superchrged + twin turbos ????
i'd like to know the cost break down between vnt warranty repairs vs. increased manufacturing costs and complexity of the compound turbo/super charger setups.
TECH Apprentice
Joined: Dec 2004
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From: fort campbell
re
Nissan also has a twin-turboed 300zx. Seen videos of them running with cobra with a simple aftermarket intake and exhaust
The 3rd gen RX-7 uses two turbos but they are diff sizes and the computer switches the smaller turbo off as the motor rises to a larger turbo to help prevent the torque of the rotary being so low.
All of our Titan crash fire trucks on post use the compound roots/turbo system and they are very reliable.
i've seen pictures of a hyundai tiburon with a turbo, supercharger, and nitrous all at once. it was a show car though so i doubt it was for performance reasons haha.
unless the guy figured he needed the turbo's to make up for the parasitic power loss caused by the supercharger, and then decided he needed nitrous to help the turbos spool faster
unless the guy figured he needed the turbo's to make up for the parasitic power loss caused by the supercharger, and then decided he needed nitrous to help the turbos spool faster
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thats exactly what its doing. vnt basically eliminates all turbo lag, but even with vnt improvements it still really isnt a longer term viable part.... although i think some diesels are now coming with them like the cummins, so who knows maybe there better and wont break as much.
i'd like to know the cost break down between vnt warranty repairs vs. increased manufacturing costs and complexity of the compound turbo/super charger setups.
i'd like to know the cost break down between vnt warranty repairs vs. increased manufacturing costs and complexity of the compound turbo/super charger setups.
hmm eliminates turbo lag?? i dont think so... it reduces it, yes, but for example the new duramax has a VNT... and still is over 3 seconds of lag from a standing start.
Superchargers and turbochargers still are orders of magnitude different in response time, VNT or not...
VNT's are expensive and are much more prone to breaking.. The technology is great, but with complexity comes cost and with 'complexity and high temperatures' comes reliability issues... The technolgy is great but its definately not the "end all, be all" of boosting..
when looking at the diesels, also consider the amount of volume the "compressor" has pressurize, its going to take time to boost regardless of actual turbo lag time.
my experience with vnt was the shelby daytonas with vnt. and those thing came up on boost instantly, there wasnt any perceivable lag time.
but ya, they were prone to breaking ... alot ...
my experience with vnt was the shelby daytonas with vnt. and those thing came up on boost instantly, there wasnt any perceivable lag time.
but ya, they were prone to breaking ... alot ...
I fished on a boat for awhile with a dual charged 1292, monster engine! with the lil 2cyl generator going we burnt 20-22gallons an hour. and between the valve train and the whine now I cant hear really high pitches to well..
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On The Tree
Joined: Oct 2008
Posts: 130
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From: Albuquerque,NM
That company is located here in Albuquerque NM! they basically wanted something cool differnt and letal ive seen the 1600hp set up and WOW! the use of the two types of FI is to basically mold the power curve turbos have a NA look but advanced in RPM SC have a sloping look think about it off idle monster torque and good solid mid and top end with turbos supplying the boost by force feeding the SC. They wanted something to perform well at this Altitude and higher ie denver well that was from the donkeys mouth so... 
Teching In
Joined: Aug 2007
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Basically, a roots-style blower can only grab N/a air up to a certain rpm of efficiency. After that, it simply cannot pull more air because of its design. It is essentially a boost multiplier. (which is why an 03 cobra has so much torque, but a comparably weak high end, and why a centrifugal blower-style car will not have the guts in the low end, but will fly by in the high end-it takes time for the centrifugal to build boost, much like a turbo).
With a turbocharger and supercharger, the turbo is used to compress the air and force it into a roots-style blower so it can multiply the boost and achieve an incredibly high compression ratio. This is mainly used in diesel engines, like redta said, because they are compression-based engines.
sorry if the question was answered already, but I just read the first few posts
On The Tree
Joined: Dec 2006
Posts: 121
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From: Aloha, OR
Could you use a centrifugal supercharger in front of a roots instead of a turbo? This wouldn't exactly multiply the boost but instead supply more top end, or am I wrong? Secondly, could one use a twin screw instead of a roots type supercharger?
TECH Addict
Joined: Aug 2004
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Chris.
Couldn't you run a small turbo that would spool. Instantly. But feed it from a centi supercharger so at high rpms the small turbo would not be limited by flow cause it would be force feed by the supercharger. Making it act like a much bigger turbo ?
Teching In
Joined: Jan 2009
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From: California
Of course the twin kit made more power than the hellraiser at the same boost. The supercharger at this point would just act as a restriction. The power increases when the boost is compounded to high psi levels.
Yes that why im thinking. lets say engine is a 402 with with dual 60 turbos should spool pretty fast right ? but be little down on max power cause the small turbos can only flow so much air. but if a supercharger is pushing 15 psi of air to the turbos they should they now be rate for double the hp now. turbos could be use to now compress the air to 30 psi.
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Chris.
TECH Addict
Joined: Aug 2004
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Yes that why im thinking. lets say engine is a 402 with with dual 60 turbos should spool pretty fast right ? but be little down on max power cause the small turbos can only flow so much air. but if a supercharger is pushing 15 psi of air to the turbos they should they now be rate for double the hp now. turbos could be use to now compress the air to 30 psi.
be nice for someone to try all these ideas though.
Chris.
