked" comment when its a dead easy job to crack test them and save you money that can go towards other things.

Whichever way you go, dont forget the oil restrictor for the head and the sump baffles. Grab a Tomei gasket kit (comes with all the gaskets for your engine) which also comes with the restrictor. The kit is pretty cheap and really good value.