Pressurizing a 2-2.5 liter 4 cyl. with 15psi of boost would act like a 4-5 liter v-8, buts that's a lot of boost for mass produced engine. More reasonable 5-7 psi boost now the 4 cyl. acts like a 6 cyl. With all the plumbing, intercooler, etc how much weight/space are you really saving?, not just going ahead and put in a v-6. The v-6 will get better low-mid range torque, be easier on oil, and get similar mpgs.Porsche? had 4 cyls up to 3 liters but need hp robbing balance shafts to keep it accectable to potential buyers. Practical common limit 2.5 liters. This should get you 185-200 hp NA. In a small light fwd car with torque steer limits do you really need more? I see little need usually for pressurizing gas engines anyway, diesels whole other thing (much better suited) .Actual displacement instead easier to get, more fun, more reliable than simulated cubic inches.Rather a moot question anyways, so here we are "mooting" it.
Why supercharged 4 cyl is not popular
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Originally Posted By: jldcol
Pressurizing a 2-2.5 liter 4 cyl. with 15psi of boost would act like a 4-5 liter v-8, buts that's a lot of boost for mass produced engine. More reasonable 5-7 psi boost now the 4 cyl. acts like a 6 cyl. With all the plumbing, intercooler, etc how much weight/space are you really saving?, not just going ahead and put in a v-6. The v-6 will get better low-mid range torque, be easier on oil, and get similar mpgs.Porsche? had 4 cyls up to 3 liters but need hp robbing balance shafts to keep it accectable to potential buyers. Practical common limit 2.5 liters. This should get you 185-200 hp NA. In a small light fwd car with torque steer limits do you really need more? I see little need usually for pressurizing gas engines anyway, diesels whole other thing (much better suited) .Actual displacement instead easier to get, more fun, more reliable than simulated cubic inches.Rather a moot question anyways, so here we are "mooting" it.
Wrong.
My turbo V6 is lighter than the typical iron 350 V8 even with the plubming, IC, and turbo.
My car ran 14psi boost from the factory and there are tons of them with 150,000+ miles without a rebuild. I can name a friend's GN that's about to turn 100K that we put a methanol kit on 50,000 miles ago that's been pushing 26psi daily with no problems.
The larger engines will not get better low-mid range torque. Quite the opposite. Stock, mine made an underrated 355lbs at 3,000rpm. Now it makes 620lbs at 3,200rpm.
Look at the Porsche 3.6L GT-3 that makes close to 500lbs at 2,200rpm. Try the BMW 335 3.0L that makes it's underrated 300lbs at 2,400rpm Both of these cars make peak power above 6,000rpm too. It's a huge flat powerband.
And again, build a NA smallblock V8 that matches the power of my car and see how streetable it is. Mine was my daily driver for years in this trim.
Pressurizing a 2-2.5 liter 4 cyl. with 15psi of boost would act like a 4-5 liter v-8, buts that's a lot of boost for mass produced engine. More reasonable 5-7 psi boost now the 4 cyl. acts like a 6 cyl. With all the plumbing, intercooler, etc how much weight/space are you really saving?, not just going ahead and put in a v-6. The v-6 will get better low-mid range torque, be easier on oil, and get similar mpgs.Porsche? had 4 cyls up to 3 liters but need hp robbing balance shafts to keep it accectable to potential buyers. Practical common limit 2.5 liters. This should get you 185-200 hp NA. In a small light fwd car with torque steer limits do you really need more? I see little need usually for pressurizing gas engines anyway, diesels whole other thing (much better suited) .Actual displacement instead easier to get, more fun, more reliable than simulated cubic inches.Rather a moot question anyways, so here we are "mooting" it.
Wrong.
My turbo V6 is lighter than the typical iron 350 V8 even with the plubming, IC, and turbo.
My car ran 14psi boost from the factory and there are tons of them with 150,000+ miles without a rebuild. I can name a friend's GN that's about to turn 100K that we put a methanol kit on 50,000 miles ago that's been pushing 26psi daily with no problems.
The larger engines will not get better low-mid range torque. Quite the opposite. Stock, mine made an underrated 355lbs at 3,000rpm. Now it makes 620lbs at 3,200rpm.
Look at the Porsche 3.6L GT-3 that makes close to 500lbs at 2,200rpm. Try the BMW 335 3.0L that makes it's underrated 300lbs at 2,400rpm Both of these cars make peak power above 6,000rpm too. It's a huge flat powerband.
And again, build a NA smallblock V8 that matches the power of my car and see how streetable it is. Mine was my daily driver for years in this trim.
op was on 4cyls. I'm comparing the weight/space used 4 cyl.,+supercharger, plumbing, and intercooler vs. say 2.5 to 3.5 liter v6's. Your 3.8 liter v6 is huge in comparison to a 4 cyl/small v6. Also the numbers built are relatively small. Again the comparison is pressurized 4cyls. vs same power in a 6cyl., as per op. There does seem to be a minumum size beyond which there is enough exhaust to supply enough power to pressurize a relatively large flow of gas. That size is likely bigger than a 2-2.5 liter 4 cyl.
Originally Posted By: jldcol
There does seem to be a minumum size beyond which there is enough exhaust to supply enough power to pressurize a relatively large flow of gas. That size is likely bigger than a 2-2.5 liter 4 cyl.
Turbochargers scale nicely. Turbocharged gas engines of under 1000 cc are not a problem.
There does seem to be a minumum size beyond which there is enough exhaust to supply enough power to pressurize a relatively large flow of gas. That size is likely bigger than a 2-2.5 liter 4 cyl.
Turbochargers scale nicely. Turbocharged gas engines of under 1000 cc are not a problem.
Originally Posted By: jldcol
op was on 4cyls. I'm comparing the weight/space used 4 cyl.,+supercharger, plumbing, and intercooler vs. say 2.5 to 3.5 liter v6's. Your 3.8 liter v6 is huge in comparison to a 4 cyl/small v6. Also the numbers built are relatively small. Again the comparison is pressurized 4cyls. vs same power in a 6cyl., as per op. There does seem to be a minumum size beyond which there is enough exhaust to supply enough power to pressurize a relatively large flow of gas. That size is likely bigger than a 2-2.5 liter 4 cyl.
It's the same thing, just on a smaller scale.
What has ruined the image somewhat are the ricers putting a T-88 on a 1.6L that makes 500hp in the last 100rpm before the revlimiter and 50hp at anything less than redline.
Turbo technology has come very far even in the last 5 years. I just installed a new 6765 DBB turbo and lowered my stall speed to 2,800rpm. If someone had told me I could be making roughly 700hp with excellent spool with a low stall convertor I would've thought they were crazy.
op was on 4cyls. I'm comparing the weight/space used 4 cyl.,+supercharger, plumbing, and intercooler vs. say 2.5 to 3.5 liter v6's. Your 3.8 liter v6 is huge in comparison to a 4 cyl/small v6. Also the numbers built are relatively small. Again the comparison is pressurized 4cyls. vs same power in a 6cyl., as per op. There does seem to be a minumum size beyond which there is enough exhaust to supply enough power to pressurize a relatively large flow of gas. That size is likely bigger than a 2-2.5 liter 4 cyl.
It's the same thing, just on a smaller scale.
What has ruined the image somewhat are the ricers putting a T-88 on a 1.6L that makes 500hp in the last 100rpm before the revlimiter and 50hp at anything less than redline.
Turbo technology has come very far even in the last 5 years. I just installed a new 6765 DBB turbo and lowered my stall speed to 2,800rpm. If someone had told me I could be making roughly 700hp with excellent spool with a low stall convertor I would've thought they were crazy.
Originally Posted By: jldcol
The v-6 will get better low-mid range torque, be easier on oil, and get similar mpgs.
A turbocharged 4 banger with an appropriately sized modern turbocharger will likely make way more torque, and "area under the curve" torque, and get much better fuel mileage then a V-6. Turbocharged engines make GOBS of torque, because the compressor in a turbo is not dictated by the speed of the crankshaft. Look at the 2 liter GM turbo Ecotec motor. Better fuel mileage and 40 more ft. lbs then the 3.5L GM V-6. And the turbo 2L Ecotec outperforms the 2.2L supercharged variant of that engine like it's tied to a stump!
The v-6 will get better low-mid range torque, be easier on oil, and get similar mpgs.
A turbocharged 4 banger with an appropriately sized modern turbocharger will likely make way more torque, and "area under the curve" torque, and get much better fuel mileage then a V-6. Turbocharged engines make GOBS of torque, because the compressor in a turbo is not dictated by the speed of the crankshaft. Look at the 2 liter GM turbo Ecotec motor. Better fuel mileage and 40 more ft. lbs then the 3.5L GM V-6. And the turbo 2L Ecotec outperforms the 2.2L supercharged variant of that engine like it's tied to a stump!
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Turbochargers are fantastic.
A decent H/C/I 5.0L Ford with a set of twins on it will make well in excess of 600RWHP with 15 or so PSI.
My friend's twin-turbo Termi made 750RWHP on only 16lbs of boost. 21psi yielded 850+RWHP. It would make the 750 on pump gas. Mild tune, car was a daily driver. Oh, and of course it made 730lb-ft of torque too
A decent H/C/I 5.0L Ford with a set of twins on it will make well in excess of 600RWHP with 15 or so PSI.
My friend's twin-turbo Termi made 750RWHP on only 16lbs of boost. 21psi yielded 850+RWHP. It would make the 750 on pump gas. Mild tune, car was a daily driver. Oh, and of course it made 730lb-ft of torque too
Originally Posted By: OVERK1LL
Turbochargers are fantastic.
A decent H/C/I 5.0L Ford with a set of twins on it will make well in excess of 600RWHP with 15 or so PSI.
My friend's twin-turbo Termi made 750RWHP on only 16lbs of boost. 21psi yielded 850+RWHP. It would make the 750 on pump gas. Mild tune, car was a daily driver. Oh, and of course it made 730lb-ft of torque too
That goes along with what I've been saying. 750rwhp AND a streetable daily driver is very hard to do without a turbo unless you build a 700+ cube monster. Some of these cars sound like a stock car with only exhaust. No lope of a big cam to give anything away. Even my little 256" engine has no lope and nothing other than a quiet aftermarket exhaust to give it away.
Turbochargers are fantastic.
A decent H/C/I 5.0L Ford with a set of twins on it will make well in excess of 600RWHP with 15 or so PSI.
My friend's twin-turbo Termi made 750RWHP on only 16lbs of boost. 21psi yielded 850+RWHP. It would make the 750 on pump gas. Mild tune, car was a daily driver. Oh, and of course it made 730lb-ft of torque too
That goes along with what I've been saying. 750rwhp AND a streetable daily driver is very hard to do without a turbo unless you build a 700+ cube monster. Some of these cars sound like a stock car with only exhaust. No lope of a big cam to give anything away. Even my little 256" engine has no lope and nothing other than a quiet aftermarket exhaust to give it away.
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Originally Posted By: BuickGN
Originally Posted By: OVERK1LL
Turbochargers are fantastic.
A decent H/C/I 5.0L Ford with a set of twins on it will make well in excess of 600RWHP with 15 or so PSI.
My friend's twin-turbo Termi made 750RWHP on only 16lbs of boost. 21psi yielded 850+RWHP. It would make the 750 on pump gas. Mild tune, car was a daily driver. Oh, and of course it made 730lb-ft of torque too
That goes along with what I've been saying. 750rwhp AND a streetable daily driver is very hard to do without a turbo unless you build a 700+ cube monster. Some of these cars sound like a stock car with only exhaust. No lope of a big cam to give anything away. Even my little 256" engine has no lope and nothing other than a quiet aftermarket exhaust to give it away.
We are definitely on the same page here
Originally Posted By: OVERK1LL
Turbochargers are fantastic.
A decent H/C/I 5.0L Ford with a set of twins on it will make well in excess of 600RWHP with 15 or so PSI.
My friend's twin-turbo Termi made 750RWHP on only 16lbs of boost. 21psi yielded 850+RWHP. It would make the 750 on pump gas. Mild tune, car was a daily driver. Oh, and of course it made 730lb-ft of torque too
That goes along with what I've been saying. 750rwhp AND a streetable daily driver is very hard to do without a turbo unless you build a 700+ cube monster. Some of these cars sound like a stock car with only exhaust. No lope of a big cam to give anything away. Even my little 256" engine has no lope and nothing other than a quiet aftermarket exhaust to give it away.
We are definitely on the same page here
I drive a 97 Grand Prix GTP, and I have to say that the supercharger is more rewarding for daily driving. Even though I know a turbo is more efficient, I'd think a super would be the way to go for "regular" vehicles that spend their lives merging onto freeways and trying to get out of their own way at traffic lights. I've driven cars with lots of top end power and no low end torque, and it's no fun unless you are always revving it.
I wonder what the engineering problem is with getting SC to meet emissions?
I wonder what the engineering problem is with getting SC to meet emissions?
Hi,
swalve - You said:
"I wonder what the engineering problem is with getting SC to meet emissions?"
There is no engineering problem - it is simply a cost-benefit-application factor
You may like to read my earlier Post on here regarding the M271 Mercedes Benz engine. Many millions of these engines have been built now and are still in the current and planned engine model lineup at Mercedes Benz. The M271 engines have a Worldwide sales application therefore meeting all current and planned emission control requirements
swalve - You said:
"I wonder what the engineering problem is with getting SC to meet emissions?"
There is no engineering problem - it is simply a cost-benefit-application factor
You may like to read my earlier Post on here regarding the M271 Mercedes Benz engine. Many millions of these engines have been built now and are still in the current and planned engine model lineup at Mercedes Benz. The M271 engines have a Worldwide sales application therefore meeting all current and planned emission control requirements
Originally Posted By: swalve
I drive a 97 Grand Prix GTP, and I have to say that the supercharger is more rewarding for daily driving. Even though I know a turbo is more efficient, I'd think a super would be the way to go for "regular" vehicles that spend their lives merging onto freeways and trying to get out of their own way at traffic lights. I've driven cars with lots of top end power and no low end torque, and it's no fun unless you are always revving it.
I wonder what the engineering problem is with getting SC to meet emissions?
The Buick V6 in supercharged and turbo form is known for low end torque. If you've ever driven a stock GN, you would know spool is just about instant. Mine even in it's current form is extremely responsive. From 0 to 26psi takes about a second but more importatly there's some boost as soon as the pedel hits the floor from a dead stop. If the car is rolling fast enough to have to merge onto a freeway, full boost is nearly instant. Trust me, you're more worried about facing the opposite way on accident than turbo lag.
I drive a 97 Grand Prix GTP, and I have to say that the supercharger is more rewarding for daily driving. Even though I know a turbo is more efficient, I'd think a super would be the way to go for "regular" vehicles that spend their lives merging onto freeways and trying to get out of their own way at traffic lights. I've driven cars with lots of top end power and no low end torque, and it's no fun unless you are always revving it.
I wonder what the engineering problem is with getting SC to meet emissions?
The Buick V6 in supercharged and turbo form is known for low end torque. If you've ever driven a stock GN, you would know spool is just about instant. Mine even in it's current form is extremely responsive. From 0 to 26psi takes about a second but more importatly there's some boost as soon as the pedel hits the floor from a dead stop. If the car is rolling fast enough to have to merge onto a freeway, full boost is nearly instant. Trust me, you're more worried about facing the opposite way on accident than turbo lag.
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Originally Posted By: swalve
I drive a 97 Grand Prix GTP, and I have to say that the supercharger is more rewarding for daily driving. Even though I know a turbo is more efficient, I'd think a super would be the way to go for "regular" vehicles that spend their lives merging onto freeways and trying to get out of their own way at traffic lights. I've driven cars with lots of top end power and no low end torque, and it's no fun unless you are always revving it.
I wonder what the engineering problem is with getting SC to meet emissions?
Unless you've driven the exact same car with a turbo, you really don't know which is more rewarding. A TDI Jetta spools almost instantly for example........
BuickGN's example is food for thought.....
I drive a 97 Grand Prix GTP, and I have to say that the supercharger is more rewarding for daily driving. Even though I know a turbo is more efficient, I'd think a super would be the way to go for "regular" vehicles that spend their lives merging onto freeways and trying to get out of their own way at traffic lights. I've driven cars with lots of top end power and no low end torque, and it's no fun unless you are always revving it.
I wonder what the engineering problem is with getting SC to meet emissions?
Unless you've driven the exact same car with a turbo, you really don't know which is more rewarding. A TDI Jetta spools almost instantly for example........
BuickGN's example is food for thought.....
Originally Posted By: OVERK1LL
Unless you've driven the exact same car with a turbo, you really don't know which is more rewarding. A TDI Jetta spools almost instantly for example........
+1 You just forget it has a turbo until you remind yourself it's a diesel car that isn't a complete slug.
Unless you've driven the exact same car with a turbo, you really don't know which is more rewarding. A TDI Jetta spools almost instantly for example........
+1 You just forget it has a turbo until you remind yourself it's a diesel car that isn't a complete slug.
Kudos to Hyundai for having a 223 hp turbo 4 in the upcoming Genesis coupe. IIRC this is not their first trip to the turbo altar, either.
Originally Posted By: jldcol
Pressurizing a 2-2.5 liter 4 cyl. with 15psi of boost would act like a 4-5 liter v-8, buts that's a lot of boost for mass produced engine. More reasonable 5-7 psi boost now the 4 cyl. acts like a 6 cyl. With all the plumbing, intercooler, etc how much weight/space are you really saving?, not just going ahead and put in a v-6. The v-6 will get better low-mid range torque, be easier on oil, and get similar mpgs.Porsche? had 4 cyls up to 3 liters but need hp robbing balance shafts to keep it accectable to potential buyers. Practical common limit 2.5 liters. This should get you 185-200 hp NA. In a small light fwd car with torque steer limits do you really need more? I see little need usually for pressurizing gas engines anyway, diesels whole other thing (much better suited) .Actual displacement instead easier to get, more fun, more reliable than simulated cubic inches.Rather a moot question anyways, so here we are "mooting" it.
Also add the inconvenient failure mode. I've witnessed some turbo-diesels which are very popular nowadays for commercial use. Once broken they're self destructing to some big expenses in the moments coasting down over to the shoulder. No warning. Extreme care is needed for long term reliablity. But it all worth for the efficiency on diesel part.
On SI engines it seemingly is a displacement tax-dodger, nothing more. I tend to favor v block ( solid-state thermodynamic gadgetry) to an equivalent turbine-gismo.
Pressurizing a 2-2.5 liter 4 cyl. with 15psi of boost would act like a 4-5 liter v-8, buts that's a lot of boost for mass produced engine. More reasonable 5-7 psi boost now the 4 cyl. acts like a 6 cyl. With all the plumbing, intercooler, etc how much weight/space are you really saving?, not just going ahead and put in a v-6. The v-6 will get better low-mid range torque, be easier on oil, and get similar mpgs.Porsche? had 4 cyls up to 3 liters but need hp robbing balance shafts to keep it accectable to potential buyers. Practical common limit 2.5 liters. This should get you 185-200 hp NA. In a small light fwd car with torque steer limits do you really need more? I see little need usually for pressurizing gas engines anyway, diesels whole other thing (much better suited) .Actual displacement instead easier to get, more fun, more reliable than simulated cubic inches.Rather a moot question anyways, so here we are "mooting" it.
Also add the inconvenient failure mode. I've witnessed some turbo-diesels which are very popular nowadays for commercial use. Once broken they're self destructing to some big expenses in the moments coasting down over to the shoulder. No warning. Extreme care is needed for long term reliablity. But it all worth for the efficiency on diesel part.
On SI engines it seemingly is a displacement tax-dodger, nothing more. I tend to favor v block ( solid-state thermodynamic gadgetry) to an equivalent turbine-gismo.
Originally Posted By: ikeepmychevytoo
Also add the inconvenient failure mode. I've witnessed some turbo-diesels which are very popular nowadays for commercial use. Once broken they're self destructing to some big expenses in the moments coasting down over to the shoulder. No warning. Extreme care is needed for long term reliablity. But it all worth for the efficiency on diesel part.
The same can be said for any engine that's not properly designed.
Also add the inconvenient failure mode. I've witnessed some turbo-diesels which are very popular nowadays for commercial use. Once broken they're self destructing to some big expenses in the moments coasting down over to the shoulder. No warning. Extreme care is needed for long term reliablity. But it all worth for the efficiency on diesel part.
The same can be said for any engine that's not properly designed.
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