Give Enough Pressure To Bypass Ecu Protection

[Cubes]

Ben, You've missed the origional question......

Forget the fact that he's running a stock turbo etc... Mr. rmahnovetsky origionally wanted to know if raising fuel pressure will gain a little more head room in making power without hitting R&R.

The answer is YES! Obviously there is a limit to how far you can push this mod, every car is different as we know some R33's hit fuel cut at 10psi on stock ecu, others hit fuel cut at 13psi stock ecu.

After all that, If he does decide to push 13psi and still see's R&R with good afr ratios using the safc, to stop R&R his only quick fix option is to 'slightly' bump up the fuel pressure, pull a little more airflow out via the safc. Hopefully pulling it under R&R resulting in a nice smooth power curve with no detonation.

Possibly you could drop some Shell 100 stuff in it and by the looks it would be a good comprimise and work well with the increased ign. timing of the lesser load points.

This possibly would work nice with a smallish turbo like the GT2530.

Should you have a few detonation issues drop an ITC on it or as I said previously try the Shell 100 stuff.

All that being said maybe raising fuel pressure safely may not be enough to get around R&R. If thats the case sell all the safc and itc crap for basically what you bought it for second hand and buy a powerfc.

I have only heard of this method being used once. It worked for that person and gave them a little more head room with what he had.

Edited November 19, 2005 by Cubes

[benl1981]

Ok - He will have to pull out enough voltage to stop R&R occuring. If this involves runing lean mictures then yes it would help. But usually the limit as to how much AFM voltage you can pull out is the timing that gets too far advanced. So you may compromise and have a slightly rich mixture to ensure detonation does not occur (i.e you can not pull out as much AFM voltage as you would like)., Read some of Sks threads they are very detailed on this matter.

I dont think the FPR will give you the resolution you need for this job. It will be very half arsed to say the least.

Edited November 19, 2005 by benl1981

[Cubes]

I understand exactly how it works.. No need to read some of Sk's threads.

Everything you have said I have already mentioned in my post.

I've said all along there is a 'limit' how far you can push this mod. Running an ITC or even that new Shell 100 crap will help you see just a little more power before hitting R&R as you can run more ignition timing without detonation.

I am assuming one would only just be hitting R&R, in this case bumping fuel pressure up slightly and pulling a little more out will work very well.

It has in the past.

A full ECU is always better.

Edited November 19, 2005 by Cubes

[rmahnovetsky]

OK the arguement is over... Fuel pump has been fitted Now for the answer!!!

today at 12:30 nice and warm I was able to pull out 10% on the SAFC (I detected little det spikes at 12% removal)and I have not touched the CAS yet..

10 PSI nice and smoooth now.

11 PSI nice and smooth and wheel spins on the onset of boost in first and throughout second.

12 PSI havent tried yet..

13 PSI OH my GOD!!!! no det (not a drop) no CAS changes and just 10% fuel removal the car is a nightmare!!!! Seriously I hoped out shaking and my heart racing!!!!! I was spinning the wheels and fishing up into half way in 3rd gear... I did not expect this!!!!

R&R, what R&R, going through the gears were so fast and smooth, I could not detect R&R at all... This upgrade was the best yet!

more chat later, I have to take the misses out

[Cubes]

Nice... Did 13psi hold to peak power?

[rmahnovetsky]

I haven't got a dual digital boost controller yet.. So it did spike at 14 psi, but 13 psi held throught the rest of the rev range.. I haven't dynoed it yet.

[benl1981]

hey - did you have a wideband 02 sensor to check you weren't running it too lean?

Did you take 10% out over the whole range of load points? If youre doing it over all the load points you don't need a SAFC - you could have just used a resistor for about 50c. Not recommended though.

Good luck with it - were you getting R&R before? And if so at what boost level?

[rmahnovetsky]

the great thing about the safc is it shows when there is knock. It also has this in graph mode so you dont have to constantly watch the safc.. much better than a resistor.. but yeah I could have saved some money there too

I was getting R&R at 10 psi...

no wideband, I'm just working off the knock sensor atm - just making sure I stay clear from any knocking, till I borrow a wideband sensor, then I can tune it properly.

I took 10% from 4k and up. Car felt a little sugglish otherwise.

If my memory server me right idle pressure now is at ~42 PSI about 8 PSI more.. I'm using the standard wiring to the pump.

[Cubes]

Dont be holding out 3rd and 4th until you get the afrs checked.

Melted piston.

Looks good though.

Edited November 20, 2005 by Cubes

[rmahnovetsky]

cheers cubes, I havent tried 4th yet.. I think it best for me to put it back to 10psi for now. I was just to eager to see how it would go

I was told bosch has a wideband sensor for about $50 - $100. These guys alway come in handy, I may aswell just get one. I have a little dick smith display kit that I can just hook straight up to it..

I wonder why it is not pinging with the standard timing as predicted. Maybe my fuel pressure isn't high enough for me to take out a lot of fuel to put me in the high ignition points.

The 040 pump is not as noisy as expected either. I could hear the std pump on prime and I can too hear the 040 on prime but it is not that much louder... I have always had a bit of an idle issue after I started my car from a 15 minute warm down. What I noticed now is when my car starts dropping revs under 750rpm idle I can here the pump more mmm . I was hoping the new pump might has fixed this problem but it didn't ..

[benl1981]

What sort off knock values are you getting?

Have you checked you base timing to see that it is at 15 deg BTDC - maybe it is less than that and that is why you aren't getting knock. Remember the knock value is only an estimate and you really should get it on the dyno with someone checking for knock with headphones and monitoring AFRs.

I too got R&R at about 9-10psi - wasn't fun. I'm now on the base map of the PFC and no probs.

If 13psi makes that much difference I want to get a better turbo so I could run 13-14psi reliably without fear of the turbo spitting it.

[The Dan]

WTF....changing your fuel pump won't increase your fuel pressure.

The standard reg is going to see to that.

Sure enough changing the reg will enable you to increase pressures.

I thought someone would have told you this already.

[rmahnovetsky]

benl1981 :

It is not knocking at all, no readings on my safc.. Well I would have thought the knock sensors were pretty good. If the manufactures use it to protect the motor then it is good enough for me. Who would give a warranty on bad knock sensors or one that dont work that well... I have been using the guidiance of the safc for 2 years now and my car has been great and my sparks plug look normal.. So I trust the knock sensors.

Timming is set at 15 deg.

At 13 psi and 14psi peak I was getting no knocking with 11% fuel removal. BUt I put it at 10% just incase. WIth 12% at ~32deg outside temp I got slight knock prob a reading of 30, this was in 3rd gear. The knock was very small as I use graph mode when Im testing, it's much easy to check for knock.

3lit3 32: please explain why, and then please explain why I can remove up 10% fuel with my car not knocking at 13 psi. Remember Im using a bigger fuel pump with has a pressure of 73.5.

My turbo screams too, I reckon it probably doing 100 000 rev/min .. Sounds great though ..

[benl1981]

The sensors would be as old as the car, there is a chance they are not doing there job properly. Remember the stock ECU has the R&R protection mechanism which goes off AFM voltages (Iit uses knock levels aswell) so the knock sensors aren't the only safeguard. They might be fine - but I think you should wait tillyou can put it on the dyno for an hour to verify what you are thinking. $100-$200 might save you an engine. I know you plan to do it but don't fang it round till you get to do a tune.

I assume better fuel pump would only make a difference if your old one was on the way out. Fuel pressure reg is made to control Rail pressure to a predetermined pressure.

benl1981 :

It is not knocking at all, no readings on my safc.. Well I would have thought the knock sensors were pretty good. If the manufactures use it to protect the motor then it is good enough for me. Who would give a warranty on bad knock sensors or one that dont work that well... I have been using the guidiance of the safc for 2 years now and my car has been great and my sparks plug look normal.. So I trust the knock sensors.

Timming is set at 15 deg.

At 13 psi and 14psi peak I was getting no knocking with 11% fuel removal. BUt I put it at 10% just incase. WIth 12% at ~32deg outside temp I got slight knock prob a reading of 30, this was in 3rd gear. The knock was very small as I use graph mode when Im testing, it's much easy to check for knock.

3lit3 32: please explain why, and then please explain why I can remove up 10% fuel with my car not knocking at 13 psi. Remember Im using a bigger fuel pump with has a pressure of 73.5.

<{POST_SNAPBACK}>

Edited November 20, 2005 by benl1981

[The Dan]

How can your fuel pump have a pressure of 73.5?

Do you understand how the fuel system works in an injected car?

The fuel pump only provides flow. The fuel pressure regulator on the fuel rail is there to restrict flow and, therefore, create pressure. As the pressure reaches a predetermined level, the regulator will bleed off any extra pressure. This maintains a CONSTANT pressure in the fuel rail and enables a CONSTANT measured amount of fuel to be injected at those pressures. The only way to increase fuel pressure is to restrict the flow more. You will find that the old pump would have been flowing close to its maximum levels, whereas the new pump will hardly be working at all.

What method are you using to check your fuel pressures?

[The Dan]

Another thing which I thought I should mention is that unless you are putting out 230-240rwkw, your injectors won't be maxing out so there is no need to increase fuel pressures. Your engine knock is most likely being caused by ignition timing incorrectly set. If you have a tired pump, blocked fuel filter, dirty injectors, dirty or old spark plugs, worn or old coil packs, inefficient cooler....these things can also cause engine knock.

It's not about the race to dump more fuel in to get higher hp figures. The more fuel you put in, the slower your car will go.

You have to tune the car to run an efficient amount of fuel air mix. You may find that by decreasing the fuel (running it not as rich) will give you more hp. You car should be able to handle 14psi with no problems at all.

[rob82]

WTF....changing your fuel pump won't increase your fuel pressure.

The standard reg is going to see to that.

Sure enough changing the reg will enable you to increase pressures.

I thought someone would have told you this already.

<{POST_SNAPBACK}>

Your right in what your saying but remeber that larger pumps flow more fuel which may be too much for the stock FPR in which case your fuel pressure can rise. ie - the stock FPR cant return enough fuel to the tank hence increasing fuel pressure. This condition might only be apparent at idle or low loads when there is not much flow out of the rail through the injectors. I have seen this happen and wouldn't you know it was a CAPA fuel system. Depends on how the the pump is wired to - from memory aren't R33 dual stage?

rmahnovetsky - what are your fuel trim levels at idle and cruise? Is there a steady progression into open loop? Also are you saying that the fuel pressure is 73.5 PSI (no vacumm?). In which case your economy is going to go to the shithouse along with others things coldstart etc.

[BHDave]

73.5psi is the pressure used for the rated flow of the 040 pump, whatever L/hr. Thats where the number comes from.

Basically bosch state their pump will flow x L/s at a pressure of 73.5psi.

Was the rising rate reg installed after all that discussion?

I'd expect your pressure to be higher at idle and low load using the stock reg, and possibly slightly richer mixtures at he top end too as your old pump would have been getting a little tired.

As for being under the rich and retard, at 10psi you would only be touching the edge of it anyway, at 12 you'll be into it, at 15 i'd expect you'd see mixtures well into the 9's, so by taking the 10% out at lower boost levels I expect you have acheived your goal.

But please, tune the thing on a dyno, don't just go pulling fuel out and winding up the boost or you'll pop the thing soon enough.

[DRIFTER]

would an emanage be a good alternative to an safc and sitc. how much power can the stock fuel pump flow

p.s. i'm just about to go through all this with my stagea in the next few weeks

[rmahnovetsky]

cheers for you input guys. Really appreciated..

fuel pressure is determined by my inline fuel pressure guage on the pump side. Im getting about 42psi on idle and 44 just off idle (ECU voltage drop/increase)..Stock is 34 then 36-38 psi

Yes slow progression to 10% fuel removal. I started at 3k and slowly worked to 10% removal at 4.5k..

I'm using stock fpr

After idle I don't know my fuel pressure. I dont have the guts to stick my head in the bonnet while Im driving

Maybe my pump was tired thats why I'm noticing such a big different in open loop. With the old pump I somtimes needed to give it +1 to +3% to avoid det on 9PSI.. But now with 13psi and 14 psi spike the acceration is constant throughout the whole range.

I have decided to leave it at 9PSI until I get it tuned properly - thanks guys appreciated. I'll get it tuned, take it to the track and see what figures I can come up with ...

I though the stock fpr ran of the vacuum from the plenum chamber not the actually pressure in the fuel rail?