Nistune Forums

Hi all,

This i kind of a long time coming due to too many reasons, but anyways..

I have a 2001 C34 Stagea (Series 2) that has proved difficult to tune. Its been to 2 different tuners (Previous owner had it tuned, and i had it retuned), and both times it hasnt seemed at good as it should (or hoped).

Current mods are: Kinugawa rebuilt stock turbo http://shopping.kinugawaturbo.com/upgra ... 50bhp.aspx , 550cc injectors, Walbro 255L fuel pump, 3 inch turbo back exhaust with split dump and varex muffler, FMIC, Apexi Pod filter, Greddy Profect B Spec 2 (which i suspect may also be attributing to issues) running 15psi.

We had the car for about 12 months before the turbo shat itself, so we replaced that. Went to have it tuned at Profile Autosports (Cleveland, Queensland) and tuner said he couldnt do much as the new turbo, although being a stock unit, was pulling more air, so we needed more fuel. So we replaced the injectors with 550cc ones and upgraded the stock to a drop in Walbro 255. Went back to the tuner and he did his business. Seemed better, but not as much as id liked. Ended up going back a few times because of a cold start issue (Matt, you may or may not remember clint calling you about this, was about september last year i think). Anywho, its way worse on fuel economy (300km/60L if nursing it, much worse if giving it some beans) and isnt very responsive below about 3000 rpm. Where i had it tuned, the tuner is top class for his day to day stuff (Falcons) but i dont know if hes aware of the intricacies of the Stagea ECU (as ive recently read). As it stands, its putting out 220kw and about 360nm, not sure of AFRs.

Ive grabbed an image of the current maps if anyone is keen to have a look and give me some tips as to where to go from here.

JECS/Bosch injectors or some drill out ?

Off the top of my head, i dont remember, although Sard is ringing a bell.

There is definately a crapload of fuel at the top of the fuel map. Would advise checking the fuel pressure since he shouldnt needed to add that much if all was mechanically sound. Normally the maps end up flatter

We dont have a dyno sheet to see the AFRs so cannot comment further on that part

I've updated the tune to use default factory scales, and adjust the injection using the injector divisor by moving the 45% fuel reduction from K to this new parameter. Check the AFRs using a wideband before using boost on the upated tune

With the cold start, not enough fuel has been pulled out on the crank enrich table. I've pulled out more fuel to assist here. Adjustment on the vehicle may be required further

Thanks Matt.

A s for fuel pressure, its running a stock fpr (I think the 25neo runs 2?)

Check fuel pressure with a gauge mounted in the line to check it

UPDATE:

Went and got the car retuned today, dyno sheets are below.

What are your thoughts Matt? They charged me for 2.5hrs of tuning after adding the modified tune you did. Didnt update to the new feature pack or anything. Excessive? I think it might be. Also, what difference does the boost sensor make plugged/unplugged?

I can post up the Bin if it helps tomorrow

Well from the dyno plots you can see the car is a lot happier now. I spoke to Matt @ ECC yesterday about the boost sensor. Its fine to run without it as long as you adjust the TP limit scales instead of the boost limit scales. Got him to adjust the min/max boost sensor voltage to avoid DTC fault codes

Mixtures were too lean from the initial runs and now around holding 11.5:1 AFR and boost around 16psi to start with. Dyno time varies depending on vehicle any if any issues. I know Matt did an initial check through of the vehicle before even starting the tune for potential issues (boost sensor was one cause for concern at the start) and time passes quickly when on the dyno

Its like driving a new car to be honest. Really pulls well now.

As for Dyno time, i understand that time would fly by, just didnt expect it would take so long i guess. You get what you pay for, and at the end of the day, im very happy with the results!

UPDATE:

Car is now manual. Is there any way to disable the auto gearbox features with DTC flags etc? so i can get rid of the CEL.

Also, ordered my flex sensor and harness today. Im upgrading to a GT3071r, 1250cc Bosch ev14 injectors, Walbro 485. Will be getting tuned to run e85/98 tune. Im HOPING for around 300kw on e85. Anyone running a similar setup?

Yes I'm running same turbo 3071 on R34 with 1000CC ID injectors so should be fine

Manual transmission - turn off the DTC filters for the AT controller and it should make the errors go away (clear DTC codes after this)

Good to know, thanks Matt.

Also, if i am to update to the new feature pack, do i need the factory nissan boost sensor, or can i just run a generic?

Sorry for the delay... been away

You cannot use a generic sensor since the ECU is calibrated for this sensor (0- 17psi). Anything over this and it flags a fault code (overboost effectively) and will trigger boost sensor DTC

Disconnecting the boost sensor makes the ECU use a default (limp) set of values when tracing the VE map (TPS only rather than TPS+boost input)

No probs Matt.

The boost sensor has been disabled during the last tune, but i was interested in replacing it so i could utilize the new feature. Seeing as the stock boost sensor only sees 0-17psi, is it going to be worthwhile if im running over 18psi? Would you say its worthwhile to replace it to simplify tuning?

If you are going over this PSI then leave it disconnected. If you were to replace with a larger BAR MAP sensor I'm not sure how to calibrate it with this ECU ...