HE200 and Giles 1.6 IP in a 1.9 AAZ Vanagon

[Alcaid]

I have known of half a dozen AAZ and AHU vanagons running boost in that range and none of them lasted very long.  ALL of them had wastegated turbos.

And all of them had old-school T2, T3, K03, K14 or K24 turbos?

[Alcaid]

Cummins has a 3.8 engine running compound turbos, only 150hp but running relatively high boost and therefore crazy lean mixture (AFR 26.5:1), the resulting EGT at peak hp = 716°F

[burn_your_money]

Call Giles if you can. He prefers that to emails usually.

Winding the star wheel probably won't help if you have smoke at full boost. Turning down the max fuel screw and then winding down the screw in the top of the LDA will.

[theman53]

I found with my Giles pump the peak EGT was what it was with the older turbos. You could turn all kinds of screws and do all kinds of things but it would still max it out no problem. The only experience I have with the holset is I cannot make EGT no matter what I do. See the video on my thread I shared, and that is with a 10mm pump head. The only thing we are looking at is the fuel right now, I know you did some stuff to make the intake/exhaust, are you getting cold air in and hot air out?

[Gizmoman]

Call Giles if you can. He prefers that to emails usually.

Winding the star wheel probably won't help if you have smoke at full boost. Turning down the max fuel screw and then winding down the screw in the top of the LDA will.

Thanks for the tip about contacting Giles.
As for smoke, I can't see any in the mirror at 65 but that doesn't mean there isn't any.
I do believe that's the first test I will do though -

Back off on the fuel screw - even slightly back from Giles setting. This may allow more boost with less fuel, and should lower EGT's.
Turn in the smoke screw (small amounts) to improve low end.

I found with my Giles pump the peak EGT was what it was with the older turbos. You could turn all kinds of screws and do all kinds of things but it would still max it out no problem. The only experience I have with the holset is I cannot make EGT no matter what I do. See the video on my thread I shared, and that is with a 10mm pump head. The only thing we are looking at is the fuel right now, I know you did some stuff to make the intake/exhaust, are you getting cold air in and hot air out?

I have a FB intercooler, a 7 X 26" double row heat exchanger and a 3+ gallon res. Intake air at the manifold is running 20-30 degrees above ambient. I have a thermocouple in the manifold. The valves are stock and the head has a medium port job.

Obviously I have an AFR that is a bit heavy on the fuel side. I believe the biggest issue is the work being performed - the van weighs somewhere in the 5K range and is shaped like a brick. With that in mind, high EGT's are always going to show up, I'd just like to see higher boost numbers when that happens. Right now it's around 14 psi - 18+ would be better.

However, as libby pointed out, I want this engine to last. Hopefully slightly higher boost with lower EGT's will provide more "efficient" power. As it is now, it's all just turning into heat.

[libbydiesel]

And all of them had old-school T2, T3, K03, K14 or K24 turbos?

You believe that peak cylinder pressures are higher with a K24 or T3 running 20 psi with EGTs @ 1250°F than with the HE200 running 30 psi with EGTs @ 1250°F?

[Alcaid]

Did they even measure egt when running K24/T3 until failure?

[libbydiesel]

Failures were not EGT related.

Do you believe the peak cylinder pressures are higher with a K24 running 20 psi with EGTs @1250 than with an HE200 running 30 psi and EGTs @ 1250?

[Alcaid]

Failures were not EGT related.

Do you believe the peak cylinder pressures are higher with a K24 running 20 psi with EGTs @1250 than with an HE200 running 30 psi and EGTs @ 1250?

How do you know it was not EGT related, did they have an EGT gauge or not?

Point is with the same amount of fuel the HE200WG pushing 30psi and still being efficient vs. a K24 at 20psi the EGT will be lower as AFR will be higher and the combustion cleaner. PCP should actually be lower even though boost is higher. PCP is more dependent on fuel quantity, fuel atomization, injection timing and temperature than it is related to boost. Lower EGT means less expansion of the burned gasses, volume is the same thus giving you lower pressures (PCP)

What hasn't been discussed much yet is EMP vs. IMP, a very good indicator on how the turbo is performing and how the working environment for the engine is. The HE200WG has a much more efficient turbine and also a fairly high turbine choke flow meaning you can push more psi efficiently without EMP climbing through the roof and choking the engine's possibility to breathe properly.

[RabbitJockey]

Failures were not EGT related.

Do you believe the peak cylinder pressures are higher with a K24 running 20 psi with EGTs @1250 than with an HE200 running 30 psi and EGTs @ 1250?

How do you know it was not EGT related, did they have an EGT gauge or not?

Point is with the same amount of fuel the HE200WG pushing 30psi and still being efficient vs. a K24 at 20psi the EGT will be lower as AFR will be higher and the combustion cleaner. PCP should actually be lower even though boost is higher. PCP is more dependent on fuel quantity, fuel atomization, injection timing and temperature than it is related to boost. Lower EGT means less expansion of the burned gasses, volume is the same thus giving you lower pressures (PCP)

What hasn't been discussed much yet is EMP vs. IMP, a very good indicator on how the turbo is performing and how the working environment for the engine is. The HE200WG has a much more efficient turbine and also a fairly high turbine choke flow meaning you can push more psi efficiently without EMP climbing through the roof and choking the engine's possibility to breathe properly.

  i think pcp is probably higher with a k24 at 20psi,  k24 has a pretty small exhaust side, and the kkk turbos from that time period which i have seen compressor maps for are all pretty inefficient above 15psi.  Even the t3 has a peak efficiency of only 68%, plus you're looking at a 30 year difference in technology.

[Gizmoman]

Been doing some reading on turbos in general and ran across this statement:

1 pound of boost for every 10hp is the maximum engine requirement. Overboost does not increase power. Excessive overboost increases the manifold EGT and reduces fuel economy due to the increased exhaust pumping losses. The "choke point" of a turbo charger is defined as the maximum exhaust volume the turbocharge can pass before exhaust back pressure rises drastically. Operating a turbo beyond the choke point is inefficient, drastically increases EGT, and can cause serious damage to the engine and turbocharger.

Quote taken from here http://dodgeram.org/tech/dsl/FAQ/turbo_faq.htm

If I'm overly optimistic and assume I'm at 150 HP, that equates to 15 lbs of boost being all I should need. It seems ironic that that's about as high as it gets even with the HE200. Sure, I can see 20 (where my controller is set) but it's only a blip, then it drops off. Perhaps it drops off due to my right foot reacting to high egt's and my backside puckering a bit

I get that more charge air may lower EGT's but based on the quote above, there is a limit. I would also think there's a limit to excessive boost (other than what the ARP studs can take) as the bearings and rods can be overstressed.
My cylinder is about 3" in diameter. That area is 7.06858in². 30 lbs of boost adds over 212 lbs to the rod and bearings. Obviously this simple math doesn't account for the added fuel which will be compressed/detonated as well.

My bearings and rods are stock and probably not designed for twice the design load (if I want it to last anyway).

By the way, Giles responded to my email just now. . .

sounds like this turbo is too big for you, I would have used the HX25.
I would have to setup the top end of your pump to work better with this turbo on the test stand
Giles

Very big of him to respond to my request - a great guy. Sadly, I'm not spending much more on this. It cost 200 bucks just to cross the border

[libbydiesel]

How do you know it was not EGT related, did they have an EGT gauge or not?

The failures I know of were rod bearings wearing out quickly (<30,000 miles), broken main saddles, tossed rods and one case of a broken crankshaft.  I know that EGT gauges were installed on most but am not sure/do not recall if that was the case for all of them.

By the way, Giles responded to my email just now. . .

sounds like this turbo is too big for you...

Unfortunately I agree with Giles.  IMO, a lack of understanding about the Vanagon application resulted in bad advice when you were turbo shopping and the whole situation now sucks considering the amount of money and labor that has gone into a disappointing result.

[Alcaid]

First off, you shouldn't believe all you read online. Psi boost multiplied by a factor is ridiculous. If it was a factor multiplied by absolute pressure it would make some sense but linearity gets screwed up multiplying with boost numbers. Factor is also dependant on engine volume and type of engine (DI, IDI, CR, petrol, alcohol)

While Giles is an excellent pump builder, he doesn't know these turbos apparantly. HX25 actually have a bigger turbine wheel and often bigger turbine housings and will always spool later than a HE200WG... HX20 would spool faster but compressor wheel is really tiny and would be a limiting factor really fast.

Do you have enough preload on the wastegate so that it doesn't open on back pressure? Can you really trust the boost controller you made yourself? Something is not right when that exact same turbo spools like the K14 on a 1.6TD and does not spool sufficient on this build. You have a home made wastegate actuator so wastegate setting is propably not as it was originally.

[Alcaid]

The failures I know of were rod bearings wearing out quickly (<30,000 miles), broken main saddles, tossed rods and one case of a broken crankshaft.  I know that EGT gauges were installed on most but am not sure/do not recall if that was the case for all

All could have been failures due to poor lubrication, old worn parts or even low oil pressure due to rebuilds while not measuring actual bearing clerarances and/or old turbos puking out hot air into the motor while choking the motor on the exhaust side with back pressure. The Vanagon failures I've seen have actually been due to lack of service, broken timing belts resulting in crashed heads and broken camshaft (!)

How many of them where using a modern turbo within it's operating range?

I am pushing 30.5psi on my daily driver 3000lbs+ 4x4, stock everything internally except 12.9 head bolts. Even done lots of laps on racetracks. Not wearing out rod bearings anytime soon as turbo is happy and capable.

A heavy car should actually assist the turbo in spooling sooner as diesel engines really need resistance to perform

[theman53]

I really don't think the turbo is too big. All bench testing and maps aside, I have a slightly bigger turbo on a .3l smaller engine and it spools fine. It spooled better than a stock k24 with a couple boost leaks. I also have had conversations with Giles and he doesn't know turbos as well as some on here, not saying he knows nothing about them but he is much better with pumps.

Don't know what your issue is gismo but I would start looking for a boost leak or as alcaid suggested something with the wastegate or on the exhaust side.

If you haven't looked at my video of how my engine builds boost I think you should. You can see my egt gauge as well as how it builds boost. I have a larger pump and slightly larger turbo but I cannot get over 800f on the hottest day here *approx. 95f this summer*. I only have an air to air IC that probably is not near as good as yours.