RichieC

Has anyone got any views on the merits, or not of running higher boost with a bleed valve or an EBC.

I have spoken at length to BPM (Thanks again Greg) about said subject and I am pretty convinced it is possible to do safely if youre sensible, i.e not running huge boost in standard trim.

Has anyone got performance comparisons with a valve, and I dont mean the cheap, crude £20 ones. Alternatively does anyone run the Blitz type EBC/SBC??

Your views are appreciated,

Richie.

[Hope this gets us away from the ongoing ECU related thread] !!

firefox

Hi again..

You can safely increase boost, within reason, aslong as you dont exceed the maximum boost pressure that the ECU can cope with (programmed into the map).

Lee uses a "crude" bleed valve to up the pressure to about 17psi I think...

This will give you move power.. but can also leak boost, as it is always open and bleeding...

An EBC is far better (but far more expensive). They (in theory) keep the wastegate closed until the preset pressure has been reached, at which point they feather the wastegate to keep the desired pressure..

This means that the "maximum" boost is achieved as soon as possible, and that this boost is maintained for aslong as the turbo can (but be careful you dont overwork the turbo. If you do, all you will be generating is heat and not anymore power).

I have run several EBC's and would recommend them. I currently have a HKS EVC IV and the HKS EVC Pro.

The Blitz dual one is very good... and offers the same features as the EVC IV.

Just remember they take time to set up perfectly...probably not an issue if you are only upping by a few PSI...

J.

Lee

Yes, true I do use one.

>>and I dont mean the cheap, crude £20 ones.

what do you mean by that ? If I charged you £50 for a valve would it be any better ? All bleed valves can be termed "crude" theyre all the same..

>>but can also leak boost, as it is always
>>open and bleeding...

this must be negligible. The restrictor in the hose limits the AMOUNT of air bled away, otherwise even the standard system would leak (I've tried removing the restrictor y'see)

I use a 3-way valve and put the bled air back into the system same as the wastegate solenoid.

Where a "crude" valve fails is it's inability to make the boost equal in all gears/load and hold the boost across the rpm range. Effectively mine "adds" 3psi to the standard, but retains the profile.
Although holding the boost at 17psi right upto the limit wouldnt be good I think...

At the end of the day, if you were willing to pay £350+ for a electronic boost controller, why not pay the extra £150 and have a possum link or remap ?

RichieC

I mean no disrespect!!

I simply refer to the badly made valves which I have seen running on RS Turbos etc, These in anyones eyes ARE crude.

No I wouldnt be happy to pay £50 for the same product, the alternative you see is the 3 way valve you metion, or a one which can be adjusted from inside the car.

Also where have you ever seen Possum Link for
£500?? I certainly havent.

What model do you have?

Im looking to run about the same, 17psi

Thanks for the comments,

Richie

Lee

Okay..I wasnt having a go at you

The valves that are in-car adjustable..I didnt choose this cos the length of tubing from turbo to interior and back again might interfere or provide overboosting problems. Jay'll know..

My 3 way valve was the demon tweeks one, I think it will be the same as the one that the RS boys fit..

I have a MY99 check out

RichieC

So have you had any problems running that setup, I take it the rest of the engine is standard??


Richie.

Lee

(Yes standard apart from this)..The only problem is that if the boost goes upto 18psi the ECU cuts the fuel, this causes a jolt in driving. This happened at lot at Donington (Colin/Sunil will tell you !) so you really need to turn the valve down if this happens..

This doesnt cause much grief, certainly day-to-day I don't have to alter the valve, but at 5AM in the morning (when its brrrr cold) I take it easy cos you get more boost when its cold.

I may get it r.roaded on wednesday..

certainly the EBC is far more elegant but I think the price is a joke in terms of what you get for your money.

My next mod will be the possum btw.

cheers
lee.

[This message has been edited by Lee (edited 21-11-1999).]