Who has the Turbo Pics
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I asked my dealer-salesman about getting the turbo for a regular sky and he just flat out said no. He felt it would be too labor intensive and not cost effective. He also felt that adding the turbo aftermarket would void warranty.fireman said:Now for the simple question. Is this going to be an aftermarket addon for the Sky 2.4 engine? And if so, $?
Thanks
I'll admit I'm not completely up to snuff on the new technology coming out in the 2.0L Turbo, but when does how you inject fuel affect turbo lag or compression ratio? Now, granted, a cooler cylendar temp will give you more room to increase compression in the design of the engine...I know that...and I'm assuming that what you meant but please elaborate if that's not what you meant and about reducing turbo lag just from direct injection.bradyb said:#1 Direct fuel injection, this puts the fuel injector directly into the cylinder with very high fuel pressure. This creates a better/faster fuel burn which allows the spark to fire sooner for more aggressive timing. This also allows a much higher compression ratio for better mileage, power, and faster boost. Direct injection kills many cons that Robotech stated above (turbo lag, low compression ratio, etc)
I'd say that's a fair assessment. I'm not up on pricing for aftermarket parts for the Ecotec but I'd see forged pistons, possibly better rods (need to find out what's in this thing for certain), etc, etc, etc, would all be necessary to run a decent amount of boost.You can slap on an aftermarket turbo kit (you'll never see a good supercharger kit) but you'll lose mileage and reliability. You're a fool if you think you can just slap on a turbo kit and drive it like a stock vehicle. Expect things to wear out twice as fast and make sure you always have enough money in the bank for that new motor you'll need down the road. To replicate the Red Line's power/mileage/reliability you'll have to spend at least $10,000.
God I hope so. Never did understand a Supercharged 4.Turbo lag will not be an issue and you guys will soon see GM phase out all four cylinder supercharging in the next couple of years. The HHR, G5, Cobalt SS will all soon be using this new turbo 2.0L.
Don't exactly agree here. Depends on the application. When you get into large displacement engines I think you see certain benefits of supercharging. Top Fuel dragsters come to mind with their large displacement engines and short ETs. With an engine running a 1/4 mile in 6 seconds or less lag does play a big part in it. But for 4 and 6 cylendar engines Turbos are a far wiser investment.Superchargers are terribly inefficient and when ever possible it's a wiser decision to go a with a turbo.
Good explination of Parasitic Drag. A very big drawback to Super Charging.Do you guys realize that if you're making 300 horsepower with a supercharger you’re losing a good 30-60 horsepower by using belts and pulleys that are attached to the crank? A turbo at 8 PSI is going to make 10% more power then a supercharger at 8 PSI because it uses the exhaust pressure that the motor is already pumping out.
But whether that is from boost or detonation because your intake charge will be so overheated would be left to the autopsy. Once past a certain boost level you must intercool...with either power adder...and if you don't detonation will kill the engine just as surely as blowing a head gasket from over-boosting. However, Turbos are known to produce a LOT of heat...perhaps more so than a roots blower and certainly more than a twin-screw blower.A turbo feeds off of itself by creating boost which creates more exhaust pressure which creates more boost pressure which creates more exhaust pressure etc... Turbos have waste gates to let the exhaust bypass the turbo so you don't over boost the motor. If you let the turbo create as much boost as it could with out restraint it would blow your motor by 4,000 RPMS.
I would disagree with the part about being easier on the transmissions. When you launch with a Supercharged car the boost is right there. You've already preloaded the transmission with the power. With a turbo, when the boost comes on it comes on hard and fast "snapping" the transmission. In the Grand Prix community we've seen a lot of transmission issues when people go turbo while the Supercharged guys...running similar ETs...tend to see fewer transmission issues. Also, it is because of the Super Chargers linear boost that makes them fantastic when you are launching the car. One of the fastest cars in our Grand Prix community (mid 9s) uses the stock M90 to launch. Once the turbo spools up, the boost of the M90 is bypassed and the boost from the turbo is delivered in its place.Turbos create boost in an exponential fashing while superchargers are stricly linear. A turbo will also be easier on the drive train with smoother power delivery. You won't have instant boost right off idle to tear up transmissions/rear end.
Essentially you get a faster burn rate which allows you to run more timing and run a higher compression ratio. More air compression creates a bigger pop which increases the exhaust pressure. Driving a high compression turbo motor is a lot of fun, "snappy" is a good adjective.Robotech said:I'll admit I'm not completely up to snuff on the new technology coming out in the 2.0L Turbo, but when does how you inject fuel affect turbo lag or compression ratio? Now, granted, a cooler cylendar temp will give you more room to increase compression in the design of the engine...I know that...and I'm assuming that what you meant but please elaborate if that's not what you meant and about reducing turbo lag just from direct injection.
Not to mention a gear driven fuel pump for 130 PSI, infinite valve timing and the engine management to run it. You also get a sweet digital boost gauge that is integrated with the factory gauges.Robotech said:I'd say that's a fair assessment. I'm not up on pricing for aftermarket parts for the Ecotec but I'd see forged pistons, possibly better rods (need to find out what's in this thing for certain), etc, etc, etc, would all be necessary to run a decent amount of boost.
Top Fuel dragsters need to ram so much fuel and air together that you don't have much of a choice fro that much volum other then a giant blower. Don't forget that the world's fastest door slammers are turbo cars!Robotech said:Don't exactly agree here. Depends on the application. When you get into large displacement engines I think you see certain benefits of supercharging. Top Fuel dragsters come to mind with their large displacement engines and short ETs. With an engine running a 1/4 mile in 6 seconds or less lag does play a big part in it. But for 4 and 6 cylendar engines Turbos are a far wiser investment.
Using an intercooler/heat exchanger is a given and I didn't think it had to be mentioned. Remember that a turbo is only going to get as hot as your exhaust manifold so it shouldn't increase the under hood temps, but with many aftermarket kits you're putting the turbo in strange places like out in front of the motor or way up high almost on top of the motor where it can melt things or burn things. High intake temps don't come from the engine bay being hot usually. There is an incredible amount of air friction involved in air compression and this is usually what heats up the air. Think of the friction that is involved with a twin scroll compared to just a turbo compressor; you have a ton of surface area that that is compressing the air.Robotech said:But whether that is from boost or detonation because your intake charge will be so overheated would be left to the autopsy. Once past a certain boost level you must intercool...with either power adder...and if you don't detonation will kill the engine just as surely as blowing a head gasket from over-boosting. However, Turbos are known to produce a LOT of heat...perhaps more so than a roots blower and certainly more than a twin-screw blower.
What do you want, a hard launch or smooth power delivery as boost increases? Boost does not come one hard and fast if you size the turbo correctly, it will go from -10 inches of vaccuum to 20 PSI from 1,000 to 4,000 RPMS nice and smooth.Robotech said:I would disagree with the part about being easier on the transmissions. When you launch with a Supercharged car the boost is right there. You've already preloaded the transmission with the power. With a turbo, when the boost comes on it comes on hard and fast "snapping" the transmission. In the Grand Prix community we've seen a lot of transmission issues when people go turbo while the Supercharged guys...running similar ETs...tend to see fewer transmission issues. Also, it is because of the Super Chargers linear boost that makes them fantastic when you are launching the car. One of the fastest cars in our Grand Prix community (mid 9s) uses the stock M90 to launch. Once the turbo spools up, the boost of the M90 is bypassed and the boost from the turbo is delivered in its place.
:cheers:Robotech said:Also, bradyb, please do not take this as a personal attack against you...I just quoted the areas I was wondering/extrapolating on to make it easier to follow. Any input you have on it would be very welcomed. Best way to learn is through posts like this that are kept civil and open minded.![]()
Mallet is using the stock transmission.Robotech said:Mallet cars swap out transmissions but it will be interesting to see what happens on the tranny front.