Stock 1uz - MAP or MAF best?

[Rollux]

Hi all
Have a LN61 surf that I just got, running a link g3 ecu. Now it is running very rich and has been converted to a MAP sensor. Now I have no plans to modify the engine and am wondering if for economy and power it would be better to return it to a MAF setup or have it retuned with the MAP?
Apparently it is putting out 170rwkw, but it feels less and the way it runs is like it has too big a carb for the engine. (I know it is efi, just trying to give an idea how it runs)
Any thoughts appreciated, and I will get it tuned professionally again at some stage.

 

[gloverman]

Have it professionally tuned and it should make more power than stock management and you should get better fuel economy.

 

[Rollux]

Supposedly was professionally tuned in Tauranga, but by the way it runs at anything except WOT I'd say that's all they did - WOT.
So is MAP based tuning for NA still good? Or is MAF more accurate?

 

[gloverman]

MAP is fine for NA. There are alot of Factory engines which run MAP. There are plenty running MAF and some now that have both. It comes down to the tuning at the end of the day. Factory 1uz management runs very low AFR at WOT. Sometimes down as far as the 10's. This is where you make gains with aftermarket ECUs on these motors. A good tuner with a crappy ECU will still get a better job than a crappy tuner with a good ECU. Its nrmally pretty easy to work out what sort of tuner has been working on a vehicle. Looking at the map for both timing and fuel a good tuner will have tuned all the load zones , including the ones which are hard to get to. The extras like air temp correction and water temp correction will be one and working and most of the time lambda will be on and working. Idle will be working correctly and cold start will be nice. Installation of the ECU will also make a big difference. If the load zones can be changed then on an N/a vehicle the boost zones will have been rescaled to be vaccuum zones. And with every tune it is possible to make it better. The factories have teams of techs who spend the year working on next years models tuning an millions of dollars.

 

[sideshow]

I tried to much around with my 1uz when I had it
i found rich mixtures where normally when tps reached over
90 or so % no matter what load on STD ecu
I had a theory in my head but never had time to fk round
with it to try stop mixtures at that full throttle being rich
I guess working on my shitbox never paid the bills so I got rid of it

 

[Rollux]

I don't mind mixtures being rich at WOT, but when you can smell the unburnt fuel in the exhaust at a hot idle or light throttle at 2500rpm it tells you some tweaking is needed.

 

[sideshow]

my innovate meter went to 10 on ym 1uz when full throttle
and most early nissan turbos used to go down to 9
all this is so motors dont come back under warranty
but the 1uz suprised me as it was not load or rev dependant i think
but more like when full throttle this is y whenever i wanted to get a good start of the lights my car went better going half throttle and progressing slowly to full as car picked up
thats y u always gain a tiny bit of power just by leaning mixtures off compared to std ecus

 

[Rollux]

Spoke to a V8 specialist not far from me and said as it's already running and everything should be hooked up a retune (up to half a day) on the dyno to improve light throttles, cold enrichment, cruising and maybe a quick tidy up of WOT would be $350. I thought that was quite reasonable.
They specialise in GM and Ford V8s that a re anything from headers and CAI to rebuilt blown 454s and they race Fiats, so I figure they should be on to it.

 

[spf_lexus]

I have seen a couple dyno plots for na uz with the Unichip piggyback. The leaned afr offers a decent gain and you can also squeeze out some more timing as well. An NA uz w/ headers + exhaust netted an additional 12% at the wheels when tuned. Not too shabby.

 

[Rollux]

Well according to the previous owner it was dyno'd at 169.8rwkw (227rwhp) so from what I have seen that is about right, but going by the smell and look of the plugs it's way to rich, so a nice boost to economy(not that you buy a v8 for economy) and smoother running/throttle progression is mainly what I want.

 

[XR8tt]

Timing does have effect on fuel ratio's also..
Try advancing timing a little..
How old are the 02 sensors ??

 

[Rollux]

Funny you ask, i had a look today and it doesn't have any! It has custom manifolds to fit and no sensors. I assume some 4 wire bosch ones will be suitable, if not better than the standard single wire they have stock? I'll have to check and see what the link is capable of running and how to wire in, but that should make a big digference on light throttles just turning the lambda control on!

 

[samsdad]

From Memory I think that the G3 can run wideband (4wire) O2s

 

[Rollux]

Had a look and the G3 can run widebands and this opens up the auto tune feature. Just set target AFRs and the ecu will alter fuelling to suit. prob the way I'll go to help maximise effeciency