"You did gain a lot of spool down low but once spooled the twin-charged version made less power throughout the powerband vs turbo alone at the same boost."
This has to be true. As you pass the air through each stage the efficiency of that stage has to be included. The benefit is that you can...
The whole point of the twincharged system was that you could 'oversize' both turbo and supercharger to benefit from higher efficiencies, whilst still having the fast response times. This is where the compound effect has a benefit (TC blowing into SC). So firstly, the SC in this application...
Exactly as Hemi said. The water cooling on the turbo provides a thermo-siphon when the engine is shut off and prevents coking in the centre housing as the oil boils on the shaft. Some systems even use a small electric pump to assist the water flow after engine shut-off. However, if the person...
I just had a crazy idea after reading through your post again-- The orientation of VNT vanes was at which position for max boost in your installation - vanes lying parallel to turbine circuference or perpendicular to it?
Warpspeed. I had better results than that on my installation (which was engine dyno tested), even before the wastegate was installed. The wastegate was installed only like an exhaust manifold blow off valve, that would relieve pressure that would otherwise cause spikes, trimming peak...
Warpspeed, I really did fit a GT15V onto a Triumph Daytona 600cc bike engine a few years ago. It worked, but control was limited to around 50% range of vane movement, and an additional wastegate was needed; like Porsche. I believe this was only due to the control being vacuum actuated and had...
Yes, exactly. The vanes themselves, the dowels that pin them. The wheel is given a much larger clearance tolerance to the housing. If the vanes had the same tolerance, the air would go right round them.
I'll post up some info in a new thread.
Hmm, the reason Garrett dont make the VGT tech for SI engines is preturbine temps above the material limit causing vanes to expand and seize; not due to the VGT mechanism causing over-restriction like you say. In fact the VGT mechanism has the opposite effect, that is why large Turbine'd VGT's...
Hey Warpspeed, interesting that you tried the VGT on a SI engine, I also had some experience of doing just that on a motorbike engine. What were the difficulties that you experienced? Vanes jamming? Poor boost control at high rpm?
As far as I am aware the only (current) production SI...
Yes, but blower boost does not mean turbo boost and therefore max boost. That will still take 'some' time to get the shaft back to speed once you have snapped the throttle closed and opened it again. Having the standard dump-valve or recirc valve helps the turbo shaft speed deteriorate less...
Smallest Eaton (M24) is 24 CI/rev, or around 393cc. This would give you 10000 l/min at 25krpm. Next up M45 would need 14krpm. If your blower P1 is higer than 1BAR then you need rpms for same mass flow.
The M24 are the blowers fitted to the VW twincharger these days, if you can source one 2nd...
What a great result! Do you have any data that you could share regarding temps and pressures at each stage?
Good luck with the sprinting, hopefully I will be able to see your beast in real life sometime soon...
I think you would be surprised to find that your intercooler CORE temp varies almost exactly as the performace does.
If you say you can sit and idle for 5 mins and still have performance for a short distance, why wouldn't the pre-compressor intake pipes already be up to engine bay temps? If...
The theory of bending throttle plates and forcing open throttles sounds plausible. But it just DOESNT HAPPEN. Manufacturers of some current supercharged pascar vehicles have the throttle after the supercharger, no burst plate, just a normal bypass valve that fails open. Thats it.... Nobody...
