Max kw atw on 565cc pinks?

[Guest]

Had a bit of a hunt on here but couldnt track down what Im after. I thought someone said 565cc pinks tapped out around 240-250kw atw. Anyone maxed a set? Will be buying top feeds at some point and want to have the potential to run 280kw atw.

I know they can be decapped and Im not after recommendations on other injectors either.

[boon]

Depends on fuel pressure...

Using the factory FPR and keeping a fairly safe AFR my 565\'s were approaching their limits at 231wkw on STM\'s dyno (probably around 240-250wkw using SAE correction) - apparently 565\'s and a VF34 run out of puff at a similar point.

280wkw seems reachable with 800\'s/850s without running silly fuel pressure. I think Funky is running injectors around this point with 300wkw and lots of boost.

That said, when it comes to top feeds (EV14s in particular) the pricing almost always seems to be the same between 800\'s and 1000\'s which is why I\'ll get 1000\'s for the headroom.

[funkytown]

i ran venom 550\'s (side fed admitadly) and i ran up to 237wkw on shreds dyno back in the day and was running reasonable IDC\'s %.

note i was only running base pressure on an in tank walbro. I wouldnt personally run 560\'s up to 250, your IDC\'s will end up quite high.

note i now run sard 840\'s and have added an 044 external to the walbro intank and running stock fuel pressure @ 78% IDC at ~320wkw (sae corrected).

[Marky]

Rule of thumb (ish) is 550cc per 100hp at crank (real give or take)

The motor / type of injector shouldn\'t play much part in that, it\'s an equation of x cc\'s can support x power unless something more to it

Sooooo call it approx 300kw crank? Depends on how happy your dyno is as to what atw that would mean

Fwiw late model evo injectors (560cc from memory?) normally see similar numbers, the older ones with 510s maxed out (like, 100 % IDC maxed out) around 230kw atw unless you started cranking base pressure to weasel that little bit more

[Guest]

Is it bad to wind up pressure to get more power with less d/c?

1000cc is bigger than my block will handle thinking 850cc would give me plenty of headroom. People have run 320-330kw with 850cc.

[boon]

No real problem as long as your fuel pump can handle the extra work.

Atomisation gets real good at high pressure too, gotta have a decent ECU though as the injectors won\'t behave in a linear manner as the pressure increases.

The problem with raising your base fuel pressure is that for every pound of boost in the manifold the fuel pressure has to increase (hence linear rising rate FPR)

So while your fuel pump might happily flow to its rating when you\'re under vacuum, when you hit 20psi and the pump has to flow the same amount but at 20psi more (plus your increase in base FP) the flow will start to fall off - if you have a big enough pump no problem but I dare say your average Walbro 255 would be starting to panic.

[funkytown]

 evowrx said:

Is it bad to wind up pressure to get more power with less d/c?

1000cc is bigger than my block will handle thinking 850cc would give me plenty of headroom. People have run 320-330kw with 850cc.

read above on my real world xp on 840s.

upping pressure is ok to a point. you will suffer in atomisation and idle ends up being a bit finiky. just makes it a bit less drivable tbh.

note as you increase base pressure as boons said about, a pump wont flow as much, so its a trade off between lph it will flow and the required fuel pressure.

boon - pre motor exploding, i ran my 840\'s @ base pressure on the walbro alone for 305wkw on shreds dyno ... this however is its limit.

[Marky]

http://www.usrallyteam.com/index.php?main_page=index&cPath=10_45

Just random graph I found on gooooogle to show idea of the relationship between flow capability and pressure demand

If you wanted you could work out the flow required by say a 550cc inj at 100% IDC, (or an 800 at 80% or whatever) work that x 4 into LPH, and then see if the pump you have will supply that at the pressure you\'re running (just to get your head around it I guess)

Then just buy a bigger pump anyway, cause fuel pumps are cheap these days whereas motors are not

[funkytown]

anything over 80 or 85% IDC is not sensible.

100% IDC is just plain fucking stupid.

[Marky]

I agree with you - it\'s more just for arguments sake of getting some numbers for LPH etc

When people ask "how much will x cc injectors be capable of" the answer can vary massively depending on if you want the answer of "at 100% duty cycle they *could* flow x each" or do you answer "safely they can do blah"

My thought are always go oh ok, if 500 will get me what I want... Just go to 700 to have headroom (or whatever is available) - ditto for the pump itself

Least they aren\'t like turbos, to a point there isn\'t a downside in going overkill (note I said to a point)

[94 Leone]

I found this on perth-wrx forums

" Originally Posted by EVL WRXCC of injector divided by 5 x how many cylinders = Max BHP at 100% duty.

So 440cc injectors in a 99 will equate to a max BHP at 100% duty cyle of 352 (263kw).

At 85% IDC to be safe it is 300hp (224kw)

Assuming around a 15% drivetrain loss, that would mean at 85% ICD the injectors can support 190kw\'s at the wheels..

At 90% ICD (still pretty safe) they\'ll hold 201kws atw...

Use an FPR to up the pressure and they\'ll hold more kw\'s at the same %\'s...

Hope this helps

Cheers "

565/5 =107

107*4 =428hp

Drivetrain loss, 428*.85= 363.8 hp

Convert to kw, 363.8*.75 = 271.3kw

That\'s obviously at 100 percent duty.

Interesting peice of math though.

[boon]

 94 Leone said:

I found this on perth-wrx forums

" Originally Posted byEVL WRXCC of injector divided by 5 x how many cylinders = Max BHP at 100% duty.

So 440cc injectors in a 99 will equate to a max BHP at 100% duty cyle of 352 (263kw).

At 85% IDC to be safe it is 300hp (224kw)

Assuming around a 15% drivetrain loss, that would mean at 85% ICD the injectors can support 190kw\'s at the wheels..

At 90% ICD (still pretty safe) they\'ll hold 201kws atw...

Use anFPRto up the pressure and they\'ll hold more kw\'s at the same %\'s...

Hope this helps

Cheers "

565/5 =107

107*4 =428hp

Drivetrain loss, 428*.85= 363.8 hp

Convert to kw, 363.8*.75 = 271.3kw

That\'s obviously at 100 percent duty.

Interesting peice of math though.

271 * 0.85 = 230wkw

Which is 85% IDC which I think most tuners try to stay around.

And matches my real-world results within 1kw or ~0.5% - intriguing.

[Shaun]

 94 Leone said:

I found this on perth-wrx forums

" Originally Posted byEVL WRXCC of injector divided by 5 x how many cylinders = Max BHP at 100% duty.

So 440cc injectors in a 99 will equate to a max BHP at 100% duty cyle of 352 (263kw).

At 85% IDC to be safe it is 300hp (224kw)

Assuming around a 15% drivetrain loss, that would mean at 85% ICD the injectors can support 190kw\'s at the wheels..

At 90% ICD (still pretty safe) they\'ll hold 201kws atw...

Use anFPRto up the pressure and they\'ll hold more kw\'s at the same %\'s...

Hope this helps

Cheers "

565/5 =107

107*4 =428hp

Drivetrain loss, 428*.85= 363.8 hp

Convert to kw, 363.8*.75 = 271.3kw

That\'s obviously at 100 percent duty.

Interesting peice of math though.

just checking your math

565/5 = 113

113*4 = 452

452*0.85 = 384.2 drivetrain loss

384.2*0.85 = 326.57 85% DC

326 bhp = 243kw

[johnny5]

interesting

[Marky]

That whole equation is working with a) a "removed from rectum" 15% drivetrain loss figure, and b) the same super approximate 5x cc conversion of cc\'s to hp per cylinder I already mentioned

There is heaps which can play a part - the dyno accuracy just one of a multitude of things

Just work with 550cc = 100 crank hp, super ultra ballpark approximation - there is no point at all in trying to over analyze it

[Ninja8)]

 Shaun']

[quote name='94 Leone said:

I found this on perth-wrx forums

" Originally Posted by EVL WRXCC of injector divided by 5 x how many cylinders = Max BHP at 100% duty.

So 440cc injectors in a 99 will equate to a max BHP at 100% duty cyle of 352 (263kw).

At 85% IDC to be safe it is 300hp (224kw)

Assuming around a 15% drivetrain loss, that would mean at 85% ICD the injectors can support 190kw\'s at the wheels..

At 90% ICD (still pretty safe) they\'ll hold 201kws atw...

Use an FPR to up the pressure and they\'ll hold more kw\'s at the same %\'s...

Hope this helps

Cheers "

565/b]5[/b]=107

107*4 =428hp

Drivetrain loss, 428*.85= 363.8 hp

Convert to kw, 363.8*.75 = 271.3kw

That\'s obviously at 100 percent duty.

Interesting peice of math though.

5 is the number of cylinders.subarus have 4 dont they?

[loner]

Did anyone mention fuel temperature? It will get higher with higher pressure... meaning more det..

[Guest]

Got what I was after cheers fellas. Im thinking walbro plus 22psi isnt going to be an issue on a street driven car.

Btw jon where is your real world xp post?

[94 Leone]

 Ninja 8)']

[quote name='94 Leone said:

I found this on perth-wrx forums

" Originally Posted by EVL WRXCC of injector divided by 5 x how many cylinders = Max BHP at 100% duty.

So 440cc injectors in a 99 will equate to a max BHP at 100% duty cyle of 352 (263kw).

At 85% IDC to be safe it is 300hp (224kw)

Assuming around a 15% drivetrain loss, that would mean at 85% ICD the injectors can support 190kw\'s at the wheels..

At 90% ICD (still pretty safe) they\'ll hold 201kws atw...

Use an FPR to up the pressure and they\'ll hold more kw\'s at the same %\'s...

Hope this helps

Cheers "

565/5=107

107*4 =428hp

Drivetrain loss, 428*.85= 363.8 hp

Convert to kw, 363.8*.75 = 271.3kw

That\'s obviously at 100 percent duty.

Interesting peice of math though.

/quote]

5 is the number of cylinders.subarus have 4 dont they?

It\'s divide by five then, multiply by cylinders.

[Pappu1]

Have done this in the past

565cc Sti pink and Walbro on stock Reg and fuel lines

Gets to 235kww and 100% dc at 11.1 AFR

This was done on a dyno day at torque performance

I wud say if it was a bit leaner maybe 240kw but that too at max or near max Injector dc

So depends what AFR u planning to run

But max ever wud be 250kww even on leaner AFR and Maxing inj dc

Can post dyno sheet if u need just gotta hunt for it

[Guest]

Ive got 100% d/c on my yellow side feed p2 and running 227kw atw on 95. Unsure on reg pressure tho.

Stock 565cc wont give me the headroom Im after. You know of a cheap set or decapped set?

[Pappu1]

 evowrx said:

Ive got 100% d/c on my yellow side feed p2 and running 227kw atw on 95. Unsure on reg pressure tho.

Stock 565cc wont give me the headroom Im after. You know of a cheap set or decapped set?

u can easily decap them and get 816cc _ again personal experience

and they run fine

depends who tunes ur setup there is almost no difference of feel and low end and idle with decap pinks

there is some writings on the interwebs abt bad things on decaps but have used and tuned personally and been perfect

or there is a for sale one in the for sale thread some 880 sards i think - brut4l selling

PS. 227 on yellows at GCP wont really get 227 on a TP dyno session

i was quoting only on the TP figure as they seem to be the reference that can be relied on

u may get difference numbers on diff dynos obviously

[Guest]

Yea well aware of the decap side of things. Just buying some then getting them flowtested they start to get expensive especially if ones too far out to use. Im going top feed unless I can adapt side feeds to a v7 mani then will just decap what I have.

[Pappu1]

true true..hopefully ur decaps wont be too out

y not just get side feeds and be done with

i mean u already have the split rail etc setup for it

[Guest]

Split rail set up costs all of $25 and I can reuse what I have set up. Fucked if Id spend money on fancy rails when factory ones work fine.

Few reasons Im going to v7 sti mani. Frees up more ecu not that I need it/fits alt in stock location/aftermarket top feeds cheaper/theoretically decap pinks better than decap yellows/mani looks far nicer.

If I go decap they will be flowtested Im not running that risk. Dont mind doing things cheap but still needs to be done properly.