take out the supercharger and replace with turbo (more)
- Thread starter mers1083
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You could benefit either way. A turbo has its pros & cons. Turbo lag is the biggest con. But lots of potential for lots of horsepower is the best part.
The Eaton supercharger you have on there is a roots-type supercharger which provides a good boost at the low-end while a turbo would not.
And you could leave the supercharger and add a turbo. That way, you'd still have that low-end boost that the supercharger provides as well as the monster power potential you can get from a turbo. But with more power, comes more risk. Make sure that the engine is going to be able to handle the extra power. And you need to find a shop with a lot of experience with these kinds of upgrades. It can be done, and it can work great, but it's expensive and it's risky.
You might be better off with just upgrading your supercharger with a good Whipple supercharger (twin-screw). I think that's what the Kenne Bell kit comes with.
The Eaton supercharger you have on there is a roots-type supercharger which provides a good boost at the low-end while a turbo would not.
And you could leave the supercharger and add a turbo. That way, you'd still have that low-end boost that the supercharger provides as well as the monster power potential you can get from a turbo. But with more power, comes more risk. Make sure that the engine is going to be able to handle the extra power. And you need to find a shop with a lot of experience with these kinds of upgrades. It can be done, and it can work great, but it's expensive and it's risky.
You might be better off with just upgrading your supercharger with a good Whipple supercharger (twin-screw). I think that's what the Kenne Bell kit comes with.
Vic_Ferrari
New Member
SWortham said:
Leaving the s/c and adding a turbo would be just plain silly.
A twin turbo conversion would kick ass but is expensive.
Cheapest way is to get a bell or whipple.
A twin turbo would have minimal lag, HUGE power and drivability (provided the tune was correct) and much better fuel mileage than the blower. The blower provides more "right now" boost but the TT cars are still more fun as they spool quickly and carry boost much higher.
Tom Evinrudes cobra is making near 700 at the tire (at half the boost it requires to make this power with a blower) and gets 25-28 MPG highway =o)
There is no question that turbocharging is more efficient than supercharging.
mers1083 said:what do you guys think of taking out the supercharger and putting in a big turbo?? what will the performance be like? will i gain or lose performance? or how about leaving the supercharger in and adding a turbo if thats possible?
WHY?
Turbos and S/Cs both have pros and cons but for me, I can't justify a turbo for the street with the cost and most turbo companies not being very solid. No, it is not a good idea to have both (what for?), plus the tuning nightmare. What's wrong with your S/C?
The twin-turbo route is not really optimal either. With a twin-turbo setup, there is more pressure loss compared to a larger single-turbo setup. And even when you're using two small turbo's, you still don't get boost until around 2,500 or 3,000 rpm's. And the supercharger boosts from idle & up.
If you're going to add a turbo, you might as well leave your supercharger on there. They don't interfere with eachother. It's been done before, and it's a good way to make some serious power.
If you're going to add a turbo, you might as well leave your supercharger on there. They don't interfere with eachother. It's been done before, and it's a good way to make some serious power.
SWortham said:
Exsqeese me?
For someone who has experience, you sure don't seem as though you know what you are talking about.
A proper setup TT will see boost damn near off idle. I would like to know what supercharger you are talking about other then a a twin screw or roots thats builds boost off idle.
Show me the DOHC that you have built with both a supercharger on there and a TT? As far as not interferring with each other you are out of your mind. It would be a tuning nightmare.
I don't have much actual experience with this. I've hung around a little when my friend has installed a custom single turbo on his Eclipse. And just picked up theory here and there.
But I do know this... roots-type and screw-type superchargers will boost off of idle.
http://www.rcspoolers.com/Root_vs_Cent_vs_Screw.htm
And typically, when it comes to the turbo systems I have read about and when riding in my friend's turbo'd Eclipse, they will not reach positive boost pressures until somewhere around 2,200 - 4,000 rpm. The point in which you start making boost varies depending on a wide variety of factors -- the size of the turbo, twin-turbo or single, efficiency, flow characteristics, etc. But when riding in my friend's car, you can watch as the boost gauge rises during load. But even at WOT, the gauge will continue to read vaccuum until around 3,200 rpm at which point it passes 0 and then quickly rises up to 10 psi and you kinda lose track of the numbers at the point... lol.
And it might be that a TT setup will achieve boost at a lower rpm than I thought... do you know of any project car w/ a V8 and twin-turbo I can take a look at?
EDIT -- and I don't see how it would be a tuning nightmare. It would be treated the same as a turbo kit would be. You need a setup which will read boost pressures and adjust fuel accordingly... when you have that in place, it doesn't matter if the boost comes from a supercharger or a turbo. Even a pure turbo setup cannot rely solely on throttle position because you would screw up your A/F ratios at idle. So it's a given that adding a turbo will complicate fuel delivery.
Also here's a few cars with both a supercharger and a turbo:
Nissan Micra
http://www.cardomain.com/memberpage/497862/3
Hyundai Accent
http://www.sromagazine.com/boards/showthread.php?t=79033&page=1
Lancia Delta S4
"This engine had a capacity of 1759cc, used an alloy cylinder head and cylinder block, had four valves per cylinder, twin overhead camshafts, fuel injection (with two injectors per cylinder) and most interestingly both a turbocharger and a supercharger with twin air-to-air intercoolers. A power of 480bhp was produced at 8400rpm."
http://www.carsfromitaly.com/lancia/index.html
But I do know this... roots-type and screw-type superchargers will boost off of idle.
http://www.rcspoolers.com/Root_vs_Cent_vs_Screw.htm
And typically, when it comes to the turbo systems I have read about and when riding in my friend's turbo'd Eclipse, they will not reach positive boost pressures until somewhere around 2,200 - 4,000 rpm. The point in which you start making boost varies depending on a wide variety of factors -- the size of the turbo, twin-turbo or single, efficiency, flow characteristics, etc. But when riding in my friend's car, you can watch as the boost gauge rises during load. But even at WOT, the gauge will continue to read vaccuum until around 3,200 rpm at which point it passes 0 and then quickly rises up to 10 psi and you kinda lose track of the numbers at the point... lol.
And it might be that a TT setup will achieve boost at a lower rpm than I thought... do you know of any project car w/ a V8 and twin-turbo I can take a look at?
EDIT -- and I don't see how it would be a tuning nightmare. It would be treated the same as a turbo kit would be. You need a setup which will read boost pressures and adjust fuel accordingly... when you have that in place, it doesn't matter if the boost comes from a supercharger or a turbo. Even a pure turbo setup cannot rely solely on throttle position because you would screw up your A/F ratios at idle. So it's a given that adding a turbo will complicate fuel delivery.
Also here's a few cars with both a supercharger and a turbo:
Nissan Micra
http://www.cardomain.com/memberpage/497862/3
Hyundai Accent
http://www.sromagazine.com/boards/showthread.php?t=79033&page=1
Lancia Delta S4
"This engine had a capacity of 1759cc, used an alloy cylinder head and cylinder block, had four valves per cylinder, twin overhead camshafts, fuel injection (with two injectors per cylinder) and most interestingly both a turbocharger and a supercharger with twin air-to-air intercoolers. A power of 480bhp was produced at 8400rpm."
http://www.carsfromitaly.com/lancia/index.html
I don't know much about turbo's but I do know this:
1. The bottom end would last .0001 seconds with a blower AND a turbo on a stock bottom end. I know of no one that has ever done this, and can't think of one reason why they would. Edit: I just saw the links above...those are not Mustangs so they have no relevance in this discussion. Two different animals.
2. There are many TT V8 cars out there...but not many Mustangs. Most Mustangs I know of are single turbo. Detroit Speedworks in Michigan had some of the baddest TT Corvette's and Camaro's I've ever seen. Phil was running high 10's in a TT Vette with a slipping clutch. TT's are bad ass and see boost throughout the entire RPM band.
3. If your friend's car isn't seeing boost, but staying in vaccuum, untill 2200-4000 RPM's something isn't set up right. I drive an 04 Saab turbo as my daily driver...when I just give it a little gas I see boost...at any RPM. As I said, I don't know much about turbo's but I'm assuming this has to do with the tune and also the blow off valve. Not sure. On the Cobra, as soon as I go WOT I start seeing boost...but that's the nature of a centrifical blower. You see boost only at WOT and it biulds with RPM.
Now, back to the original question.....
1. Do not do both a supercharger and a turbo. I don't even think it's possible, and unless you have crazy cash to burn, just doesn't make sense.
2. Replacing the blower with a turbo would be cool...again if you can afford it. Not many people go with the turbo option, so cost is still high and finding a tuner to tune it right might be a little more difficult. A lot of fabrication has to be done typically as well.
3. You will see more performance out of a turbo than a blower. You will see a LOT more torque. Again, it costs money.
By all means, if you have the finances to support a turbo go for it. You would be very happy. But a stock bottom end wouldn't hold up long at all. So start there. Biuld a stong motor, then either up the boost of the blower or start over and do a turbo.
1. The bottom end would last .0001 seconds with a blower AND a turbo on a stock bottom end. I know of no one that has ever done this, and can't think of one reason why they would. Edit: I just saw the links above...those are not Mustangs so they have no relevance in this discussion. Two different animals.
2. There are many TT V8 cars out there...but not many Mustangs. Most Mustangs I know of are single turbo. Detroit Speedworks in Michigan had some of the baddest TT Corvette's and Camaro's I've ever seen. Phil was running high 10's in a TT Vette with a slipping clutch. TT's are bad ass and see boost throughout the entire RPM band.
3. If your friend's car isn't seeing boost, but staying in vaccuum, untill 2200-4000 RPM's something isn't set up right. I drive an 04 Saab turbo as my daily driver...when I just give it a little gas I see boost...at any RPM. As I said, I don't know much about turbo's but I'm assuming this has to do with the tune and also the blow off valve. Not sure. On the Cobra, as soon as I go WOT I start seeing boost...but that's the nature of a centrifical blower. You see boost only at WOT and it biulds with RPM.
Now, back to the original question.....
1. Do not do both a supercharger and a turbo. I don't even think it's possible, and unless you have crazy cash to burn, just doesn't make sense.
2. Replacing the blower with a turbo would be cool...again if you can afford it. Not many people go with the turbo option, so cost is still high and finding a tuner to tune it right might be a little more difficult. A lot of fabrication has to be done typically as well.
3. You will see more performance out of a turbo than a blower. You will see a LOT more torque. Again, it costs money.
By all means, if you have the finances to support a turbo go for it. You would be very happy. But a stock bottom end wouldn't hold up long at all. So start there. Biuld a stong motor, then either up the boost of the blower or start over and do a turbo.
"1. The bottom end would last .0001 seconds with a blower AND a turbo on a stock bottom end. I know of no one that has ever done this, and can't think of one reason why they would. Edit: I just saw the links above...those are not Mustangs so they have no relevance in this discussion. Two different animals."
I don't really want to try to convince anyone that using a supercharger along with a turbocharger is the absolute best way to go. Because it would be extreme, and it would be expensive. You would probably have to rebuild the motor at its weak points just as my friend did with his Eclipse. He has built his little 2.0L 4-cylinder to support 450whp. He's upgrading the turbo & fuel system one step at a time to reach his goal. And with a rebuilt 4.6L, there is A LOT more potential than that.
As for the option of single-turbo vs twin-turbo... you can look at how most Supra turbo kits cranking out 700 - 1,000 rwhp are single turbo's. They do this for the efficiency purposes.
All I'm saying is take this info for what it's worth. I'm not saying that this is what I would do... because I couldn't afford it. Then again, I can't even afford a SVT Cobra to begin with.
I don't really want to try to convince anyone that using a supercharger along with a turbocharger is the absolute best way to go. Because it would be extreme, and it would be expensive. You would probably have to rebuild the motor at its weak points just as my friend did with his Eclipse. He has built his little 2.0L 4-cylinder to support 450whp. He's upgrading the turbo & fuel system one step at a time to reach his goal. And with a rebuilt 4.6L, there is A LOT more potential than that.
As for the option of single-turbo vs twin-turbo... you can look at how most Supra turbo kits cranking out 700 - 1,000 rwhp are single turbo's. They do this for the efficiency purposes.
All I'm saying is take this info for what it's worth. I'm not saying that this is what I would do... because I couldn't afford it. Then again, I can't even afford a SVT Cobra to begin with.
I just thought of something. Because of the nature of a roots-type supercharger you'd have to bolt the turbo on so that air flows through the turbo before the supercharger. And that wouldn't work since the supercharger is driven directly by the engine and isn't free to rev up.
The air would have to go through a centrifugal supercharger, then the turbo, and then into the engine. That's the only way I can think of that would work. So you'd be supercharging your turbo, allowing it to boost sooner and more responsively. With that combination you don't get that boost at idle from the centrifugal supercharger, but it's still better than just a turbo by itself.
So that means that the answer is no. Since you have a roots-type supercharger, you cannot leave it and just add a turbo. You'd have to replace it with a centrifugal supercharger. Hmm... now that's a very interesting setup.
The air would have to go through a centrifugal supercharger, then the turbo, and then into the engine. That's the only way I can think of that would work. So you'd be supercharging your turbo, allowing it to boost sooner and more responsively. With that combination you don't get that boost at idle from the centrifugal supercharger, but it's still better than just a turbo by itself.
So that means that the answer is no. Since you have a roots-type supercharger, you cannot leave it and just add a turbo. You'd have to replace it with a centrifugal supercharger. Hmm... now that's a very interesting setup.
I think that Richard Holdener, in MM&FF, has discussed using both systems on a car before. It certainly can be done.
As for wrecking your bottom end, how? To me, 10# is 10#. As the RPM increases and the turbo spools up, it would gradually overtake the blower, providing the higher boost. You get the best of both worlds, the low to mid-range power from the Roots and the mid to high RPM power from the turbo. Think of it as a door being held closed by air pressure. As the air pressure decreases on one side and increases on the other, the door gradually swings the other way until it is fully open.
I can't see where this is too much different than adding nitrous to our '03 Cobras.
As for wrecking your bottom end, how? To me, 10# is 10#. As the RPM increases and the turbo spools up, it would gradually overtake the blower, providing the higher boost. You get the best of both worlds, the low to mid-range power from the Roots and the mid to high RPM power from the turbo. Think of it as a door being held closed by air pressure. As the air pressure decreases on one side and increases on the other, the door gradually swings the other way until it is fully open.
I can't see where this is too much different than adding nitrous to our '03 Cobras.
I must admit there are a lot of unknowns with doing this.
CobraCruiser, I don't understand what you mean. I don't know how you could get this to work with the stock supercharger. How would you route the turbo piping so that the turbo still aids in providing boost? It seems to me that you'd have to run it directly into the supercharger inlet. And I don't think there's any way to make that work when you can barely make the air rush through a supercharger faster than the supercharger can pull on its own...
And I just realized that even with my idea, when the exhaust gasses push hard enough to spool up the turbo to the point where it's trying to pull in air faster than the supercharger can feed it air, then you've just reached your limit. I don't know how you'd get around that.
At this point, it would really be helpful if somebody with a supercharger and a turbo installed on their Mustang could chime in and explain this better.
CobraCruiser, I don't understand what you mean. I don't know how you could get this to work with the stock supercharger. How would you route the turbo piping so that the turbo still aids in providing boost? It seems to me that you'd have to run it directly into the supercharger inlet. And I don't think there's any way to make that work when you can barely make the air rush through a supercharger faster than the supercharger can pull on its own...
And I just realized that even with my idea, when the exhaust gasses push hard enough to spool up the turbo to the point where it's trying to pull in air faster than the supercharger can feed it air, then you've just reached your limit. I don't know how you'd get around that.
At this point, it would really be helpful if somebody with a supercharger and a turbo installed on their Mustang could chime in and explain this better.
I really don't know how it could be done. I was hoping to see it in MM&FF. Holdener is quite the authority on the subject and it would be interesting to hear his opinion.
My intent with my post was just to point out that the boost wouldn't be equal to the power adders combined, but to which one was putting out the most boost at a given RPM, hence the door analogy.
My intent with my post was just to point out that the boost wouldn't be equal to the power adders combined, but to which one was putting out the most boost at a given RPM, hence the door analogy.
I started a thread about this over at ElantraXD.com. I just offered my idea of using a centrifugal supercharger and turbo combo. And the Forced Induction moderator, Elantra2.001 responded:
"I have seen it done. Once the turbo has spooled, or most often a certain rpm is reached, there is a valve that opens up to bypass the supercharger. One strange effect some have noticed with this effect is that since the supercharger spins the compressor faster than it could be spun on its own by the turbine, the turbine is spun faster also which seems to suck air out of the exhaust manifold and head. It only happens for a short while, but may explain why these systems dont seem to have the low rpm parasitic affect of a normal supercharger."
So from what he described, the turbo and supercharger really seem to compliment eachother. And it makes better sense to me now. It may be really expensive to do, but I think the results would be incredible.
"I have seen it done. Once the turbo has spooled, or most often a certain rpm is reached, there is a valve that opens up to bypass the supercharger. One strange effect some have noticed with this effect is that since the supercharger spins the compressor faster than it could be spun on its own by the turbine, the turbine is spun faster also which seems to suck air out of the exhaust manifold and head. It only happens for a short while, but may explain why these systems dont seem to have the low rpm parasitic affect of a normal supercharger."
So from what he described, the turbo and supercharger really seem to compliment eachother. And it makes better sense to me now. It may be really expensive to do, but I think the results would be incredible.
