Surrey rolling road day

[Fusion Ed]

ok, the solenoids are easy to clean, so that's simple enough to check.

 

[youngsyp]

90% is really quite high for 1 bar. You sure its plumbed in right?

I'd agree with that. Mines set at around 55% duty all the way to the redline for 1 bar.
Running 1.1 bar, as I was on the dyno day, it was set to around 59% duty to the redline and the graph looked like it had been drawn with a ruler, just ramping up to around 1.15 bar from 6.5k rpm !

 

[youngsyp]

Just out of interest, what is the widely accepted transmission loss % for the GTiR, between flywheel/crank and wheels ?

My graphs were calculated with a 22% loss between the flywheel/crank and wheels !

 

[ashills]

20-23% is a fair guess id say but thats all it really is i think

 

[Fusion Ed]

sounds about right to be honest 20-25% anyway.

depends on lots of stuff!

 

[gtirx2]

ok, the solenoids are easy to clean, so that's simple enough to check.

Looks like i am going to be pulling the solenoid apart soon then,if youngsyp is on 55% duty i may well have a problem.I always put it down to the intercooler pressure drop.

 

[youngsyp]

Here are my dyno graphs !

1. Power and torque at the flywheel:
http://i51.photobucket.com/albums/f365/youngsy/19082007014.jpg

2. Power and torque at the wheels
http://i51.photobucket.com/albums/f365/youngsy/19082007015.jpg

3. Boost
http://i51.photobucket.com/albums/f365/youngsy/19082007016.jpg

4. AFR
http://i51.photobucket.com/albums/f365/youngsy/19082007017.jpg

If you have any theories on that AFR curve, please post them up. After plugging in Conzult, we're pretty sure why that's happening but, any other ideas are welcome !

Here's a few pics too:
http://i51.photobucket.com/albums/f365/youngsy/Paul20Photo201-1.jpg
http://i51.photobucket.com/albums/f365/youngsy/Paul20Photo202-1.jpg
http://i51.photobucket.com/albums/f365/youngsy/Paul20Photo206.jpg

My engine mods are:
Custom Hayward & Scott 3" elbow and downpipe, tapering down to 2.5" just before the decat pipe, with 2 straight through silencers and lagged downpipe.
Blitz intake kit with all inlet and outlet points on rubber intake pipe blocked off and 100mm cold air feed.
OE breather, including PCV and throttle body pipes removed.
Carbon canister and associated pipe work removed.
Cusco catch tank, venting to atmosphere.
Port matched turbo to intercooler pipe.
Mildly ported metal turbo intake pipe.
TMIC lagged with heatshield under 'cold side' and mild porting work carried out to inlet and outlet pipes.
8 gauge earth bonding kit attached to alternator, head, block, plenum and body.
MAF earthing reinforced.
TPS earth reinforced.
Re-wired fuel pump to give full 14.4v alternator voltage at pump.
Apexi AVCR running 1.15 KG/cm (roughly 1.1 bar).

I think that's it and everything else is stock Nissan....

 

[gtirx2]

I see what you meen about your afr:? know that i have learned how to read them that is:lol:
If i was you i try and get a gauge on my fuel line and just check that you are getting the right fuel pressure and your fpr is ok.Or the other option is to try what some else serjested and get a adjustable fpr and turn up the fuel pressure maybe?
I also see that you get the bigger graph scale as you cracked 300bhp that go's up in 50's instead of 40's like us lesser powered cars;-)

 

[youngsyp]

I see what you meen about your afr:? know that i have learned how to read them that is:lol:
If i was you i try and get a gauge on my fuel line and just check that you are getting the right fuel pressure and your fpr is ok.Or the other option is to try what some else serjested and get a adjustable fpr and turn up the fuel pressure maybe?
I also see that you get the bigger graph scale as you cracked 300bhp that go's up in 50's instead of 40's like us lesser powered cars;-)

Thanks for the suggestions bud !

I am keen to check the fuel pressure but, it would seem that when we plugged in the Conzult and loaded the car up, as soon as it made full boost, the datalog indicated that it went right off the load scales for both fuelling and ignition timing, on the stock map.
That would say to me that regardless of what I changed down the line from the ecu, whether it be fuel pump, FPR or injectors, it wouldn't make any difference as, the stock fuel and ignition maps, can't keep up with the amount of air the intake track can now flow. I.e. the ecu can't physically compensate with more fuel, for the amount of air it's seeing.
I guess that shows in the power the car made.... 318 bhp from just 1.1 bar, seems pretty high to me ?!

I could of course be way off, and a different explanation and cause could be the case ?!

The thing that keeps coming back to me is that the MAF is going off scale when the car is on boost so, isn't accurately instructing the ecu as to the amount of air that's flowing through it !

 

[gtirx2]

Tbh mate i am not to clued up on the mapping of cars so i am not to sure.But what are you saying about the maf is it maxing out with to much air flowing though it,as in it sends say a 5volt signal to the ecu when working flatout and your car is flowing more air than the afm can read?
Also what about the throttle position sencor,if say it was out of adjustment and telling the ecu that it was getting only 3/4 throttle when infact you are at wide open throttle or visverser would that confuse the ecu and take it off the load scales,if you know what i meen?

 

[youngsyp]

Tbh mate i am not to clued up on the mapping of cars so i am not to sure.But what are you saying about the maf is it maxing out with to much air flowing though it,as in it sends say a 5volt signal to the ecu when working flatout and your car is flowing more air than the afm can read?

That's right mate, that's what I meant ! ;-)
Also, to add to that thought. One of the dyno operators suggested that it may be a dirty MAF that was causing the issue. I guess if it was dirty, the resistance properties of the hot wire will change so, I might not necessarily be maxing the MAF out, just so, as it's dirty..... I'm gonna take the MAF apart and give it a clean tomorrow, just in case it is that !

Also what about the throttle position sencor,if say it was out of adjustment and telling the ecu that it was getting only 3/4 throttle when infact you are at wide open throttle or visverser would that confuse the ecu and take it off the load scales,if you know what i meen?

That's another good suggestion but, my AVCR reads the throttle position, as you'd expect. That and the boost reading are what I have displayed all the time !

 

[Fusion Ed]

Throttle position isn't important, it is not used to calculate engine load, disconnect the tps plug and go for a drive, in some cases you wont even notice.

If the airflow meter was dirty, it would read less voltage, not more and so would not go off the scale like I demonstrated. Fuel pressure may be a tad low, however AF base in closed loop was normal, however it wouldnt harm to check base pressure.

The MAF is not maxed out, its just going beyond the limits of the standard load scaling map. This is common on nearly every pulsar I see running 1.1 bar + however usually they will be richer than yours was. It points to a possible fuel pressure prob, compounded by the fact of your well placed mods making matters worse. I have not looked at a mines map, I may buy an ECU just to download the map from it, it will probably help, but I suspect you will still be lean and may have to increase/check fuel rail pressure.

 

[youngsyp]

The MAF is not maxed out, its just going beyond the limits of the standard load scaling map. This is common on nearly every pulsar I see running 1.1 bar + however usually they will be richer than yours was. It points to a possible fuel pressure prob, compounded by the fact of your well placed mods making matters worse. I have not looked at a mines map, I may buy an ECU just to download the map from it, it will probably help, but I suspect you will still be lean and may have to increase/check fuel rail pressure.

So, does the ecu know it can't supply enough fuel and so move up the load scale some more, in an effort to pump more fuel in ? But, in my case, there isn't sufficient fuel pressure to supply any more ?

Well, at least that gives me a focused point to check before anything else. And of course, it's still on the stock fuel pump !

Does anyone have a fuel pressure gauge I can rent ? :lol:

Another though is could this be a fuel filter issue ? Maybe it's blocked...... again ?!

 

[pulsarboby]

what pump are you running paul?
the guy whos mines i fitted the other day just ran a 12.6 at santa pod with stock injectors and afm at 1.2 boost with standard tubby

this would indicate that you either have a faulty afm (but would show up on diagnostics) or as you said there is fuel starvation!
the guys car was recently mapped at engine advantages and was running within spec of the standard afm at 1.2 bar, so this would suggest that its fine if working correctly at that level of boost.

i have a pressure regulator gauge you can borrow, if you suspect that, but i think you have hit the nail on the head with a fuel starvation problem!

 

[youngsyp]

what pump are you running paul?

I'm still on the stock pump but, I have re-wired it to get full alternator voltage.

i have a pressure regulator gauge you can borrow, if you suspect that, but i think you have hit the nail on the head with a fuel starvation problem!

The point that I can't understand though is that when checking the ecu map, when I loaded the car up in 3rd, the engine went right off the fuel and ignition load scales, that the OE ecu uses. Would this be because it can't get enough fuel to the engine, because of a fuel pressure issue or, that it is physically seeing more air through the engine than it can cope with, on the stock maps ?

I can't see that being the case as, although it's clearly making good power for the given boost level others running at that power level see overfuelling, not leaning out ?!

 

[pulsarboby]

not really my field tbh with you paul but people have run the stock ecu at 1.2 without any major issues other than ignition, which the mines deals with!

i know you have rewired pump but i would still be suspicious if its putting out enough fuel under heavy load, to run the sort of figures you are achieving!

 

[GINGA]

You'll probably find it is reaching the limit of your map, but not enough to make the fuelling and timing a issue, you can remedy this by either fitting larger injectors or raising the fuel pressure 0.5bar or so with a adjustable fpr, then use a s-afc to compensate for the increase in fuel, what this does is lowers the signal from the maf that the ecu sees and hence it doesn't use quite as much of the map as before, giving you alittle extra room to play with. The maf will still be maxing out but the ecu will not see this as the s-afc will be setup to compensate for that, also the timing will need checking as it would be further advanced than normal, due to the ecu thinking theres less air going in than there really is.
Tbh I wouldn't bother with s-afc's and just go straight for a std ecu remap with larger injectors and z32 maf, this will be a much better solution and will give you everything you need if you wish to push the power up in the future.
Deffo fit a uprated pump aswell, the std pump on the std wiring tends to be on its limit at just 1 bar.

 

[youngsyp]

not really my field tbh with you paul but people have run the stock ecu at 1.2 without any major issues other than ignition, which the mines deals with!

i know you have rewired pump but i would still be suspicious if its putting out enough fuel under heavy load, to run the sort of figures you are achieving!

Totally agree Bob. The fuel pump is at the top of my list, next to a new fuel filter !

I'm definitely still interested in the Mines ecu though as, I think it will provide that extra protection !

 

[youngsyp]

You'll probably find it is reaching the limit of your map, but not enough to make the fuelling and timing a issue, you can remedy this by either fitting larger injectors or raising the fuel pressure 0.5bar or so with a adjustable fpr, then use a s-afc to compensate for the increase in fuel, what this does is lowers the signal from the maf that the ecu sees and hence it doesn't use quite as much of the map as before, giving you alittle extra room to play with. The maf will still be maxing out but the ecu will not see this as the s-afc will be setup to compensate for that, also the timing will need checking as it would be further advanced than normal, due to the ecu thinking theres less air going in than there really is.
Tbh I wouldn't bother with s-afc's and just go straight for a std ecu remap with larger injectors and z32 maf, this will be a much better solution and will give you everything you need if you wish to push the power up in the future.
Deffo fit a uprated pump aswell, the std pump on the std wiring tends to be on its limit at just 1 bar.

According to Conzult, the MAF wasn't maxing out though ! Everything was fine (although we didn't log the injector duty under load), accept the fuel and igintion load scales which, were beyond what the ecu could cope with !

 

[Fusion Ed]

So, does the ecu know it can't supply enough fuel and so move up the load scale some more, in an effort to pump more fuel in ?

No, on full throttle it has no fuel feedback, so it has no idea weather it is fuelling right or not, the load map is totally related to airflow voltage and RPM, higher the voltage/rpm higher up the map.

But, in my case, there isn't sufficient fuel pressure to supply any more ?

Would appear sufficient fuel pressure full stop.

Well, at least that gives me a focused point to check before anything else. And of course, it's still on the stock fuel pump !

Another though is could this be a fuel filter issue ? Maybe it's blocked...... again ?!

Possibly, as it gets leaner right up the top end where according to the map it should be richer. (and as shown by almost every other GTi-R)