Boost return mod leading to poor MPG?

[Chris M 0]

Hi,

 

I’ve had my g60 4 months now and in that time I’ve had the boost return removed for 2 of those months. I do love the sound it makes and have noticed the difference it makes when going through the gears, it seems a lot more lively as you enter your next gear.

 

BUT and it’s a big BUT

 

The fuel economy is absolutely SHAT it even made me consider getting rid of the car, but I thought I’d try it back on again and thank fook alls well again.

 

with the boost return removed with a blanking plate on the charger and two filters on the breather and the ISV (until i could get a catch can) the car wouldn't do any better than 18mpg and that was serious Miss Daisy driving on BP Ultimate.

 

On Saturday I thought I’d try it on again, so I piped it all back up and Sunday I was helping a mate move house (Corrado not the ideal car I know) but anyway did quite a lot of stop starting and a few blasts up and down my local duel carriageway but mostly round town driving and it was never below 26mpg and averaged 34mpg at the end of the day.

 

I know there are other benefits to this mod and the noise is nice but i just cant justify the amount of fuel it was using, maybe when I’m more flush it might come off again.

 

Just thought I’d let you guys know what I’d found and you can make your own decisions. I was going to start a new thread but found this one.

 

Chris.

[G60Dan 0]

Hi,

 

I’ve had my g60 4 months now and in that time I’ve had the boost return removed for 2 of those months. I do love the sound it makes and have noticed the difference it makes when going through the gears, it seems a lot more lively as you enter your next gear.

 

BUT and it’s a big BUT

 

The fuel economy is absolutely SHAT it even made me consider getting rid of the car, but I thought I’d try it back on again and thank fook alls well again.

 

with the boost return removed with a blanking plate on the charger and two filters on the breather and the ISV (until i could get a catch can) the car wouldn't do any better than 18mpg and that was serious Miss Daisy driving on BP Ultimate.

 

On Saturday I thought I’d try it on again, so I piped it all back up and Sunday I was helping a mate move house (Corrado not the ideal car I know) but anyway did quite a lot of stop starting and a few blasts up and down my local duel carriageway but mostly round town driving and it was never below 26mpg and averaged 34mpg at the end of the day.

 

I know there are other benefits to this mod and the noise is nice but i just cant justify the amount of fuel it was using, maybe when I’m more flush it might come off again.

 

Just thought I’d let you guys know what I’d found and you can make your own decisions. I was going to start a new thread but found this one.

 

Chris.

 

Something wrong there mate. Colder air means more fuel efficaiant. At a guess, I'd say it sounds like you could have a leak where the blanking plate meets the charger??

[andycowuk 0]

I have come to my own conclusion about mpg with boost return removed. Mechanically, there is no reason for the boost return to affect the mpg, all you are doing is redirecting air that you engine isnt using anyway. I think the change in mpg is entirely down to the driving style. you need to have your foot almost to the board for the boost to build up, and give u the tish for each gear change.

 

I noticed when driving my mates car the amount of pull i am used to when driving round normally just wasnt there (its a civic vti). I know that there are obvious differences in the cars(!) but, what i realised was, the amount of pull, is directly proportional to the amount of petrol being used, and although i wasnt reving the tits out the raddo all the time, basically I was driving with a digital right foot! :oops:

 

Once i got over this, my mpg went up by about 7-8 around town.

 

HTH (and makes even a little sense!!!)

[Chris M 0]

Even if there was a leak where the plate meets the charger it wouldn't make any difference apart from drawing in un filtered air.

 

If you think about it the fact that there is pressurized air being forced into the charger all be it warm, it has to be helping it spin plus surely the charger wont have to work as hard to pressurize already pressurized air thus taking loads of drag off the crank when not at full throttle. That’s my logic any way.

 

I just can't see any other explanation for the fact that my MPG has doubled over night and that is the only think that’s changed.

[G60Dan 0]

Even if there was a leak where the plate meets the charger it wouldn't make any difference apart from drawing in un filtered air.

 

If you think about it the fact that there is pressurized air being forced into the charger all be it warm, it has to be helping it spin plus surely the charger wont have to work as hard to pressurize already pressurized air thus taking loads of drag off the crank when not at full throttle. That’s my logic any way.

 

I just can't see any other explanation for the fact that my MPG has doubled over night and that is the only think that’s changed.

 

didn't really think about that one did it. :oops:

 

it won't be the boost return kit making your mpg go down. Give G-werks a call & speak to them mate. Quickest way to determine your mpg prob.

[Chris M 0]

need to speek to G-Werks any way, so i'll see if he can shead some light on it.

 

what sort of MPG figures are other people getting with removal kit on?

 

sorry G60jet if i've hijacked your thread maybe i should have started a new one :oops:

[Henny 0]

45power'd, I've split the thread to make it a seperate one for ya! 8)

[Chris M 0]

cheers henny

[h100vw 0]

So g-man, whats the score? I was considering a return removal but as my mpg is unbelieveablely low I wouldn't want to make it worse.. :|

 

Is it just the change of driving style/

 

Gavin

[stevemac 0]

what sort of MPG figures are other people getting with removal kit on?

My mpg hasn't altered at all - I removed the boost return & fitted Bosch W5DPO (slightly colder than standard) plugs at the same time. What a boost in performance 8)

 

I went to the CCGB meet at Longleat a few weeks ago & averaged :-

23mpg @ 100mph on the way there (20 mile section of the M5)

38mpg @ 70mph on the way home

 

I'm using a breather filter on the ISV & the cam cover oil breather is vented to atmosphere (piped to the back of the front subframe)

Oh - throttle response has improved too 8)

[h100vw 0]

That's more encouraging Steve. :mrgreen:

 

Gavin

[W3RKD 0]

45power'd have you also removed the carbon canister ?

 

the boost return will make NO differance to your fuel unless as andrew mentions you are going WOT in every gear before gearchanges to hear noises.. :lol:

[Chris M 0]

yes i have removed the carbon canister but did't put it back on when i put the boost return back on because i've used the hole for a cold air feed

 

when i first took the boost return off i was driving it heavy footed just to hear the noises lol :oops: but like i said its been off for 2 months now and i've been driving like i've got a glass accelerator lately because i can see my bank balance lol

[markmcie 0]

what sort of MPG figures are other people getting with removal kit on?

My mpg hasn't altered at all - I removed the boost return & fitted Bosch W5DPO (slightly colder than standard) plugs at the same time. What a boost in performance 8)

 

I went to the CCGB meet at Longleat a few weeks ago & averaged :-

23mpg @ 100mph on the way there (20 mile section of the M5)

38mpg @ 70mph on the way home

 

I'm using a breather filter on the ISV & the cam cover oil breather is vented to atmosphere (piped to the back of the front subframe)

Oh - throttle response has improved too 8)

 

@ Steve - Would you recommend the W5DPO plugs on a stage 4 G60 ?

[W3RKD 0]

w5dpo are standard plugs for the g40 and can be used with no problems in ANY tuned g60.

[stevemac 0]

Steve - Would you recommend the W5DPO plugs on a stage 4 G60 ?

Definitely :rambo:

 

They didn't make much noticable difference low in the rev range but pulls like a train right round to the red-line now 8)

 

Not cheap though - £10 each :shock:

[markmcie 0]

These ones are half the price :wink:

 

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... eName=WDVW

[Shilakadaddy 0]

Bought a set of those exact ones earlier today.. oh and they're brand new, and £20 gets a set of 4 (I asked :))

 

Meanwhile, I'm quite interested in what difference removing the CC makes to the MPG... I've just done this, but havn't yet tested the mpg?

[stevemac 0]

Meanwhile, I'm quite interested in what difference removing the CC makes to the MPG... I've just done this, but havn't yet tested the mpg?

I think the key is to seal the vacuum pipe outlets properly (I used diesel injector blanking plugs) & leave the fuel tank vent pipe open to atmosphere (tucked the end of mine into a hole in the inner wing :wink:)