5tox

someone told me tonight (and ive done a little digging online)
That if i drill out the little nylon restrictor inside the amal valve which goes to the turbo then it will come on boost much harder

is this true?

oldford

The boost will be higher, but then your chip must also allow this.
Otherwise you would hit the boost limit and the engine cuts out.

tabetha

As above, I took out all the restrictors as soon as I got my car on a different ecu, as well as gaining 140 miles per tank range.
tabetha

5tox

its currently chipped to run light greens and is approx 260 bhp, will be chipping it to 315bhp with an MSD chip next year

can i drill the nylon restrictors out now or would it cause problems

BigErn

no need to drill them to take them out, just wind a screw a couple of turns in to the hole and pull them out.

5tox

i guess if the car boosts too high i can always buy another one,

will it still be running 14 psi but just kick in quicker and stronger or will it actually increase the level of boost, if so what will it increase it to?

5tox

http://media.turbosport.co.uk/2004/6...2120725002.jpg

ok so heres the amal valve, we have 3 ports which are:

R - to airbox

C - from turbo

W - to actuator


Ive been reading up on this and i want to just clear up a few things

I believe that the air entering the valve from the turbo is shared between the air box (R) and the actuator (W) drilling out 'R' will increase the amount of air being vented (diverting some of the air going to the actuator) which effectively means the wastegate stays shut longer which = more boost

I have been told that by drilling the turbo feed (C) it will make the turbo boost up to (say for arguments sake 14 PSI) far quicker than before rather than hitting 14 psi progressively

is this correct?

Heitmann

iTrader: (1)

As far as I understand, by drilling out the (R) port you will increase boost, and it will come on boost earlier.
Another mod is making the (C) port smaller, which should also help the boost come sooner, but this will not affect the max boost pressure as such, only how quickly it will get on boost.

chaffe

just remove it and use an aftermarket bleed valve instead, much more control

Fezman1

iTrader: (1)

I dont think bleed valves and cossies is a good thing.
For precise control use air-air injector set up.
Bleed valves its all to tempting to 'give it another screw and see what happens' = melted dead motor. Ive seen many an rs turbo go this way.
As for the amal mod - your talking risks for small gains.
A proper set up stage3 cossie will come on boost quick and boost hard as it should.

James @ M Developments.

iTrader: (2)

Jetting the Amal valve is a normal thing to do, You generally increase the size of port R to increase boost pressure as it allows the valve to bleed more air off. It needs to be done so you dont have to overload the actuator to acheive your target boost pressure. we dont recomend ever running over a hole of pre load, so the rest needs bleeding off.

The valve is totally adjustable IF you know how and have the equipment to do it. Fuelling and boost/det will need to be carefully measured while playing with boost control.

It has one big gain over any std mechanical bleed valve, and that is that it can be controlled by the ecu, so you can have a Peak/Hold boost map, as the valve can be closed to drop the pressure if required. You would need long arms to do that on a std valve fitted under the bonnet.

chaffe

totaly understand what your saying there james, i always personaly prefer to run one high boost limmit though. My point with the manual bleed valve was that you have more adjustability without fannying about on the lathe making plastic jets (assuming you have a lathe)

5tox

after reading all that i think ill just leave the valve as it is in standard form (mainly because i'm not 100% sure what i'm doing, i've just fitted my samco hoses and big knN filter so the 'R' valve is just vented to atmosphere.
summertime after new rings and shells i am going bigger power with the MSD 315(ish) chip greens and 3 bar map sensor so as said above it should boost up nicely anyway

crumpet

id bypass it and run straight off the actuator to turbo comp

chaffe

but then you would need a mental sprung/pre-loaded actuator

Stu @ M Developments

iTrader: (12)

Thats a terrible idea mate, please dont do that...

crumpet

dont worry, im a spacker, these amal valves confuse me proper, i couldnt sleep as night because i was thinking about them

Paul_RS

iTrader: (4)

Bit off topic, but i'd like to get my head round this...

See the whole 1/2 hole preload? That doesn't work for me lol. My car runs about 10 psi max if i did that. Why is this? Wrong length actuator? I've MSD air injectors.

chaffe

you may need a restrictor BEFORE you bleed off, that way limmiting the amount of air flow going to the injectors in the first instance, so in effect they have to bleed less off for a bigger increase in boost.

Paul_RS

iTrader: (4)

It was the same with the amal valve though?

James @ M Developments.

iTrader: (2)

you can run more than 1/2 hole of preload,

one hole is the max we usually run.

martynhomer01

iTrader: (1)

i got to agree. why take such a big risk when you are going to get it done properly in a few months anyway. the amal valve is there for a reason.

chaffe

An amal valve IS a bleed valve though. Cossies run 7 psi out the facory for a reason too lol

chaffe

Its only the penis who screws it right up who knobs the engine with a bleed valve. Worth noting this is no different to taking a boost control pipe off, either way the car will run as much boost as it can make, people fuck cars not bleed valves IMO.

martynhomer01

iTrader: (1)

yes, i fully agree, but also with a bleed valve, the ecu will have no control over it at all, and lets be honest, its too late to turn a bleed valve down when the engine has shat itself all over the floor isnt it,

chaffe

good point, but if the engine is going to shit itself on max boost i would be looking further ahead than the amal valve, tuning issue? build issue? oil level? water level? ok the ecu can drop the boost, but if you have a problem it will still be there.

Stu @ M Developments

iTrader: (12)

Not true... as a simple example, if the issue was detonation due to poor fuel and the ECU dropped the boost, the engine would be saved. Same as when the air temp gets really hot, the ECU is programmed to slow the turbine down to reduce intake temperatures.

5tox

Sorry but I'm sitting here pissing myself with laughter like a big kid, I've never heard that expression before... is that a technical term

quality

chaffe

ecu would need to have knock sensing? most dont, if it was det it would usualy retard the timing, but as i said, GOOD POINT, I AGREE, it will help a highly stressed engine running silly boost pressures when it starts to inevitably fall appart lol

chaffe

lol, you will hear it much more if you interfere with your boost control without knowing what your doing

James @ M Developments.

iTrader: (2)

i think you will find most DO, as the 4x4 L8 is the most produced Cosworth, then add on the P8 Escos, then the Small turbo escos, all have knock sensors fitted as standard.

chaffe

morning james, good stuff, we will leave it at that then.

5tox

does that mean that my 2wd wont have a knock sensor? i think its l6 isnt it?

chaffe

knock knock?

martysmartie

iTrader: (1)

Nope no 2WD, (So 3DR and Saph) have knock sensors, 4x4 Saph does as well as Escos.

L1=3DR
L6=Saph (So yes you are right)
L8=4x4 Saph
P8=Escos

Martin

martynhomer01

iTrader: (1)

hehe, i am full of technical terms such as this matey...lol

5tox

Cheers buddy, i'm still learning at the moment, upto now i've always been into the vauxhall scene. pretty clued up on the XE's and LET's

.... that is until i sold my project astra GSI turbo to stick down a deposit on my cossie, never looked back

BIL N KEL

you got any more pics of the cossie? is that mercury grey? i just finished painting mine

5tox

https://passionford.com/forum/restor...-cosworth.html

got a few on here .... yes mate mercury Grey, apparently there aren't that many left (or so i was told)

5tox

just realised your only up the road from me, i'm March Cambridgeshire