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exactly, if we went to the sr20 forums and told them 555s can make over 300rwkw then showed them an rb25 picture we be kicked out...lol

Fuel pressure and injector size don't magically change between two 6 cylinder engines. That motor is running standard 3 Bar fuel pressure.

Edited by Super Drager

but it is running at least 500cc extra, thats assuming its a stock engine which I doubt??

As i said , show me an RB making 400atw on 555s and I will shut up..but generally each cc of injector is worth around 1 hp at the flywheel on an RB as far as i know...

generally each cc of injector is worth around 1 hp at the flywheel on an RB as far as i know...

That can't be correct. I run 740cc in my SR with stock rail pressure and currently make 270rwkw with 85% duty cycle on E10 100 oct.Or are the extra 2 cyls and .5 ltr making that much of a difference?

Edited by slippylotion

My Hypergear experience- part deux!

Hi all, I posted a few weeks ago about my Hypergear experience up to and including fitting of the turbo and a quick run.

I had the car tuned yesterday by TOSHI and here are the final results;

Car Specs for those who missed the last post;

R33 S2

Unopened RB25 ~100,000km

Hypergear PU Highflow (non SS1)

Blitz return flow FMIC

Splitfire Coils

Metal intake with std airbox

Z32 AFM

S15 480cc injectors

Gizzmo Boost controller

Xtreme Cushion button clutch

Peak power of 287.4 RWKW at 20psi which tapers off to around 17-18psi

We turned the boost down a little bit and got repeatable runs of around 280-285.

TOSHI spent basically a whole day tuning the car and was very very thorough. I would definitely recommend TOSHI without hesitation- he has done a great job with the car and even managed to have the turbo come on alot sooner than i had anticipated!

If you need a tune, call TOSHI or PM him on here.

The car feels great and when full boost arrives at around 4,500-4,750 it pulls like a train. Put it this way, if one were to open it up on the street (in controlled conditions of course!) you would run out of road pretty quick :-)

Any questions feel free to ask away, ill put up some more photos etc when i get around to it.

The photo attached is just a photo of the peak run- i have a print out of another run but its in HP which is annoying!

Cheers!

post-55684-0-79230800-1335477995_thumb.jpg

post-55684-0-30452600-1335478040_thumb.jpg

^^^Well look at that, 480hp from 480cc injectors ..:woot:

I think a couple of other things worth noting on the zx, they are not nismo sidefeeds (not that it makes any difference) and it is also running huge -8 fuel lines..so even when pushed to 100% duty it has plenty of fuel supply, trying doing that with a stock rail and you might find it difficult..

its a fairly inaccurate rule rule of thumb to say 1cc is 1hp, when I was buying injectors I mentioned it at they just looked at me funny..

A better rule rule of thumb I think is to figure out the bare minimum size you would need then get injectors around 30% bigger so your duty will be around 80% tops..sure you can push anything to make more power than it should but push anything out of its efficiency zone and your asking for problems. Sooner or later you will get what you ask for..

This whole thread has been testament to this with HG constantly pushing his turbos to limits most tuners aren't happy to match knowing their customer will be out there driving it everyday..inefficiency monitored in a controlled environment on a dyno is one thing compared to inefficiency out there on the road everyday..I don't even have gauges in my car, when I get a tune I want it pushed to its limits in the room, but when I drive out I want a tune that's almost idiotproof:D

That can't be correct. I run 740cc in my SR with stock rail pressure and currently make 270rwkw with 85% duty cycle on E10 100 oct.Or are the extra 2 cyls and .5 ltr making that much of a difference?

Nah that is right mate.. Remember you have 50% more injector on an RB simply because there are 6 of them, which is essentially 50% more flow capacity. Total fuel and total boost equals a power figure, because you simply have more fuel you can simply add more air and therefore make more power with the same size injector.

Remember also that pressure ratio changes the motors effective efficiency. IE a 2 litre motor run at 2 bar of boost is as efficient (size wise) as a 4 litre motor run on 1 bar. Every bar of pressure added beyond atmospheric effectively doubles the motors size. Or such is the science behind it.

FWIW I've also had a Toshi tuned car in the family, it went very well.

My Hypergear experience- part deux!

Hi all, I posted a few weeks ago about my Hypergear experience up to and including fitting of the turbo and a quick run.

I had the car tuned yesterday by TOSHI and here are the final results;

Car Specs for those who missed the last post;

R33 S2

Unopened RB25 ~100,000km

Hypergear PU Highflow (non SS1)

Blitz return flow FMIC

Splitfire Coils

Metal intake with std airbox

Z32 AFM

S15 480cc injectors

Gizzmo Boost controller

Xtreme Cushion button clutch

Peak power of 287.4 RWKW at 20psi which tapers off to around 17-18psi

We turned the boost down a little bit and got repeatable runs of around 280-285.

TOSHI spent basically a whole day tuning the car and was very very thorough. I would definitely recommend TOSHI without hesitation- he has done a great job with the car and even managed to have the turbo come on alot sooner than i had anticipated!

If you need a tune, call TOSHI or PM him on here.

The car feels great and when full boost arrives at around 4,500-4,750 it pulls like a train. Put it this way, if one were to open it up on the street (in controlled conditions of course!) you would run out of road pretty quick :-)

Any questions feel free to ask away, ill put up some more photos etc when i get around to it.

The photo attached is just a photo of the peak run- i have a print out of another run but its in HP which is annoying!

Cheers!

Another good result from Toshi.

The power figure is good, check the actuator reload, it appears if the gate is not 100% sealed, you can find instructions on actuator pre-loading under my youtube account: taosg2001 This is an easy operation that can be done with the turbo still attached.

Once gate is sealed and loaded, the car will be able to gain much more response and mid range power.

Fuel pressure and injector size don't magically change between two 6 cylinder engines. That motor is running standard 3 Bar fuel pressure.

I'm no fuel injection expert, but I would think the hundreds of different variables between the two engines, not the least being an extra 500cc of displacement or different fuel types, would throw out the maximum achievable power by a fair bit. People might just be playing it safe with bigger injectors, but I haven't seen any 400rwkw RB25s on 555s.

That can't be correct. I run 740cc in my SR with stock rail pressure and currently make 270rwkw with 85% duty cycle on E10 100 oct.Or are the extra 2 cyls and .5 ltr making that much of a difference?

As Scott said, you have 50% more injectors in an RB supplying to only 25% more displacement, it makes a big difference. Thus S15 injectors are a common upgrade for RB25 engines because they are larger, despite similar factory power outputs for both engines.

I'm no fuel injection expert, but I would think the hundreds of different variables between the two engines, not the least being an extra 500cc of displacement or different fuel types, would throw out the maximum achievable power by a fair bit. People might just be playing it safe with bigger injectors, but I haven't seen any 400rwkw RB25s on 555s.

As Scott said, you have 50% more injectors in an RB supplying to only 25% more displacement, it makes a big difference. Thus S15 injectors are a common upgrade for RB25 engines because they are larger, despite similar factory power outputs for both engines.

Yeah I understand the extra displacement and 2 extra injectors allowing for more power on a same sized injector. More so questioning the theory of 1cc = 1hp.

Yeah I understand the extra displacement and 2 extra injectors allowing for more power on a same sized injector. More so questioning the theory of 1cc = 1hp.

Yeah its not a real definite rule of any sort, just a reasonable way to calculate injector size.

IE if i was going to aim for 500whp I would probably run a 800cc injector in the RB25, giving me ability to run the injectors at no more than 80% duty cycle and hit the target. (98 ron example here)

Thats all it is mate, a rule of thumb to help with picking the right injector size.

Absolutely a rule of thumb. And absolutely subject to a few extra variables. But on ANY 6 cylinder engine of reasonable flow ability (so not an old Holden grey or slopey Valiant motor) the rules holds approximately true. 6 x 600 cc injectors is about enough fuel for 600HP. About.

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