Give Enough Pressure To Bypass Ecu Protection

[rmahnovetsky]

maybe a sard adjustable or a malpassi?

[Cubes]

If its 2:1 grab it..

[benl1981]

So what you are saying is you want to take out heaps of AFM signal via the SAFC and add the fuel in via the extra pressure?

Then you are going to retard the timing a heap via the CAS. You dont need an adjustable fuel reg to do this!! Your better of sticking with standard fuel pressure and tuning with the SAFC and seeing iff this is ok. You are making it worse by bringing in the extra Fuel pressure. Just check it on the dyno. Your standard fuel system should handle up to around 200rwkw.

You will only need an adjustable fuel pressure regulator if you are leaning out. You will only find this out on the dyno!!!! or with a widesband sensor under load

Edited November 17, 2005 by benl1981

[Tangles]

Yeah, well, SydneyKid said to me in a Stagea-section post that rising rate regulators ie Sard, are harder to tune correctly with a SAFC.... an item such as a Nismo adustable (to +10psi) is far more accurate to tune - apparently. Im going by memory and not experience.

So Ive gone by what he recommended - he 'seems' to know what he's on about!!!!!! lol

Brendan

[rob82]

Sards are 1:1 only. ie set rail pressure to the specified injector recomendation usually around 45psi (no vacumm) so at 10 psi of boost you have 45 + 10 = 55psi of rail pressure. What you want is a higher rate of rising so that at 10psi you have say 65psi.

This is probly what your going to have to do I think capa have a FPR that is adjustable down to 2.5:1 minimum which may cause it to drown. This is what capa does on alot of their supercharger kits and it is totally the wrong way of doing things, not only are you imposing more strain on the injectors which may cause shitty atomisation but your also loading all your fuel lines which is just plane dangerous. Injectors should change the amount of fuel an engine consumes not the ancilleries to making them work.

Your essentially using aged technology to gain a result in a day and age when there is a cheap product on the market (PFC) I just dont know why you wouldn't go down that route there will be far less headaches.

Sorry for being the grench and it is only my opinon. But I think by the time you weight up the cost of braided fuel lines FPR and the like you would have been better off with a chip or PFC.

[benl1981]

Amen. He wants to use it for the wrong purpose. You use them to allow more fuel to pass through your injectors for a given pulse. This is presumably when you want to run higher boost and extra fuel pressure allows you to have fuel for that extra boost - or in a NA car that you turbo.

Edited November 17, 2005 by benl1981

[Tangles]

So is it wrong to be using a Nismo adj. fuel pressure regulator, with highpressure fuel lines and bigger fuel pump, to force more fuel thru the injectors, rather than buying larger injectors?

The z32 afrm will sort out the voltage side of the afm and the ability to read a larger air flow (?), and the SITC will be able to adjust the ignition timing. The SAFC will then be able to be re-fine tuned to get to 12.1 thru the rpm range.

Not going to go PFC as Ive got an auto. Oh well, already got the fuel pressure regulator, so its going on the car!!

BW

[benl1981]

BW - What you are doing is the intended purpose of the adjustable fuel pressure regulator. Quite different to what the original poster is wanting to use it for. You haven't got much choice with the auto...sounds like your plan should work quite well with some time on the dyno. SK or somwone else would know best..

[rob82]

Your missing the point a sard or nismo FPR is 1:1. The reasoning behind this is to achevie a consitent fuel pressure across the injector ie the designed fuel pressure for the injector in use. So say your injector will flow 550cc/min of flow at 43psi you set your FPR to 43psi with no vacumm applied. So that when your under 15psi of manifold pressure the pressure behind the injector is 15psi onto of the rated fuel pressure.

A 6:1 rising rate malpassi at 15psi of boost pressure will make 90psi of rail pressure. At 20 psi will make 120psi get the idea. What you guys with auto's want is an Xede.

[Cubes]

So what you are saying is you want to take out heaps of AFM signal via the SAFC and add the fuel in via the extra pressure?

Then you are going to retard the timing a heap via the CAS.

You dont need an adjustable fuel reg to do this!! Your better of sticking with standard fuel pressure and tuning with the SAFC and seeing iff this is ok.  You are making it worse by bringing in the extra Fuel pressure

<{POST_SNAPBACK}>

Not necessarily retard the timing... It really depends on how it all runs.

All we need to do is step under the R&R; the thread starter initially looked at running 14psi, and has suggested that he will run in to R&R.

If I remove my old fuel pump and replace it with the bosch 040, will it provide enough fuel pressure to bypass my ECU protection (rich retard) for up to 14 psi? So basically I'm going to increase the fuel presure and tune it with the safc so I can bypass the ecu protection so I can run higher boost with the rb25det flat spot.

If extra fuel pressure isn't required; great, if it is then look at what I have suggested. This would be a last ditch effort to make more power on the stock ecu.

Powerfc cheap or not.. its irrelevant.

Obviously this mod will be done on a dyno.. as his origional thread starting post suggested.

2:1 reg may be a little high... especially if running 14-15psi.

40psi base + 30psi -> 70psi. Thats right on the limit.

Start at the most simplest/cheap.

Try and see.

Edited November 17, 2005 by Cubes

[Tangles]

Thanks Ben - I thought I was on the right track.... cheers to you for the very helpful comments.

BW

[rmahnovetsky]

Cubes: possible outlook that what I like to see...

My whole idea is the make the skyline as fast as possible with the littlest amount of money. If I cant just use a bigger fuel pump and a safc then I have spend a bit more get a fpr and try that, if no good then maybe sitc then maybe power fc.. But the whole idea for me is to show myself and others how make realiable power as cheap as possible... It would be great to have a r33 in the 12s with < $2000 spent on it..

[Tangles]

Cubes: possible outlook that what I like to see...

My whole idea is the make the skyline as fast as possible with the littlest amount of money. If I cant just use a bigger fuel pump and a safc then I have spend a bit more get a fpr and try that, if no good then maybe sitc then maybe power fc.. But the whole idea for me is to show myself and others how make realiable power as cheap as possible... It would be great to have a r33 in the 12s with < $2000 spent on it..

<{POST_SNAPBACK}>

Thats a great goal - best of luck with it. Im on your side with the budget mods as such, as I like to buy stuff off ebay 2ndhand from Japan.

Nismo fuel pressure adj regulators are for $160 delivered on Nengun, and Im sure you could sell it for over $100 if it didnt work out as you planned, and then try a rising rate regulator.

By the way, SITC's arnt expensive but are quite rare, so if you find one grab it!

Good luck with it, keep us posted.

[Cubes]

At the end of the day you can buy a second hand safc etc and pretty much sell them for what you paid.. I think its worth a play, especially if you are a bit of a fiddler like I.

[Sydneykid]

From what I have read this thread is going around in circles, there area few items of logic being missed;

1. rmahnovetsky wants to make 240 rwkw with standard injectors, that’s possible but the fuel pressure required would be around 55 psi (above boost). A Bosch 044 (or similar rated at 73.5 psi would be OK. A Walbro wouldn’t handle the pressure for very long, not enough electric motor torque. That’s a ~$400 cost.

2. A standard turbo isn’t going to make 240 rwkw, move on from that thinking

3. Making 240 rwkw with 14 psi, regardless of the turbo, is going to be very difficult with the limited mods listed. More like 19 to 20 psi, going on our past experiences

4. To run 55 psi + 19 psi = 73 psi rail pressure he is going to need a serious upgrade in hoses and fittings. I personally wouldn’t be using clamp on hoses, screw fittings would be my choice. Count on spending around $300 on fittings, hose and welding.

5. A fairly decent adj FPR is going to be needed to accurately control that sort of fuel pressure. I would allow $250 -$300 including mounting and hose fittings (remember it has to hold 73 psi from the fuel rail to the FPR).

6. The SAFC reduces the voltage that the ECU sees, this means less fuel is squirted. But it also means that more ignition advance is used. It is always a compromise, between A/F ratios and pre-ignition, you go round in tuning circles for along time. And that’s at 200 rwkw and 1 bar using a high flow turbo. I can’t imagine how hard it is going to be at 240 rwkw and 1.3 bar. Better budget a whole day on the dyno for tuning, that’s $1,000 or so.

So let’s add it up;

$400 + $300 + $300 + $1,000 = $2,000

Then compare that with the alternative, GTR fuel pump $150, SITC $200, SARD injectors $900 and a normal SITC/SAFC dyno tune $300.

$150 + $200 + $900 + $300 = $1,550

Even if some of the numbers are a little rubbery, the fact is the proposed cheap method is in fact no cheaper than the more common route. Plus it is damn site more dangerous and difficult. Maybe that’s why no one bothers, plenty have tried and found out the hard way that the common way is the best way. Perhaps that’s why it is so common.

cheers

Edited November 18, 2005 by Sydneykid

[rmahnovetsky]

Sydneykid, cheers for your reply and yeah if I was looking for 240kw then I would definitely not go this direction. But I'm just looking for a cheap way to bypass the R&R. With a full exhaust and 9psi (2 psi more than stock) I managed a 14.051 down the 1/4 from a 14.9 stocko. So Im hoping the get another 1 sec off my time with 13 psi. Thats 4 psi more. If I can get into the 12s I'll be really happy.. So if I can pull it off thats only a fuel pump and a safc..

[rmahnovetsky]

how the hell do you get to the pump.. I have taken the lid off just under the parcel tray and the pump is just visible with a touch.. It's on the other side of the tank..

[rmahnovetsky]

ok I just saw a thread on how to do it... Now I feel stupid I took the back seat out... hehehe...

Look like to fit the 040 it is not as easy as remove and replace.. Looks like I need to get an attachment so the fuel line can be clamped and the pump needs to be lowered a fair bit...

[rmahnovetsky]

I want to make sure I get every bit of fuel in the tank, so I lathed up an attachment to fit the original filter on ... Pump will be installed tomorrow morning, actually this morning...

[benl1981]

So now you can see that you will only need the adjustable FPR when you have reached the limits of the stock fuels system. At 13psi you should be more worried about your turbo..stick to about 10-11psi..

Edited November 19, 2005 by benl1981