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In my VX's current state, would a 10psi upgrade be safe?

Rooney69

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Firstly I apologize for asking what is probably a repeated question but the entire forum for me on my current desktop isn't letting me view posted threads when I click on them which is a problem I am trying to fix but until I fix it I wanted to at least try and see if I could get some info on this anyway.

My car is a 02 VX series II S with the L67 motor and just 135k K's on it. Everything is stock apart from a twin 2.5 inch exhaust with rear resonator. I do the engine oil/filter every 10k, and the transmission oil/filter every 30k and only use 98 octane fuel.

I plan to buy a K&N filter for it, one of those $90 ones from supercheap auto. As well as a set of those Topgun leads I think they are called, and some decent sparkplugs that were around $70 for 6.

Just wondering if my car (after the above paragraph of things included) would be in an appropriate state to handle a mace 10psi pulley on it? I don't flog my car at all apart from giving 2nd/3rd a prolonged wind-out once or twice a day, and prefer cruising around everywhere just using torque.

It's not uncommon for myself to get 600k's from a tank over the last year at least.

So yeah, I am just really hesitant as to if I should do this or not, would maybe a 8psi kit be fine instead, or 9psi? I don't know hey pls fill me in if you can help me out please cheers.
 

EYY

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10psi will be fine - just use 98. Some people even experience better fuel economy as even less throttle is required in every day driving situations due to more low down torque.
 

krusing

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Not sure it will be a better option,
increase the boost to 10 PSI,
but have to use 98, which you pay more for fuel per litre,
Which would out weigh the whole point of trying to save money for a better economy,
Where you would tend to put the foot down,
then use more fuel,
then you would have to fill it up more.
I can not balance those figures.
If it aint broke, don't fix it.
 

Wozza

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OP has said he only uses 98 so its not a factor :).....Bung it on have some fun, if its not to your liking switch back
 

Immortality

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That's the game you play...

I don't think our VX uses much more fuel running a 3.2" pulley than it did stock standard but the fun factor is much greater.

Economy wise I think gearing is a problem with the ecotec/L67 motors. As mine sits now cruising at road legal speeds it uses 10-11L/100km but at 120-130 it drops to about 7.5-8.5L/100km. I think on something like your Hume highway were hit cruise control and let it go it would do even better. I do like the twisty stuff but you use more gas ...:D

I say put a 3.4" pulley on it but add a CAI, TB, 180 degree thermostat and tune as the results will be better. With these engines keeping it cool improves the fun factor and longevity.
 

Rooney69

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That's the game you play...

I don't think our VX uses much more fuel running a 3.2" pulley than it did stock standard but the fun factor is much greater.

Economy wise I think gearing is a problem with the ecotec/L67 motors. As mine sits now cruising at road legal speeds it uses 10-11L/100km but at 120-130 it drops to about 7.5-8.5L/100km. I think on something like your Hume highway were hit cruise control and let it go it would do even better. I do like the twisty stuff but you use more gas ...:D
I haven't looked into your post history so don't know anything about your VX but is the 3.2" 12psi? if so what other mods do you have (if any) to support that? or do you find 12psi safe so use on it without other supporting mods? And yeah I am aware that I somewhat contradicted myself in my post when I mentioned fuel economy. Tbh I just want more low end torque and the ability to get up and go if the conditions present themselves : )
 

Immortality

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The stock Maf is basically at its limit with the 3.4" pulley.

I also have the Mace CAI that is modified, 1.9 rockers and chromoly push rods, 25mm insulator match ported to a ported Lim which is hpc coated, larger elbow with 69mm TB, 180 degree thermostat and insulated fuel rail with new 36lbs injectors, 10% OD balancer, full twin V8 exhaust system and I've spent a lot of time tuning it using a MAT sensor in the lim instead of the factory AIT sensor. Tuning at this level is critical, I've turned down the rev limiter because I've exceeded the maf and the valve springs are tired at 227,000km.... I also bypassed the boost solenoid which improves throttle response even more.

Future mods include LS style maf, water injection, 3.73 diff with tru-trac centre and new LS6 valve springs. Also fighting with the stock converter atm so that may need modification and more boost depending how all that goes. Unfortunately I'm waiting on surgery for an old injury before I can complete most of those mods. It drives like stock when you are gentle on the gas but rapid throttle movement brings in the boost quick. The missus has no idea what it can do if you get up it:cool:
 
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