What are downfalls with FI?
01-13-2008, 12:10 AM
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What are downfalls with FI? I am considering a blower or turbo setup.
Will either of these cause overheating in summer traffic jams with a/c on?
Which one of these is most fuel efficient? With my prior experience, I have had turbo cars, and they get excellent mileage as long as you don't use any boost. Is this the case for people here? I would like good mileage so I can drive to work in this car.
I have never had a blower. It seems to me that since blowers are always making boost it would always need more fuel and therefor always get worse mileage, even if you are just driving to work. Is this true? On the other hand, it takes the same amount of horsepower to maintain 70mph on a flat highway with a given car, no matter whether there is a blower or not. So by that logic the mpg would be the same. What are your experiences with regard to mpg? This is very important to me, since gas has doubled in price in the last 3 years, and it will most likely double again in the next 3.
Are there any other side effects? Does the a/c still work good, etc?
The engine will be in a C5 corvette or a GTO, or a THIRD gen firebird.
Will either of these cause overheating in summer traffic jams with a/c on?
Which one of these is most fuel efficient? With my prior experience, I have had turbo cars, and they get excellent mileage as long as you don't use any boost. Is this the case for people here? I would like good mileage so I can drive to work in this car.
I have never had a blower. It seems to me that since blowers are always making boost it would always need more fuel and therefor always get worse mileage, even if you are just driving to work. Is this true? On the other hand, it takes the same amount of horsepower to maintain 70mph on a flat highway with a given car, no matter whether there is a blower or not. So by that logic the mpg would be the same. What are your experiences with regard to mpg? This is very important to me, since gas has doubled in price in the last 3 years, and it will most likely double again in the next 3.
Are there any other side effects? Does the a/c still work good, etc?
The engine will be in a C5 corvette or a GTO, or a THIRD gen firebird.
01-13-2008, 01:39 AM
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Superchargers are not making boost all of the time. Only at WOT will you be in boost. If not in boost you will be in vacuum.
Due to the crank pulley and supercharger pulley there will be a little more drag on the engine.
Somebody else can answer the rest.
Due to the crank pulley and supercharger pulley there will be a little more drag on the engine.
Somebody else can answer the rest.
01-13-2008, 01:45 AM
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only downside to the turbo is the constant checking up on it, as in checking that oil lines are nice and tight, all piping is good and connected, nothing is dripping oil, nothing in the engine bay decided to move and get melted, stuff like that
01-13-2008, 04:49 AM
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Supercharger always has some kind of boost as long as the engine is turning the supercharger right? It's linear, as you add RPM you add boost i thought. i don't know much, so maybe I'm off...
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01-13-2008, 06:00 AM
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The boost is made and only kicks in when you start to accelerate hard and of course that includes going WOT, but on my car 3/4 throttle acceleration will start making some boost also, but not until WOT does it kick in full steam.
The boost is made as soon as you step on the gas hard, with normal accleration when not hot rodding no boost with Procharger (and I almost positive most other centrifugal superchargers).
01-13-2008, 07:05 AM
#9
An ATI ProCharger is always making boost, try taking the outlet tube from it and fire it up at idle! The reason the engine does not see this boost until the engine is nearly at wide open throttle, is because there is a vacuum operated bypass valve.
Under high vaccum conditions the boost is being bled off through the bypass valve, which also occurs when you suddenly let off the gas and the throttle blades slam shut.
TurboChargers are not without a parasitic loss as the turbo is a restriction in the exhaust system.
Here is a list I put together that may help you out.
http://www.exoticperformanceplus.com....html?item=540 Bob
Under high vaccum conditions the boost is being bled off through the bypass valve, which also occurs when you suddenly let off the gas and the throttle blades slam shut.
TurboChargers are not without a parasitic loss as the turbo is a restriction in the exhaust system.
Here is a list I put together that may help you out.
http://www.exoticperformanceplus.com....html?item=540 Bob
01-13-2008, 08:41 AM
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A centrifugal adds power across the RPM band even when you are not WOT. It would be a long discussion about boost pressure vs vacuum and then throw in the bypass/blow off valve effect. For instance as you start to add throttle the vacuum gauge might read 8 lbs. vac. on a NA motor but because the blower is kicking in air it might read 3 lbs. vac. I feel the power of the blower big time just driving around kinda hard and letting the power push you back in the seat, never going WOT. You might not see much on the boost gauge but the engine is taking in way more air than NA because of the blower.
01-13-2008, 09:02 AM
#11
A centrifugal adds power across the RPM band even when you are not WOT. It would be a long discussion about boost pressure vs vacuum and then throw in the bypass/blow off valve effect. For instance as you start to add throttle the vacuum gauge might read 8 lbs. vac. on a NA motor but because the blower is kicking in air it might read 3 lbs. vac. I feel the power of the blower big time just driving around kinda hard and letting the power push you back in the seat, never going WOT. You might not see much on the boost gauge but the engine is taking in way more air than NA because of the blower.
01-13-2008, 09:03 AM
#12
a lot depends on how fast the s/c is spun-pulley size, etc-you might not see it on the gauge, but its there-try on a carb'ed blow thru pulling the fuel bowl level plug out with the engine running, it is under pressure and will blow the gas right out
i might see a couple pounds running at 50 mph, again, pulley size, rear gears, etc all just bring it in sooner-and as noted, some is bleed off thru the surge valve, some is even lost in the i/c
i might see a couple pounds running at 50 mph, again, pulley size, rear gears, etc all just bring it in sooner-and as noted, some is bleed off thru the surge valve, some is even lost in the i/c
01-13-2008, 05:36 PM
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If it's a daily, turbos are a bad idea as there is a lot to maintain and a lot to go wrong. If you go with a Procharger (or any other blower, for that matter) the maintenance is a lot more livable, and the car will be more reliable. However, turbos do, generally, see better performance numbers.
There are a lot of DD Procharged cars on this site. If you're interested, talk to Bob at Exotic Performance Plus. He's the Procharger guru and has the best prices on top of that.
As 02NBMFormula pointed out, though, the biggest downfall is the cost.
There are a lot of DD Procharged cars on this site. If you're interested, talk to Bob at Exotic Performance Plus. He's the Procharger guru and has the best prices on top of that.
As 02NBMFormula pointed out, though, the biggest downfall is the cost.
01-13-2008, 05:38 PM
#16
I prefer turbo but I guess I am kinda biased b/c I've never had a s/c only friends. The most cost effective, relibale setup for the street I'd have to say call up EPP and get a ATI D-1 kit and be done. Allot of varibles with a turbo kit but taking the time, etc it will pay off for sure. You'll be happy with either, FI rules and can't beat it IMO. Like mentioned, the cost is the biggest downfall. With a good setup, tune, etc it will be fun, relibale and be able to kick some more *** on the street!
01-13-2008, 05:44 PM
#17
either way you go make sure you get a good tune and go to a good dyno shop. i found that out the hard way on both..... tuner is well know at camaroz28.com (mail in tuner) but my car never ran right with his tunes and another guy i talked to had the same problem wit hhis blower motor. no dyno places around me,so i heard of a place that was 1hr 50mins away that dyno tuned. long story short motor tanked a week later. i never beat my car as its a garage queen in case anyone was thinking that.
It not that hard to learn how to controll it though. 
