E36 Injectors Dont use

[cabrio327i]

Just finished my 2.7 build, 284/272 cam, large bore throttle body, ported head,and six branch ready to go on, But a word of warning! I tried E36 325/m3 injectors Bosch No finishing 415, standard E30 325 No- 715, Nearly ruined my engine, massively over fueling excess fuel coming out of the exhaust like a blue smoke, and engine oil dilluted with fuel, pulled them out and put standard ones back no problems,so there you are i thought i was being clever dick, but its true what some people have allready said about these injectors before, there crap in a E30 M20,Cheers Dave

[Demlotcrew]

[chu346]

Would they work better if you had the car tuned on a rolling road?
Or maybe if you turned the fuel pressure down?


BTW your cars beautiful!

[E30Adam]

Dave, if that's a genuine motorsport cab then get your name down on the list in the meets section for the motorsport cab meet. When we get enough people, we'll have a mag feature!

[Templ8e30]

Good advice Dave

I was considering upgrading my injectors, will look at something else now.

Any idea how much power you are making ?, need to get mine on a dyno. I seem to be making a lot of power, I blew off a 200bhp rover 620ti turbo and almost kept up with a new vauxhall astra vxr 2 litre 16v turbo (240 bhp) at the weekend.

And considering that I have a standard cam I seem to be making more than the 180bhp I thought I might get

Cheers,

Iain T

[Andy_magic]

My take on selecting injectors for an engine build has been to work out the power you engine will make (being realistic about it)

If you know your engine is going to make 200bhp at the crank, there is no point sticking injectors in that can flow enough for 400bhp.

Using the 200bhp target as a guide, you need to have some headroom in your injectors, so aim for enough fuel flow for 220bhp

The formula for this is CC flow rate of your injector divided by 5 and then times the number of cylinders to give the BHP capacity of the injectors.

170cc/min 170/5*6 = 204bhp
180cc/min 180/5*6 = 216bhp
200cc/min 200/5*6 = 240bhp

Hope that helps

[Templ8e30]

Thanks Andy, that makes a lot of sense.

Any idea what engines were fitted with the 200cc/min injectors ?

I'll be adding a shrick cam eventually so might as well go for the 240bhp limit

Also does anyone know what the standard 325i injectors (715) flow ?

Cheers,

Iain T

[astondg]

A book I have here says 149cc/min for Bosch # ending 715. The same book says for kW (not so usefull for you guys but I thought I'd let you know anyway) it's cc/min divided by 7 multiplied by cylinders so for 149cc/min = 149/7*6 = 127.7kW
or by the bhp rule: 149cc/min = 149/5*6 = 178.8bhp

Aston

[hogweed]

As far as I can remember (not much...) the whole E36 injector thing started with an American website, where some guy (I have the link on a different computer, I'll try to send it) figured that M20's tended to underfuel anywhere near the top end. I know mine does, badly, after the rolling road day. So his answer was to fit the E36 injectors.

I also remember Ant saying that Bexley fitted them to his Sport when they found it underfuelled with a Schrick 284/272 in it, but that may just have been coincidence. Ant knows what he's talking about, so maybe he could tell us if his overfuelled or not, or whether he fitted an adjustable fuel pressure thingy to turn it down a bit...

I bought some ages ago and have never fitted them as (to me anyway) it's a pig of a job. In the meantime I asked Bosch - they said they flowed an extra 11% fuel under the same conditions.

I'd dearly love to have this one cleared up. Dale325i also had them in his, but didn't know if he was suffering from bore wash or not...

[Gunni]

When you put in bigger injectors you need to lower the fuel pressure, then drive around, and slowly raise until your back where you started,

I recommend rolling road or piggyback tuning to get the fuel out of the injectors

[hoshy]

would it be better to have slightly lower flow injectors on higher pressure to help with atomisation of the fuel??

[cabrio327i]

Hi Adam, no mines not a motorsport, but its got everything a motorsport had including air con factory fitted, so i wont be eligible for the meet sorry to say. Dave

[hogweed]

When you put in bigger injectors you need to lower the fuel pressure, then drive around, and slowly raise until your back where you started,

Care to elaborate on that mate? Sounds interesting... I assume you're talking about the ECU's ability to "learn", although I'm haivng a hard time understanding how an ECU with no Lambda sensor (and therefore no feedback) can learn anything...

[Rearwheel_nick]

i have those injectors and a chip ready to put in, not got round to it yet as its effort but... if i bought a chip programmed for usin the 415's on m20 wont that be alright?

[Andy_magic]

Oooh, look at this