pistion type dump valve

danbmx_69 · 11th February 2013, 20:39

fitted one of these to my car the otherday am very happy with it as it dosent go off all the time so you can drive normaly with out it sounding, it dose sound but very quiet but i do think i may have a problem as the first day i fitted it when comeing of full boost it was quite loud when dumping the air, but now after a few days it seams to have gone very quiet evan letting of form accelerating quite hard ie on to a motoway, evan before you could be doing say 30 in 4th gear put your food down just to build full boost and then let off and it would sound quite loud but now doing the same a few days later it seams very quiet, so i am wondering is it possible that i have a boost leak and the air is now getting out some where else when the throttle is closed, or is it at all possible the vavle itself could be stuck open sligtly?

VVC-Geeza · 11th February 2013, 22:11

I would say give it a few more days,very easy to start imagining different sounds when something new has been fitted.You could always source a Forge one if your not happy with it.Love mine Tishhh

E_T_V · 11th February 2013, 22:25

Check the pipes haven't come off!

danbmx_69 · 12th February 2013, 06:51

After my drive to work today I do think I have a boost leak as now my boost gauge goes up to 12psi and then tails back to around 10psi and before it use to stay at a solid 12psi and not move at all

E_T_V · 13th February 2013, 22:42

Is 12psi standard boost?

danbmx_69 · 14th February 2013, 09:29

No 12 psi isn't standard boost I dont think, mine is running 12 due to the map

VVC-Geeza · 14th February 2013, 09:46

Standard boost is 9 psi

E_T_V · 14th February 2013, 13:03

Is it a clean 9psi or is it artificially modulated to lower levels at low revs (like the T16 turbos that I'm used to).

I think I already know the answer to that as if it was a natural 9psi then there would be no need for the boost control valve.

T16 turbos were 7psi up to 4500prm and then modulated gradually up to 11.5psi at the top end. This was done to protect the gearbox and give a nice linear power progression. Is the K turbo similar?

And what is the dinky little original turbo capable up to?

VVC-Geeza · 14th February 2013, 17:35

Quote:

Originally Posted by E_T_V

Is it a clean 9psi or is it artificially modulated to lower levels

Standard factory map,boost is bottom line

E_T_V · 14th February 2013, 20:09

EEeek those curves look pretty horrid. Turbo is obviously too small as boost tails off above 5k. Not sure I like the torque/boost spike either.

Did they do AFR's on the run too?

11th February 2013, 20:39	#1
danbmx_69 Gets stuck in zt 160 Join Date: Aug 2012 Location: swansea Posts: 970 Thanks: 21 Thanked 62 Times in 43 Posts	pistion type dump valve fitted one of these to my car the otherday am very happy with it as it dosent go off all the time so you can drive normaly with out it sounding, it dose sound but very quiet but i do think i may have a problem as the first day i fitted it when comeing of full boost it was quite loud when dumping the air, but now after a few days it seams to have gone very quiet evan letting of form accelerating quite hard ie on to a motoway, evan before you could be doing say 30 in 4th gear put your food down just to build full boost and then let off and it would sound quite loud but now doing the same a few days later it seams very quiet, so i am wondering is it possible that i have a boost leak and the air is now getting out some where else when the throttle is closed, or is it at all possible the vavle itself could be stuck open sligtly? __________________ Now 320BHP 407nm 1.8T ZT https://www.the75andztclub.co.uk/for...d.php?t=122691

11th February 2013, 22:11	#2
VVC-Geeza This is my second home 2005 Connoisseur SE 1.8 Turbo,2004 45 1.8 Connoisseur and my beloved 1998 VVC Coupe. Join Date: Nov 2009 Location: Derby. Posts: 8,803 Thanks: 2,022 Thanked 1,016 Times in 739 Posts	I would say give it a few more days,very easy to start imagining different sounds when something new has been fitted.You could always source a Forge one if your not happy with it.Love mine Tishhh __________________

12th February 2013, 06:51	#4
danbmx_69 Gets stuck in zt 160 Join Date: Aug 2012 Location: swansea Posts: 970 Thanks: 21 Thanked 62 Times in 43 Posts	After my drive to work today I do think I have a boost leak as now my boost gauge goes up to 12psi and then tails back to around 10psi and before it use to stay at a solid 12psi and not move at all __________________ Now 320BHP 407nm 1.8T ZT https://www.the75andztclub.co.uk/for...d.php?t=122691

14th February 2013, 09:29	#6
danbmx_69 Gets stuck in zt 160 Join Date: Aug 2012 Location: swansea Posts: 970 Thanks: 21 Thanked 62 Times in 43 Posts	No 12 psi isn't standard boost I dont think, mine is running 12 due to the map __________________ Now 320BHP 407nm 1.8T ZT https://www.the75andztclub.co.uk/for...d.php?t=122691

14th February 2013, 09:46	#7
VVC-Geeza This is my second home 2005 Connoisseur SE 1.8 Turbo,2004 45 1.8 Connoisseur and my beloved 1998 VVC Coupe. Join Date: Nov 2009 Location: Derby. Posts: 8,803 Thanks: 2,022 Thanked 1,016 Times in 739 Posts	Standard boost is 9 psi __________________

11th February 2013, 22:25	#3
E_T_V Loves to post MG ZT-T Join Date: Feb 2013 Location: Scunthorpe Posts: 423 Thanks: 8 Thanked 9 Times in 9 Posts	Check the pipes haven't come off!

13th February 2013, 22:42	#5
E_T_V Loves to post MG ZT-T Join Date: Feb 2013 Location: Scunthorpe Posts: 423 Thanks: 8 Thanked 9 Times in 9 Posts	Is 12psi standard boost?

14th February 2013, 13:03	#8
E_T_V Loves to post MG ZT-T Join Date: Feb 2013 Location: Scunthorpe Posts: 423 Thanks: 8 Thanked 9 Times in 9 Posts	Is it a clean 9psi or is it artificially modulated to lower levels at low revs (like the T16 turbos that I'm used to). I think I already know the answer to that as if it was a natural 9psi then there would be no need for the boost control valve. T16 turbos were 7psi up to 4500prm and then modulated gradually up to 11.5psi at the top end. This was done to protect the gearbox and give a nice linear power progression. Is the K turbo similar? And what is the dinky little original turbo capable up to?

14th February 2013, 20:09	#10
E_T_V Loves to post MG ZT-T Join Date: Feb 2013 Location: Scunthorpe Posts: 423 Thanks: 8 Thanked 9 Times in 9 Posts	EEeek those curves look pretty horrid. Turbo is obviously too small as boost tails off above 5k. Not sure I like the torque/boost spike either. Did they do AFR's on the run too?