Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[ngrainqey]

Hello,
just a bit of a debate time maybe or not depending if it gets shot down with a big AA gun lol!

firstly... Can you use the piezo crystal newer injectors on the omega if they're the same flow rate for example or do you need the ones like the standard omega ones with the springy tyre valve old school rubbish in it?

and secondly even though the gains are foooook alll....
I was thinking about remapping the 2.6 blah blah this and that, exhaust and stuff and would fit a little bit bigger injectors rather than just that stupid fuel pressure regulator shite which i'd probably fit anyway

oh sod it...lastly am i right in thinking on the facelifts you can just chop the second cats out on the downpipe after the lambda probes for long term fuel trim?

thanks
alex

[GastronomicKleptomaniac]

Be interesting to see if they make any difference, if you can fit them - I'm as far removed from an expert as Rita Sullivan, but I'd imagine getting the injectors to talk to the ECU might be tricky?

>watches with interest<

[Kevin Wood]

2.6 has same injectors as the 3.2 so it would be fair to say they are generously proportioned for that engine.

You can fit bigger ones, but it'll make precisely no difference as the ECU will trim the fuel back to where it was before.

[ngrainqey]

thanks for that woody...
do you know how far the ecu can trim the fueling back and if the omega injectors are e.g EV6 or EV1 or EV14 for example? on my old T5 there was a certain percentage that the ecu could trim back fuel for the injectors as i was running 470cc ones on that

i have some bosch 390cc injectors and i'd be having it mapped if i put bigger injectors in anyway along with catback, possibly headers if i can be bothered and 3.0/3.2 cams and different intake like the steinmetz even though they're rarer than rockin horse plops lol!
thanks
alex

[TheBoy]

If you pump more fuel in, you need more air. This is where NA engines will fall over, as not a massive amount you can do - with forced induction you can overcome this to an extent.

The ECU will monitor how rich/lean the burn is, and trim down/up to ensure its right.  If the trims go too far from what it expects (20% on the long term trims on a 2.6), the ecu will flag this, and most likely use some kind of limp (maybe, maybe not noticibly reduced power).

I think there is probably mileage in higher flowing injectors if the std ones are borderline, or if you are tweaking forced induction engines, but I would not expect any gains whatsoever on the Omega.

[Kevin Wood]

I can't remember the exact injector but the part number is on here somewhere.. They are Bosch, 0280155xxx where xxx is the bit I can't remember.

They are high impedance (12 ohm IIRC), around 250cc/min @ 3BAR and, on the 2.6 and 3.2, operate at 3.8 BAR IIRC.

[ngrainqey]

0280155045 i think and +1 TB unless i force it in a bit lol!
what can be done about say porting the intake manifold spacer and intake manifold for example to increase cross sectional area and throttle butterflies?
thanks
alex

[ngrainqey]

urm... can i remove the second cats lol?
alex

[Kevin Wood]

urm... can i remove the second cats lol?
alex

Yes, but it'll fail the MOT emissions test.

[ngrainqey]

really :/ ? thats a bit pants, i thought the long term fuel trim lambda was before the second cat?
alex

[Kevin Wood]

You need the second cat to pass the emissions test. Could probably do away wit the pre-cat, though, as they die on most Omegas anyway.

Mixture control lambda sensor is before all the cats otherwise it would get a false reading.

[feeutfo]

After numerous discussions on this, the general feeling is that the exhaust manifold is, afawct, the restrictive part for air flow due to the gm tune for low down grunt and a flat power curve needed for a passenger orientated executive car. (think chaufer driven at one end of the scale, up to police persuit at the other)
OE Exhaust manifolds are a plenum style used for flow at low revs and avoid the peaky delivery which might suit someone like yourself. So, general advice is manufacture some tubular manifolds with tube lengths optimised for scavenging exhaust gases at high rpm. Not cheap.
 It will then hopefully allow more induction air in, as the exhaust gases from adjacant cylinders firing through the manifold suck air in to the cylinders from the imtake. Result, more air flow, THEN you'll need to pile more petrol in, and only then will you know if the injectors are capable of keeping up or not.

Fit the highest flow injectors in the world, it will only match the available air flow to the correct mixture. So increase air flow first.

Sports cats arent too offensive, and the pre cats can go as they are buggered by now amyway.

As i understand it anyway. New manifolds are unproven on here though i think? Due to cost?

[ngrainqey]

oh i totally agree about the manifolds chris, the vxr engine has restrictive manifolds and intercooler pipework

if i can be bothered to then i'll take the ac compressor off and put a supercharger on it lol! it'd need different intake pipework mind but its not 'that' much work

alex

[feeutfo]

oh i totally agree about the manifolds chris, the vxr engine has restrictive manifolds and intercooler pipework

if i can be bothered to then i'll take the ac compressor off and put a supercharger on it lol! it'd need different intake pipework mind but its not 'that' much work

alex

Historically, thats been a good route to blow the bottom end out, and is exactly how the ls1 v8 omega came into existance. For road use keep it normally aspirated unless you want to drive around near the hard shoulder covering the clutch all the time.
260-270bhp max ...?

Funny how these conversations always lead to the door of a v8

Normally aspirated tuning; alot of effort and expense for little gain and knocking on the door of reliability issues.

Forced induction; fair bit of effort and expence, hand granade on wheels.

Other lump, mega bucks for LS v8. Alot of work and a tight fit. Bit if a jump from bigger injectors though.

[feeutfo]

Or, buy a 3,2.

Or fit a 3.2 lump. Probably easiest if you want go keep that particular car...?