Author Topic: High EGT on my AAZ (Read 14143 times)

myke_w · « **Reply #15 on:** December 30, 2008, 01:38:59 pm »

I'd start with -

Quote from: "orbitald"

1) reduce fuel with max fuel screw

David

Th starwheel is "boost present" specific - the max screw seems to affect the whole rpm range.

jimfoo · « **Reply #16 on:** December 30, 2008, 08:53:42 pm »

Quote from: "orbitald"

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.

dillenger1 · « **Reply #17 on:** December 31, 2008, 04:53:55 am »

Quote from: "libbybapa"

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!

jimfoo · « **Reply #18 on:** December 31, 2008, 05:34:05 am »

Quote from: "libbybapa"

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.

orbitald · « **Reply #19 on:** January 01, 2009, 10:24:43 am »

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

jimfoo · « **Reply #20 on:** January 01, 2009, 10:39:47 am »

No, burning more fuel makes more heat. You can increase boost or add an IC to help cool things down though.

vwt4 · « **Reply #21 on:** January 01, 2009, 12:28:45 pm »

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

jimfoo · « **Reply #22 on:** January 01, 2009, 12:32:09 pm »

He's only running 11 psi though, not terribly high in my book.

vwt4 · « **Reply #23 on:** January 01, 2009, 12:41:47 pm »

Quote from: "jimfoo"

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!!

Baxter · « **Reply #24 on:** January 01, 2009, 12:46:13 pm »

Quote from: "vwt4"

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!

vwt4 · « **Reply #25 on:** January 01, 2009, 01:05:16 pm »

Quote from: "Baxter"

Quote from: "vwt4"
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

A whole heap of other stuff on dervs is different though sadly! which is where you lot come in

vwt4 · « **Reply #26 on:** January 01, 2009, 03:31:47 pm »

Quote from: "libbybapa"

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.

vwt4 · « **Reply #27 on:** January 02, 2009, 06:39:07 am »

Quote from: "libbybapa"

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?

Baxter · « **Reply #28 on:** January 02, 2009, 02:13:44 pm »

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.

orbitald · « **Reply #29 on:** January 05, 2009, 11:11:33 pm »

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