Dump valve hose?

[Andyp]

Hey all,

Just been reading the previous thread today on not being able to keep the boost up. Was on my way back home today and was behind some dumb merc that wouldn\'t move out the way. Was going about 4k revs when he moved over and put my foot down and wasn\'t getting any pick up really so I let off and changed into 5th and got a real loud pressure release / squeak come from the dump valve.

Turbos are fine through the lower gears bt the way

After reading the thread I went out and check my hoses, all looked well apart from the one attached to top DV. Looks as if it\'s pinched in? Is that normal?

I enclose a pic



thanks

Andy

[Iwan]

hi m8,

no its not ok so.

the valve will let escape the air above 4000 rpm (between 4000 and 5000). This valve controls the second charger. It close, when the vacuum apears, so the second charger can kick in. In your case, there is no vacuum so the valve can\'t close, the air will escape and the second charger will not kick in. You should get it sorted.

Ask Geff at Reworx for Viton hose, them are the best for this job.

Best Wishes
Iwan

[Andyp]

thanks very much matey, you\'re a superstar!

are there any aftermarket ones like samco or is it best just to get another one? (not worth this hastle)

[Iwan]

cheers m8y,

no use about samco, sorry.

Just call Geff and ask for viton, him knows than what you are talking about.

The heat is the bigest problem there, so not everyone hose will be OK for this.

Iwan

[Andyp]

Ok will do

thanks again!

[awheelhouse]

Andy,

Are you sure that was a photo of your engine, \'cos it looked just like mine!

I went to my local car bits shop on saturday & bought 2 metres of samco hose, then spent far longer than I expected changing hoses. There will be lots of old rubber hoses that have been hardened to feel like metal brake pipes when you start looking, so buy more hose than you need and expect to spend a sunday afternoon on the task. Be very careful with any hoses that have the inline valve things in, if they are really hard you can snap the end of the valve trying to remove the hose. Araldite seems to do the trick though!

I found some useful info here :-  http://www.rx7turboturbo.com/robrobinette/hoses.htm

Andrew

[Andyp]

Yep def my engine and def my finger poiting in there hehe

I\'ve now been told that these hoses commonly look like this. Must have been a heat related issue as it hasn\'t done it since (odd) Gonna keep an eye on it, next time it does it i\'ll park up and look at them

thanks for the link tis good

[awheelhouse]

Andy,

I think it must be due to the tight bend that the hose is forced to make. As the hose hardens due to age and heat maybe it is unable to keep the normal round shape?

Andrew

[BenF]

Fellas,

Could you let me know if that particular hose kink was causing all the trouble.  I have the exact situation with mine, and the second turbo is not performing, although I get a stutter as if its trying its damndest.  I just thought I\'d check before I take the car in and get my pants removed for a job i could have done myself !

I have looked for cracked hoses but have not found any, and persumed that the kink in the said hose was always going to be there due to the tight corner it has to turn, so I was left scratching my head.

If you could let me know I would be most greatful !

Cheers

Ben

[awheelhouse]

Ben,

I think my car is performing better after I replaced the hose, but I also found that the large diameter pipe from the turbos to the intercooler was not fixed as tightly as I would have thought it needed to be.

It doesn\'t really take long to replace the bent small hose, so it\'s worth a try. I\'ve got a short bit of red silicone hose left that would be more than enough if you want to email me your address to andrew@wheelie.net I\'ll put it in the post.

Andrew

[Andyp]

Heya,

Mine hasn\'t done it at all since I posted last, which leads me to think it was a heat problem. Jimmy\'s said it was common for them to look like that.

However, wouldn\'t mind replacing it if it smooths out performance, so I wouldn\'t mind a peice of that!

[awheelhouse]

Andy,

The hose looked like that all the time, so I can\'t see how it is heat related. When I removed it the hose was very hard and would not change shape back.

Email me your address and I\'ll share what\'s left of the hose between you and Ben!

Andrew

[BenF]

I\'m hoping this is the answer to my problem, so I\'ll let you know how I go........I\'ve e-mailed you by the way Andrew

Ben

[Andyp]

cheers dude you got pm