BOV vacume feed

[Splashout]

Boost controllers like the Greddy one I am having fitted have an overboost warning.

Mine will be set at 0.8 bar and will go red and bleep like an Eddie Murphy performance on children's TV.

Gives you a chance to slow down before the bang clatter clatter!

<{POST_SNAPBACK}>

So hurry up and get your car back and test it so we all know its good and can copy lol

[Splashout]

Oh...I dont know what to do now.

I do like the Greddy install on the http://invenair.com/ site but just realised by fitting this I would have no overboost protection (not that I did anyway with the Lotus contraption), and replacement wastegates that are more reliable are mucho money 

Too much to think about.....giving me a headache 

<{POST_SNAPBACK}>

There is nothing stopping you doing a similar install but fitting a good make pop off valve which is what i am now thinking.

This would give you the true let off bov and a reliable overboost protection add this to the boost controller that Robin is having and it should be a fairly sorted setup

[richcamb]

Boost controllers like the Greddy one I am having fitted have an overboost warning.

Mine will be set at 0.8 bar and will go red and bleep like an Eddie Murphy performance on children's TV.

Gives you a chance to slow down before the bang clatter clatter!

<{POST_SNAPBACK}>

Robin...you are getting your own back and making me to spend my money now.

This might well be an option as any warning is better than none....though if committed during an overtake....as my car was with the previous owner...then it will still go bang!

Whats the low boost thingy you mentioned on your wastegate in the Boost controller topic?

[Splashout]

Robin...you are getting your own back and making me to spend my money now.

This might well be an option as any warning is better than none....though if committed during an overtake....as my car was with the previous owner...then it will still go bang! 

Whats the low boost thingy you mentioned on your wastegate in the Boost controller topic?

<{POST_SNAPBACK}>

Basically the controler controls the amount of boost that the waste gate sees and as such can have a number of settings set to what you like.

[richcamb]

There is nothing stopping you doing a similar install but fitting a good make pop off valve which is what i am now thinking.

This would give you the true let off bov and a reliable overboost protection add this to the boost controller that Robin is having and it should be a fairly sorted setup

<{POST_SNAPBACK}>

Glyn

Would you envisage fitting the new pop-off valve between the plenum dump valve exit and the new BOV? (Hope that makes sense)

[Splashout]

Yeah what i am thinking is to have a bracket made up that will utalise the current fitting (hence it is totaly reversable) kind of like a box extension to the plenum, which would accomodate the BOV on one side and the pop off valve on the other.

Hope that makes sense as you may have guessed i am no expert and these are just my thoughts.

[richcamb]

Yeah what i am thinking is to have a bracket made up that will utalise the current fitting (hence it is totaly reversable) kind of like a box extension to the plenum, which would accomodate the BOV on one side and the pop off valve on the other.

Hope that makes sense as you may have guessed i am no expert and these are just my thoughts.

<{POST_SNAPBACK}>

Yes...makes perfect sense.

Are these pop-off valves adjustable?

I have gone from wanting 1 thing to 3 now. Just need to find a way of plumbing it all together now, and of course making it easily retrofittable and reversable.

Just noticed Greddy do 'Relief Valves' too. They seem to do all we need.

Edited August 26, 2005 by richcamb

[Splashout]

i havent looked too hard for pop off or relief valves yet but will make it my mission insted of working for the last hour lol

I believe they must be otherwise they would have to make every single one the clients spec

[Evil_Dr_Fish]

There are three boost 'modes' on the digital controller. You assign them to be whatever boost setting you want and can switch between them while you're driving.

Low - (for me) Stock - ie fuel economy or crap weather, pussy mode!

High - Vroom! will be .69 (or was that .67?) This is what they pushed the HC engine up to.

Scramble Boost - 15 seconds of a slightly higher setting again .75 (this was the highest Lotus seemed to push their non CC cars) Good for a passing manouvre or that git in an R32 up your chuff!

[Evil_Dr_Fish]

One thing occurs to me...

If I am still on full .75 boost after 15 seconds... then as it is essentially a bleed valve, surely it will STAY at .75 bar until I go below that for it to re-trigger the wastegate at the lower boost level?

Or am I seriously not understanding the way the whole system works?

Ah... (thinks!) would it simply allow more pressure through to the wastegate to make it open MORE perhaps? Thus letting more boost out?

[Splashout]

robin it is like a boost valve i believ it simply vents all pressure when above a set value......

but thinking about it would this then not mean that it simply opens and shuts????

Maybe it opens and then needs resetting??

something to look into

I have emailed greddy(USA) to ask

Edited August 26, 2005 by Splashout

[Evil_Dr_Fish]

Yep it is a digitally controlled bleed valve...

And exactly - I thought it was just open and shut originally - hence why my train of thought led me to wonder what happens after the 15 seconds is up, if you still have your foot flat on the floor?!

[Splashout]

I have emailed greddy(USA) to ask

<{POST_SNAPBACK}>

In relation to a relief valve not the controller

[richcamb]

In relation to a relief valve not the controller

<{POST_SNAPBACK}>

Greddy sell an adaptor for the Relief Valve....which might come in useful.

Trawled the net everywhere looking for a picture of it (the adaptor) but havent had any luck.

Spent last hour sketching a Fuel Pressure regulator bracket & a BOV/Relief Valve kinda adaptor thingy.

[Splashout]

Greddy sell an adaptor for the Relief Valve....which might come in useful.

Trawled the net everywhere looking for a picture of it (the adaptor) but havent had any luck.

Spent last hour sketching a Fuel Pressure regulator bracket & a BOV/Relief Valve kinda adaptor thingy.

<{POST_SNAPBACK}>

LOL yeah i noticed that too will wait and see what comes from emails

so hows the bracket comming on B)

[AJay]

The HC engine has an overboost switch set at 12psi which cuts the ignition if an overboost situation occurs, could be plumbed into your boost gauge line if you are worried about overboost.

The lotus valve thingy is called a dump valve by Lotus technical it is designed as a relief valve for overboost and is set at 10Psi so robin you will have to remove this if you want boost higher than 10 psi.

Also like everything on the car it only sticks if it not used. the origional boost of 8 Psi should not release the valve under normal conditions.

When running at 9.5 Psi it operates at spirited driving conditions between gear changes. I have tested mine and it actualy operates at 11psi so not too accurate.

Hope this helps.

[Splashout]

The HC engine has an overboost switch set at 12psi which cuts the ignition if an overboost situation occurs, could be plumbed into your boost gauge line if you are worried about overboost.

The lotus valve thingy is called a dump valve by Lotus technical it is designed as a relief valve for overboost and is set at 10Psi so robin you will have to remove this if you want boost higher than 10 psi.

Also like everything on the car it only sticks if it not used. the origional boost of 8 Psi should not release the valve under normal conditions.

When running at 9.5 Psi it operates at spirited driving conditions between gear changes. I have tested mine and it actualy operates at 11psi so not too accurate.

Hope this helps.

<{POST_SNAPBACK}>

Thanks for that Ajay

Reply from greddy

Thanks for your interest in Greddy performance products.  The product you are inquiring about basically gets attached to the charge pipe before the throttle body through the available relief valve adapter.  When the boost pressure in the charge pipe exceeds the spring pressure in the relief valve the valve will remain open until boost pressure decresases below set boost pressure on the spring.  This is used only as a secondary boost safety device and should not be used as the primary source of boost control.  Thanks for the email.

So this would do exactally the same as the lotus one but would be adjustable too.

Glyn

[AJay]

I am probably wrong, as it is not the conventional view. may be i need to read more and stop driving the car.

<{POST_SNAPBACK}>

[Splashout]

will do it is next on the agenda once she is running again

[Evil_Dr_Fish]

Hmmm Andy you raise a good point... I was hoping to have my scramble boost set to .75 bar = 10.87 psi - so I COULD be lucky and just get away with mine being sufficiently inaccurate

TBH.. the difference is so miniscule that I'm not really sure I'd notice anyway! lol

[AJay]

Hmmm Andy you raise a good point... I was hoping to have my scramble boost set to .75 bar = 10.87 psi - so I COULD be lucky and just get away with mine being sufficiently inaccurate

TBH.. the difference is so miniscule that I'm not really sure I'd notice anyway! lol

<{POST_SNAPBACK}>

I have been running 10 psi and have recorded 70-90mph in 5.48secs.

After you lot frightening me about the tranny i reduced the boost to 9psi and recorded a 70-90 time in 5.8 secs not a big difference but the difference in the way the car drives and delivers the power is quite noticable.

Not sure where i am going with the boost, the extra tourque is adictive but!!!!!!!!!

[richcamb]

Yeah what i am thinking is to have a bracket made up that will utalise the current fitting (hence it is totaly reversable) kind of like a box extension to the plenum, which would accomodate the BOV on one side and the pop off valve on the other.

Hope that makes sense as you may have guessed i am no expert and these are just my thoughts.

<{POST_SNAPBACK}>

Just ordered the GReddy BOV & Relief Valve with adaptor from the US from

www.racingworks.com

They have a sale on at the moment...which is nice!

Should arrive within a week, and then I can get on to making the piece that will hold it all together on the plenum.

Will keep you all updated on developments.

Richard

[hovgaard]

Before this thread gets out of hand, may I suggest that you read up on my dump valve mod in the garage. I realise that the older cars are not setup quite like mine, but I would argue that the same principles apply.

Summing up:

1: You do need a dump valve of some sort, just make sure you don't dump into the atmosphere if you care about engine longevity (unless you put a good airfilter on your valve (in which case it would seem easier to run a pipe to the compressor intake!)).

2: Do you also need a safety valve? I don't know, I haven't got that on any of my cars.

The valve I used cost less than the equivalent of $40 at the local Saab/GM dealer. Contrary to popular belief, it is good for any boost pressure your engine can stand, since, while under boost, the pressure is applied to both sides of its membrane.

Do you need funnier noises or prettier valves? Or does overpriced stuff impress your friends? Can't argue with that.

Cheers!

[WayneB]

My 3d worth on this subject

Martin Cliffe did an excellent job designing the Turbo setup on our cars

My car runs great with all the original stuff functioning well

Never had a problem with my dump valve.

Car goes like sh1t off a shovel with 8psi boost.

Rather than messing about making changes, wouldnt time be better spent making sure the stock setup is running optimally ?

i.e. no missfires, stuck wastegates etc,etc.

[Guest teigan]

i read up on your modifications jens.

from a conservation of energy standpoint, it sounds far superior to the lotus equipment.

i'd guess you burn less fuel and have more available power.

is there any detectable spool up time between gear changes? even the best blow off valves leave a lag time. could i test drive your car next time i'm in sweden?