fuel pressure mod (with modified inlet systems)

ANARCHY

Member
Quote me "So on the standard air intake pipe on a XV220 oppsite"

Honestly I was not drunk it was dinner time, I am now but now I can spell!
 

vocky

Staff
Europa Blue SE1 said:
Vocky sorry it's a totally off topic question but what kind of coolant is that you are using mate?
Thanks
Alan

just standard red antifreeze 50/50 mix :)

it looks very dark in the pic but it's not that bad :LOL:
 

Europa Blue SE1

Senior Member
Thanks Neil it does look really dark in the pic I thought it was mibbe that 4life stuff or something just I'm doing a flush and refill soon and was wandering 1.what if any flush is okay to use on the z22se engine and 2.what antifreeze to use the normal red VXL stuff or something like that 4life???
Thanks mate...
 

Muncher83

Regular Member
I had been running with the FPR mod done on a 2.4 inlet manifold for several weeks.

Put it back to normal today and it feels much, much better :)
 

Europa Blue SE1

Senior Member
So you think it runs better without the FPR mod Muncher? Just I'm still not sure wether to put the FPR pipe back on or not till I get the car back on the rollers so I can see what the difference is with the mod done on a dyno...
 

MikeS

Former Staff
Senior Member
i did some air intake work on my calibra ecotec where the fpr pipe is attached to the tb

i did notice it running leaner with it hooked up and i noticed best performance when the pipe slid off the fpr

i personally feel that any modification to increase air intake by way of filters and pipework will result in loss of fuel pressure, i personally think that the fpr should be left to breath normally and any other connections should be blocked off

but i stress this should only be done when you know that more air is being sucked into the engine at a higher and quicker rate
 

MikeS

Former Staff
Senior Member
i hooked up my elm327 interface today to look at the lambda graphs and stuff as i have noticed an increase in idle speed

bank 1 lambda [pre cat] is ranging from .5 to 1.1 volts meaning it is running slightly rich on idle

bank 2 lambda [post cat] is ranging at .8 static on idle and reduces to .4 when over 2k rpm

it means basically that when the fpr vacuum is not hooked up to either the tb pipe or manifold then the engine is running rich at idle and when over 2k rpm the mixture is balanced out

i got a feeling anyone with the fpr disconnected will probably fail an emissions test on the mot at idle

i would however block off the fpr when going for a mot as it would run lean through the rev range as well as idle, but only do this if your cat is shagged :)

realistically the bank2 lambda should struggle to get past .6 volts and should idle in a smaller wave pattern at around .3 - .4 volts whereas bank1 should go from .5 - .8 volts in a bigger wave pattern
 

miniator

Regular Member
Digging up an old thread but I've just done this mod to my astra which has a K&N fitted.

It all came about when i actually broke the FPR vac pipe in half resulting in a very irritating drive, and in fairness, even before i broke the pipe the car was not a smooth drive.

Even with the pipe in the original place, (breaking the FPR exaggerated the symptoms), the car had a very annoying flat spot around 1500-2000 revs.

So i found some spare pipe i had in the shed, hooked up this mod and the results are brilliant!! Instant pick-up from any revs and no flat spot. Will be interesting to see how my MPG is effected as it wasnt very good!
 

shlomi_beno

Member
so after 10 pages i still didn't understand what to do on astra with k&n moded air box and vectre c pipe
coonect it to the manifold to the original pipe leave it open or block it
maybe somebody will give final conclusions
thank u
 

vocky

Staff
the inlet manifold is a good option, but sometimes the ecu figures out it's changed and then alters the fuelling, so my advice is to try it on the inlet manifold and see what happens (y)
 

damon

Member
are we saying in standard configuration there will at no point be sufficient vacuum to activate the FPR, in other words its static at around 4bar from idle to WOT?.
as it would appear from other peoples findings to take a lot of vacuum to make it adjust to 3.2bar, however moving the FPR to the manifold does create sufficient vacuum at Idle and overun to adjust to 3.2bar as the engine is sucking against a closed throttle thus creating the vacuum (which should help MPG little until the ECU adjusts), however going back to the standard set up i just dont see even on a standard or modded inlet that there is sufficient vacuum created to activate/not activate the FPR in any running condition (except a blocked filter, or maybe thats what the airbox trumpet is for). i may have missed it but can some one confirm what the fuel pressure reads on a modded inlet (derestricted air box, vec c pipe, panel filter etc) against a standard set up at idle and WOT not just the vacuum readings, as i struggle to believe at idle the standard inlet is creating a vacuum sufficient to activate the FPR, also have we confirmed exactly how much vacuum is required to activate?
 

damon

Member
going to get my self a fuel pressue gauge for the rail and i will post my findings, i have done the vec c pipe to air box mod and taken the trumpets out the air box using standard airbox to TB pipe, and after doing some maths and reading on fluid dynamics i think i will replace the post filter trumpet in the air box and replace the lower ducting with some thing a bit wider as i have never been happy with it since doing the mod, the vec c inlet to airbox adaptor is a horrible fit and sits on the rad hose and kinks, i digress, i was just very interested to see how all these mods could affect the fuel pressure...... or not as the case may be....... to be continued
 
After a long time now, what are the conclusions.
With this mod the car picks better up, but what about the fuel consumption.
Has anyone experience with better fuel economy after some time, with this mod.. or do the car drink more.. :confused:
 
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