Gtr 26/30 With Cams And -5S

[Scooby]

I'm sure when I call Jim he'll have the answers, he hasn't failed me yet. Just single tank, we haven't talked power I've just left him alone what he gets is what he gets. Been itching to do -5s and custom cams from the start to satisfy my curiosity so we'll see how it goes.

[GTScotT]

Recently had an issue with a genuine walbro in a GTR failing at 300kw.

Direct wired the pump to a quality relay and suddenly had ample fuel (700cc injectors).

Give that a shot if your wirring is factory.

[Marko R1]

here is a clip of my previous gtr which made 345rwkw @ 19psi, it had drop-in poncams & -5s on it!

mark, you will get your 350rwkw without a problem!

[Beer Baron]

I still think replacing the nismo for the 044 is a waste of time and money. direct wire the nismo with a relay and then test the flow (as explained earlier in the thread). no point just upgrading on a hunch and it's very debatable whether the 044 actually is an upgrade over the nismo anyway. In my experience a single nismo pump supports more power than single 044s do.

[Harey]

+1 Beer Baron, from my little experience I have heard exactly the same. I know Trent from Status Tuning rates the Nismo intank fuel pump very highly. He said he has seen over 400rwkw numerous times on his dyno.

[Scooby]

Jim says the torque is the thing that's sucking fuel and the current pump isn't up to it for an RB30 with my config. He can get it to 300awkw but that's it. He's got a test kit with a 044, hooked it up and reckons the difference is significant.

He's sending me a dyno graph with the current set up so I'll post it up when it arrives.

[Marko R1]

There u go

When I built my rb30 and made 405awkw, ppl couldn't understand how I was hitting 70% injector duty cycle with bosch 1600cc injectors...its the torque that chews fuel!

[R31Nismoid]

There is zero chance a working Nismo pump will be maxed with those turbos, let alone @ 300.

There have been 2.8lt strokers making 420-440rwkw with a single Nismo pump on 800cc injectors. So not just 2.6lt here. I realise a 30 is another 200cc more, but it's not a magical fuel eating beast. Extra - yes, but it's >10% capacity that isn't going to use 50% more fuel, thats just ridiculous.

And going off what you are saying RE: 1600/70% - if that's the case then Scoob's 600cc injectors will be maxed @ 300.

The only way to explain that is two ways

1. The pump was dying (rare & super ez to check)

Or

2. Wiring wasn't correct, and as part of 044 install, that was fixed.

[R31Nismoid]

There u go

When I built my rb30 and made 405awkw, ppl couldn't understand how I was hitting 70% injector duty cycle with bosch 1600cc injectors...its the torque that chews fuel!

Or a tune with a bucket of fuel in it.

[Marko R1]

...Which is required for a 3ltr. I know it might sound ridiculous, however, that extra 400cc makes a world of difference in terms of the required fuel

[R31Nismoid]

200cc you mean (when comparing to the 3-4 2.8lt results so far in the dyno threads).

TangoMatt was one of those as well don't forget. Over 400/2.8/Nismo. Aaron34 - almost the same setup.

[Marko R1]

I can't comment on the above cars, I'm talking from my experience only

[R31Nismoid]

I knew there was some results of flow testing... Finally found it. Bit long winded but I think it's some pretty good info. (Gotta love a 12hr night shift for research purposes)

http://www.stealth316.com/2-fuelpumpguide.htm

Factory GTR pump flow: 230L/hr @ 72psi (13.5V)

So lets assume a Nismo pump is the same as stock GTR pump (its 25% more apparently, I have reason to think its the same, thats for another discussion)

Bosch Flow Rate PDF (63kb).

Bosch 044: 200L/hr @ 72psi (12V)

So clearly the Bosch if wired up @ 13.5V will flow more, and that overall the Bosch would be the better pump - I'm sure we can all agree on that.

However we are not talking about max flow rate

What are we talking about? Flowing enough fuel to supply 600cc injectors.

Now this has nothing to do with torque, just maxing the injector on a flow based level. So power output is irrelevant, size of motor etc.

To achieve this you need 3.6L/min as Rob82 said before.

Flow required: 216L/hr @ approx 60psi. (40psi base + 20psi boost to be generous)

So clearly both Nismo & Bosch flow rates are more than adequate for 600cc injectors that are @ 100% duty.

Even if you bumped the base pressure to 50psi + 20psi you still have enough room.

If the Nismo pump is not flowing enough, it is as i said earlier one of two things

1. Nismo is dying.

2. Nismo is not wired correctly.

Both are possible, both are very easy to check. Hope it adds a bit to the discussion.

I'd be asking for that Nismo pump and flow testing it if I were you Scooby

[Duncan]

The thing I don't understand...is it is dead easy to check the fuel pump is supplying enough fuel (fuel pressure guage, can even be inline to the fuel line on the dyno). If fuel pressure suddenly starts to drop especially at max torque, you are having a fuel pump flow issue.

[Beer Baron]

agreed. for the sake of $200 I permanently have a fuel pressure gauge in car. it's referenced to boost too (so stays steady at base pressure unless something is wrong) so it's very easy to spot lack of supply to the rail. cheapie mechanical ones can be had for about $60. and any workshop would have one.

[rob82]

There u go

When I built my rb30 and made 405awkw, ppl couldn't understand how I was hitting 70% injector duty cycle with bosch 1600cc injectors...its the torque that chews fuel!

That's the dumbestest thing I've heard. Torque has nothing to do with fuel usage. The more power you make at the lower the rpm the more torque. You also have more allowable time to inject the fuel if your making high hp at low rpm (torque).

I've regularly make 360rwkw on an xr6t with 440cc injectors on pump fuel and they make more torque than most rb30's at this power level!

[Marko R1]

That's the dumbestest thing I've heard. Torque has nothing to do with fuel usage. The more power you make at the lower the rpm the more torque. You also have more allowable time to inject the fuel if your making high hp at low rpm (torque).

I've regularly make 360rwkw on an xr6t with 440cc injectors on pump fuel and they make more torque than most rb30's at this power level!

I don't take offence to your comment, however, I 'DO' listen to ppl in the know who have been building and tinkering with gtr's when u were probably riding a push bike...I am talking about the likes of CRD, RIPS racing and Red R Racing.

Why don't u pick up the phone and have a chat with these guys, rather than unleash as I am only the messenger

[rob82]

I don't take offence to your comment, however, I 'DO' listen to ppl in the know who have been building and tinkering with gtr's when u were probably riding a push bike...I am talking about the likes of CRD, RIPS racing and Red R Racing.

Why don't u pick up the phone and have a chat with these guys, rather than unleash as I am only the messenger

You've obviously misunderstood them because what you have stated makes no sense.

Generally the higher the bore/stroke ratio the higher the bsfc - hence the better the conversion of fuel to hp.

[Marko R1]

I understood them clearly and have been in the gtr scene for 10yrs (how time flies), unless they are all telling the same lie...anyway, let's move on.

[bigmikespec]

You've obviously misunderstood them because what you have stated makes no sense.

Generally the higher the bore/stroke ratio the higher the bsfc - hence the better the conversion of fuel to hp.

So if you are making more torque and roughly the same power what is happening? (i.e. assume RB26 vs RB30)