Technical High impedance injectors??

[fordcosworth]

Hi everyone.

Right......I am after a set off four high impedance injectors to go with the new big turbo on the cento and i have have a fueling setup planned for MPI for a few months until i can afford to go standalone, i need a set that will be a straight swap for Punto 75 injectors, does anyone no if Coupe turbo injectors etc will fit straight into the 75 manifold and rail? and if so they are high impendence injectors ? i.e high resistance.
I need a set of four that will flow enough fuel for 150-175 bhp's worth of fuel without a problem so i thought the coupe turbo ones would be an ideal swap, i believe most cars use high impedance injectors but im not sure so choosing a set i can get for a reasonable price will be tricky!

Any help would be great thanks

jason

 

[rallycinq]

Can you not use low impedance and add a resistor to the circuit?

Cheers

SPD

 

[fordcosworth]

Can you not use low impedance and add a resistor to the circuit?

Cheers

SPD

This is something i have considered and yes i surpose i could, although im not to sure on the kind off resistor id use to fit into the supply wire to the injectors?? (mainly wanted high impedance items for ease of fitment)
My main thought is to find a set that will swap with the 75 injectors, it would be nice if the coupe turbo ones did?

thanks

jason

 

[rallycinq]

I had to put a resistor in the circuit for using the omex management with my SPi TB.

Cheers

SPD

 

[fordcosworth]

I had to put a resistor in the circuit for using the omex management with my SPi TB.

Cheers

SPD

And what kind off resistor did you use?? (im guessing you just fitted it to the live going to the injector from the ecu?)

thanks

jason

 

[rallycinq]

And what kind off resistor did you use?? (im guessing you just fitted it to the live going to the injector from the ecu?)

thanks

jason

It was a resistor inside a heat sink and, yup, just added to the power feed to the injector.

I don't know whether you would need four or not.

Cheers

SPD

 

[fordcosworth]

It was a resistor inside a heat sink and, yup, just added to the power feed to the injector.

I don't know whether you would need four or not.

Cheers

SPD

Aahhh good point, id not thought about needing one or four

Im going for Omex or something similar later this year but for now i need to get the car set-up MPI on the new turbo and my plan is to use the MF2 to control the four that sit in the MPI manifold, its states on ERL's website that the MF2 can control four high impedance injectors or two low impedance injectors, so im not sure how it would work using a resister then

thanks

jason

 

[fordcosworth]

Just been thinking..... i would have to run four resistors, one for each injector because if the MF2 is surposed to be able to run 4 high resistance injectors (say 12ohms) then it would make sence that when using 4 low impedance injectors (2.5-3ohms) you would run resistors to bring each one upto the required "high impendence" ohms reading......sounds about right wouldnt you say so??

I actulaly have a set of volvo T5 injectors and a set off 140-170bhp 2.4 volvo injectors at work in my tool box so ill have a look tomorow to see if they are the same as the 75 injectors, if they are then i can check the resistance to see if they are high or low impendance and go from there as they would be a good candidate for the fuel delivery i need!

thanks

jason

 

[fordcosworth]

Im a little confused, i read on the internet that low impendance injectors are 2.5-3 ohms and high impendance inbjectors are 12ohms, well ive just hooked up the multimeter upto the terminals of the 75 injectors and some volvo 2.4 injectors and it reads 0.01ohms at the 20k setting, i tried it on 200k and this read nothing at all. only on one ohms setting would it read anyhting (the setting is marked 200k and a siren signal???) on this setting the stanadrd 75 injecotrs read 14.00 and the volvo injectors read 17-18.00. The standard SPI injector read 1.00,,,im confused as these results dont match up to the claims on the internet and also confuses me as to why they dont read on any other ohms setting??? any ideas?
I tried the ohms meter on the 20k setting on a coolant temp sensor and i read a perfect normal 5.73ohms.

its not helping to choose a set that wount kill the MF2 the first time i use them.

help would be great thanks

jason

 

[fordcosworth]

ignore the above i have been doing a little research

seems there is only one setting on the ohms meter that will read resistance on an injector for some reason, i found a site that states the injector resistance off Sr20DET injecotor should be 11ohms and i have a set at work so i poped the multimeter on on the (200k continuity sounder) setting and it read exactly 11.00 ohms.

Standard cinq SPI injector must be low impendance as that read 2.5ohms.

Stanadrd punto 75 injectors - 14ohms

And the volvo injectors i plan to use from an 850 2.4 20v are reading 17ohms.....very high but i dont think it would kill the mF2 due to ERL stating (can run 4 high impendance injectors or two low etc).

anyone have a theory on the 4 17ohm injectors i plan to use with the MF2?? im a little nervous about wiring it up and finding out the MF2 had burnt out

Thanks

jason

 

[allanhelen]

What is the flow rate of the 75 injectors isn't around 180 or 200cc at stock pressure?

The current bob 2nd injector if it's a cossie one will only be probably 280cc. So if you are using the 4 75 injectors for just on boost fuelling for now they should be fine and I'm pretty sure they are high impedance (I know the 16v ones certainly are are) and you can always up the FPR for more fuel

DTT was using 329cc IWP043 injectors and they were good for an easy 160BHP

 

[fordcosworth]

What is the flow rate of the 75 injectors isn't around 180 or 200cc at stock pressure?

The current bob 2nd injector if it's a cossie one will only be probably 280cc. So if you are using the 4 75 injectors for just on boost fuelling for now they should be fine and I'm pretty sure they are high impedance (I know the 16v ones certainly are are) and you can always up the FPR for more fuel

DTT was using 329cc IWP043 injectors and they were good for an easy 160BHP

I surpose i could use the 75 injectors to get me around yes (and they are high impedance yes) but id ideally like a set to put in that will get me straight to nobles setup to see what it will do at 15psi, and i dont think that stanadard 1.2 injectors will see me too that goal
The Bosh 803 that i run is good for 95bhp on its own so four off them will see 380bhp on a cossie.

Id like to try and keep it setup the saem way in terms of fueling the stanadard spi injector with 1 bar so that it has very little to do with the fueling on boost leaving the better mpi setup to take over, although i would imagine the MPI manifold is alot better as distributing the fuel from spi even though it wasnt meant too. Its also been worring me a little about the side effects off running the spi injector on the MPI manifold due to the pooling which may cause problems for starting due to rich mixtures from the fuel vapour rizing off the manifold floor, unless the issue isnt that bad.

(329cc IWP043)......any idea what that injector is from or what make the injector is??

thanks martin great help

jason

 

[allanhelen]

Jason

If you keep using the SPI for off boost and only use the MPI for on boost as tricker did the 4 75 injectors will give you a min of 720cc flow rate so good for 150BHP in there own right so you are well within the limits of your setup

If you go the custom ecu then you should loose the SPI injector and get 4 bigger MPI ones and then go for the IWP043 they are std webber parts so available on quite a few stock cars

 

[fordcosworth]

Jason

If you keep using the SPI for off boost and only use the MPI for on boost as tricker did the 4 75 injectors will give you a min of 720cc flow rate so good for 150BHP in there own right so you are well within the limits of your setup

If you go the custom ecu then you should loose the SPI injector and get 4 bigger MPI ones and then go for the IWP043 they are std webber parts so available on quite a few stock cars

huge help as usual martin thanks

Ill use the 75 injectors for now then and go for around 140-150bhp running a little extra fuel pressure to the SPI injector so there is plenty of fuel available, the turbo will give enough flow for 140-150bhp all day long at little boost so im going to go ahead and pop the head off tonight or tomorow to swap it for my 75 (ported) head and inlet with the tricker 40mm sitting proudly ontop
Its off the road till the end of the week so that gives me enought time to fit the head then all i have to do is sort out getting the 16v rods and pistons at a later date, idealy i should be doing them while the head is off but i dont have the money for the 16v engine....plus im getting payen head kits for the 75 engine at 15 quid and a HG for 8 quid so its not much to do later on

Just have to sort out some way of piping the puch fit fuel pipes onto the 75 rail now and shes up and running MPI/SPI combo

thanks

jason

 

[allanhelen]

You have to remember you have 70ish BHP's worth of fuelling from the SPI injector so with the 4 MPI injectors in addition to that you are well safe.

 

[fordcosworth]

You have to remember you have 70ish BHP's worth of fuelling from the SPI injector so with the 4 MPI injectors in addition to that you are well safe.

Ye i see but my concern there was the fact that running 15-18psi would mean the SPI injector would be nothing but a dribble at standard fuel pressure unless i run the SPI injector at the same pressure as the MPI injectors? i still worry about it running to rich though (seen as i have that issue already) and becoming even more undrivable off boost.....although i remember you saying you ran yours with the standard reg at full pressure without a problem ??

thanks

jason

 

[allanhelen]

Yep mine was cranked right up as far as it would go, the only issue I got was it was a bit chuggy on starts when it was very cold until it went into closed loop

 

[craigb244]

are you planning on running the spi on the punto 75 intake manifold? will run like a bag of ****e if so (uneven fuel distribution/fuel pooling)

my injectors are 280cc from a 1.8 mg zr. direct replacement for p75 injectors.

iirc punto75 injectors are only "safe" for around 100bhp with turbo on their own (you dont really want to be running 100% duty cycle + stupid fuel pressure)

 

[allanhelen]

Tricker has been running this set up with no problem and getting very good results

 

[signwerx]

Punto 75 Injectors are 143cc

Alfa 156 T-Spark 1.8 / 2.0 and 2.5V6 all use same injectors. they are 196cc.

I use them on my track seicento. Work very well set up with MBE engine management.

PM me if you need more info - (I have 2 spares, as took them off my dead V6 engine)