Pre face lift stock boost

[disco-ian]

Hi all

Ok so almost at a point with the leggy where I'm happy with everything and next year will start with a few 'light' sensible did upgrades.

However just want to check something with someone that might know on here

What is stock boost on a pre face lift 1997 manual vr4 jdm ment to be.

At full boost I'm making just a shade under 0.5 bar. Is that right?

Sent from my Galaxy sIII

Ian

[Kryton]

You will want to change the head before upping the boost

It seems to vary from car to car slightly but manuals fl or pfl should be the same iirc, it's only the autos that are different. I believe it to be 0.6 but sure someone will come along soon to confirm

[Adam.Findlay]

PFL manual 9-10psi
PFL auto 6-7 psi
all FL (except type v galants) 9-10 psi

[Davezj]

Yeh I believe the stock boost for a pfl manual should be around the 0.7-0.8 bar region.
Autos are about 0.5-0.6 bar.

Work on 1 bar is 14psi and you won't go far wrong.

Boost leak test is the best thing to do if you think something is not quite right with regard to holding the boost you think you should be getting.

All the boost leak test will do is tell you if you pipework and recirc boost vale are capable of holding the amount of boost pressure you set the boost leak tester to without leaks. Not that your turbos can produce that much boost pressure. But it is a good start.

Then you can very briefly see what sort of boost you turbos re capable of produceing by disconnecting the boost pipes to the wastegates. This will effectively give you no boost control and allow the turbos to build boost pressure to the maximum they can. This will prove if your turbos are at fault or not. But you only need to to do ths for a couple of seconds.after disconnecting he wastegates A quick plant the accelerator in third, should see the boost reach at least 1.2bar. This will make you engine run lean but it is for such a short amount of time your engine will be ok. But I can't stress enough that this is only to be done as a one hit wonder.
The car will feel very very quick in comparison to running 0.5 bar but don't be tempted to carry on accelerating like this as it will lead to massive knock and termination of you engine, you have been warned.

Once you know the outcome of these very simple tests you will be able to determin what the best thing to do going forward, e.g. If the leak tet shows no leaks and the no control boost test shows high boost can be made then it points to some form of boost cotrol problem. Which is easily sorted.

[elnevio]

It can vary from car to car, and with the weather, but that sounds about right without any upgrades at all. Decat, better exhaust, bigger intercooler would all likely increase the boost slightly. But the figures I have seen quoted before is PFL auto = 0.45 bar, all others 0.55 bar, i.e. about 6-7 psi and 8-9 psi respectively.

[disco-ian]

Hi all

Thanks for all the replies. Other than Chris.... change the head gasket??? You crazy basted how will that help when my rear view mirror is still attached. :-) lol

Anyway... Dave. Thanks for the info on running without the waist gates connected. I have a wideband installed as well so would be cautious anyway and understand the implementations of doing what you are suggesting.

As I don't have a compressor at home are there any other easy ways of doing a leak test? I keep considering buying a pressure tester for the cooling system as I have a leak on my landy at the moment.

Do you think I could adapt that tester?

Sent from my Galaxy sIII

Ian

[disco-ian]

If after a leak test I do run with the waist gates disconnected will I not hit fuel cut before I reach 1 bar

Sent from my Galaxy sIII

Ian

[swinks]

You got it wrong
All of you had quoted wastegate actuator pressure
PFL auto stock boost is 0.6 bar, manual 0.8 bar.

[disco-ian]

Well I'm defo down on boost then as it always sits between 0.4 and 0.5 bar on full boost.

Sent from my Galaxy sIII

Ian

[Davezj]

Hi all

Thanks for all the replies. Other than Chris.... change the head gasket??? You crazy basted how will that help when my rear view mirror is still attached. :-) lol

Anyway... Dave. Thanks for the info on running without the waist gates connected. I have a wideband installed as well so would be cautious anyway and understand the implementations of doing what you are suggesting.

As I don't have a compressor at home are there any other easy ways of doing a leak test? I keep considering buying a pressure tester for the cooling system as I have a leak on my landy at the moment.

Do you think I could adapt that tester?

Sent from my Galaxy sIII

Ian

Compressors can be bought pretty cheap these days and then you only need a regulator (0-30psi) and a bung to correct to boost pipework, which can be made from a drain pipe seal off cap ( this is what I used in the end).

Have a search on "boost leak test" I did a thread on it.

As for fuel cut you are spot on, a 3rd gear run will hit fuel cut, do it in 5th. This will give you a slightly inflated boost pressure as the engine is not consuming the built up pressure/air flow as it would in a higher reving run in 3rd.

[disco-ian]

Do you think this sort of thing would be suitable

http://www.ebay.co.uk/itm/Wolf-FOX-A...item3a79541ef8

[SEAN-NZ]

im guessing spiking to about 9psi then farely quickly dropping back to 6psi is not good lol, would this potentially be a turbo or leak issue?

[SEAN-NZ]

is the pipe circled in red the one to pull off? i just assumed it was before i pulled it off lol, and just plugged the end of the T piece, as far as i can tell the T isnt leaking at all, pulling the pipe off, i got a massive increase in boost, of 1psi, so spiked to 10 and dropped to 7, seems to indicate a problem to me, dying turbos?

IMG_02451.jpg

[Davezj]

Do you think this sort of thing would be suitable

http://www.ebay.co.uk/itm/Wolf-FOX-A...item3a79541ef8

I would go for one with a minimum of 50L tank, otherwise it will be continuously running trying to fill the tank as you are useing it. If you want to use air tools with it as well then you have to go for a high flow rate.
Most air tools will specify a minimum flow rate to make them work correctly.
But if you just want a air supply for leak testing then 50L is fine.
Check out screw fix, I got my 50L wolf one from there for less than £50.

[Davezj]

is the pipe circled in red the one to pull off? i just assumed it was before i pulled it off lol, and just plugged the end of the T piece, as far as i can tell the T isnt leaking at all, pulling the pipe off, i got a massive increase in boost, of 1psi, so spiked to 10 and dropped to 7, seems to indicate a problem to me, dying turbos?

IMG_02451.jpg

That pipe you have pulled off either goes to the throttle body that operates traction control/vacuum assist or goes down to the recirc valve to dump you excess boost when lift of the throttle to stop your turbo's stalling.
So that pipe in the pic should be connected up where ever it goes to.
What makes you think it should be disconnected.

Oh you mean to do the un controlled boost test.
If so, then NO.

The pipe you want it the one going to the wastegate actuators. You can see one in your second picture bottom right.
You could remove that pipe, or more commonly the one that comes from the big plastic elbow off the front of the throttle body. It has a red circle around the pipe. Pull it off and block the hole.
As long as you have stock pipework no extra boost controller then this will open of the wastegate actuators to normal air pressure and the will not open allowing boost to build the max it can achieve.

[disco-ian]

Cheers dave. Im now watching a sealy 50 litre one on ebay thats not too far away from me.

Cant find any decent compressors on screw fix for under 100 quid at the moment so hope I get this one.

Sent from my Galaxy sIII

Ian

[Adam.Findlay]

That pipe you have pulled off either goes to the throttle body that operates traction control/vacuum assist or goes down to the recirc valve to dump you excess boost when lift of the throttle to stop your turbo's stalling.
So that pipe in the pic should be connected up where ever it goes to.
What makes you think it should be disconnected.

Oh you mean to do the un controlled boost test.
If so, then NO.

The pipe you want it the one going to the wastegate actuators. You can see one in your second picture bottom right.
You could remove that pipe, or more commonly the one that comes from the big plastic elbow off the front of the throttle body. It has a red circle around the pipe. Pull it off and block the hole.
As long as you have stock pipework no extra boost controller then this will open of the wastegate actuators to normal air pressure and the will not open allowing boost to build the max it can achieve.

i think rorys car is manual so it will be the dump valve (blow off valve vac line)
left disconnected it will cause the valve to leak boost terribly.
my turbos have had a damn hard life at at the moment they are smoking quite bad but they still hold almost 14psi to redline so doubt your turbos are toast rory.

[Ryan]

You mean Sean?

[Adam.Findlay]

You mean Sean?

yes. oops dont know why i thought it was rory. pay attention

[SEAN-NZ]

haha, i got a little confused, couldnt see any rory posting on this thread lol, sometimes it is a really good thing to be wrong, pulled off the red tipped pipe off the intake elbow, blocked off hole, took it out, got over 15psi, very pleased, left it off as i had go to someones house, just tried to boost below about 10psi, hit fuel cut a couple times at about 12 psi, pipes back on now though, car felt very quick at 10psi, need to figure out why itl only get about 6 normally