Discussion
Just a basic question on having turbo(s) fitted to an engine.
My understanding is that you would be able to adjust boost levels from within the cabin, so you could wind the power increase up or down at will.
What happens if you move this to zero so the turbo is not applying any increase. I'm thinking that you will lose some of the standard performance due to the turbo mechanicals inhibiting smooth flow etc?
What I am getting at is whether you could fit turbos but essentially be able to dial in the enhancement from zero up to a suitable level of boost so you can drive around in normal conditions without using the turbo but wind it up as you want?
Silly, sensible, missing the point completely?
My understanding is that you would be able to adjust boost levels from within the cabin, so you could wind the power increase up or down at will.
What happens if you move this to zero so the turbo is not applying any increase. I'm thinking that you will lose some of the standard performance due to the turbo mechanicals inhibiting smooth flow etc?
What I am getting at is whether you could fit turbos but essentially be able to dial in the enhancement from zero up to a suitable level of boost so you can drive around in normal conditions without using the turbo but wind it up as you want?
Silly, sensible, missing the point completely?
If you dial it to zero, as you say, the engine will feel anemic. Reason being, your engine has to be suited for the turbo, including low compression ratio pistons if you plan on running high boost. Therefore, if you have low C/R and go low or no boost, it will not be a pleasant drive at all.
Most people use the in-cabin adjustments not for everyday driving but for changing between mild and wild levels of boost, where running with the latter in daily life would otherwise reduce engine life.
Most people use the in-cabin adjustments not for everyday driving but for changing between mild and wild levels of boost, where running with the latter in daily life would otherwise reduce engine life.
The turbo works on exhaust pressure so as you increase the throttle exhaust pressure builds up which increases the turbo speed which increases it's effect. Essentially it's a closed loop type effect.
So to avoid using the turbo more just stay away from the higher rev range.
I am not aware of any way to manually intervene in turbo operation like you ask but more intelligent people then me will answer that one.
The latest developments are looking at various methods, twin turbos, one electric driven etc. All would have in mind restricting/controlling etc the turbo effect and maximising it for performance and economy etc.
What's the main reason you ask you just thinking it would increase economy or wear and tear on the turbo?
So to avoid using the turbo more just stay away from the higher rev range.
I am not aware of any way to manually intervene in turbo operation like you ask but more intelligent people then me will answer that one.
The latest developments are looking at various methods, twin turbos, one electric driven etc. All would have in mind restricting/controlling etc the turbo effect and maximising it for performance and economy etc.
What's the main reason you ask you just thinking it would increase economy or wear and tear on the turbo?
DonkeyApple said:
Just a basic question on having turbo(s) fitted to an engine.
My understanding is that you would be able to adjust boost levels from within the cabin, so you could wind the power increase up or down at will.
What happens if you move this to zero so the turbo is not applying any increase. I'm thinking that you will lose some of the standard performance due to the turbo mechanicals inhibiting smooth flow etc?
What I am getting at is whether you could fit turbos but essentially be able to dial in the enhancement from zero up to a suitable level of boost so you can drive around in normal conditions without using the turbo but wind it up as you want?
Silly, sensible, missing the point completely?
I think, and without wanting to be insulting. It's a far more complex situation, this whole turbocharging thing.My understanding is that you would be able to adjust boost levels from within the cabin, so you could wind the power increase up or down at will.
What happens if you move this to zero so the turbo is not applying any increase. I'm thinking that you will lose some of the standard performance due to the turbo mechanicals inhibiting smooth flow etc?
What I am getting at is whether you could fit turbos but essentially be able to dial in the enhancement from zero up to a suitable level of boost so you can drive around in normal conditions without using the turbo but wind it up as you want?
Silly, sensible, missing the point completely?
My advice would be go off and read up on how and why turbo's work, how they are configured and controlled. Along with how an exhaust works on an IC engine.
This way you'll be able to answer your own question and actually understand the answer.
not quite how turbo's work.
a turbo is basically a pump or fan driven by exhaust gasses. the turbine speed or 'pressure' is governed by the exhaust gas pressure and waste gate to release the pressure (slow the turbo) which by passes the turbine. take my car for example the waste gates opens at 0.8 bar as a pre-set. and the boost controller allows me to have it stay closed till 1.2 bar this is all I am happy to throw at my engine. I could adjust it to take more, however my injectors aren't big enough to get the fuel in.
if you had zero as a pre-set at the waste gate the engine wouldn't run very well if at all. if you drive economically and keep out of the revs then the turbo barely spools up so like not having one. although it is working as the engine needs it to draw air through the inter-cooler.
hope this helps
VR
a turbo is basically a pump or fan driven by exhaust gasses. the turbine speed or 'pressure' is governed by the exhaust gas pressure and waste gate to release the pressure (slow the turbo) which by passes the turbine. take my car for example the waste gates opens at 0.8 bar as a pre-set. and the boost controller allows me to have it stay closed till 1.2 bar this is all I am happy to throw at my engine. I could adjust it to take more, however my injectors aren't big enough to get the fuel in.
if you had zero as a pre-set at the waste gate the engine wouldn't run very well if at all. if you drive economically and keep out of the revs then the turbo barely spools up so like not having one. although it is working as the engine needs it to draw air through the inter-cooler.
hope this helps
VR
AUDIHenry said:
If you dial it to zero, as you say, the engine will feel anemic. Reason being, your engine has to be suited for the turbo, including low compression ratio pistons if you plan on running high boost. Therefore, if you have low C/R and go low or no boost, it will not be a pleasant drive at all.
Most people use the in-cabin adjustments not for everyday driving but for changing between mild and wild levels of boost, where running with the latter in daily life would otherwise reduce engine life.
Thanks. This is what I assumed. Just having it doing nothing will result in a turd of an engine, so in essence you would set your zero level at the minimal level of boost in order to allow the engine to run the outputs that the cc etc would be capable of if NA.Most people use the in-cabin adjustments not for everyday driving but for changing between mild and wild levels of boost, where running with the latter in daily life would otherwise reduce engine life.
The reason for this thinking is that I've always preferred SC as the way to force induction. My experience of turbos is from the 80s when they either catapulted the vehicle off the road or burnt it to the ground. Obviously the world has moved on somewhat and recently more people have been telling me that sticking a turbo onto a RV8 unit is smarter than fitting a SC. I've not been able to see the advantage other than controlling the levels of boost?
DonkeyApple said:
AUDIHenry said:
If you dial it to zero, as you say, the engine will feel anemic. Reason being, your engine has to be suited for the turbo, including low compression ratio pistons if you plan on running high boost. Therefore, if you have low C/R and go low or no boost, it will not be a pleasant drive at all.
Most people use the in-cabin adjustments not for everyday driving but for changing between mild and wild levels of boost, where running with the latter in daily life would otherwise reduce engine life.
Thanks. This is what I assumed. Just having it doing nothing will result in a turd of an engine, so in essence you would set your zero level at the minimal level of boost in order to allow the engine to run the outputs that the cc etc would be capable of if NA.Most people use the in-cabin adjustments not for everyday driving but for changing between mild and wild levels of boost, where running with the latter in daily life would otherwise reduce engine life.
The reason for this thinking is that I've always preferred SC as the way to force induction. My experience of turbos is from the 80s when they either catapulted the vehicle off the road or burnt it to the ground. Obviously the world has moved on somewhat and recently more people have been telling me that sticking a turbo onto a RV8 unit is smarter than fitting a SC. I've not been able to see the advantage other than controlling the levels of boost?
I honestly think you'd be better off researching this on your own, then come back with a few more focused questions.
Some guidance:
1. Think about the exact engine setup you talking about and how it will/won't be affected.
2. How are you actually going to achieve what you are proposing? I suspect in reality your described scenario is not actually possible, or at least not feasible. So if you want a useful meaningful answer you need understand what you are really asking in order to truly understand the answer.
Depends ont he engine, some use a light pressure turbo to fill in the torque curve a bit, say for some unknown reason you could divert the exahust flow so it didnt hit the turbo and assuming the ecu understood the change and mapped fuel and ignition accordingly then it would work, not sure it would be much fun bit if it is a low boost application the compression ratio would be high enough to function like a low compression N/A engine, like they used to stick in vans and stuff. The higher the boos used in a given installation the lower the Compression ratio has to be to give the headroom for the comrpession inrease due to boost, a lot of people change twin turbo's for a "Big Single" and end up with a much faster but less pleasant to drive car, less is sometimes definitely more in terms of driving experience.
I think people talk to much about turbo's "Kicking in", I suspect that by the time we perceive a change in power delivery its already been doing some work but is just making a lot more boost, remove it and I expect it would feel worse across a wider rpm range than you expect.
Not sure how you would divert the engine gasses but it could be done, people sometimes rear mount turbos so I am sure a valve could be inserted in the gas flow, one to atmosphere or optionally to the turbo, that would rule out the turbo altogether as I suspect if its not making boost its just in the way interupting the exhaust gas flow which would hamper the currently normally N/A engine, same idea as a PAS equipped car without the pump running isnt just a manual rack, fully opening the waste gate wouldnt approximate an N/A car either.
Did see some excellent tuning done to a Nissan 200ZX a mate had in for some work, why mess with wastegate opening pressures, just weld the fecker shut
apparently it was running fine and was extremely quick.
Please rate the above post on how well my half baked thoughts compare with reality.
I think people talk to much about turbo's "Kicking in", I suspect that by the time we perceive a change in power delivery its already been doing some work but is just making a lot more boost, remove it and I expect it would feel worse across a wider rpm range than you expect.
Not sure how you would divert the engine gasses but it could be done, people sometimes rear mount turbos so I am sure a valve could be inserted in the gas flow, one to atmosphere or optionally to the turbo, that would rule out the turbo altogether as I suspect if its not making boost its just in the way interupting the exhaust gas flow which would hamper the currently normally N/A engine, same idea as a PAS equipped car without the pump running isnt just a manual rack, fully opening the waste gate wouldnt approximate an N/A car either.
Did see some excellent tuning done to a Nissan 200ZX a mate had in for some work, why mess with wastegate opening pressures, just weld the fecker shut
apparently it was running fine and was extremely quick.Please rate the above post on how well my half baked thoughts compare with reality.
300bhp/ton said:
I'm afraid AudiHenry isn't exactly correct. Their answer if very generic and makes some pretty big assumptions.
I honestly think you'd be better off researching this on your own, then come back with a few more focused questions.
Some guidance:
1. Think about the exact engine setup you talking about and how it will/won't be affected.
2. How are you actually going to achieve what you are proposing? I suspect in reality your described scenario is not actually possible, or at least not feasible. So if you want a useful meaningful answer you need understand what you are really asking in order to truly understand the answer.
I get the basics!!!!I honestly think you'd be better off researching this on your own, then come back with a few more focused questions.
Some guidance:
1. Think about the exact engine setup you talking about and how it will/won't be affected.
2. How are you actually going to achieve what you are proposing? I suspect in reality your described scenario is not actually possible, or at least not feasible. So if you want a useful meaningful answer you need understand what you are really asking in order to truly understand the answer.
Just looking for some elementary colour while I mull some things over. I'm not seeing the advantage of turbos over SC.
DonkeyApple said:
Silly, sensible, missing the point completely?
To me it's missing the point. Remember that unless you have a true exhaust bypass valve of some sort (i.e. not ALS), like the old Bristol Rotomaster "priority valve" set-up, the turbine is always spinning in the exhaust flow if the engine is running - it's a closed system. Doing something like that with a modern turbo system would be totally pointless.
You can of course control the boost pressure via a boost controller, but I could never see the point in messing once it had been set up (particularly so as unless you have switchable maps you will be running the same map just with less boost).
Match the turbo and engine carefully to your needs (i.e. don't think of it as some additional power-adder, it's part of a whole), set and forget.
Ok, my undestanding,
Turbo, scavenges energy from exhaust gas to spin a turbine, quite efficient in principal but the fact is you need to put more fuel in to go with the additional air means in practice it may not always seem it. Turbo's need to get into positive boost, i.e. greater than atmospheric pressure to be effective and depending on the exhaust gas speed and volume and the turbine size this can take varying amounts of time, hence lag.
Superchargers are driven via a belt which turns vanes to make boost, there are losses involved to drive the supercharger as is use viable engine power to drive it where the turbo is using waste gasses (over simplification but for the most part true I think), the Supercharger relies on making more power than it uses, I did read that an AMG Supercharged V8 something or other used a 100 bhp to drive the charger but made an extra 300, so a net 200 over the N/A engine.
Superchargers are driven at all time, no boost threshold to worry about, or not to the same extent so you get postive boost from lower rpm and a linear increase across the rev range.
I seem to remember that the S/C is easier to switch off, ironically kind of answeringyour original question, I think it was the Mad Max type Ford Falcon or a derivative that had an electric clutch like you get with aircon compressors that allowed the supercharger to be "turned off", i.e. the engine didnt drive it so it didnt make boost, this was switchable for the driver,I guess to save fuel but may have been just for the films, would like some further info on this.
So turbos are more effecient as a rule, especially when the engine is not under boost, the S/C has the belt losses all the time, probably why the original Cooper S was so poor on fuel and the subsequent Cooper S with a turbo was a lot better.
Turbo, scavenges energy from exhaust gas to spin a turbine, quite efficient in principal but the fact is you need to put more fuel in to go with the additional air means in practice it may not always seem it. Turbo's need to get into positive boost, i.e. greater than atmospheric pressure to be effective and depending on the exhaust gas speed and volume and the turbine size this can take varying amounts of time, hence lag.
Superchargers are driven via a belt which turns vanes to make boost, there are losses involved to drive the supercharger as is use viable engine power to drive it where the turbo is using waste gasses (over simplification but for the most part true I think), the Supercharger relies on making more power than it uses, I did read that an AMG Supercharged V8 something or other used a 100 bhp to drive the charger but made an extra 300, so a net 200 over the N/A engine.
Superchargers are driven at all time, no boost threshold to worry about, or not to the same extent so you get postive boost from lower rpm and a linear increase across the rev range.
I seem to remember that the S/C is easier to switch off, ironically kind of answeringyour original question, I think it was the Mad Max type Ford Falcon or a derivative that had an electric clutch like you get with aircon compressors that allowed the supercharger to be "turned off", i.e. the engine didnt drive it so it didnt make boost, this was switchable for the driver,I guess to save fuel but may have been just for the films, would like some further info on this.
So turbos are more effecient as a rule, especially when the engine is not under boost, the S/C has the belt losses all the time, probably why the original Cooper S was so poor on fuel and the subsequent Cooper S with a turbo was a lot better.
Greg_D said:
if you ran an adjustable wastegate on its minimum boost and an electronic boost control unit, you could run very low boost (say 3-4psi) or higher boost (up to a sensible max) at the press of a button
without all the confusing guff being spouted above, the quick answer is yes...hth
The answer is yes, but it's pointless.without all the confusing guff being spouted above, the quick answer is yes...hth
Trommel said:
DonkeyApple said:
Silly, sensible, missing the point completely?
To me it's missing the point. Remember that unless you have a true exhaust bypass valve of some sort (i.e. not ALS), like the old Bristol Rotomaster "priority valve" set-up, the turbine is always spinning in the exhaust flow if the engine is running - it's a closed system. Doing something like that with a modern turbo system would be totally pointless.
You can of course control the boost pressure via a boost controller, but I could never see the point in messing once it had been set up (particularly so as unless you have switchable maps you will be running the same map just with less boost).
Match the turbo and engine carefully to your needs (i.e. don't think of it as some additional power-adder, it's part of a whole), set and forget.
I'd be running something like the Syvecs system so mapping for various set ups isn't an issue. This is what got me thinking about this in the first instance.
I'm still undecided on the engine option for the Rangie you see.
a NA RV8 isn't going to achieve the targets regardless of cc. JE's SC AJ-V8 fits the bill perfectly but I've reigned in the costs on this project and so sticking with a Rover lump is likely to be a less expensive route.
SC options are readily available and will definitely give the required output but recent comments re turbos made we want to look at this side as well. By running an intelligent management system we can tie in maps to different boost settings and having variable boost has its merits in some regards. Why put excess pressure on the running gear when you don't need to. Although the throttle pedal gives you reasonable control
I'm not looking to bypass a turbo, but rather turn it down to the point that it has no dicernable impact, either positive or negative.
Trommel said:
Greg_D said:
if you ran an adjustable wastegate on its minimum boost and an electronic boost control unit, you could run very low boost (say 3-4psi) or higher boost (up to a sensible max) at the press of a button
without all the confusing guff being spouted above, the quick answer is yes...hth
The answer is yes, but it's pointless.without all the confusing guff being spouted above, the quick answer is yes...hth
DonkeyApple said:
I get the basics!!!!
Just looking for some elementary colour while I mull some things over. I'm not seeing the advantage of turbos over SC.
The basic advantage of turbocharge over supercharging is efficiency.Just looking for some elementary colour while I mull some things over. I'm not seeing the advantage of turbos over SC.
i.e. if you want the most power or economy then the turbo is likely to be the best bet.
Control over the level of boost produced can also be found with centrifugal superchargers.
You will note that turbos are more popular in the OEM world than supercharger. They see the efficiency advantage and go with that one. In the aftermarket world LOTS of other considerations come into play hence both turbochargers and superchargers are popular.
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