max power with standard air flow meter?

[PACEMAKER]

Hi all,

What is the max power that can be made with the standard AFM? I have just run in my motor and have been un able to make more than 12 psi boost. I have tried several bleed valves with no success.

Im using an XTR 450 hp high flow skyline turbo by GCG that is internally gated using 6 psi actuator.

Im assuming the restrictive AFM is the problem as the eng doesnt fuel cut and makes smooth good power @ 12 psi just wont make more than 12 psi.

Also does any one sell injector, eprom and AFM packages? If not which is the best AFM to use?

Thanx in advance,
Michael...

 

[olly]

don't think it is your afm. have you connected your boost controller correctly?

 

[PACEMAKER]

Im running the bleed valve between the ic pipe and the actuator. i have tried 3 diff bleed valves. On all of them 12 psi is the max i can run. With the standard turbo i was running 16 psi

 

[brisvr4]

Have you tried a boost leak test yet? Even with the stock afm you should be making more than 12psi.

 

[PACEMAKER]

Nope. The simplest way to do this is?

 

[brisvr4]

Pretty easy done. You will need a compressor though.
1. look up http://www.vfaq.com/index-main.html
2. Go to the intake section.
3. look for the "Intake leak tester" under misc intake.
4. be prepared to have leaks all over the place the first time you do this!
5. Anymore questions, just ask

 

[mattrat]

ya know tim everytime ive done one. always had a leak at intake mani gasket... why..

 

[brisvr4]

Did you try replacing the intake gasket and spraying it with copper spray Matt?

 

[PACEMAKER]

looks pretty easy. I will do this tomorrow and let you know how i go.

Thanx guys.
Michael...

 

[mattrat]

yer tim, just always seemed to be a leak there on 3 engines lol

 

[PACEMAKER]

Ok so i did the pressure test today. I removed the outlet pipe from the compressor housing and fitted the end cap with a tyre valve pressed in it. I just used my workshop compressor and a tyre guage/pump. With the throttle wide open i was unable to make more than 16psi with the tyre pump after holding it on for about 40 seconds.

The only leaks i could find were a tiny leak from injector 3 seal, throttle shaft only when i wiggled it and from the dip stick where the compressed air passed the rings. Has anyone done this and not been able to make more pressure?

ANy way i put it back together removed the turbo from engine checked both wheels for damage but all good. I refitted turbo and wired the wastegate shut. I removed the bleed valve and blocked off the hose on the ic pipe.

i took the vehicle for a drive and it was no diff. In 4th gear @ 3300rpm it makes 5psi
@ 3800 rpm makes 10psi
@ 4500 rpm 12 psi
@ 6000 rpm still 12 psi.

In second gear 5psi @ 4000
10 psi @ 4900
12 psi @ 5100
12 psi @ 6000
12 psi @ 7300

Im very frustrated. Any ideas???

 

[JAP63]

Your saying with your waste gate permanently shut your making no more than 12psi!?

Of course something is wrong, do you have a B.O.V? if so, have you checked that for leaks?

 

[brisvr4]

So you didn't actually take the intake pipe off and pressurize the cold side of the turbo as well?
Looking at the gcg site I am guessing that your turbo has a T04E compressor cover, these do tend to leak pressure badly unless they have an oring seal from factory. Easiest way to sort it out if it is leaking is a very very light bead of silicone.
Look here for more info.
http://www.dsmtuners.com/forums/tur...rim-owners-check-your-compressor-housing.html

This will probably not cure your problem but it should help!
When you did the pressure test did you spray soapy water on ALL of your silicone joiners?

 

[PACEMAKER]

There was no airleaks arond the BOV. I blocked off the air release pipe incase it was leaking into the intake pipe. I then removed the pipe and sprayed detergent into the BOV. I even changed the BOV with another one just incase. Didnt make any difference. The eng held pressure for about a minute. Dropping very slowly from 15psi down to about 3psi.

As far as the comp cover it runs the standard nissan rb25 cover and exhaust housing. Tomorrow i will pressurize the elbow and comp side of the turbo and see what happens.

Can any one give me an idea of what boost vs rpm for a tdo5 20g thanx.
From what i understand these 2 turbos are of similar power and flow.

Thanx. Michael.