FC Injectors - Part 2

[grinder]

im starting this to split it away from the FC Apexi thread

in my continuing hunt for FC knowledge i came accross this :

http://www.hitman.hm/injectors.htm

can someone confirm that the info is correct

if this is the case i just need to get some injectors from a 12a

*** edit ***

TII injectors are TOP feed - so FD ones wont work as they are side feed

TII - TOP Feed
FD - Side Feed
12a - ??

ta

Stu

[Ricco_04]

Wow, I never would have thought the 12a\'s where bigger!

Sorry I dont know how they are plummed in

[sadgoth]

you have to remember that was only off the 12aT and all the Gen1s we got in the UK were carb and not injection. Might be a problem to find them even if they are top feed!

[Prof]

I think there were some EFI versions with aftermarket turbo\'s - even in the UK.

There was also the Gen1 with a 13B engine - so these are a direct swapper, but I can\'t see what size these were!

I have a couple of SARD 720cc\'s that came on an intake manifold, but the complexity of adding tertiary\'s put me off using them.  Also the inlet pipe was somewhat brutally cut - so its a welding job to put a new pipe on - if anyone wants the metal work, then I am willing to let it go, as I have a Greddy intake to match my ARC intercooler now and don\'t need it.  I might want to keep the injectors though - depending on how this thread develops  :mmmm

They are top feed, but I suspect they are low impedance, so I would have to use resistors with these.

The inlet is drilled and fitted with mountings for the 2 additional injectors.  I can supply a pic if required.

[sadgoth]

I think there were some EFI versions with aftermarket turbo\'s - even in the UK.

There was also the Gen1 with a 13B engine - so these are a direct swapper, but I can\'t see what size these were!

I have a couple of SARD 720cc\'s that came on an intake manifold, but the complexity of adding tertiary\'s put me off using them.  Also the inlet pipe was somewhat brutally cut - so its a welding job to put a new pipe on - if anyone wants the metal work, then I am willing to let it go, as I have a Greddy intake to match my ARC intercooler now and don\'t need it.  I might want to keep the injectors though - depending on how this thread develops  :mmmm

They are top feed, but I suspect they are low impedance, so I would have to use resistors with these.

The inlet is drilled and fitted with mountings for the 2 additional injectors.  I can supply a pic if required.

the 13b engined gen 1 was the GSE-LX (I think) only for the US market I believe. The 12aT was not officially avail here so although there are a few here they would eb hard to find.

[grinder]

i think you should donate the injectors to me to be honest

next plan is to look at jags , evo , scoobie to see what they run

its all fun and games owning a rex

Stu

[Ricco_04]

Grinder, Ideally, what size injectors are you after for primary and secondary?

[Iwan]

I can not confirm all the information provided, but can drop my 2p about the injectors for sec. gen.

We should be limited to cars avaliable in UK / EU or cars which come to UK from Japan, as the import scene is quite big here.

We should not look at the cars which were avaliable in US. This includes the GSL-SE version of 13B EGI engine. The injector sizes are still unconfirmed on this one, as some say them are 2x 680cc the others 2x 720cc... Also the 12A Turbo from Japan is an exotic car, even in UK. I would be very carefull in getting used injectors from this cars, as there is also a time injectors were used which will influence the injectors condition. I would recomend to use a pair of brand new injectors before getting two 20 years or even older injectors.

All other cars are equiped with following set of injectors:

12A engines for UK / EU are all carburator type. So no injectors there
13B EGI comes with 4x 440cc injectors. Them are LOW impedance, TOP feed.
13B Turbo Series4 (180hp version) comes with 4x 550cc injectors. Them are LOW impedance, TOP feed.
13B Turbo Series5 (200hp) comes with 4x 550cc injectors. Them are HIGH impedance, TOP feed.
13B Turbo Cosmo engine comes with 4x 550cc Injectors. the primarys are SIDE feed, the secondarys are TOP feed type. Them are HIGH impedance.
13B REW comes with staged injector- Setup. we all know about them. They are HIGH impedance.
20B Cosmo engine comes with 6x 550cc injectors. Them are all SIDE- feed. Them are HIGH impedance type.

Upgrading the fuel system depends on the target power- output. Also is the ECU is important factor of the setup you want to run.
I will try to provide some very basic fuel to power calculation on a ported 13B engine:

4x550cc injectors: up to 300-320hp on the fly
2x550 and 2x700cc injectors: up to 330-360 hp on thy fly
4x700cc injectors: up to 370-410 hp on thy fly
2x550 and 2x1000cc injectors: up to 400-440 hp on thy fly
2x700 and 2x1000cc injectors: up to 440-490hp on the fly
4x1000cc injectors: up to 520-580 hp on the fly
4x550cc and 2x550 in the plenum: up to 420-470hp on the fly
4x 550cc and 2x700cc in the plenum: up to 470-520hp on the fly
4x700cc and 2x550cc in the plenum: up to 520-570hp on thy fly
4x700cc and 2x700cc in the plenum: up to 550-620hp on thy fly

what injectors are avaliable.
all the HKS Greddy SARD PowerEnterprice etc. are all DENSO injectors. Many of them are made only for one reseller, like scooby injectors for PowerEnterprice only from my knowlage.

you have the option of LOW impedance TOP feed injectors:
550cc
650cc
700cc   square connector, blue colour
720cc   square connector, brown colour
800cc   oval connector, yellow green colour
1000cc  oval connector, blue colour

you have the option of HIGH impedance TOP feed injectors
550cc
650cc   oval connector, yellow colour
800cc   oval connector, purple colour
You can use all of the low- imp injectors with a resistor (at least 10W resistor!)

all this injecotrs will fit FC3S fuel rail without any modifications.

You can use a set of Bosch type injector sized at 1680cc which will require fuel rail modifications on FC3S. Them are TOP feed LOW impedance!

It depends on the ECU you are running, in your choice of injectors and the right impedance.
if you use Microtech ECU, you can use HIGH or LOW impedance injectors, like 4x low imp or 4x high imp. You should not mix the injectors.

if you use Apexi Power FC, you will need to run HIGH impedance injectors or LOW impedance with resistor to provide about 14 OHM per injector driver.

Hope this helps.

REgards
Iwan

[Prof]

i think you should donate the injectors to me to be honest

next plan is to look at jags , evo , scoobie to see what they run

its all fun and games owning a rex

Stu

I reckon they mostly run our hand me downs.  :Tongue1

There are always loads of 550cc ones on ebay - so someone must be upgrading !

I think because the rotaries drink so much, the injectors are good for more bhp on other cars.

I am trying to undestand the relationship between the size of the injector and how much fuel is actually squirted - seems that fuel pressure and duty both determine how much actually goes in.  So just pushing up fuel rail pressure will get more fuel - but what\'s the downside ?

Does anyone know how they arrive at a particular size rating ?

I am also interested in a Fuel Pressure Reg - any recommendations ?

[Prof]

Nice one Iwan - pretty comprehensive stuff. :Thumbs-up

[Iwan]

I reckon they mostly run our hand me downs.  :Tongue1

There are always loads of 550cc ones on ebay - so someone must be upgrading !

I think because the rotaries drink so much, the injectors are good for more bhp on other cars.

I am trying to undestand the relationship between the size of the injector and how much fuel is actually squirted - seems that fuel pressure and duty both determine how much actually goes in.  So just pushing up fuel rail pressure will get more fuel - but what\'s the downside ?

Does anyone know how they arrive at a particular size rating ?

I am also interested in a Fuel Pressure Reg - any recommendations ?

All the injectors are rated on a given pressure. The normal pessure injectors are flow- tested/ rated is 43,5PSI.
If you rize the pressure in using a fuel pressure regulator, your injectors will flow more than specified.
Fuel pressure regulators are a very important upgrade on modified cars. best example is FD3S. You can rize the boost up to max of about 1.2 BAR. using the stock pressure regulator will end in a very lean condition and probably a blown engine. Rising the fuel pressure will compensate the need of more fuel without changing the injectors.

from a basic fuel to power calculation you can see the difference in rizing the fuel presure:
figures are for stock FD3S injectors at about 85% injector duty
at 40 PSI fuel presure: up to 340hp
at 50 PSI fuel presure: up to 380hp
at 60 PSI fuel presure: up to 410hp

you get about 70hp more power just from rising the fuel pressure. But nobody will recomend to you runing 60 PSI fuel presure, this is just an example just to show the effect.

REgards
Iwan

[grinder]

ekk that took some reading !!

im after 720\'s ideally - nothing over the top - and easy to adjust ( using safc for now - will go microtech later on )

SOOOOOOOOOOOOOOOOOOOOO - its just finding some that arent wallet shatteringly expensive !! LOL

so this config is idea prob : 2x550 and 2x700cc injectors: up to 330-360 hp on thy fly

gonna drop a FD pump into the car as a cheap safety measure for delivering the fuel

Stu

( Iwan - thats one hell of a post - esp if you typed it off the top of your head ! )

[Prof]

Slightly off topic - but it\'s still injector-ish.

You mentioned WI in an earlier post - I presume Water Injection - what\'s the best place to do this - I am guessing into the pipe between IC and the throttle body ?

Has anyone done this and got it working - maybe a new thread ? :Typing

[grinder]

he he he i looked into that aswell

its supposed to be VERY good for a rotary ! - steam cleans the engine as it runs

you can set it to actaivate on boost - so once you hit say 6psi - then the water comes on - this way you can still accerate gradualy to the red line and it wont fire - it will only do it WOT ( which is on boost ! )

i have looked on the FC and you should bebale to stick it in the pipe that comes out the TMIC ( inlet side ) - its made of metal - so simple job - this will cool the air before the IC

that looks the best place - after the IC its all rubber piping ( although you can still do it .. somehow )

its Kev\'s fault - he runs a dual stage WI - one before the FMIC fires at 0 bar - just as you come out of vac - then the other stage fires on the after the FMIC at .9 bar ( i think )

very very good system to be honest

thing is - you have to carry water round with you to fill the tanks up if they run down

its cheaper that a FMIC and doesnt need loads of fabriaction work

hope this helps - you would need to read more into it - as im not 100% sure my self !!

you are looking at around £200 for the kit to do it

Stu

( i will just keep sticking up random thread about mods - there are lots of clever people on here - i have learnt so much in the last few months from this place - its great )

[grinder]

just reading Iwan\'s post again

from a basic fuel to power calculation you can see the difference in rizing the fuel presure:
figures are for stock FD3S injectors at about 85% injector duty
at 40 PSI fuel presure: up to 340hp

so if i drop in a FD fuel pump ( which im fdoing anyways ) - that should handle upto 340 BHP - its just the injecotors that wont ?

SOOOOOOOOOOOOOOOOOO

a good starting point to modding an FC is to aim for a min of

2x550 and 2x700cc injectors: up to 330-360 hp on thy fly
with FD Fuel pump

Stu