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Discussion Starter · #1 ·
Like, the title says, what is the maximum BHP (at the wheels) i should be looking at (and still keeping reliability) before i need to upgrade to bigger injectors?

I have already ordered some new things for the engine today :D , and will be fitted in about 2 weeks (will put new post in my 'projects and restorations' thread when done)

Just want to do the best i can on stock internals before i have to start digging deep into my pockets.
 

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Well... as a rough guide mine used to run 234 at the wheels on std injectors running @ 90% duty cycle. Really you dont want to go over 80% to be safe.
Std internals are good for some say 450bhp others 500-550 bhp But the supporting mods ie injectors fuel pump afm etc MUST be done also.
 

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size of injector in cc X number of injectors / 5

a rough calc - bearing in mind that this calc attributes 100% duty cycle and, theoretically, you should'nt exceed 85% or so.
 

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Fly

So it'd be (370 x 6 / 5) x .85% = 375bhp ish? Don't forget it's rough, and that increasing fuel pressure at the reg can get a little more
 

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Discussion Starter · #7 ·
is there also any kind of equation then that relates bhp at the fly to the wheels?

Or is that vary dramatically from car to car?

I want to bump up the BHP, but want to do it sensibly, and keep the engine running smooth with the least amount of strain on the internals as possible.
 

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is there also any kind of equation then that relates bhp at the fly to the wheels?

Or is that vary dramatically from car to car?

I want to bump up the BHP, but want to do it sensibly, and keep the engine running smooth with the least amount of strain on the internals as possible.

it's dramatic from rolling road to rolling road and really all you should be interested in is hub power and what's relevant to what you came from to what you are now, rather than comparing against someone elses' car. To give you an idea, 253 at the fly was 213 at the wheels on my old car, but 250bhp fly is 214 at the wheels on my current car.... I've seen some lose less than 10%, others lose 30% plus

The way to keep the engine reliable is a) have a very safe fuel map without going wild on the advance, leaning out to obtain more power or equally shoving fuel in just because you think it might det, b) having an engine/setup that's well specced throughout all of it's components, ie it hasn't got a rediculously laggy turbo that kicks like a mule at 5500rpm with poor mapping before and after it and c) good quality maintenance
 

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Discussion Starter · #9 ·
To be honest, it is not about comparing with others, it is a kind of bench mark to set for myself. Not one that HAS to be obtained, but one that is desired.

I am still kinda new to this, so i am getting info from all sources where i can, because some of the things i have been told vary quite dramatically on the route to go in achieving a decent amount of power, while still having the ability to use the car as a reliable car for very day use.

Because i am new to this (and also not loaded!) keeping all the engine components on a par is also something i am keen on doing as well as keeping it well maintained.
 

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To be honest, it is not about comparing with others, it is a kind of bench mark to set for myself. Not one that HAS to be obtained, but one that is desired.

I am still kinda new to this, so i am getting info from all sources where i can, because some of the things i have been told vary quite dramatically on the route to go in achieving a decent amount of power, while still having the ability to use the car as a reliable car for very day use.

Because i am new to this (and also not loaded!) keeping all the engine components on a par is also something i am keen on doing as well as keeping it well maintained.
That's exactly how it should be. You judge your own car by it's own cover - because someone having 20 more bhp than you doesn't necessarily make their car faster ;)

Like I say, I think realistically you'll struggle to map up reliably keeping standard injectors to anything over 380bhp without raising fuel pressure slightly. Most skyline tuners seem very keen to do this, probably because "upgrade" injectors are far harder to come by for 6 pot RB's than 4 pot CA's where GTR injectors fit nicely.
 

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Generally im like you saitsman, I wouldnt mind a bit more power but dont want to compromise reliability, I think generaly no matter what you upgrade has a knock on effect on other parts of the car and where do you stop.
 

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Discussion Starter · #12 ·
well, all this may be a little way off yet anyway. Like i said, i am not loaded. But i do have my first set of engine mods going in the next couple of weeks, which should make the car a little more fun, and then after a couple of months when i have got £1500 or so to spare, the next set of mods will be put on order and put in.

Have been told that this should see me to about 330BHP, after that is when i will have to make a decision and find more info about which other avenues i should be exploring before choosing the 'MY' correct path to enlightenment. :D
 

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Don't forget the handling dept, there's more to be had there than power IMO;)

good luck with the project anyways :)
 

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Discussion Starter · #14 ·
Generally im like you saitsman, I wouldnt mind a bit more power but dont want to compromise reliability, I think generaly no matter what you upgrade has a knock on effect on other parts of the car and where do you stop.
That is why i am getting professionals to fit the parts to my car, and have them running it sweetly, then i can go back to them and adjust anything to my liking if it if a possibility, or a needs be.
 

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Discussion Starter · #15 ·
Don't forget the handling dept, there's more to be had there than power IMO;)

good luck with the project anyways :)
Cheers arry. Handling is important to me. Especially seeing as i rolled my BMW down a hill a couple of years ago.

But the car had been lowered previously to me buying it, and it also has some big boots on it too :)
 
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