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Discussion Starter · #1 ·
To all-
I have noticed a strange problem after installing turbos, injectors, fuel pressure regulator complete list of stuff done is at bottom. I have set the Power FC to the VG 30 airmeters that I have, and car does great on Full boost (around 1.45 bar) when on vg30 setting, but totally loads up at stop, hesitates when leaving light, unless you rev motor a tad before letting clutch out. Idle bounces around 1200 rpm-800rpm, and when driving at just a cruise, it surges back and forth ever so slightly, just annoying, and wants to die if you are on the gas and just let off and push clutch in when coming to a stop, need to let motor engine brake a tad before pushing clutch in. O2 sensor are all over the place at idle and cruise, but stick to .8 volts at full boost. What I've noticed is that the idle is perfect and cruise is perfect when I move Power fc to rb25 setting, O2's search at idle( .05 to .8 volts) like they used to before upgrades, no hesitation when leaving a stop, but runs like total crap on 3/4 to full boost! I had the box out and sent to a tuning shop to install performance injector map by a good tuning shop in California-I am in US. I've tried leaning it out on low end of map, nope. I've tried playing with the injector settings, nope. Any suggestions???

I have a GTR r33 with VG30 air meters, Power fc with hand controller, hks 2530's, hks intercooler piping, HPI exhaust manifold, 720cc injectors, fuel pumps, HKS fuel pressure regulator, HKS fuel rail, quad core intercooler.
 

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us v spec

Your PM box is full
Gary
 

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Hans,

The power FC ECU does not stay perfectly mapped when switching between air flow meter types.

It will be necessary to redo the fuel and ignition maps.

Step 1 is to find a tuning shop with a wideband Lambda which will allow you to set the fuel mixture. I tune for 16:1 AFR for economy on light throttle cruise, 14.7 for gentle acceleration building to 12.5:1 for flat out acceleration.

Best to have an exhaust gas temperature sensor fitted to keep below 900° C after the turbo or 1000° C before the turbo when leaning off the fuel mixture.

The ignition map in your car will, if it was previously mapped correctly, be close up to the boost used on your old turbos,

You will be able to get at least 1.6 bar and assuming your head is still standard, probably 1.8 bar from the HKS 2530's
 
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Discussion Starter · #6 ·
Yes....

I am printing everything on the thread to take with me when I go to the dyno..... 75 pounds to set up and 75 per hour... I will want all the parameters avail. to tune.
H
 

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Considering the added stress on the engine / transmission mechanicals when mapping on a rolling road.

Get it done on the open road if you can.

The dyno will also make your car run hot and will require the ignition to be retarded more than is needed for road use.
 
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Discussion Starter · #8 ·
What to do..

Hugh- What to do without the Wideband Lambda sensor? Should I wait til I get one installed before trying to accomplish this? I have a few places to do 3rd gear pulls around me... Just at present having this hard time with idle.
H.
 
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12.5 air fuel ratio

Hugh,
are you sure about 12.5 afr on full load?
Us at ABBEY have been spending time on our dyno we have noticed that if you run a car at 12.0-1 the car will give reasonable horsepower but lack torque. Run a car at 11.5 to 1 you will gain approx 5% torque all through the rev range and your engine will be safe [ask shin about AFR ]
'do your tuning on the road' 'you will have to retard your ignition
to cope with the extra heat'
would you notice if your cars was 25/30lb/ft torque down at a certain rpm I think not ,and would you notice if you car had a flat spot at 6000 rpm !!. You have clearly not been in a properly cooled dyno room.
The trouble with doing runs on the road is the road ENDS, Can
you do 2 runs the same.
I could go on for hours about tuning cars but then I will not be using the dyno finding bhp and increasing drivability of my customers cars.

Mark
 

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AFR figure

Hi Mark,

Thank you for your comment.
Our AFR figure is one of our confidential matter to produce ideal performance both for horse power, for torque and for durability.
So, I cannot disclose detailed AFR figure of us.
Please just take your car to Abbey and experience the difference of our knowledge.:D

Yours,
Shin
 
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Discussion Starter · #11 ·
Would love to Shin,

But as my name entails I am in the US, but thanks for the heads up...:D If This keeps up and with me a 5200 ft altitude I may be shipping one of those guys from Abbey to my town! Problem I think I may be having is that all the tuner online live and work at or near sea level, and as with bikes I need to run a tad leaner to compensate for lack of O2 and barametric pressure.....BUT as boost comes on, it somewhat makes up for my lacks-O2 and barametric pressure, so my fuel needs to be almost as rich as sealevel...... So any maps sent to me will be rich throughout for me, and leaning it out thru injector duty currently at 74.2 and 6 mil/sec will be ok at idle but rich at load or visaverse.
H.
 

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Mark,

I absolutely agree that the road runs out very quickly when tuning which makes it very hard to repeat the results. A dis-used airfield might be a good option for some if there is one near.

I also believe from the brief conversation we had about dyno cooling that you have the ability to be much nearer road use conditions, with your new set-up, than any rolling road I have experienced. I do know that I have had to pull timing out of the ignition map when on a rolling road to stop detonation that was not present on the road which for me means that on road tuning is still the best. However I would also agree that the Dynopack with it's lack of wheel slip would give great results on the exact AFR to produce the best response throughout the rev range. You also may have the cooling so good that the ignition can not be advanced further on the road - tell us more.

I guess it comes down to the tools available to you to tune your engine and the ability to judge any changes you make. For me it is still work in progress as I have yet to do back to back runs at the different air fuel ratios / cam timing to prove the ones that are best on my set-up.

Hans,

The idle / low load problem you have is the easiest one to fix as the narrow band Lambda's fitted to your car are able to accurately judge the air fuel ratio around stoichiometric 14.7 : 1

ECU Pin 29 is O2 sensor front and Pin 55 is the O2 sensor rear, attach a multimeter to either of the O2 pins, switch off the feedback mode on your lambda's and start mucking around with the fuelling. You can change individual map points, or adjust things generally by changing the percentages on the airflow meter. The voltage you see at the O2 will be very sensitive to the changes you make. As you lean it off , the voltage will go to 0 which will be around 14.9 / 15 :1 AFR.

The standard Lambda's have no temperature compensation and almost no resolution away from stoichiometric, so do not attempt to tune for power with them, but the above will get you past your idle problems.

Air density problems are significantly less with turbo cars as the % of oxygen in the air is still more or less the same at any altitude, things like humidity affect % more. At 1 bar of boost your engine will have more or less the same oxygen % at any altitude. On non turbo cars and off boost on your car, the volume of air to get the same number of oxygen molecules increases hence the comment you made about leaning off.

Shin,

I could put my Mines ECU in the car and log the air fuel ratio just to see what it is, but where would be the fun in that.

Why does the Mines front pipe pro have a bung for a wideband lambda, is it used to set - up the Mines ECU?
 
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