Fuel injectors?
Discussion
Vauxhall (Opel) X18XE and X20XE injectors (Siemens/Bosch), have the parts # somewhere at home - yes, you will need to remap and no, they won't give any more power by themselves (ok, maybe a tiny bit because of the better spray pattern vs the Lucas inj's).
How do you know you need them? Put the car on a rolling road for mapping - if you have bumped up the fuel pressure at the regulator from 2.5 to 3.0 bar (put it in a vice and squeeze it by a quarter of a turn - that does the trick normally), fuel pressure remains stable under full load all the way up and you still can't maintain a decent A/F ratio at the top end without exceeding 85 (or so)% injector duty cycle, you know you need them.
How do you know you need them? Put the car on a rolling road for mapping - if you have bumped up the fuel pressure at the regulator from 2.5 to 3.0 bar (put it in a vice and squeeze it by a quarter of a turn - that does the trick normally), fuel pressure remains stable under full load all the way up and you still can't maintain a decent A/F ratio at the top end without exceeding 85 (or so)% injector duty cycle, you know you need them.
Here are the details:
Application: Vectra B, Astra, Omega with x18xe & x20xev engines (1995-2002)
GM part no: GM 90501588
Siemens OEM part no: 5WK90761
Flow: 250cc @ 3.0 bar
Impedance: High (14.2 – 15.3 Ohm)
Compare this with the original Lucas injectors:
Land Rover part no: ERR722
Flow: 200cc @ 3.0 bar
Impedance: High (16.2 Ohm)
I chose to fit the GM/Siemans injectors for a number of reasons:
1) They are readily available & cheap
2) In my opinion a pintle type injector is infinitely superior to the Lucas disc type
3) They have the potential to flow 25% more than the Lucas injectors
Another benefit to buying a set of Vectra injectors rather than reconditioning my old Lucas ones was the the car could remain on the road with no real down time.
Just an hour or so to swap the injectors over and I was back on the road.
Most injector specialists will have plenty of these Vectra injectors knocking about, so there is no real need to go grubbing about in scrap yards.
I paid £160.00 for 8 fully reconditioned Vectra injectors that were accurately flow matched as a set of eight.
At the time of fitting I did have my Mark Adams Tornado chip fitted, but I did not have the car re-mapped for the injectors.
The car ran perfectly on the Vectra injectors without any adjustments to the fuelling.
I have since had the car rolling road tuned by Mark Adams who was initially suspicious of my Vectra injectors & insisted two were removed for testing.
I wasn't convinced this was necessary and showed Mark the flow chart supplied by my injector specialist.
In the end I backed down and two of my Vectra injectors (one from each bank) were put on Mech Repairs injector flow rig with a Lucas injector for comparison.
My Vectra injectors flowed within 1% of each other and gave a very nice spray pattern, the Lucas one gave an appalling spray pattern.
Mark conceded, concluding that my Vectra injectors were excellent and gave a far superior spray pattern than any Lucas injector could hope to deliver.
He then made some jokes about how bad the Lucas injectors are, my Vectra ones were popped back in.
The whole exercise added about an hour of labour to my bill & only served to confirm what I knew already, the Vecra pintle type injectors are far superior to the Lucas disc type & my injector specialist did a good job of reconditioning & flow matching them.
It's hard to say what improvements the Vectra injectors give in the real world, my 4.0 litre Chimaera made 188hp on the Lucas injectors and was producing a small amount of black smoke at high RPM.
This is what prompted my injector change, the black smoke being un-burnt fuel & evidence the Lucas injectors required reconditioning or replacement.
The next time the car went on the rollers was with the Vectra injectors and it made 233hp, however by this point it had also benefited from a cam change.
So you can't really say the considerable 24% improvement was all down to the injectors.
Although my original cam was not horribly worn I still expect most of the improvement came from the Stealth cam.
However just looking at the improved spray pattern on the Vectra pintle injectors against the Lucas disc type they must have helped, the black smoke at full throttle was also completely eliminated.
All in all I would say don't expect miracles from the Vectra injectors.
But if your original Lucas type need reconditioning, then replacing them with a set of 8 reconditioned Vectra pintle type is an absolute no brainer.
Hope this helps, Dave.
Application: Vectra B, Astra, Omega with x18xe & x20xev engines (1995-2002)
GM part no: GM 90501588
Siemens OEM part no: 5WK90761
Flow: 250cc @ 3.0 bar
Impedance: High (14.2 – 15.3 Ohm)
Compare this with the original Lucas injectors:
Land Rover part no: ERR722
Flow: 200cc @ 3.0 bar
Impedance: High (16.2 Ohm)
I chose to fit the GM/Siemans injectors for a number of reasons:
1) They are readily available & cheap
2) In my opinion a pintle type injector is infinitely superior to the Lucas disc type
3) They have the potential to flow 25% more than the Lucas injectors
Another benefit to buying a set of Vectra injectors rather than reconditioning my old Lucas ones was the the car could remain on the road with no real down time.
Just an hour or so to swap the injectors over and I was back on the road.
Most injector specialists will have plenty of these Vectra injectors knocking about, so there is no real need to go grubbing about in scrap yards.
I paid £160.00 for 8 fully reconditioned Vectra injectors that were accurately flow matched as a set of eight.
At the time of fitting I did have my Mark Adams Tornado chip fitted, but I did not have the car re-mapped for the injectors.
The car ran perfectly on the Vectra injectors without any adjustments to the fuelling.
I have since had the car rolling road tuned by Mark Adams who was initially suspicious of my Vectra injectors & insisted two were removed for testing.
I wasn't convinced this was necessary and showed Mark the flow chart supplied by my injector specialist.
In the end I backed down and two of my Vectra injectors (one from each bank) were put on Mech Repairs injector flow rig with a Lucas injector for comparison.
My Vectra injectors flowed within 1% of each other and gave a very nice spray pattern, the Lucas one gave an appalling spray pattern.
Mark conceded, concluding that my Vectra injectors were excellent and gave a far superior spray pattern than any Lucas injector could hope to deliver.
He then made some jokes about how bad the Lucas injectors are, my Vectra ones were popped back in.
The whole exercise added about an hour of labour to my bill & only served to confirm what I knew already, the Vecra pintle type injectors are far superior to the Lucas disc type & my injector specialist did a good job of reconditioning & flow matching them.
It's hard to say what improvements the Vectra injectors give in the real world, my 4.0 litre Chimaera made 188hp on the Lucas injectors and was producing a small amount of black smoke at high RPM.
This is what prompted my injector change, the black smoke being un-burnt fuel & evidence the Lucas injectors required reconditioning or replacement.
The next time the car went on the rollers was with the Vectra injectors and it made 233hp, however by this point it had also benefited from a cam change.
So you can't really say the considerable 24% improvement was all down to the injectors.
Although my original cam was not horribly worn I still expect most of the improvement came from the Stealth cam.
However just looking at the improved spray pattern on the Vectra pintle injectors against the Lucas disc type they must have helped, the black smoke at full throttle was also completely eliminated.
All in all I would say don't expect miracles from the Vectra injectors.
But if your original Lucas type need reconditioning, then replacing them with a set of 8 reconditioned Vectra pintle type is an absolute no brainer.
Hope this helps, Dave.
Thanks Chimpantonic, after fitting my Tornado, ACT large bore induction hoses a bigger AFM and a 72mm plenum I shortened my trumpets and the old girl (Chimaera 400) gives me 247bhp on a dyno so I am looking to just pop over the 250 mark, I think after I change the injectors I will invest in some time with Mark Adams!
Thanks
PS I was under the impression that Green top Bosch injectors were the ones to go for!
Thanks
PS I was under the impression that Green top Bosch injectors were the ones to go for!
That's quite a bit of induction modification you have done there 
I think Mark Adams usually recommends Bosch 'red' tops to get the maximum benefit of a remap. It may be worth contacting Mark first before getting any injectors otherwise you may fit them and then find out they may not flow enough for Marks requirements.
The Bosch red tops are quite expensive but a search on PH will indicate some Ford injectors which have comparable flow rates but are less expensive
Bodders
I think Mark Adams usually recommends Bosch 'red' tops to get the maximum benefit of a remap. It may be worth contacting Mark first before getting any injectors otherwise you may fit them and then find out they may not flow enough for Marks requirements.
The Bosch red tops are quite expensive but a search on PH will indicate some Ford injectors which have comparable flow rates but are less expensive
Bodders
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