Bailey Dump Valve

[Blue_Bullet]

Me again sorry!

Probably another stupid question but I know some of yous will have a sensible answer and the rest will make me laugh!!


I have a Everest Chip installed Peco Exhaust Ported wastegate + K+N drop in filter and was thinking of adding a Bailey Dump Valve. Will this work and if so what increase in power (bhp) could be expected by fitting one of these + advantages/disadvantages?


Any help fully appreciated.

[theelanman]

the dump valve doesnt make any difference.....
it helps release pressure on your turbo....trying to preserve its life...
the exhaust and chip os where you'll get the power

[Blue_Bullet]

But it will reduce any turbo lag correct?

Just i was thinking Reduction in Turbo Lag = more power available during this period???

What does a dump valve do?

It eliminate compressor surge when changing gears. Excessive back pressure is created when the throttle is closed during gear changes or deceleration, causing turbo cavitations. This is detrimental to the life of your turbocharger, however fitting a dump valve will substantially improve this problem. By installing a dump valve you will significantly reduce turbo spool up time. You will notice a substantial improvement in response from your turbo between gearshifts. Boost will come on earlier giving an increase in torque at lower RPM.

Quote from http://turborevs.org.uk/Dump%20Valves.htm

[theelanman]

mmmmmmm.......not sure about 'lag'.....
youre turbo should kick in pretty much straight away at about 2500 rpm.....
if it doesnt you may be getting boost creep.....
this could either be your exhaust or your waste gate

[Blue_Bullet]

Ok so people just install them for the woosh noise and prolonging the turbo? My turbos 20 years old nearly and still going like a gooden !!!

[tweetdriver63]

It will reduce "lag" in a sense. That is, the turbo will be able to spool back up faster when the backpressure isn't there. However, you probably wouldn't be able to notice it. My understanding is that it will significantly reduce wear/extend the life of the turbo. Mine's 18 years old and going strong too, but it only went 50K miles in the first 16 years, so that may have a little to do with it.

If you don't like the whoosh sound, get a re-circulating vavle.

[dapinky]

Turbo 'lag' is a result of having the turbocharger too far from the cylinder head, therefore the exhaust gasses have to travel further before they spin the thing round - not a problem with the elan design.

It can also be exacerbated by having a big fan blade in the turbo, so it takes longer to spool up - again, not a problem with the elan one.

It is most associated with earlier generation turbos (big things bolted into available spaces in an engine bay back in the 80's), not with matched units designed into the original specs.

The dump valve releases the back pressure on throttle closing, and may or may not give a 'whoosh' sound (depending on type).

It may or may not extend turbo life, and as you say it is still going strong - but for how long???

A few have been wearing out recently, and they are all the same age, so spending £100 now may prevent you having to get a new turbo next week for a lot more.

I believe that the reduction in lag is so minimal that you will not notice it.

[CJ101KT]

Can anyone recommend who is best to buy the valve and fitting kit from + any photos of it installed? I've seen a few that look pretty flimsey when put on the pipework. Thanks.



The other thing is where can I get the Intercooler Pipes and Blow Off Valves that are more expensive and look to fit the car better or are these only purchased from the LGM group buy a while ago now?

[Blue_Bullet]

Nice looking bling parts!!! sorry m8 I haven't got a clue what pipes are good quality! There are other post and write ups on this, I think if you try searching for Samco pipes/hoses it will help!

I see the bailey dump valve and fitting kit on Ebay if thats any help!
http://cgi.ebay.co.uk/BAILEY-DUMP-VALVE ... 518c73044d

Maybe i will give the dump valve a miss for a while then and anyway i think i will be upgrading the Turbo in the future! ! (Good idea? any suggestions?)


But i am still wondering what step to take next in my quest for more and more BHP lol

[tigerdog]

Having researched this more than a bit recently, I would actually shy away from any dump/blow off valve that vents to atmosphere. If the spring is strong enough to hold the valve closed at high vacuum (idle, deceleration, etc.) then it's so strong as to not open quickly enough to keep the turbo from partially stalling during shifts. If it's weaker, it opens to atmosphere and lets your engine breathe in unfiltered air. Neither is good.

Instead, look at Marie's installation or the thread I wrote about the valve I fitted to Smaug. The valve is plumbed back into the clean side of the air filter. I find better throttle response off idle and much quicker turbo spooling between shifts bec cuase the valve is actually open at idle and just off. I hypothesize this is because it provides a less restrictive intake path.