Recirc or blank off aN LEAVE in?

[merc85]

just a thought i fitted a dv, and blanked off the recirc valve and left it in the turbo.

Since then she suffer's from turbo lag, But now she has been holding back very low down in the rev range and also when rev's pick up she hesitates wen on boost.

I'm thinking fuel pump BUT could this all be down to not taking out and blanking off the recirc valve properly??

[The Flying Moose]

Really you need a proper blanking plate as your valve will still be working but obviously it wont be recirculating.

From experience dump valves if not set up correctly will slow your car down. Despite however when set up correctly they have no gain whatsoever unless running well over 400hp.

[mitchyboy01]

This may be the problem I'm having with my T4. Mine has a dumpvalve and the recirc, withexactly the same symptoms as yours. What would cause the holding back??

[mitchyboy01]

I was also thinking fuel pump as it seems like it lacks power at full throttle at hesitates low down.

[merc85]

I was also thinking fuel pump as it seems like it lacks power at full throttle at hesitates low down.

Going to change it back to recirc valve tomorrow will keep u posted, thanks for the reply's

[mitchyboy01]

I was also thinking fuel pump as it seems like it lacks power at full throttle at hesitates low down.

Seems to much of a coincidence to be the fuel pump though. You reckon it's dump valve related? Not sure how though?

[merc85]

Been runing a dv for about a month now but it's always been laggy , so going to change it as it's got 100 times worse, gotta be worth a shot aint gonna cost nothing an will rule it out.

[Jamest5r]

This may be the problem I'm having with my T4. Mine has a dumpvalve and the recirc, withexactly the same symptoms as yours. What would cause the holding back??

They are both trying to do the same job, there is no need to have a dv, the recirc is well up to the job and works well with the turbo its designed for.

[mitchyboy01]

They are both trying to do the same job, there is no need to have a dv, the recirc is well up to the job and works well with the turbo its designed for.
I know mate, only had the car 6 days lol. Trying to work out why it's hesitating and sorting the other bits as I go. I need a makeshift dump valve blanking plate.

[Jamest5r]

I know mate, only had the car 6 days lol. Trying to work out why it's hesitating and sorting the other bits as I go. I need a makeshift dump valve blanking plate.

The recirc is just a valve you can open it up and sort of disable it :hidesbehi, not very high tech i know but if your not intending on using it again.....

[LiamT4]

Well my car is laggy as fu&k! without an mbc. Hopefully when i fit the new bcs or actutuator it'll get better boost.

To be honest turbos p*ss me off as they have more to go wrong with them and are more tricky to set up properly.

My bothers 200sx is, now as quick as my car to about 90mph, where as my old t4 would have destroyed it!!!

[p fandango]

the cars are getting old now & the recirc valve is only a rubber diafram so may have a split in it. I'm not running a recirc or dump valve (here comes the video lol)

http://www.youtube.com/watch?v=fmNucK8712M

[mitchyboy01]

What does the bcs look like on the t4? Dont think mine has one. Checked under the airbox. Has something with 2 electrical connectors and 2 small boost/vac pipes connected to it?

[T4Rick]

the cars are getting old now & the recirc valve is only a rubber diafram so may have a split in it. I'm not running a recirc or dump valve (here comes the video lol)

http://www.youtube.com/watch?v=fmNucK8712M

Hi mate thats a nice sound,i thought you had to either have a recirc or a dumpvalve?Do i just remove the recirc and bolt the cover back on? sounds very good though mate

[p fandango]

Hi mate thats a nice sound,i thought you had to either have a recirc or a dumpvalve?Do i just remove the recirc and bolt the cover back on? sounds very good though mate
no not running either valve, i blanked my recirc off with a proper Forge blanking plate it replaces the recirc valve LINK (http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=&product=FMBPVRM)

http://www.forgemotorsport.co.uk/images/products/FMBPVRM.jpg

[merc85]

DO you also blank the intake manifold connection off?

Also how is the car dumping without either??

Where does the gases go sorry but not that clued up with Turbo's lol

[T5frankie]

when you fit a dump valve you take out the recirc. valve and throw it away lol, blank off the hole with the forge cover as above you don't use both.

[merc85]

what about the connector on the intake manifold ?

[p fandango]

DO you also blank the intake manifold connection off?

Also how is the car dumping without either??

Where does the gases go sorry but not that clued up with Turbo's lol
yeh you have to bung the vac pipe up after you've removed it. The noise is turbo chatter, because the turbo has got momentum when you back off the throttle it still creating boost. as you've closed the throttle butterfly the excess goes back out thru the air intake which is the noise your hearing. Some people say it creates extra lag because the system has to recharge with air, & that it puts excess strain on the turbo but quite a few people are running the same & we don't run high pressures anyway