Hybridlader, was passt zusammen und ist sinnvoll??? | Posts 16+

Hello everyone, I have been able to gather some additional information. Regarding the combination of GT1749VB and GT2052V, a holding pressure of at least 2 bar should be permanently possible (according to Motair). Whether the cylinder head can withstand this load permanently remains to be seen. In connection with the appropriate... Head bolts and intact gasket, along with careful handling of the engine's power, I think it will work.
@ Ulf
The turbocharger will be slightly larger in this combination (compared to the stock charger). The exhaust side remains unchanged and is, of course, driving the compressor. The total mass (at the compressor inlet) is slightly higher than the standard, therefore the turbo lag and responsiveness (almost) should remain unchanged.
I can't really understand why hybrid chargers are rarely used in large-scale production either. They are common in motorsports and serious tuning shops. I think the reason is cost, and they are actually used to withstand higher boost pressures. However, this is not necessary in the standard performance ranges (90-130 horsepower). "Perhaps this will change with future models, as the engine size remains largely the same and performance continues to increase... this calls for better charging and better HD injection systems..."

One more small addition to the GT1749VB
I've seen the "performance diagram" for the charger, and it's already operating near its performance limit at 1.5 bar of overpressure. The RPM is at around 160-170,000 RPM (rated up to 168,000 RPM). If the overpressure is further increased, the efficiency will rapidly decrease, and the RPM will continue to rise (I'm thinking up to around 200,000 RPM, possibly more, and this RPM will easily be reached at around 1.7-1.8 bar). Whether this will last if the performance is frequently used is questionable. I'll see if I can get the performance chart as a PDF, and I'll be happy to provide it if you're interested.

Zak1976 wrote:

This turbocharger gap will be slightly larger in this combination (compared to the stock charger). The exhaust side remains unchanged and is, of course, driving the compressor. The total mass (at the compressor inlet) is slightly higher than the stock, therefore the turbo lag and responsiveness (almost) should remain unchanged.

Hm, I would only believe that if I compared both.

In every turbine-compressor pair, it's also important what the compressor achieves with a mass flow of air X, given the power Y supplied by the turbine – and this is over a relatively wide mass flow range.

For example, if a large compressor primarily requires torque, while a relatively small turbine mainly provides speed, then in essence, even in "stationary operation" (i.e., without load changes or engine over-revving, I hope this term is appropriate here), no reasonable compressor performance or only a very poor efficiency will result - because you cannot insert a gearbox between the turbine and compressor to adapt them
Compared to a 17/17 standard loader, a 17/20 combination would generally tend towards this direction.

This doesn't mean that a 17/20 combination can only be bad (otherwise, it would likely not have become a tuning trick), but the background is already more complex than you have outlined - and unfortunately, reality often significantly reduces simple predictions


The diagram of the GT1749VB would, of course, be quite interesting

Hello Ulf,
Basically, I would 100% agree with what you wrote, if it weren't for the fact that it's about a VTG loader. Don't you think that the described behavior can be corrected almost to factory settings by adjusting the throttle position sensor (if it exists) and the pedal position sensor to near-factory settings (regarding response and turbo lag) ???

Zak1976 wrote:

Don't you think that the described behavior can be corrected almost to series level by adjusting the VTG (if it exists) and throttle position sensor characteristic curve

No, that's not possible - the LD control characteristics of the series motors no longer have any unused reserves, because the "VTG effect" = more LD in the low-speed range is already fully exploited in the original product (e.g., GT1749V?).

Trying to push the VTG to more than 100% to compensate for the increasing "turbo hole" due to the 20-inch compressor is simply not possible

The only way out, as mentioned, is to clear the blockage in the turbocharger. Then the hole will become a bit smaller, at the cost of a "bad diesel appearance" = soot clouds.

... it's a shame that there isn't a 1.9L TDI Biturbo with, for example, 2 VNT15 turbos...

Let's try something different.

Does anyone know if the barrel diameter of the MKB: AGR Wellenloader is the same as
from GT17V or from GT22V?
The AGR loader is quite small, so it probably won't fit.

After 5 years with Chip, one kind of gets a craving for more.

hello

I have a "GT2049" in my car, which is one of the hybrid chargers you described. However, I haven't found the "turbo lag" that some people mention. It's not really noticeable, and it's not much different from the GT1749VB, which doesn't actually have any.

christian

audi 80 tdi wrote:

I have a "GT2049" in my car, which is one of the hybrid chargers you described. However, I haven't found the "turbo hole" there yet. It's not really any bigger than the GT1749VB, and that one doesn't really have one either.

Hm, "Turboloch" seems to be quite subjective... For example, when using the GT1749VB at speeds below 1700 rpm in a high gear, I can clearly notice that the VB lags behind the KP39B by approximately [amount].
And I suspect that using a larger compressor on the VB wouldn't necessarily be better...

If "Acceleration" is inherently linked to RPMs > 2000 in a personal driving profile, you hardly notice a larger gap in the VB (Variable Boost) charger's performance...