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runnin 12 psi in factory turbo 4.2 gu

Posted: Thu Jul 09, 2009 8:01 pm
by J.Dixon80
heard of any problems without it being intercooled, and can it handle it?

Posted: Thu Jul 09, 2009 8:11 pm
by its aford not a nissan
fit an egt guage , and it will handle it if the motor is in good nic

Posted: Thu Jul 09, 2009 8:25 pm
by weeman
its aford not a nissan wrote:fit an egt guage , and it will handle it if the motor is in good nic
You can increase your boost to 12psi however wont necessarily give you more power because to make power you require more fuel.

1. Fit a PYROMETER i.e Exhaust Temp Gauge then increase the fuel delivery on your injector pump this can either be done yourself with some simple tools or go somewhere and get in tuned.

Its quite common to see non turbo GU models tuned with 12psi boost, however seen some dodgy tunes who haven't got it right.

Most of the time boost is your friend as it reduced your inlet temps, more boost can can cause issues more with the turbo than the motor itself, you start having motor issues when its starts to get hot i.e. the turbo isn't being efficient or your inter cooler.

Posted: Fri Jul 10, 2009 9:08 am
by Dirty
I am running 11psi with factory turbo and no-IC. Does it but temperatures are high. With an EGT you can drive accordingly though.

I wouldn't go to these levels (no-IC) without a EGT gauge though.

- David.

Posted: Fri Jul 10, 2009 9:14 am
by J.Dixon80
cheers guys yeah its already runnin 10 psi with more fuel through it, i was just wondering if i could get just a little bit more through it before intercooling it. the motor is an 02 with 216 000 on it so should be fine, just heard different from some people.

josh

Posted: Fri Jul 10, 2009 5:11 pm
by Auto-Craft
MAchine the turbo exhaust housing, run a good [not MTQ] dump pipe and bigger exhaust, to get rid of the heat, and 12 psi should be fine tuned properly.

Put a light on the air con off switch for temp rise in engine coolant, so you know if the coolant temp is rising.

Posted: Fri Jul 10, 2009 6:58 pm
by GQSWB42td
MAchine the turbo exhaust housing, run a good [not MTQ] dump pipe and bigger exhaust, to get rid of the heat, and 12 psi should be fine tuned properly.
can i ask why not to use an MTQ dump pipe.

Posted: Fri Jul 10, 2009 10:10 pm
by bogged
GQSWB42td wrote:
MAchine the turbo exhaust housing, run a good [not MTQ] dump pipe and bigger exhaust, to get rid of the heat, and 12 psi should be fine tuned properly.
can i ask why not to use an MTQ dump pipe.
Some "3inch" dumps arent exactly 3inch. that maybe the reason

Posted: Sat Jul 11, 2009 9:48 am
by Auto-Craft
GQSWB42td wrote:
MAchine the turbo exhaust housing, run a good [not MTQ] dump pipe and bigger exhaust, to get rid of the heat, and 12 psi should be fine tuned properly.
can i ask why not to use an MTQ dump pipe.
Measure one internally, and you will see they are 2 1/4 inch only, but they bolt up to a 3" flange.


Worth 10-15 rw kw, and gets rid of heat faster with a proper 3" dump pipe.

Posted: Sat Jul 11, 2009 11:26 am
by 84mksd33t
weeman wrote:Most of the time boost is your friend as it reduced your inlet temps, more boost can can cause issues more with the turbo than the motor itself, you start having motor issues when its starts to get hot i.e. the turbo isn't being efficient or your inter cooler.
higher boost causes higher inlet temps - air heats as it compressed. lower EGT's are made by more air into the cylinder and thus a cooler burn due to less fuel being burnt - despite the higher intake temps.

intercooling helps to provide cooler charged air. i recommend intercooling over 12psi to get the most from your tune. more fuel can be added when intercooled as your EGT's will be up to 30-50 degrees cooler. - depending on your cooling solution.

i use methanol/water injection and that has helped me reduce intake charge temps and my EGT's have dropped 30 degrees. this is another kettle of fish ;)

td42 with 12 psi intercooled and a nice match of fuel and you will have a stump puller (to an extent ;))

Posted: Sat Jul 11, 2009 12:25 pm
by weeman
Assassin_Offroad wrote:
Worth 10-15 rw kw, and gets rid of heat faster with a proper 3" dump pipe.
Really has this been documented and recorded on a dyno as when i did a dump pipe and full 3" exhaust on my gu there was no power and after talking to a number people that tune them they're isnt much difference what so ever just sound and allows the turbo to spool up well...You only start to make power once you deliver more fuel via the injector pump.

Posted: Sat Jul 11, 2009 12:33 pm
by weeman
84mksd33t wrote:
higher boost causes higher inlet temps - air heats as it compressed. lower EGT's are made by more air into the cylinder and thus a cooler burn due to less fuel being burnt - despite the higher intake temps.
So your saying to have more efficient vehicle with lower EGTs is to run the lowest possible amount of boost possible?

I have to disagree with that comment, higher inlet temps are made from more fuel not boost, its common when you add more boost to increase fuel hence there is a correlation of higher inlet temps.

Im running 28 psi and my inlet temps were better than when i was running 15psi mind you im running a ball bearing turbo and 4" pipes and a larger cooler, however the basic principal exists more fuel = more heat. If you increase your air intake either via larger turbo or more boost and provided the turbo is still in its operating specifications more air will make it run cooler.

I know when im pushing the vehicle in the bush i wind out a couple more psi to alleviate heat issues.

Just my 2c.

I think if your ever in doubt, fit a pyro and see how the vehicle is running if its constantly getting high egt it could mean a number of things which can be discussed in more detail as the vehicle as already got 216 on the clock and may be due for injectors, pump, turbo....

Posted: Sat Jul 11, 2009 2:29 pm
by chunks
weeman wrote:
Assassin_Offroad wrote:
Worth 10-15 rw kw, and gets rid of heat faster with a proper 3" dump pipe.
Really has this been documented and recorded on a dyno as when i did a dump pipe and full 3" exhaust on my gu there was no power and after talking to a number people that tune them they're isnt much difference what so ever just sound and allows the turbo to spool up well...You only start to make power once you deliver more fuel via the injector pump.
You didn't notice any improvment in low down response? My gu with the stock exhaust is shocking below 1500rpm. My 60 series with an old school turbo 2H and 3" exhaust was more responsive down low.

Posted: Sat Jul 11, 2009 4:46 pm
by weeman
chunks wrote:
You didn't notice any improvment in low down response? My gu with the stock exhaust is shocking below 1500rpm. My 60 series with an old school turbo 2H and 3" exhaust was more responsive down low.
yeah it was a little bit but i wouldnt say wow i can feel the power difference...

i think my before and after dyno tune from memory went up 20 or so kw and i could feel that for sure but 10 -15kw from the exhaust... its got me beat i can understand in a turbo petrol car like wrx but in a patrol not really... You only make power when you add more fuel

Posted: Sat Jul 11, 2009 11:06 pm
by Dzltec
Inlet air temperatures are derived from compressing air. The more its compressed the hotter it gets, loosing density as it rises, meaning it becomes thinner and having less oxygen. If a turbo goes out of its efficiency range it heats air up more than one that works in its right zone.

Garrett bb turbos are designed to run up to 25 psi and be efficient, some will go as high as 4.5 in their pressure ratio. No amount of fuel going into a diesel will raise inlet air temps. Ambient temperature, where the air is picked up from for the air filter play a factor in inlet air temps.

We haved dynoed td42t before and after dump pipe changes with 5-7rwkw results. Toyota v8 diesels will give a 10kw increase in just an exhaust change.

12 psi will be the limit to go, you may have to change the pressure valve and fit a plug in it. Even though you are raising inlet temps, you are making the engine consume more air, this results in lower egt's.

Do fit an egt guage, it should be mandantory.


Andy

Posted: Sun Jul 12, 2009 4:28 pm
by chunks
What about blocking the EGR? Is it ok to just remove the valve and making blanking plates?

Posted: Sun Jul 12, 2009 7:43 pm
by Dzltec
It depends on how the egr valve is intergtaed into the system. The easiest way is to just use blanking plates.


Andy

Posted: Sun Jul 12, 2009 8:54 pm
by chunks
Its a late 06 gu td42 it has the cast elbow off the intake for the egr. If you remove the egr completely you would have to make 2x blanking plates, but I can't see any other way to do it at this stage.

Posted: Mon Jul 13, 2009 8:52 am
by Dzltec
Just use a blanking plate after the egr valve.


Andy

Posted: Mon Jul 13, 2009 7:23 pm
by IN24BZ
how about a blanking plate the same shape as the tube on the back of the heat exchanger in the egr system , i have a million gaskets the same shape for it at work you can just trace onto steel and make a plate , still looks legal but is just blocked off.. can do from up the top under the bonnet easy with a 12 mm spanner

Posted: Mon Jul 13, 2009 8:28 pm
by chunks
Is it worth going to the extra effort of blanking it off around at the manifold? Do you get lower egts as a result of blanking it off?

Posted: Mon Jul 13, 2009 9:06 pm
by IN24BZ
nah not really i dont think it would make much difference where you did it , end of the day it just means the gas cant get thru

Posted: Tue Jul 14, 2009 2:47 pm
by chunks
My fuel screw looks like it has a metal cap covering it to prevent people from tampering with it. I presume i just pry it off?

Posted: Tue Jul 14, 2009 3:01 pm
by Auto-Craft
yep, if your careful, you can also re fit it.

Posted: Tue Jul 14, 2009 5:16 pm
by chunks
Cool, thanks for the info fellas!