What injector size for 450-500 whp ?

[Master Chief]

Hi all.

I am looking to buy some injectors for about 450-500 wheel hp, target.

I am tuning with the Haltech E11v2, and its a S14, SR20DET VVT.

I want something i could plug right in, and not need to mess around to much with the harness, or adding resistors etc.

So i was looking at the Nismo/Tomei's 740cc.
The thing is that they might bet marginal for my power aims, so i would like to have something that will work for the power i want, but leave some little bit of head room.

I would like them not to pass around 80% duty cycle for the above power.

Can anyone recomand some injectors, or confirm wheter or not the 740cc's will do the job ?

I need side feed BTW.

Thanks for the Help,
Dany.

[xkamikazestormx]

i think the nismo 740cc should be fine

[ROIDMONKEY]

1000cc and 2 fuel pumps for 500.i had 740cc b4 . 1000cc now and like i said 2 walbros pump. u would have to go top feed
im going to dyno again tuesday now that i put my 2nd fuel pump . one fuel pump got me to 440whp , thats about maxing out

[DDSR240]

RC Fuel Injection use this injector calculator its very helpfull.

[((sr)) kelly]

you can make over 450 with 740 cc and a good tune along with supporting mods... let me know if you need a tuning unit, i have a power FC for sale

[xkamikazestormx]

Originally Posted by ROIDMONKEY

1000cc and 2 fuel pumps for 500.i had 740cc b4 . 1000cc now and like i said 2 walbros pump. u would have to go top feed
im going to dyno again tuesday now that i put my 2nd fuel pump . one fuel pump got me to 440whp , thats about maxing out

thats way OVERKILL just for 500whp

Originally Posted by ((sr)) kelly

you can make over 450 with 740 cc and a good tune along with supporting mods... let me know if you need a tuning unit, i have a power FC for sale

exactly.

[DDSR240]

Originally Posted by xkamikazestormx

thats way OVERKILL just for 500whp



exactly.

idk some people dont like one of there fuel pumps to lose pressure and the motor starts leaning out and you lose your 500 hp sr just my .02

[jspaeth]

I am running tomei 740s on my 2871r sr and at 17 psi on a 3bar fuel pressure tune, my injectors hit ~80% duty at max hp (around 320 or so).

I am going to get retuned at 4bar fp.....I think to squeeze out 500 hp, you definitely will have to raise the base fp.

yeah

[ROIDMONKEY]

Originally Posted by xkamikazestormx

thats way OVERKILL just for 500whp



exactly.

do the RC fuel injection conversion for 500whp . i beleive it says 880cc or some like that.. why having a set of 740cc almost max out when u can have a set of 1000cc that cost the same amount of money. !!!!!

[jspaeth]

Originally Posted by ROIDMONKEY

do the RC fuel injection conversion for 500whp . i beleive it says 880cc or some like that.. why having a set of 740cc almost max out when u can have a set of 1000cc that cost the same amount of money. !!!!!

bing bang boom bingo

[Master Chief]

Originally Posted by ROIDMONKEY

why having a set of 740cc almost max out when u can have a set of 1000cc that cost the same amount of money. !!!!!

Because to use the 1000cc's i would have to replace my manifold, my fuel rail etc - and would get me far over the price of the 740's.

As i said, i want the biggest i can use, with the setup i have now, and i gues the sards are the ones....


ZipTiedCoupe - relax. I am not YET making that much power - and since i want to, i want to know what others are using to confirm my thoughts.


I guess that SARD make the biggest Side feeds around - any view of them in general ?
Do i need to use a resistor or chenge the plugs or something, or are they a streight fit.

Thanks.

[ROIDMONKEY]

JGY sells a rail that u can use with ur stock manifold and also use ur nismo FPR if u have that. but i understand if u trying to save money. get the sard's 850 then

Originally Posted by Master Chief

Because to use the 1000cc's i would have to replace my manifold, my fuel rail etc - and would get me far over the price of the 740's.

As i said, i want the biggest i can use, with the setup i have now, and i gues the sards are the ones....


ZipTiedCoupe - relax. I am not YET making that much power - and since i want to, i want to know what others are using to confirm my thoughts.


I guess that SARD make the biggest Side feeds around - any view of them in general ?
Do i need to use a resistor or chenge the plugs or something, or are they a streight fit.

Thanks.

[ZipTiedCoupe]

If your using Haltec and making that much horsepower and dont know what size injectors you need or dont know the formula you need, you should quit now.

RC Fuel Injection

[jspaeth]

^When using that calculator, remember that the pressure that you input should include the base fp (with the vacuum unplugged) PLUS the amount of boost you are running, since when you are getting on it and drawing fuel, most fprs use a 1:1 pressure raise with boost.

So, with stock fpr and 1 bar of boost, you should input ~57-58 psi or so.

[fliprayzin240sx]

I personally say Sard 850. Ive seen a guy out here pump out 470whp with 740cc and he's pinging dead close to 99% duty cycle at 22-24psi on a TD06-25G.

PS: I got the 850s cuz they were cheaper than the 740s. I got my SARD for $310 vs Nismo/Tomei 740s $550 brand new.

[Master Chief]

What dies that have to do with what i asked about ?
A strong pump or pumps is a must - but i was just asking about the injectors.

ROIDMONKEY - do you hae a link to that rail you reffer to ?

Thanks.

[fliprayzin240sx]

Only thing with the Sard is is that its not plug and play. You have to splice in the connectors they give you with the injectors. Not hard at all to do tho.

Beauty of 850s, idles rock solid...I was in the impression that the idle would suffer due to the size of the injectors. Drives like it still got the stock 370s in there...

[ROIDMONKEY]

here is the link.. JGYCustoms.com - 240sx / Silvia Fuel System Upgrades
fipra im running 1000cc and my car idles pretty good , over 1000cc its when idles problems bigging
now.. the 1000cc are low impedance soo u have to use resistors(JGY sell them)

[Master Chief]

Thanks, but as i thaught - that JGY fuel rail is for S13 Manifold - and a Greddy pleanum above all.
It would not fit the S14 - defenetly not without changing the pleanum etc...

fliprayzin240sx - how much power/duty cycle are you runing ?

[fliprayzin240sx]

Originally Posted by Master Chief

Thanks, but as i thaught - that JGY fuel rail is for S13 Manifold - and a Greddy pleanum above all.
It would not fit the S14 - defenetly not without changing the pleanum etc...

fliprayzin240sx - how much power/duty cycle are you runing ?

Well, im in the middle of a full rebuild and im in the sandbox right now. Wont be back to give you an answer on that till feb ish. I was running a Greddy T518Z with the 850s. Was sitting roughly between 350-370hp and ive never seen my duty go above 72%. Swapped it out for a top mount T04S with HKS compressor housings. Im holding my breath for about 420-430whp with the setup..hell I break 400hp and ill be happy...

Anyways, my question to you is, what turbo are you planning on running on hit over 450whp???

[Master Chief]

Well, for now i have a GT3071r-wg, and i plan to squize as much as i can from it, though not sure how much would that be - i dont think i'll hit much above 400 WHP with it, at wich point i think it would be plenty.

Even so, i want to have the engine able to reach 450WHP more or less, when i will deside to get there, though i dought it will be with the GT3071...

BTW: Why are you rebuilding - just curious if its because some damage that happend, what was it ?

[fliprayzin240sx]

Please please tell me that GT3071R is on a top mount setup. If you try to stay bottom mount with the stock T2 flange, you may have EGT issues. I did when I tried to stick a GT3071R bottom mount on my HKS manifold. The T2 flange was restricting the airflow, causing my EGT to spike at anything over 1.1 bar. Tried everything from retarding the timing, to adding fuel, didnt do much of a difference. Thats the reason why i ended up with a T04S.

Anyways, im rebuilding my old block. Nothing was wrong with it, i swapped Koopa Troopas old engine in my car and guess the oil pump on that engine was going bad. I was only getting 3-4bar under full boost (1.5 bar on the T04S) and I started getting rod knock on it. So I figured imma just rebuild the engine I pulled out while im gone. Bottom ends bored out to 87mm with Greddy slugs already. Slap some fresh rings on it, Eagle Rods, fresh nismo bearings, oil pump, seals and re-use Koopas head (Fully built Tomei head, ported/polished by them with all Tomei goodies). So I should have an engine that will last me for a long while. Once I break it in, Im leaning on getting a ballbearing CHRA on the T04S and re-use the housings. Should help spool up a bit sooner and should make a bit more power up top.

[Master Chief]

I see about the engine - good luck with that !

As for my turbo, it is a LOW mount, T25 Flange.
I belive it will run out of breath around 400WHP, but as FOR EGT's - i dont agree it wil be a problem.
The main problem with the T25 would most defently be excesive back pressure - not high EGT's.
The exesive back pressure, will limit the amount of boost i will be able to run before detonation etc - wich will limit my total power output potential.

High EGT temps are caused by:
1. Too lean mixture - wich will usualy cause detonation or melt something - way before you will actualy see high EGT's.
2. Too much RETARD will cause high EGT's because the fuel in the mixture will not have time to completly burn inside the cylinder, and will partly burn in the exhaust and rise the EGT temps.
3. Too Rich mixture, for a given timing point - again, like the above - will cause exess fuel to burn in the exhaust and rise the temps.

Soo.... if you try to fight high EGT's by adding fuel and RETARDING - you are actualy making things worse.
The right way to fight high EGT's, is to make sure the A/F ratio is rich but not too rich, and actualy ADVANCE timing, and not retard.

The thing is the ADVANCING is usualy limited by knock - so sometimes you can only try using some high octane fuel to be able to advance, or simply - turn down the boost.


Bottom line - this is what i have now - so will try to get the maximum of it - when i'll get tyred of that, or tyred of trying - i will go top mount with something decent !