1 bar boost afr's on stock ecu..rich or lean - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

n boost · 26th July 2008, 03:35 AM

What afr' do gtr r33 nomally run @1 bar on stock ecu?
Checked mine with my lm-2 and am getting low 12's 4-6000 rpm range and 11.6/5 between 6-8000 rpm.
I thought gtr normally run rich at 1 bar. I think i might have a remapped ecu if they are supposed to run rich but there are no stickers on the ecu and car was virtually stock when i bought it.
Would u guys consider low to mid 12's as lean if you got no det and running on 99 oct v-power?

Steve@React · 26th July 2008, 07:04 AM

That is running rich, lower than 14.7:1 (stoichiometric) is rich & anything higher than that is lean

As far as I know the stock ECU will run 1 bar but will over fuel like mad, that's why you can see some large power/torque improvements after a dedicated remap.

n boost · 26th July 2008, 02:09 PM

At full load if i was in the high 10's then i would consider that to be rich but obviously i am getting low/mid 12's under boost midrange and only dips into mid 11's after 6k rpm which i consider to be bordeline on the lean side and idle is 15.2/3 afr.
so am just trying to find out if this is normal for a stock ecu as my deffo aint overfuelling.
Trying to justify a remap but if afr's are acceptable and no det then how much extra hp can i gain and also my stock injectors are at 85% duty cycle so not much left in them.

Sidious · 26th July 2008, 02:23 PM

The fueling is perfect for a turbo car, leave it well alone, the ECU map on the RB26 and a few other Japanese turbocharged cars were setup to work best on 100 RON petrol even on stock boost.

It is not uncommon for other turbo cars run ratios of 10:1 and under with stock configuration as the RPMS rise.

UKPAISLEY · 26th July 2008, 05:46 PM

The a/r is ok, its the ig time and the Knock I would be worried about.

n boost · 26th July 2008, 07:34 PM

Quote:

Originally Posted by Sidious

The fueling is perfect for a turbo car, leave it well alone, the ECU map on the RB26 and a few other Japanese turbocharged cars were setup to work best on 100 RON petrol even on stock boost.

It is not uncommon for other turbo cars run ratios of 10:1 and under with stock configuration as the RPMS rise.

That's what i thought but wanted to make sure. If i richened the mixture then i would probably lose some hp as well, so reckon if it is safe at this afr then i will leave it alone.
i know some people run mid to high 12 afrs without any probs but uk cars are mainly mapped around the low to mid 11's on full boost.
I didn't pick up any det so should be o.k, but will double check for knock.

26th July 2008, 03:35 AM	#1 (permalink)
n boost GTR Register Member Join Date: Jun 2008 Location: birmingham Posts: 170	1 bar boost afr's on stock ecu..rich or lean What afr' do gtr r33 nomally run @1 bar on stock ecu? Checked mine with my lm-2 and am getting low 12's 4-6000 rpm range and 11.6/5 between 6-8000 rpm. I thought gtr normally run rich at 1 bar. I think i might have a remapped ecu if they are supposed to run rich but there are no stickers on the ecu and car was virtually stock when i bought it. Would u guys consider low to mid 12's as lean if you got no det and running on 99 oct v-power? Last edited by n boost; 26th July 2008 at 03:39 AM.

26th July 2008, 02:23 PM	#4 (permalink)
Sidious GTR Register Member Join Date: Jul 2006 Location: S.E London Posts: 529	The fueling is perfect for a turbo car, leave it well alone, the ECU map on the RB26 and a few other Japanese turbocharged cars were setup to work best on 100 RON petrol even on stock boost. It is not uncommon for other turbo cars run ratios of 10:1 and under with stock configuration as the RPMS rise. __________________ . The ridge ricer Last edited by Sidious; 26th July 2008 at 02:25 PM.

26th July 2008, 05:46 PM	#5 (permalink)
UKPAISLEY GTR Register Member Join Date: Jan 2003 Location: NORTH EAST Posts: 281	The a/r is ok, its the ig time and the Knock I would be worried about. __________________ DP

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26th July 2008, 07:04 AM	#2 (permalink)
Steve@React GTROC Member Join Date: May 2006 Location: West Yorkshire Posts: 181	That is running rich, lower than 14.7:1 (stoichiometric) is rich & anything higher than that is lean As far as I know the stock ECU will run 1 bar but will over fuel like mad, that's why you can see some large power/torque improvements after a dedicated remap.

26th July 2008, 02:09 PM	#3 (permalink)
n boost GTR Register Member Join Date: Jun 2008 Location: birmingham Posts: 170	At full load if i was in the high 10's then i would consider that to be rich but obviously i am getting low/mid 12's under boost midrange and only dips into mid 11's after 6k rpm which i consider to be bordeline on the lean side and idle is 15.2/3 afr. so am just trying to find out if this is normal for a stock ecu as my deffo aint overfuelling. Trying to justify a remap but if afr's are acceptable and no det then how much extra hp can i gain and also my stock injectors are at 85% duty cycle so not much left in them.