Metako Posted January 30, 2007 Report Share Posted January 30, 2007 There's been some interesting developments in turbos comming into passenger cars lately like the variable vane turbo in the deisel 407 HDi, Jaguar deisel, Volvo SUV and the Porsche 911 Turbo. I wonder how long it will be till these will be available in aftermarket turbos. I guess the computer control of the vanes will be a huge complexity and there'll be the added expense of having to buy the computer! Dont know if the deisels also have computer control though. There's also the twin-scroll turbo on the new little 207GT/Griffe and Mini Cooper S, and the new Golf GT has 1.4 litres and a supercharger AND a turbo! I would love to have a drive of that! I can also imagine putting a larger turbo on the 505, like a GT2871 or GT30R and using a supercharger to make up for the added lag. Of course it would be a huge job to add the supercharger and I dont really need another huge job at the moment. Quote Link to comment Share on other sites More sharing options...
Guest Posted January 30, 2007 Report Share Posted January 30, 2007 The "VNT" turbos are very common in medium to high performance tuned diesel engines. Although not available as aftermarket parts, but installing a vnt from a bigger engine, the result is more power. The vanes are usually controlled with a "frequency valve", a solenoid valve with pulse width modulated signal fed into it. It's not too difficult to make an electronic control device by yourself, If you have sufficient electronic skills and if you can make your own PCB's. On the other hand, the vanes can also be controlled via a simple wastegate actuator. Those are also used with good results, you just lose the unlimited adjustability. The sequential turbos are also discussed a lot amongst the diesel enthusiasts. In US they have twincharged f.ex. cummins diesel engines with very good results. Also the sequential charging is must in some tractor pulling classes, if you want to win. Quote Link to comment Share on other sites More sharing options...
Bean Posted January 31, 2007 Report Share Posted January 31, 2007 New turbo technology is amazing stuff - but I think the real power is in stand alone engine management. Combine that with a quick spooling turbo that flows a ton of air - and the power potential of the 2.2L 4 cylinder we have can get pretty staggering. (with drivability to boot!) The variable vane turbo's used in the last of the Turbo Dodges were neat - using the wastegate to control the pitch of the vanes - so it gave a really linear power curve. Add computer control to that vane control - and it gets even better. Rabin Quote Link to comment Share on other sites More sharing options...
Metako Posted January 31, 2007 Author Report Share Posted January 31, 2007 Combine that with a quick spooling turbo that flows a ton of air Rabin Yes, thats the perenial challenge-one mostly reduces the other. And how much lag am I willing to live with for the sake of better top end? Mmm... anyone know of a Dodge being wrecked (parted out)? Quote Link to comment Share on other sites More sharing options...
Guest Posted January 31, 2007 Report Share Posted January 31, 2007 You can find many sizes of those vnt or vvt turbos on eBay, f. ex. The only drawback is that they are almost all designed to diesel engines, which mean they can't cope with high exhaust temperatures. I don't know how much is safe, but I suppose you shouldn't exeed 900 degrees celcius. Quote Link to comment Share on other sites More sharing options...
august Posted January 31, 2007 Report Share Posted January 31, 2007 New turbo technology is amazing stuff - but I think the real power is in stand alone engine management. Combine that with a quick spooling turbo that flows a ton of air - and the power potential of the 2.2L 4 cylinder we have can get pretty staggering. (with drivability to boot!) The variable vane turbo's used in the last of the Turbo Dodges were neat - using the wastegate to control the pitch of the vanes - so it gave a really linear power curve. Add computer control to that vane control - and it gets even better. Rabin Rabin, do you remember what year / make of turbo dodge had the vvt turbo's? Metako, if the dodge that had the vvt turbo was available and popular in the US, i'd imagine there are a ton of wrecking yards where you could pickup a core, for pretty cheap. Quote Link to comment Share on other sites More sharing options...
SSB Posted February 1, 2007 Report Share Posted February 1, 2007 I have some background with VNT's from back in the mid to late 70's. The vanes on ours were regulated through a rather simple pressure sensing of the intake manifold. We (TurboTech, North Hollywood, CA. R.I.P.) sent a prototype to Cummins Diesel and the test result were about 80% effieient (compared with less that 20% with a standard turbo). The problem was the clearances had to be extreemly close (much closer than a normal turbo when it comes to housing to impeller) to acually act as a nozzel (think garden hose) . Because of the heat issues, close tollerances were difficult to maintain. So, today the VW TDI, the Peugeot powered Mini, Mazda Speed's and all "twin Scroll" compressors are nowhere near the effieiency they could be as the clearances are not very close. The big increases in power today are from pressure regulation and timing. I submit that if an N9TEA had a modern high pressure direct injection system, one would have trouble keeping rear tires on the car. As far as the turbos handling the heat, I doubt it would be a problem as the materials used are the same from Diesel (1000 deg.f) to gas (1600 deg.f) (inconel & berillium (sp?)) Quote Link to comment Share on other sites More sharing options...
Guest puck_supra Posted February 1, 2007 Report Share Posted February 1, 2007 Hi I dont mean to but into your thread, but I am am thinking about up greadting my turbo. I like to try and look at all the opions thow befor I do anything. I have herd a little about the variable vain turbos, and they sound like the way to go. But i also know of an egale talon that it running a sortof costom hybrid. Last I checked he was running a 9.43 in the 1/4 mile. He also drives the car to work evey day. I will see if i can find the specs and post them. Rabin- If you can come up with a part numer or years/model for those dodge turbos you where talking about I would be happy to ask around and get some info on them. There is a local diesel shop that deals with losts of turbos that could probly answer any question you have about it a diesel turbo could handle that much heat. There are a few srap yards in my area I can look in for them and there are a ton of diesel around here that do turbo upgrade to so one could probly find a used turbo cheap. Quote Link to comment Share on other sites More sharing options...
Metako Posted February 3, 2007 Author Report Share Posted February 3, 2007 I was half joking about looking for a s/h Dodge turbo-but maybe they are worth looking into. What size are they? T25/T3? We never got them in Australia so I may have to look a bit on ebay. SSB:From all I've read (which is not much) you cant use a deisel VNT turbo on a petrol car because deisels have a lower temp requirement, and would just melt on a petrol engine-not so? Quote Link to comment Share on other sites More sharing options...
Bean Posted February 3, 2007 Report Share Posted February 3, 2007 The Turbo dodges that ran the VNT if memory serves is actually a pretty rare bird. Googled it and found this: VNT Probably going to be a hard find since every TD guy worth his salt would strip it bare in a heartbeat. Rabin Quote Link to comment Share on other sites More sharing options...
Metako Posted February 4, 2007 Author Report Share Posted February 4, 2007 Nice link Bean. It sounds like the turbo worked really well. It surprises me that use and development of VNT turbos on petrol cars didnt forge ahead, especially in Japan. Maybe the Dodge turbos didnt last due to the heat factor. Otherwise I cant see a good reason for not using them in other cars long before the latest Porsche. Quote Link to comment Share on other sites More sharing options...
Guest puck_supra Posted February 4, 2007 Report Share Posted February 4, 2007 I well look around. I will be near that diesel shop I was talking about some time mid week. I will ask around to see what I can find. I will also stop by a few wreckig yards see what I can dig up. May be with any luck I will find something. Chase Quote Link to comment Share on other sites More sharing options...
Guest adegnes Posted February 8, 2007 Report Share Posted February 8, 2007 I often see people with high hp racing engines using turbos ( like the Garret gt40) from trucks (dont know if that's what it's called in english; long, big cars, many wheel's, transport stuff) Those truck's usualy have diesel engine's, so the heat shouldnt be a problem... (If the GT40 is an ordinarry gas-turbo, forget this post) Quote Link to comment Share on other sites More sharing options...
SSB Posted February 12, 2007 Report Share Posted February 12, 2007 SSB:From all I've read (which is not much) you cant use a deisel VNT turbo on a petrol car because deisels have a lower temp requirement, and would just melt on a petrol engine-not so? Sorry about the late response (big turbo, you know). Most of my knowledge comes with a disclaimer of being at least 20 year old info. However, that being said, when building a turbine wheel that needs to spin 225,000 rpm, the material needs to be quit hard. Ceramic has been used for years in some turbos (Buick GXN surprisingly). The VAT (varible area turbine) used on the TDI VW and the Turbo Gas VW while having different mapping charature would only have a material differance in the turbine housing at most if any differance. But as in both applications are cast iron turbine housing, I would be surprized if they used a lighter material on the diesel. So while they would not be interchangable, I doubt heat is why. Quote Link to comment Share on other sites More sharing options...
Guest puck_supra Posted February 13, 2007 Report Share Posted February 13, 2007 Ok I finly and a moment to run over to the diesel shop i was talking about and threw so qusetion at them. As far as the varable vain turbos thay said good luck finding one and if you want an after market on you will be looking at some big $$$ figures. But I remeberd that someone was taking about pulling a diesel turbo and puting it on a petrol motor. they said all the internals are the same and the heat will not hurt it any. all you have to worry about is sizes the turbo for what you want to accomplish. I have a grarett turbo i am going to bring down ther and get cleaned up and sized it is what i think it is i will probly put it on my 505.Well if any one has any more questions throw them my way i can run back daown to the diesel shop and get some awnsers. Quote Link to comment Share on other sites More sharing options...
Metako Posted February 14, 2007 Author Report Share Posted February 14, 2007 Let us know what else he says. Maybe ask the prices on diff sizes eg 300hp, 400hp max etc. Here's an interesting write-up on a VNT 25 install on a truck: http://www.houlster.com/amigo/turbo2/index.htm http://www.houlster.com/amigo/turbo2/VNT-25/vnt25.htm http://www.houlster.com/amigo/turbo2/turbo_header.htm and a good article by a Garret tech: http://www.thedodgegarage.com/turbo_vnt.html Quote Link to comment Share on other sites More sharing options...
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