RB26 vs RB30 crankshafts

[Predator1]

2 minutes ago, BK said:

Yeah I know Nitto "rate" the 3.2 to 10000rpm and they "rate" the 2.8 to 11000rpm. As my 2.8 crank came from them with test results balanced up to a confirmed 10000rpm, I bet the 3.2 is only "tested" before delivery to 9000rpm to be safe, knowing realistically no one is spinning a 3.2 past 9k and a 2.8 past 10k.

Did you pay extra for it? I have a 3.2 but i didnt receive such a report.

[BK]

Yeah ? I have purchased 2 Nitto 2.8 stroker kits before and both were included with them from Nitto. 1st crank went to Rick Corbett engineering in Adelaide and 2nd crank went to CRD and whoever they use for machine work to double check Nitto reports. I'll dig up one from Nitto.

[GTSBoy]

There's a big difference between spinning a crank up to high rpm bare (without actual engine loads, ie combustion) and using it at the same rpm making a lot of power. There's a certain sized grain of salt required when looking at a balancing report that says the crank was spun to X rpm. Sure, it was fine under those conditions, but add the reciprocating loads up and down the conrods onto the journals and it is suddenly not the same as spinning it from one end.

[BK]

Absolutely, but what else can you go off ? The fact the pretesting is not done right up to claimed max rpm is more realistic real world documentation. I wonder how Nitto is coming to the conclusion of their max rpm and power limits then ? Probably just estimates / calculated guess ? Anyway its proven to be pretty good gear, and more than adequate for what 99% of people are going to throw at it.

[DaymoR32]

Theres some intersting discussion in this video about high RPM & horesepower applications and the issues they faced during development