New 5-0 Motorsport injectors on their way

New injectors have been ordered from Bruce at 5-0 Motorsport www.fiveomotorsport.com

$380 delivered for:

4 x primary Bosch Motorsport (low impedance) 380cc (5.5 bar max)
2 x 270cc Bosch (Ford SVO for the Cobra SVT-R) (6 bar max)

Excellent value - latest deisgn with good spray pattern - should liven throttle response. These match the specs from Garry and Dermot pretty closely. The primaries are slightly smaller than stock but the secondaries are a good deal larger for high boost application.

Unfortunately I forgot to pay the extra to have them flow matched ('blueprinted') but after having spoken to Bruce he assured me Bosch units were pretty well matched form outset with 1-2% max variance.

Note from Garry

"I would look for a standard 380cc injector; remember though the Lotus fuel
system runs at 3.8 bar; or in the case of the S300 4.2 bar - a lot of
injector flow is quoted at 3 bar; so check with the supplier what pressure
the injector is rated at. What you want is good atomization; RC engineering
offer some suitable for the Esprit, Bruce at Five-O may be able to help; he
supplies the new Bosch series 3 injector; which have great atomization but
they are high impedance; I think you need low impedance primaries and high
impedance secondaries. However, you may be able to run the higher impedance
ones; the Carlton injectors are definitely high impedance; Dermot may be
able to advise you if that will work OK. I know it is usually a problem to
go the other way; i.e. fitting low impedance into a system designed for a
High Impedance injector; but I have a feeling it is probably Ok the other
way around."

"You honestly just need stock size primaries; the car won't make significantly different power to a stock engine until the boost is well up. The secondary injectors don't trigger until 75% throttle opening and I think 0.75 bar of boost.

I did one that had an old style T3/T4: basically an S300 turbo. It illustrates the power and fuelling requirements quite well: it picked up about 180hp in 1200 rpm as the engine came on boost. So you can see it is really the secondary injectors that do all the work when the engine is producing high power.

The other thing to bear in mind is that the Esprit management system is a kind of half way house between batch fire and fully sequential; most modern engines are now fully sequential and they require much larger injectors than batch fire systems. You may see the current crop of Jap cars quoting huge injectors sizes; they need them because they are running fully sequential injection and as such need the higher capacity injector.

I would look for a standard 380cc injector; remember though the Lotus fuel system runs at 3.8 bar; or in the case of the S300 4.2 bar - a lot of injector flow is quoted at 3 bar; so check with the supplier what pressure the injector is rated at. What you want is good atomization; RC engineering offer some suitable for the Esprit, Bruce at Five O may be able to help; he supplies the new Bosch series 3 injector; which have great atomization but they are high impedance; I think you need low impedance primaries and high impedance secondaries. However, you may be able to run the higher impedance ones; the Carlton injectors are definitely high impedance; Dermot may be able to advise you if that will work OK. I know it is usually a problem to go the other way; i.e. fitting low impedance into a system designed for a High Impedance injector; but I have a feeling it is probably Ok the other way around. Dermot is probably best placed to advise you about secondary injector
sizes; I believe that stock is 190cc. I recently put together an engine that went to Turkey and was designed for 400hp; I think I used a 270cc secondary injector for that engine; but in all honesty until you get it on the dyno rollers it is a bit of guesswork."

We shall see..