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Engine Specific Info and Questions => IDI Engine => Topic started by: orbitald on June 19, 2008, 05:03:54 pm
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Questions,
I have an AAZ in my Vanagon Syncro:
- K03 turbo
- 2.5" exhaust
- GTD nozzles
- SAAB blackstone intercooler with 800cfm fan
- EGT sensor pre-turbo
- Boost at about 11psi
- I'm running 235/70/16 with stock gearing
I'm trying to find the right balance of power and low EGTs.
I've rotated the boost pin 1/2 turn and the van has plenty of power now but my EGT temps are climbing over 1250 on longer hills. Will increasing my boost also increase my EGT?
What does rotating the star wheel do?
How do I lower my EGT and keep the power?
Thanks,
D
http://picasaweb.google.com/Orbitald/DieselVanagonStuff/photo#5194145059298034050
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High EGTs are unburnt fuel. More boost (or a colder charge) lowers EGTs. Reducing backpressure also lowers EGTs. Bad injectors, worn pump, bad timing are also causes of high EGTs
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you think 1250F is hot??? thats normal... when you hit 1400F come back :lol:
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Thanks Burn - so increasing my boost slightly might actually bring my EGT down a bit which would be nice. My motor only has about 3K miles on it so I don't think its excessively worn but I should check the timing.
I'm guessing it best to check the timing after boost / fuel pin adjustments are made?
jtanguay - since my motor is kinda new I'm trying to stay in a comfort zone; keeping EGTs and boost as low as possible and still make it over the hill doing 55mph which is somewhat of a balancing act with a Syncro Vanagon with big wheels / tires. I think it would actually go up to 1400F but I back off the petal and shift down to 3rd to keep it around 1250F cresting a big hill at around 50mph.
I could also go with a liquid cooled intercooler but thats another bag of money I still waiting to drop from the sky.
Any insight on what the rotating the star wheel does?
D
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The starwheel decreases fuel with boost if it is screwed up, and increases it if screwed down.
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Thanks Jimfoo,
Is there a procedure for setting all the variables so that maximum burn is achieved?
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Yeah, trial and error unfortunately.
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double your boost.
Here is my setup:
Syncro
225/70/16
final drive ratio 4.86
third gear 1.14
4th gear .77
New AAZ
Non intercooled (for now)
2.5" exh
K03 turbo
fuel screw turned in about two turns
star wheel screwed almost all the way down
1.6td boost pin rotated in the direction of funtime power
vehicle wieght is 5200lbs unladen
I can easily hit 1300 on the freeway during acceleration. I usually keep it around 10-1200. I am at sea level. Mountain pass at a 5% grade will put me in 3rd gear @ 42 MPH. anything more than that will make the EGTs climb.
HTH. Ill be watching this thread ;)
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Well I was able to raise the boost to around 13psi and I can keep my EGT readings around 1300F now. On the longer hills I back off a bit and shift down to 3rd because it will probably rise up to 1400F if I dont. Raising the boost definitely lowered my EGTs!
I'm thinking maybe 14psi would be OK? I want a long lasting motor and hear conflicting reports on boost. Some say 20psi is fine while my mechanics say stick with 7-9psi.
Also, I have a Saab intercooler with a fan and I'm thinking about a liquid-air intercooler. Any recommendations for a Vanagon?
Thanks for your help.
David
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I've been running 20+ psi for a few years now. Go for 20+ psi
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I've been running 20+ psi for a few years now. Go for 20+ psi
X2
Turn it up.
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I would'nt run the k03/t2 past 15-17 psi as they are not bullet proof running 10 psi on stock engines.You can run the k14 with its bigger shaft at 18 psi forever and it will handle it.The k24/T3 can hold 21-22 psi all day long however they have much more lag than the k14.The k14 is the best turbo for a slightly modded 1.6 or 1.9 even my MK4 TDI will be getting a k14 to make 18 psi.
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Just to note peugeot supplied the younger 1.9 turbo diesel engines in the 306 model with a kkk k03 turbo and it was set standard to 14psi with a top mount intercooler so id say its safe enough to run at 14 or even higher.
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Another question about this.
If I want to lower my egt going up large long hills on the highway (mountain driving) and I have three choices:
1) reduce fuel with max fuel screw
2) turn boost pin back around slightly
3) back star wheel up a little
Which should I choose and why?
Thanks,
David
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You might want to read a bit about water/methanol injection. There are a few threads here & lots on info on the internets. For those once in a while long hills it would be nice to have. Your rear washer tank is already full of an almost perfect injection blend.
Real nice looking van BTW!
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I'd start with -
1) reduce fuel with max fuel screw
David
Th starwheel is "boost present" specific - the max screw seems to affect the whole rpm range.
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Another question about this.
If I want to lower my egt going up large long hills on the highway (mountain driving) and I have three choices:
1) reduce fuel with max fuel screw
2) turn boost pin back around slightly
3) back star wheel up a little
Which should I choose and why?
Thanks,
David
4) Let off the pedal slightly
Why?-don't need to change anything, absolutely same result as reducing max fuel screw, have more power than #1 for when you are passing.
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Yeah, but what if the wife is driving?? "What gauge? Oh, the one that's reading 2,000°F?" :lol: :lol:
I could see it now!luckily mine cant drive stick and she hates my truck anyway.I guess i wouldnt like anything that took her away from me either! :) :D :) :D
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Yeah, but what if the wife is driving?? "What gauge? Oh, the one that's reading 2,000°F?" :lol: :lol:
True, but the wife doesn't get to(or want to) drive mine.
Yeah, maybe you'd have to install the "dripping metal" indicator light.
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I guess that's my question; adjusting the max fuel screw, boost pin position and star wheel adjusts the amount of fuel being sent to the injectors at any one moment? The isn't any thing to adjust on the injector pump to reduce my egt on the long hills other than using less fuel?
David
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No, burning more fuel makes more heat. You can increase boost or add an IC to help cool things down though.
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Increasing boost increases IATs. (intake air temps)
due to the air being more compressed at higher boost, it heats up more as well. So you ideally need to run an efficient intercooler or charge cooler if running high boost
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He's only running 11 psi though, not terribly high in my book.
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He's only running 11 psi though, not terribly high in my book.
Agreed.
I was meaning more in relation to if he does decide to go to 20psi plus.
However the OP didnt seem very keen on raising the boost to these levels so I think its probably a moot point that I mentioned it!!
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Increasing boost increases IATs. (intake air temps)
due to the air being more compressed at higher boost, it heats up more as well. So you ideally need to run an efficient intercooler or charge cooler if running high boost
You've been reading the T4Forum too much!
:lol:
More boost, less fuel by whatever means.
Less restrictive exhaust.
Slow down!
Water injection are all going to resolve the problems.
Trial and error till you find the right balance.
I'm in a similar position with my 2WD T3 Westy Atlantic, well, EGT's were edging towards 1200°F, luckily the Westy has a onboard 55 litre fresh water tank!
Guess whats coming next!
:)
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Increasing boost increases IATs. (intake air temps)
due to the air being more compressed at higher boost, it heats up more as well. So you ideally need to run an efficient intercooler or charge cooler if running high boost
You've been reading the T4Forum too much!
:lol:
More boost, less fuel by whatever means.
Less restrictive exhaust.
Slow down!
Water injection are all going to resolve the problems.
Trial and error till you find the right balance.
I'm in a similar position with my 2WD T3 Westy Atlantic, well, EGT's were edging towards 1200°F, luckily the Westy has a onboard 55 litre fresh water tank!
Guess whats coming next!
:)
No mate ;) though your derv info has been very helpful on there.
just built a few high hp petrol engines....
Thats my 'thing' and IATs are IATs, derv or gasser :D
A whole heap of other stuff on dervs is different though sadly! which is where you lot come in :D
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With a diesel, tho, when the fuel to air mixture is reduced, the combustion temps decrease which is opposite a gasser. Therefore, running increased boost WILL reduce EGTs up to about 15psi or so where the added heat from compression is not offset by the reduced fuel to air ratio.
Andrew
Interesting info Andrew.
However I was referring only to IAT (intake air temperatures) and these will stil be higher even if the EGT is lower with the increased boost.
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Right, intake air temps will be progressively higher with boost, but this thread is not really about intake air temps, but rather controlling EGTs. Even un-intercooled, increasing boost is a very effective way to reduce EGTs on a diesel up to about 14-15 psi. If effectively intercooled, increasing boost is an effective way to reduce EGTs regardless of current boost level.
Andrew
Good info Andrew
Does this mean that I would be safe to turn up the boost on my ABL to 14-15psi without using an EGT gauge then? :wink:
Does fuelling have to be increased inline with boost for the EGTs to drop?
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ABL is basically a AAZ, with 8mm valves, an extra drilling for a water blead in the head and no drilling for a dipstick.
the injection pump is like a NA version, no LDA and flat top, switches for EGR.
Common mod is to swap to AAZ pump, or take a Peugeot or similar pump top to gain LDA facility.
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I'll try and turn my boost up a bit and see what happens to my EGT. If I can bring my EGT down with more boost I guess that's OK. The K03s are actually pretty reasonably priced so if I totally blow it out it wont break my heart, or my wallet.
If that doesn't work I may look at a bigger turbo because I need power and I think I have enough fuel and just need more air and a liquid-2-air intercooler looks like a bigger project.
What are the best performance upgrade replacement turbos for the K03 on the AAZ. I have heard people mention K04, K14, K24 and Garret. Any suggestion, recommendations or comments?
Thanks,
David
Oakland, CA
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I'll try and turn my boost up a bit and see what happens to my EGT. If I can bring my EGT down with more boost I guess that's OK. The K03s are actually pretty reasonably priced so if I totally blow it out it wont break my heart, or my wallet.
If that doesn't work I may look at a bigger turbo because I need power and I think I have enough fuel and just need more air and a liquid-2-air intercooler looks like a bigger project.
What are the best performance upgrade replacement turbos for the K03 on the AAZ. I have heard people mention K04, K14, K24 and Garret. Any suggestion, recommendations or comments?
Thanks,
David
Oakland, CA
Its not the turbo you should be so worried about!! More the pistons melting if it goes wrong!
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Is that an instantaneous threat? Wouldn't I need to run at high egt for a bit for that to happen. I always assumed there would be some noise from a failed turbo and high egt and I would just shut her down a pull over to the side.
David
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I see a lot of posts here suggesting you can "turn up your boost", irrespective of where your fueling is set (usually stock, or close to stock).
My own experiments on my AAZ-powered Vanagon worked in reverse to this.
That is, I disconnected the wastegate hose entirely, so the turbo would create whatever max boost pressure it would create. At stock fuelling, that was about 10 psi max. If I wanted to see 16 psi, I needed to turn up the main fuel screw on the pump.
This is a contrarian view to add to common wisdom. I can't see how people "turn up the boost" to cool EGTs. That did nothing at all for me... the wastegate was disconnected so boost was "turned up" to an infinite amount. The reality was that I needed to turn up the fuel FIRST for more boost, which in turn creates enough heat that boost will increase, and in turn that will raise EGT.
I figure that I'm running "minimum fuel" to support 16 psi now. If I lower the fuel screw, then I automatically reduce boost pressure.
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Is that an instantaneous threat? Wouldn't I need to run at high egt for a bit for that to happen. I always assumed there would be some noise from a failed turbo and high egt and I would just shut her down a pull over to the side.
David
you can get a good feel for high EGT from the smoke coming out the back... but a hard pull in 5th gear could also do some good damage without the telltale smoke. mild power tweaks are okay such as turning up the boost and increasing fuel slightly.
you should also limit the amount of time that you stay at full throttle. i would say 5 seconds or so without an EGT gauge. the temps might rise to 1600F (with proper fueling :twisted:), but there won't be enough time for melting to occur.
just don't be too ignorant of EGT's as they can ruin your motor.
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Thanks everyone for the comments. I do have an egt gauge positioned right in the manifold. I have to back off the hills and sometimes shift down to 3rd (syncro vanagon) because the egt start to climb over 1200. I shift down at around 1250 or so.
I am hoping that a little more air will give me a better mixture because it feels like the power is there but it just gets too hot.
David
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youve got a 1.9 and all that weight.....i think a k24 would be great..
all that load will help spool it up...lol
honestly....k24 turbo and water/meth would probably do wonders for you. much more power and lower EGTs and in a absolute world...a Giles pump...all those together, you will probably making much more reliable Power at the same EGT level
thats just my 2 cents though
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I have a 1.6td in my 82 diesel van and have been having the same problems. Right now running 12psi, no intercooler, 2.5 exhaust with a cherry bomb muffler, backed out fuel screw a little. It really seems that if you want to actually use the power from both 1.9's and 1.6's, in a van they produce more heat than is easy to dissipate.
Before I adjusted fuel down a bit I could easily, almost instantaneously spike up (and beyond if I kept my foot in it) 1250 degrees when on the highway and would have to baby the throttle to keep EGTs at a safe level.
When I find the time between other projects I am going to fit my Saab IC with a fan but in the meantime I have two questions:
1. Do Golf/Jetta drivers using this engine have the same problem or is it just the size, shape and weight of the Van that does it?
2. Has anyone out there come up with a formula of mods that works for 90-100 hp in a van without having to keep a permanent eye on EGT's?
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im guessing fuel consumption could give you an idea if you're pulling too much weight for the little 1.9 litres
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I have a 1.6td in my 82 diesel van and have been having the same problems. Right now running 12psi, no intercooler, 2.5 exhaust with a cherry bomb muffler, backed out fuel screw a little. It really seems that if you want to actually use the power from both 1.9's and 1.6's, in a van they produce more heat than is easy to dissipate.
Before I adjusted fuel down a bit I could easily, almost instantaneously spike up (and beyond if I kept my foot in it) 1250 degrees when on the highway and would have to baby the throttle to keep EGTs at a safe level.
When I find the time between other projects I am going to fit my Saab IC with a fan but in the meantime I have two questions:
1. Do Golf/Jetta drivers using this engine have the same problem or is it just the size, shape and weight of the Van that does it?
2. Has anyone out there come up with a formula of mods that works for 90-100 hp in a van without having to keep a permanent eye on EGT's?
Fit a charge cooler and a front mounted oil cooler, and do go daft!
I need to dyno mine but I should imagine it's up near there somewhere and miles better than my Mtdi I had a few years ago.
AAZ, Hybrid turbo, Barrel charge cooler, FM oil cooler, 2.5" exhaust, Rover boost pin. Thats in a Westy pop top.
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Well I turned up my boost to around 16/17psi max and it sure is making a difference. Maybe a little more power but much lower EGTs on the long hills.
Last weekend I drove over Hwy 17 to Santa Cruz and this weekend I'm hitting bigger and longer hills so I'll give a better update later.
Another question; is there some type of exhaust gauge which can tell me the perfect combo of fuel to air? I know many have said trial and error but there must be something that reads unburnt fuel so I can adjust my max fuel screw?
Also, my boot pin is half way around to max right now. What is the advantage to spinning my boot pin all the way around to the maximum position? Should I back off on my max fuel screw to do this if it seems I already have enough fuel?
Thanks once again,
David
Vanagon Syncro: AAZ, K03 turbo, 2.5" exhaust, GTD nozzles, SAAB blackstone intercooler with 800cfm fan, EGT sensor pre-turbo, Boost at about 16psi, 235/70/16 with stock gearing
http://picasaweb.google.com/Orbitald/DieselVanagonStuff/photo#5194145059298034050