Tuning a NUR - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

Bateman · 9th August 2006, 06:58 PM

I´m under the impression that a standard R34 GTR shouldnt be tuned above 600hp to maintain reliability, but it should be different with a NUR engine, right?
Is 700hp ok for a NUR on low miles?

Cheers

ANDY H · 9th August 2006, 07:07 PM

NO! the con rods are the same as a standard rb26 so the same bhp ,600 is a bit high 550 will be good!

Bateman · 10th August 2006, 09:44 AM

Quote:

Originally Posted by ANDY H

NO! the con rods are the same as a standard rb26 so the same bhp ,600 is a bit high 550 will be good!

So the rods are the weakest point in the RB26!?
I thought they could hold some serious power accually..

ANDY H · 10th August 2006, 06:40 PM

Is 550bhp not serious power for a production engine then!

Bateman · 10th August 2006, 09:51 PM

Quote:

Originally Posted by ANDY H

Is 550bhp not serious power for a production engine then!

Yes it is!!
But isnt there some people that tune their engines way past 550bhp on factory bottom end and it last for quite some time!?
If so, how come the con rods last in these engines?
I mean they shouldnt wear down really, they should just break at a certain power lvl, right?

Just some thoughts.

ANDY H · 10th August 2006, 10:05 PM

The rods and the pistons are the weak link ! 550 bhp is a safe ish power to run on standard rods maybe other people do run higher hp but for how long before they go bang.

R33_GTS-t · 10th August 2006, 10:13 PM

The crank isn't fully balanced on the standard engines or the N1s. This plays a factor in conrod deaths.

Strangely, there's a drag Sentra in the US running 1300bhp on a stock bottom end but it has uprated cooling and dry sump lubrication. Reliability is not black and white but very grey. Different people have different ideas of 'reliability'.

Again, in the US, I hear people saying that the stock Lotus Esprit transmission is good for 500+rwhp, and even statements by people who've ran it this way for 30,000 miles. Most UK tuners would say that the Esprit gearbox isn't even reliable with stock hp.

ANDY H · 10th August 2006, 10:38 PM

Put it this way nur's are like rocking horse s*** and theres no way i would put more than 550 bhp through mine ,that why ive got tomie rods and pistons! but the choice is yours!
and yes the crank and flywheel being balanced is the way forward as the standard items arnt that good.

RH9 · 11th August 2006, 03:57 AM

Standard conrods are fine to 700hp - prob to 750hp IMHO.

Its revving over 8000rpm that kills them and thats usually only due to the standard conrod bolts stretching.

I'm making 560hp at 4 wheels on a hub dyno so I guess i'm prob just shy of 700hp at the engine. Done 58,000kms on 1.6 bar without throwing a rod.

Also seen a 34 NUR tuned by the same chap who tuned mine - that make about 580hp at 4 wheels and runs stock bottom end. He's travelled around 15,000kms without incident.

I think a fresh R34 motor should have no problem making well over 600hp reliably if you keep rpm down and the tune detonation free

Bateman · 11th August 2006, 08:17 AM

Quote:

Originally Posted by RH9

Standard conrods are fine to 700hp - prob to 750hp IMHO.

Its revving over 8000rpm that kills them and thats usually only due to the standard conrod bolts stretching.

I'm making 560hp at 4 wheels on a hub dyno so I guess i'm prob just shy of 700hp at the engine. Done 58,000kms on 1.6 bar without throwing a rod.

Also seen a 34 NUR tuned by the same chap who tuned mine - that make about 580hp at 4 wheels and runs stock bottom end. He's travelled around 15,000kms without incident.

I think a fresh R34 motor should have no problem making well over 600hp reliably if you keep rpm down and the tune detonation free

Awesome numbers mate!!
What turbo/s are you running?

Thanx for your input guys!!

R33_GTS-t · 12th August 2006, 11:11 PM

Is 560bhp@hubs 700bhp@flywheel?

9th August 2006, 06:58 PM	#1 (permalink)
Bateman GTR Register Member Join Date: Dec 2003 Location: Sweden Posts: 17	Tuning a NUR I´m under the impression that a standard R34 GTR shouldnt be tuned above 600hp to maintain reliability, but it should be different with a NUR engine, right? Is 700hp ok for a NUR on low miles? Cheers

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9th August 2006, 07:07 PM	#2 (permalink)
ANDY H GTR Register Member Join Date: Mar 2005 Location: maidstone Posts: 1,240	NO! the con rods are the same as a standard rb26 so the same bhp ,600 is a bit high 550 will be good!

10th August 2006, 06:40 PM	#4 (permalink)
ANDY H GTR Register Member Join Date: Mar 2005 Location: maidstone Posts: 1,240	Is 550bhp not serious power for a production engine then!

10th August 2006, 10:05 PM	#6 (permalink)
ANDY H GTR Register Member Join Date: Mar 2005 Location: maidstone Posts: 1,240	The rods and the pistons are the weak link ! 550 bhp is a safe ish power to run on standard rods maybe other people do run higher hp but for how long before they go bang.

10th August 2006, 10:13 PM	#7 (permalink)
R33_GTS-t GTR Register Member Join Date: Apr 2005 Location: [510] days from disposing of Labour. BNFL are shit. One repossession, one (bank) window. Posts: 8,241	The crank isn't fully balanced on the standard engines or the N1s. This plays a factor in conrod deaths. Strangely, there's a drag Sentra in the US running 1300bhp on a stock bottom end but it has uprated cooling and dry sump lubrication. Reliability is not black and white but very grey. Different people have different ideas of 'reliability'. Again, in the US, I hear people saying that the stock Lotus Esprit transmission is good for 500+rwhp, and even statements by people who've ran it this way for 30,000 miles. Most UK tuners would say that the Esprit gearbox isn't even reliable with stock hp.

10th August 2006, 10:38 PM	#8 (permalink)
ANDY H GTR Register Member Join Date: Mar 2005 Location: maidstone Posts: 1,240	Put it this way nur's are like rocking horse s*** and theres no way i would put more than 550 bhp through mine ,that why ive got tomie rods and pistons! but the choice is yours! and yes the crank and flywheel being balanced is the way forward as the standard items arnt that good.

11th August 2006, 03:57 AM	#9 (permalink)
RH9 GTR Register Member Join Date: Jun 2003 Location: Auckland N.Z Posts: 85	Standard conrods are fine to 700hp - prob to 750hp IMHO. Its revving over 8000rpm that kills them and thats usually only due to the standard conrod bolts stretching. I'm making 560hp at 4 wheels on a hub dyno so I guess i'm prob just shy of 700hp at the engine. Done 58,000kms on 1.6 bar without throwing a rod. Also seen a 34 NUR tuned by the same chap who tuned mine - that make about 580hp at 4 wheels and runs stock bottom end. He's travelled around 15,000kms without incident. I think a fresh R34 motor should have no problem making well over 600hp reliably if you keep rpm down and the tune detonation free

12th August 2006, 11:11 PM	#11 (permalink)
R33_GTS-t GTR Register Member Join Date: Apr 2005 Location: [510] days from disposing of Labour. BNFL are shit. One repossession, one (bank) window. Posts: 8,241	Is 560bhp@hubs 700bhp@flywheel?