Gtr 26/30 With Cams And -5S

[Scooby]

G'day

Car is being tuned and I've been told the Nismo pump is running out of puff. Recommendation is to fit a 040 in tank.

Anyone here know what power a Nismo pump starts to struggle at? Searched but not much info.

Cheers

[TiTAN]

nismo intank will flow as much as a bosch 044 (which will flow more than a 040)

[R31Nismoid]

Seen many Nismo's go into the 400-440rwkw region. 380rwkw for example is a walk in the park.

Yours perhaps might be tired?

[Scooby]

It's about 3 years old and has about 5000 km on it so I suspect tiredness probably isn't the issue. I haven't done the wiring conversion so I'm wonder if it's a volt drop problem.

And sorry my bad, they're recommending 044.

Only other thing I can think of is that the Nismo purples are the issue although they should be good for 600hp or so at the fly?

[R31Nismoid]

Check the fuel pressure and you'll soon know if its the pump, or then the voltage.

Either way should be fine so you have an issue somewhere.

What CC are the injectors? You'd know if they were running out though due to duty cycle. Either way the Bosch isn't the answer just yet.

[R32 TT]

It's about 3 years old and has about 5000 km on it so I suspect tiredness probably isn't the issue. I haven't done the wiring conversion so I'm wonder if it's a volt drop problem.

And sorry my bad, they're recommending 044.

Only other thing I can think of is that the Nismo purples are the issue although they should be good for 600hp or so at the fly?

Scooby, I have a 044 in-tank and also had a fuel issue which had us stuffed for a while. It acually ended up being the stock pickup. It has a plastic 'skeleton' which keeps its shape. Turns out it had cracked, but while you had it in your hand it didn't look like it. This caused the filter to collapse at higher RPM/load and stifle the pump.. on dyno it just looked like the pump was running out of legs.

May not be your issue, but thought I'd suggest it just in case. Nismo pump should be good for some serious hp. (and yes, do the relay thing as well)

[Marko R1]

hey mark - if you are going to upgrade your pump, get the pierburg which flows 360lph, when compared to 044 which is rated @ 200lph it flows 65% more!

although, i'd also agree to firstly the source as to why the nismo will not flow as much & support your setup.

[Scooby]

Hey Marko

Saw your thread re in tank fuel pumps and the Pierberg. At what pressure does it flow 360 lph? I've seen the 044 quoted at 200 and 300, but the 200 was at 5 bar and I think the Nismo's 276 lph was at 3 bar.

But yeah as others have suggested I need to find out the problem first, I'd have thought 600cc inj would be close to maxing if the Nismo pump can't keep up. I'll have a talk to Jim tomorrow to find out what's happening.

Cheers

[R31Nismoid]

You only have 600cc injectors?

Probably a tad small unless you up the rail pressure.

[Scooby]

Thanks for the input everyone.

Lol yes everything was fine until the -5s and cams came long...-7s were always on boost and falling over by 6750 rpm with stock cams. Adj cam gears made little difference. About 300rwkw on a very conservative tune.

I thought rule of thumb was roughly 1cc/hp so 600cc injectors should be good for 600hp/447kw at the fly. Assuming that's not totally wrong they should be good for 350rwkw? I'm not keen to go over that as I want longevity.

[R31Nismoid]

Well depends - you need to go and check everything

Fuel pressure

Injector duty (are they maxing out?)

Fuel pump voltage

Fuel filter been changed recently?

So how much power are you currenty limited too? Sounds like less than 350rwkw?

And ye, -7 fall over ~7000rpm, given they come on @ 3300rpm, fair trade. Can't have response and top end

[Marko R1]

Hey Marko

Saw your thread re in tank fuel pumps and the Pierberg. At what pressure does it flow 360 lph? I've seen the 044 quoted at 200 and 300, but the 200 was at 5 bar and I think the Nismo's 276 lph was at 3 bar.

But yeah as others have suggested I need to find out the problem first, I'd have thought 600cc inj would be close to maxing if the Nismo pump can't keep up. I'll have a talk to Jim tomorrow to find out what's happening.

Cheers

hey mark,

The Bosch 044 runs 200lph @ 5bar (more info: http://www.bosch.com...s/fuelpumps.pdf)

The Pierburg (aka Bugatti Veyron pump RAAAAR) runs 330lph @ 5bar (more info http://www.compsyste...2:ecu&Itemid=14)

[Scooby]

Tried to talk to Jim today but he wasn't around. They've gone ahead and ordered the 044, giess it's what they're used to but I told them not to install until they can explain what's going on. Hopefully find out tomorrow.

[R31Nismoid]

They ordered it anyway?

I'd be wanting to know its been tested, and proven dead before you pay anything.

[rob82]

I dont see why people dont test their fuel systems before tuning - its the simplest thing to check.

Boost gauge and air compressor is all that is needed. Put whatever boost pressure your going to run onto the fuel reg - watch you boost gauge to see the pressure. Put the return line into a measurable container (arround 5L), then start and run car for 1 minute. If there is 6x600cc/min = 3.6L/min then you have enough fuel system.

We need a sticky on this - as I know it pisses me off as a tuner when you get setup on the dyno only to find no fuel flow on the first dyno run.

[Scooby]

They ordered it anyway?

I'd be wanting to know its been tested, and proven dead before you pay anything.

Yes they did, my thoughts exactly, but I think they'll easily use it on someone else's if not mine. I told them not to go ahead until I find out what's happening. I actually do trust their judgement but I still want to know what the issue is.

Ash I did see a thread in which I think you suggested there was conjecture around whether a Nismo pump is the same as a stock Nissan one but a third of the price? What pump are you running on the GTR?

[R31Nismoid]

Nismo

I see 65% max duty on PULP with 700cc injectors on a 4 degree night. 20psi (2.6l) with -5 and 365rwkw.

Not running factory fuel pressure though, i have a modified reg so it would probably be closer to 70%, maybe 75% if using a stock reg.

Still room to move either way, your 600's "should" flow enough for 350rwkw and be 80% or less duty. Hence if you do have 100% duty its somewhere in - pump / voltage / pressure

Rob - do a write up, ill gladly link it to the FI Guide

[JonnoHR31]

at the same time though every engines different, aswell as every dyno. sure something might not be up to scratch but its not always a given. for example i maxxed (properly maxxed, 100% on cold mornings) standard 25 injectors at 185rwkw with adequate fuel pressure. combination of an engine that never made as much power as others, a slightly lower reading dyno and a slightly rich tune. on the same low powered engine and same dyno i came close to maxxing nismo 555s at 250rwkw.

but yer, flow test the pump first

[Marko R1]

hey mark - you know you are in the best hands possible @ crd & there is absolutely no way that jim would have ordered the 044 without further diagnosis...jim is always of the opinion if its not setup right, he is not happy to push it & this is great, signs of a perfectionist IMO

are u just running the single 044 intank mark? i.e. no other external pumps or surge tank?

what power level are u aiming for & what did jim say he can achieve for you?

[R31Nismoid]

350rwkw was mentioned earlier...