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Engine Specific Info and Questions => IDI Engine => Topic started by: paolomarks on February 12, 2012, 08:31:11 pm
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I have a vanagon with a newly rebuilt AAZ with Ko3 turbo and no intercooler. I've installed a Westach EGT meter pre turbo and was dissapointed to see that it was easy to go upwards of 1500 degrees on a long uphill pushes. I turned the fuel screw down until I top out at just under 1300. Before I was boosting 10psi now with the fuel turned down it's about 8psi. I' keep hearing about people getting 15 psi and more with the AAZ. If I turned my fuel way up and adjusted the waste gate I could probably get there but my EGTs would be way high, no? Is there a way to increase boost without turning the fuel up.? If I added an intercooler what kind of numbers could I expect? Thanks, Paolo
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intercooling will greatly increase the amount of boost you will be able to run with cooler EGT's.
the reason it is so high is because the k03 turbo is the size of your fist, and it is trying to run A LOT of air through it on a hard pull.. major bottle neck. inter cooling will decrease the over all temperature of the intake air, and thus reduce the EGT's.
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I think you are finding what I found with the micro 1000 egt probe. It reacts so fast and accurately that it scares you. Many running other gauges and setups have different philosophy on what is the top number. In a heavy van and with the hills you have in WV I would try to go conservative. You probably aren't way up in elevation, but definately not at sea level...thinking in my head and typing. If you want more boost you need more heat to spin the turbo. It seems that your fueling is limiting boost and not the overboost or wastegate. So if you add the IC you can turn up the fuel more and get more boost and go. I definately recommend I/C as I got on average about 5mpg better after installing and everthing ran cooler. If it takes you a long time to get to 1500F you maybe ok. My micro 1000 probe and westach gauge I could hit 1500 in about 4 to 6 seconds depending on where I was sitting before punching it. So if it takes you a minute and your gauge reacts as fast as mine did I wouldn't worry as much. Think of this too, it is cold outside, come summer you will want more cool air.
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I think there's something not quite right with your setup. I recently installed a 1.6TD in a vanagon with a K03 turbo. The 1.6TD has a reduced exhaust volume so spooling the turbo should take longer and require more heat. I set the wastegate to boost up to about 12 psi, no intercooler. I adjusted the pump to hit about 1300-01400° pre-turbine on an extended hard pull. It would boost up to 12 psi very quickly and easily. You might have some LDA adjustment to do or your turbo/wastegate may not be functioning properly if it will only boost to 8 psi with that kind of fueling. Leaky wastegate would cause the symptoms you describe as would a knackered compressor or turbine wheel. Try loosening the locknuts on the wastegate adjustment and rotating the nuts so that they move closer to the end of the shaft. Set the outer one just before the end of the shaft. Readjust fueling to hit 1400° on an extended hard pull. If you are still having trouble building boost with that fueling then pull the turbo and inspect the wheels for damage and proper clearance. Adding an intercooler will help EGTs.
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I think there's something not quite right with your setup. I recently installed a 1.6TD in a vanagon with a K03 turbo. The 1.6TD has a reduced exhaust volume so spooling the turbo should take longer and require more heat. I set the wastegate to boost up to about 12 psi, no intercooler. I adjusted the pump to hit about 1300-01400° pre-turbine on an extended hard pull. It would boost up to 12 psi very quickly and easily. You might have some LDA adjustment to do or your turbo/wastegate may not be functioning properly if it will only boost to 8 psi with that kind of fueling. Leaky wastegate would cause the symptoms you describe as would a knackered compressor or turbine wheel. Try loosening the locknuts on the wastegate adjustment and rotating the nuts so that they move closer to the end of the shaft. Set the outer one just before the end of the shaft. Readjust fueling to hit 1400° on an extended hard pull. If you are still having trouble building boost with that fueling then pull the turbo and inspect the wheels for damage and proper clearance. Adding an intercooler will help EGTs.
Not that my post is going to be 100% relavant, but just on the topic or intercooling and lower EGT's. I have a 93 AAZ and have had a pyrometer in it for quite a while. First off I used the probe that came with my autometer gauge, which was a huge 1/4" slow acting probe. With my stock K14 and a stock pump with maybe 1 turn on the fuel screw the hottest I even saw my temp go was 1000F, non intercooled. With the intercooler I rarley saw it go over 800F.
Last year I rebuilt the motor and put compounded K14/K24 turbos on it. I also installed and Arospruce? 1/8th probe, which made a world of a difference in the gauges reaction to exhaust temp change, now the hottest I have seen my temp go was about 700F, maybe less.
This was all with a 2.5" staight exhaust also.
This isnt really to relavant for your topic but it does show the drastic affect IAT's (Intake Air Temps) and the amount of air flowing into the engine have on the EGT's.
I know compound turbos arent for eveyone ;) especially with a vanagon as I can imagine space is limited, but even putting a larger free flowing intake with an AEM dry filter, free flowing, larger exhaust and downpipe, possibley a different intake manifold or even porting to the head can make the difference.
Cheers,
Willie
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Thanks for all the responses. To check my wastegate , could I simply remove the rubber hose to the wastegate and prevent it from opening at all, and see if my boost goes up. Then adjust fueling to the max EGT temps.? A question about Intercooling, does a boost psi of say 10 warrant the use of an intercooler ? Thanks, Paolo
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Thanks for all the responses. To check my wastegate , could I simply remove the rubber hose to the wastegate and prevent it from opening at all, and see if my boost goes up. Then adjust fueling to the max EGT temps.? A question about Intercooling, does a boost psi of say 10 warrant the use of an intercooler ? Thanks, Paolo
you COULD test your wastegate that way, but you risk overspeeding your turbo, and grenading it..
and no, 10psi does NOT warrant an intercooler.. 10psi is stock boost settings. air isnt even getting heated up much. so it would just add lag time basically..
i would pull the downpipe off, and visually inspect the wastegate valve, and seat for cracking or erosion.. just because the actuator is operating, does not mean the wastegate is actually operating like it should..
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All stock TDI's run an inter-cooler and they too only spike to 12-13psi. You could run the same 10-12psi with the inter cooler and it would have more power.
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All stock TDI's run an inter-cooler and they too only spike to 12-13psi. You could run the same 10-12psi with the inter cooler and it would have more power.
its alot of added piping, and you need the real estate to actually mount the cooler, as well as having it in a direct path of cool air flow..
in a vanagon, with only 10psi boost, i wouldnt even worry about it. more hassle than its worth IMHO. like i said, its going to add ALOT of lag time to your turbo. noticeable lag..
i could tell the difference between having my VNT with or without an intercooler.. it spooled INSTANTLY without a cooler. it lagged with an intercooler.
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Adding the Saab 900 intercooler to the D-pillar area is a small enough addition to intake volume that there isn't any noticeable increase in lag. The only other reasonable option is a liquid to air setup which also does not add any noticeable lag.
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Adding the Saab 900 intercooler to the D-pillar area is a small enough addition to intake volume that there isn't any noticeable increase in lag. The only other reasonable option is a liquid to air setup which also does not add any noticeable lag.
good call.. forgot about A2W..
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I honestly think that every turbo diesel regardless of psi should be intercooled.. the added huge bonus of cold air is worth it.
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I honestly think that every turbo diesel regardless of psi should be intercooled.. the added huge bonus of cold air is worth it.
90% of all diesels ive laid hands on, were non-intercooled..
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Mostly 80's and 90's cars no doubt?
There is a reason why The Rover Company put an inter cooler (properly named after cooler) on its 1963 2.5L 4cyl. This wasteful practice (when intercoolers are not used) nearly eliminates the gain in engine efficiency from charging. There is no reason why you should not run an inter cooler.
Even 8-10psi will benefit greatly from inter cooling. Its not just for the big power players you know.
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You may want to consider water/methanol (or straight water) injection...
for about the same money as you'll spend on a decent intercooler setup you can have a water injection system that does exactly the same thing; lowers intake air temp, and consequently lowers EGTs. You set it to start spraying at a certain boost pressure, and you can simply turn it off when you want to.
Spend more on it, (lots more :( ) and you get computer-controlled injection that varies by boost and EGT... If you use water/meth mix (ie. wndshield washer fluid) you also get an added power boost.
Just a thought, do some research on it, very interesting stuff... I'm planning an install later on after I get the van running & broken in, I'm putting a very small nozzle pre-turbo (misting right into the compressor wheel) and a larger one misting into the intake manifold.
Some light reading here; http://www.devilsowninjection.com/en/
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So I adjusted my wastegate linkage and now I'm boosting 12 psi :) EGT's have dropped about 100 degrees going up the same hill at the same speed. I havent turned up the fuel yet, I want to see what kind of mileage i'm getting first. Thanks for the help guys, Paolo
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add a manual boost controller and crank up the boost. More boost = lower EGT temps.