i just used a 1.6 pan/sumpok so vnt is the way forward, but sounds to me like id go through about 1 per week so its out of the question for me, as i hav no money just friends with a scrap yard and doubtfull id find loads of these, i thort up an easyer way to get rid of lag, all you need is old scraps of metal an alternator and a bit of time,esentualy atatch a shaft to the turbine in the turbo and then take the clutch wheel off a tdi alternator and uve got a super charger that when the engine produces enough gasses will then turn into a turbo :wink: i call it the superturbo :idea: did i just invent sumthin?
can't find a video where he shows boost, but this is a VNT-20 on a 1.6TD!http://fr.youtube.com/watch?v=dCOJ8afz9oA&NR=1http://fr.youtube.com/watch?v=2p9skPj8b14&feature=related is that a boost gauge?
http://fr.youtube.com/watch?v=hzaqBfKPa50&NR=1 these guys actually used some sort of vacuum device to control the vanes...
I've taken apart many wastegated and VNT turbos and can say that there is nothing more robust about a wastegated turbo. I do however believe the information that there are more turbo problems now with new vehicles than there were in the days wastegated turbos. There are three reasons for this as I see it. One is that the turbo vanes have very little room for movement on the VNT. Any carbon buildup will quickly cause the vanes to stick. The second is that they spin a lot faster and will easily surge under the "right" conditions. In an attempt to eliminate turbo lag, the turbos fitted to most new applications are IMO too small for the engines they are being fitted to. I have a KKK that was fit to a 1.9 TDI that looks like it would fit a chainsaw. I can't fit my thumb in the compressor outlet. The conditions where the turbo will be damaged are then attempted to be controlled by the computer. Any issues with the sensors or control system over any period of time can result in significant damage to the turbo. The final is that there are quite a few "turbo problems" that are actually problems with the sensors or vane control system itself. I think that you would be hard pressed to blow up a VNT unless you ran one that was considerably too small and ran too much boost through it consistently. I also think you would need one of considerable size to hold down consistent levels of 35-40psi of boost on an AAZ. You would likely want a VNT 20 or VNT 25. I am quite sure that if you used one of those you would be replacing connecting rods much, much more frequently than turbos. :wink: I would also mention that EGTs are waaaayyy cooler running a VNT than a wastegated turbo at similar boost or power levels. We haven't been able to get above 900°F pre-turbine on my friend's quantum despite trying an extended run on a highway 6% grade. From a stop at the bottom of the hill we were going 80+ MPH before it got above 900°F. We also can't seem to keep the boost below 20 psi with an intercooled VNT17 on a 1.6TD and boost is any time you want it. Andrew
I read somewhere that on some of the new makes of diesels with cats, that the engine would periodicly surge the egt's to burn out any build up of soot etc.Would an occasional egt spike like this help burn out any build up inside the vnt turbo's?
Quote from: "libbybapa"I've taken apart many wastegated and VNT turbos and can say that there is nothing more robust about a wastegated turbo. I do however believe the information that there are more turbo problems now with new vehicles than there were in the days wastegated turbos. There are three reasons for this as I see it. One is that the turbo vanes have very little room for movement on the VNT. Any carbon buildup will quickly cause the vanes to stick. The second is that they spin a lot faster and will easily surge under the "right" conditions. In an attempt to eliminate turbo lag, the turbos fitted to most new applications are IMO too small for the engines they are being fitted to. I have a KKK that was fit to a 1.9 TDI that looks like it would fit a chainsaw. I can't fit my thumb in the compressor outlet. The conditions where the turbo will be damaged are then attempted to be controlled by the computer. Any issues with the sensors or control system over any period of time can result in significant damage to the turbo. The final is that there are quite a few "turbo problems" that are actually problems with the sensors or vane control system itself. I think that you would be hard pressed to blow up a VNT unless you ran one that was considerably too small and ran too much boost through it consistently. I also think you would need one of considerable size to hold down consistent levels of 35-40psi of boost on an AAZ. You would likely want a VNT 20 or VNT 25. I am quite sure that if you used one of those you would be replacing connecting rods much, much more frequently than turbos. :wink: I would also mention that EGTs are waaaayyy cooler running a VNT than a wastegated turbo at similar boost or power levels. We haven't been able to get above 900°F pre-turbine on my friend's quantum despite trying an extended run on a highway 6% grade. From a stop at the bottom of the hill we were going 80+ MPH before it got above 900°F. We also can't seem to keep the boost below 20 psi with an intercooled VNT17 on a 1.6TD and boost is any time you want it. Andrewi suspect that you are correct about sizing being the problem...anyone running a vw with a t3 will always say that t3's are indestructible - because they don't work very hard for their whole lifetime! a t3 is a big turbo - much bigger than really needed for a 1.6 or 1.9 - hence, max rpms are seldom reached, the turbo goes forever.likewise, vnt's are probably contructed better than any older turbo's, but die to the sizing, they do run crazy rpms. this has a shortening effect on the life of bearings etc, and the longer your turbo runs at max revs (which is the goal of a vnt) then the faster you can expect it to wear, and possible fail.even the k14 is (from a traditional persective) a little large for a 1.6 - but perfect in real driving terms.i don't think from any performance perspective that a vnt could fall behind a wastegated turbo - the technology is superior. but the application must be correct. - and since the goal of modern engine production in the tdi area is to burn clean and torquey, then the goal fir the engine producer (vw) is to make as much boost right through the low rpm rev range as possible, yet still be useable up the top end for that kW selling point. thus, you fit a small, highly stressed vnt that if driven hard, will wear out fast.if, on the other hand, your goal is to make an ever lasting 70hp slogger, that doesnt spool much around town but gives you a hand up the grades on the freeway, then mr vw engineer puts a t3 on a 1.6 IDI and it goes forever and ever and ever.
The preference of turbos vs. superchargers is due to the fact that the added boost from a turbo is "free" energy recovered from exhaust heat (makes the engine 10% more efficient) and, in contrast, the added power produced by a supercharger costs energy by being a direct drag on the engine.
Topic: best turbo (Read 13822 times)
