WHAT BOOST SHOULD MY G60 RUN??

[unitfight 0]

for a while ive been wondering whether my charger is knackered, as sometimes on full throttle, its pants!

 

ive got a stage 4 charger and 68mm pulley, big valve head and 272 cam. just fitted my boost guage and its pushing about 10-11 psi. is this normal??

 

any help appreciated

[mimjed 0]

its weak for a stage 4. should be seeing at least 15 on a 68 mm.

 

last service? possible boost leak.....

[wormy 0]

Not too far off I think, considering you got a big valve head.. Those "eat" boost... :clap:

[unitfight 0]

was last serviced in 2002! thats why i thought it could be the apex seals, thats a good 8 yrs ago! was gonna send it off for rebuild anyway, just wanted to know what boost figures i should get.

 

also, my mate thinks its a 72mm pulley i have o there? would the figures be about right for that pulley?

[JMC 0]

10-11 psi not too far off, but it all depends on the head and cam really. Mines similar on a healthy charger (maybe 12psi on a nice cold day, lol). Definately worth getting the charger checked though with it being that age. If it's rubbish occasionally make sure the WOT microswitch is activated whehn the throttle is fully open, and make sure the throttle cable is properly adjusted. Minor changes in that can cause the butterfly valves in throtte not to close fully on WOT and the WOT not to activate.

[unitfight 0]

thought it may be the WOT switch so i replaced them with a 2nd hand set. admitidaly they may be duff to! but a new set is expensive. i havnt actually tested them since they have been fitted actually??

 

how would a big valve head and cam eat boost?? especially when the boost reading is taken from the inlet manifold?

 

oh, and only made about 9psi of boost today. christmas bonus = supercharger recon!

[wormy 0]

To make a long story short, it'll flow alot more air = less "restriction" (boost)..

And flow > boost.. :grin:

 

9psi seems a tad low thought..

[mimjed 0]

for a 78mm pulley then 11psi is probably not far off what it should be.

 

but still would reccomend lengthening the fuse on the time bomb.

 

but with todays figures id say sooner rather than later, choose who does it wisely though, i had a shockingly bad experience when mine was done. id rather scrap my car than ever pay them another penny.

[Supercharged 2]

but with todays figures id say sooner rather than later, choose who does it wisely though, i had a shockingly bad experience when mine was done. id rather scrap my car than ever pay them another penny.

 

Agreed, get it done asap - mimjed, who did yours then??

[mimjed 0]

Im ready to be slated for it but your sig answers the question sadly

[unitfight 0]

annoyingly its my daily, so gotta find a week off to get it sorted!

 

ran 8psi today :(

[mimjed 0]

you can run without a charger, need a 6 rib belt 1250-1275mm, i have one in the garage from when i had mine done, and bodged some flexi hose from the air box to the intercooler pipe.

 

mine is my daily and took 27 days to come back if i remember correctly.

 

will be better on fuel but pretty god damn slow.

[mimjed 0]

oh and need to blank off the oil feed pipes, i used an m8 and m6 bolt with washers, and ptfe tape to seal it up.

 

does sound like its about to go bang.

[unitfight 0]

had my charger rebuilt by jabba. £310 and had it back on my engine within 10 days!! excellent service

 

anyway, to the chase, just finished running in my charger and im now getting healthy readings of 14-15 psi full throttle :clap:

 

solved my boost problem, but digi-lag is at its element now still running standard chip. one on order though

[Yandards 0]

had my charger rebuilt by jabba. £310 and had it back on my engine within 10 days!! excellent service

 

anyway, to the chase, just finished running in my charger and im now getting healthy readings of 14-15 psi full throttle :clap:

 

solved my boost problem, but digi-lag is at its element now still running standard chip. one on order though

 

Nice, sounds like you need some mods to the inlet duct to get the most from your set-up, as for an off the shelf chip don't waste your money you really need a custom one to get the fuelling correct on full throttle - DG Autotech would be the folks to go to for that up near Birmingham.