Lextreme II
Just call me "Lex"
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Matt,
Your FISH was shipped.
Your FISH was shipped.
The Fish V2
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The 1UZFE EGR Delete Kit is available for sale here.
I'm sorry but that boost curve is not even close to what you would achieve will a turbo or turbos sized for that peak hp. With twins i could (do) see that boost by 3500rpm.
Stout figures none the less.
Yeap, thats exactly why I will never bother with a centrifical supercharger. Only turbo or positive displacment type superchargers.
Thats the problem with centrifical superchargers, boost production is 100% RPM dependent.
As CJ says when you start bleeding air you'll quickly find you are pushing the compressor well out of the ideal efficiency islands. These wheels are also less efficient than a turbo wheel so already make more heat (it's got nothing to do with the method of drive) and intercooling can only do so much.
I just think you size the SC to suit your engine and optimize all the bits....don't try to make it something it's not? For mine, you will make much more HP from a tuneable ECU than you will trying to 'trick' the SC with a bleed valve.
All that mustang driver has done is detune his setup so he can run pump fuel...there are no boost curve benefits from what he has done at all.
Lex, I agree 100% that all off them have thier pros and cons and yeah, it is user application. But like Justen said, dont try to make something into something that it is not. Im also trying to make a point and show that that setup is not anything new for starters and just because someone is doing it on some forum doesn't meen that it works or is golden idea or what not. The idea has been around for ages and its not a great idea or I would think that Paxton, Vortech, and Procharger would have it as part of or an add on to thier kits from the factory. They have a lot more time and money to R&D something thing like this then your average enthusist and by now would have had something on the market if it were worth it and a good workable idea..
RedPhoenix
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Thank you Lex 
!
!
RedPhoenix
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Got it Lex, thanks!
spf_lexus
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Just found an interesting article on Wastegate supercharging. The application is a 5.0 Mustang that maxed his vortech at 20psi and throttled down to 15psi and netted a "super aggresive boost curve". The stang was pulling 850rw (race fuel) at 20psi and 650rw at 15psi. This beat down a whipple cobra at 19psi... the system works but I just need to start saving parts.
http://www.musclemustangfastfords.c...ercharger_wastegate_install/dyno_results.html
http://www.musclemustangfastfords.c...ercharger_wastegate_install/dyno_results.html
JustenGT8
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I'm sorry but that boost curve is not even close to what you would achieve will a turbo or turbos sized for that peak hp. With twins i could (do) see that boost by 3500rpm.
Stout figures none the less.
cjsupra90
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Yeap, thats exactly why I will never bother with a centrifical supercharger. Only turbo or positive displacment type superchargers.
Thats the problem with centrifical superchargers, boost production is 100% RPM dependent.
spf_lexus
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Yes your right CJ but your overlooking the entire point. I'm not saying its better than this or better than that, comments like that just kill threads... Why would anyone bother to keep going if everyone replies "Yeah well turbo's better" how about something positive? maybe an idea that might help out the thread? Don't have anything positive to add maybe not worth the time? . You say no boost until 3500? thats correct!!!! totally correct!!! YAY! someone knows what a centrifugal is!!! This "throttle" systems knocks that figure down into the 2000rpm range.... now why is that such a horrible attribute? I say it's the best of both worlds... and yes the stang isnt a Twin turbo i'm sure you guys cant beat that down but thats not what i wanted when i posted this. I'm not trying to see whos **** is bigger than whose.... maybe some positive criticism? maybe some ideas for future development? I guess this forum is a little scared of new ideas. Or too biased towards turbo being the only dog.... variety is king fellas.
Hey Cj.... read your reply " Thats the problem with centrifical superchargers, boost production is 100% RPM dependent". If you read a little more you might have understood the entire point of the post and that was because there's a way to customize the boost curve. Last time i checked turbocharging is based off of RPM...what do you think spools it up? Exhaust gasses take time to build with rpm so i don't know what you mean when Centi is rpm based and turbo is not... contradicting yourself. Can a non pully driven turbo benefit from this? no. Turbo specs cannot be suddenly "changed" on a whim. Boost levels yes but not impeller characteristics. The whole idea is to build boost earlier..... reading helps... :biggthumpup:
Why did you even bother to reply? it's A CENTRIFUGAL thread....
Hey Cj.... read your reply " Thats the problem with centrifical superchargers, boost production is 100% RPM dependent". If you read a little more you might have understood the entire point of the post and that was because there's a way to customize the boost curve. Last time i checked turbocharging is based off of RPM...what do you think spools it up? Exhaust gasses take time to build with rpm so i don't know what you mean when Centi is rpm based and turbo is not... contradicting yourself. Can a non pully driven turbo benefit from this? no. Turbo specs cannot be suddenly "changed" on a whim. Boost levels yes but not impeller characteristics. The whole idea is to build boost earlier..... reading helps... :biggthumpup:
Why did you even bother to reply? it's A CENTRIFUGAL thread....
spf_lexus
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I guess if your not triple-turbo'ed with full EMS and 38 ALKI injectors it's not worth posting about...
JustenGT8
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Jeez hit a nerve?
My post was just pointing out that their 'claims' were a tad optimistic and just saying you can get a centrifugal setup working as well as a turbo setup does not make it so
Just so you know where i stand...centrifugals combine the worst attributes of turbo and positive displacement SCs. Doesn't make them bad and i actually like them for a number of reasons. Mostly for their simplicity to set up, but the linear boost response does have some advantages.
On the right sort of engine.....generally larger capacity with higher comp ratio the linear nature of their boost response really does mimic just a larger capacity n/a engine. In terms of predictable throttle response and torque curves this can make them a lot easier to drive hard as a high power engine.
Now, you are obviously looking to optimise your setup as best you can but really you can only mess with the basic design so much. Claims like the posted link aren't much help if innaccurate (notice he couldn't find a turbo setup to compare ).
As for the how's, bleeding air is rarely a good idea and as discussed before you are just pushing the compressor outside it's eff peak. If it has enough headroom then not so bad but at the end of the day you will not get the same boost response as either a twinscrew or turbo setup.
Every mod is some type of compromise and all 3 boosted options have their downsides. Horses for courses
My post was just pointing out that their 'claims' were a tad optimistic and just saying you can get a centrifugal setup working as well as a turbo setup does not make it so
Just so you know where i stand...centrifugals combine the worst attributes of turbo and positive displacement SCs. Doesn't make them bad and i actually like them for a number of reasons. Mostly for their simplicity to set up, but the linear boost response does have some advantages.
On the right sort of engine.....generally larger capacity with higher comp ratio the linear nature of their boost response really does mimic just a larger capacity n/a engine. In terms of predictable throttle response and torque curves this can make them a lot easier to drive hard as a high power engine.
Now, you are obviously looking to optimise your setup as best you can but really you can only mess with the basic design so much. Claims like the posted link aren't much help if innaccurate (notice he couldn't find a turbo setup to compare
).As for the how's, bleeding air is rarely a good idea and as discussed before you are just pushing the compressor outside it's eff peak. If it has enough headroom then not so bad but at the end of the day you will not get the same boost response as either a twinscrew or turbo setup.
Every mod is some type of compromise and all 3 boosted options have their downsides. Horses for courses
spf_lexus
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The Procharger P1sc will support 30psi... now how many 30psi turbochargers can support that and still throw some reasonable boost at 2000rpm? Point being... if you have a head unit supporting those numbers running a 20-25psi pulley throttled to 10psi isn't causing any abnormal strain, I.E "Bringing the unit out of it's efficiency" and we both know heat isnt a factor at all... they just don't produce enough with a gear setup and intercooling rules out the factor all together. it's just not near a large enough heat source so why not crank up the potential? I can understand if your head unit only allows 15psi then "throttling" might not be such a great idea.... probably not worth the cost. I call it "Active Step-up". That stang has a fairly mild step-up... only shaving 5psi off and as a side note that YSI-Vortech maxes out at 20psi and spins 10,000rpm slower than the P1sc and it accounts for a 10psi higher ceiling. I am aiming for 25psi pulley with 10-12psi cutoff and I would hope for half boost at 2500. Nemesis was seeing a few psi at 2k and that was just a 10psi pulley.
Yeah I had a nerve hit but not from your input. Just don't see a reason to enter a discussion to discuss the negative when the given is it hasn't become mainstream. "Since it has the worse attributes I think I might as well trash it and buy a tricycle...." I mean... why am I even wasting my time? right?
Justin
What are your feelings on bleeding air? The vette community has commonly used this type of setup and even with the drastic pulley/boost ceiling it had it's centrifugal reliability. I still don't see how cracking the wastegate to level off would be so crucial... it's electronically controlled valve inside the wastegate will open/close to keep constant rate of boost and should not encounter any hiccups if setup correctly.
.........End of Rant
Yeah I had a nerve hit but not from your input. Just don't see a reason to enter a discussion to discuss the negative when the given is it hasn't become mainstream. "Since it has the worse attributes I think I might as well trash it and buy a tricycle...." I mean... why am I even wasting my time? right?
Justin
What are your feelings on bleeding air? The vette community has commonly used this type of setup and even with the drastic pulley/boost ceiling it had it's centrifugal reliability. I still don't see how cracking the wastegate to level off would be so crucial... it's electronically controlled valve inside the wastegate will open/close to keep constant rate of boost and should not encounter any hiccups if setup correctly.
.........End of Rant
cjsupra90
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If centrifical superchargers were so good, then why are most or your "american muscle" guys going to turbo setups? Im not trying to kill a thread by any means, Im just stating an obvious fact that has been proven time and time again.
No, turbos are not really RPM dependent. They are engine load dependent This is why two identical cars (lets say stock MKIII supra's but one being auto trans and the other being manual trans), the manual trans car will (does) build boost faster then the auto trans car and the manual trans car has a higher peek boost too. This is all because of the slippage that is inharent with the auto trans and this less load is actually being applied to the engine.
Mainstream no, but for reason.... That idea has been around for almost as long as centrifical superchargers have been. It is nothing new by anymeans. A local guy here back in the 90's who held the record for the fastest street legal fox body mustang in Florida had basically that identical setup and this is back in as early as 93 from what I recall. In 96 he converted to a custom twin turbo setup and bet his own record time by almost 3/10th's of a second at the same peek boost as the supercharger setup. So yes the idea has been around for ages and never maid it mainstream cause its an inferior setup.
No, turbos are not really RPM dependent. They are engine load dependent This is why two identical cars (lets say stock MKIII supra's but one being auto trans and the other being manual trans), the manual trans car will (does) build boost faster then the auto trans car and the manual trans car has a higher peek boost too. This is all because of the slippage that is inharent with the auto trans and this less load is actually being applied to the engine.
spf lexus said:
Mainstream no, but for reason.... That idea has been around for almost as long as centrifical superchargers have been. It is nothing new by anymeans. A local guy here back in the 90's who held the record for the fastest street legal fox body mustang in Florida had basically that identical setup and this is back in as early as 93 from what I recall. In 96 he converted to a custom twin turbo setup and bet his own record time by almost 3/10th's of a second at the same peek boost as the supercharger setup. So yes the idea has been around for ages and never maid it mainstream cause its an inferior setup.
cjsupra90
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As for the possibility of being out of the efficiency is likely and what can be even more of a problem is surging the compressor and thus destroying the wheel. Turbos suffer this issue also. Centrifical compressors whether it be a turbo or a centrifical supercharger have as surge limits and as you probably know, operating the compressor at to high of boost at low MAS flow rate (I.e. surging the compressor) will destroy it in short order.
What Im pretty sure that Justen is saying about running the compressor beyond its efficiency range is if that essentially its like running to small of a compressor for a given engine size. Remember, boost is the resistance to airflow so as soon as you open up some form of bleed off, your making the the compressor work as if you all of a sudden was on a larger engine. Look at any compressor map and lets say that your running it pullied to 15psi (2.0 pressure ratio) and lets say your MAS flow rate would have been 30lbs/min at that PR (pressure ratio) for your engine if you were to leave it with no bleed off. Now you put a bleed off to bring the pressure say 8psi (1.54 pressure ratio) the compressor still has to flow roughly that same 30lbs/min or the boost drops. So if you plotted these two points on the compressor map, you will see that operating the compressor at 8psi is far less efficient then it at 15psi. This could easily get into the 40 to 50 percent efficiency range if not worse in the higher rpm range of the engine.
As for having good boost at say 2000rpms with a turbo, brake boosting on a properly set up turbo system running 30psi can easily get 10 to 15psi at 2000 rpm's. I doubt that a centrifical supercharger will give that much at 2000 rpm's. Either which way, you still run into the issue of compressor surge.
What Im pretty sure that Justen is saying about running the compressor beyond its efficiency range is if that essentially its like running to small of a compressor for a given engine size. Remember, boost is the resistance to airflow so as soon as you open up some form of bleed off, your making the the compressor work as if you all of a sudden was on a larger engine. Look at any compressor map and lets say that your running it pullied to 15psi (2.0 pressure ratio) and lets say your MAS flow rate would have been 30lbs/min at that PR (pressure ratio) for your engine if you were to leave it with no bleed off. Now you put a bleed off to bring the pressure say 8psi (1.54 pressure ratio) the compressor still has to flow roughly that same 30lbs/min or the boost drops. So if you plotted these two points on the compressor map, you will see that operating the compressor at 8psi is far less efficient then it at 15psi. This could easily get into the 40 to 50 percent efficiency range if not worse in the higher rpm range of the engine.
As for having good boost at say 2000rpms with a turbo, brake boosting on a properly set up turbo system running 30psi can easily get 10 to 15psi at 2000 rpm's. I doubt that a centrifical supercharger will give that much at 2000 rpm's. Either which way, you still run into the issue of compressor surge.
JustenGT8
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As CJ says when you start bleeding air you'll quickly find you are pushing the compressor well out of the ideal efficiency islands. These wheels are also less efficient than a turbo wheel so already make more heat (it's got nothing to do with the method of drive) and intercooling can only do so much.
I just think you size the SC to suit your engine and optimize all the bits....don't try to make it something it's not? For mine, you will make much more HP from a tuneable ECU than you will trying to 'trick' the SC with a bleed valve.
All that mustang driver has done is detune his setup so he can run pump fuel...there are no boost curve benefits from what he has done at all.
The more interesting side is what I posted a link to in the other thread, using intake restrictor/s to control peak boost. The idea is that you don't consume the same CFM as you would when bleeding boost, which would push the efficiency way down. The lower CFM actually improves efficiency, the charger is not pushing the insane amounts of air that would only get bled off post charger with a 25psi pulley, like Justen and CJ were saying.
I'm not getting into the what's better arguement, but with just a 0.2" smaller pulley than spf i'm starting to see boost some 1500rpm earlier. It works well if set up right, but i'd seriously consider the efficiency of the blower, I wouldn't touch a 25psi pulley, maybe a 15psi capped to 10. With the sizes needed on a 1UZ the pulley would have to be tiny, the blower would be spinning at the speed of light hehe...
At the end of the day, pedantics aside, boost is boost and I know my 4WD is fun as hell now with a basic centri blower that cost less than $2k AU to set up (used blower)
I'm not getting into the what's better arguement, but with just a 0.2" smaller pulley than spf i'm starting to see boost some 1500rpm earlier. It works well if set up right, but i'd seriously consider the efficiency of the blower, I wouldn't touch a 25psi pulley, maybe a 15psi capped to 10. With the sizes needed on a 1UZ the pulley would have to be tiny, the blower would be spinning at the speed of light hehe...
At the end of the day, pedantics aside, boost is boost and I know my 4WD is fun as hell now with a basic centri blower that cost less than $2k AU to set up (used blower)
Lextreme II
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There are pros and cons in any system. It is users application.
cjsupra90
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Lex, I agree 100% that all off them have thier pros and cons and yeah, it is user application. But like Justen said, dont try to make something into something that it is not. Im also trying to make a point and show that that setup is not anything new for starters and just because someone is doing it on some forum doesn't meen that it works or is golden idea or what not. The idea has been around for ages and its not a great idea or I would think that Paxton, Vortech, and Procharger would have it as part of or an add on to thier kits from the factory. They have a lot more time and money to R&D something thing like this then your average enthusist and by now would have had something on the market if it were worth it and a good workable idea..
JustenGT8
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XR8tt
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I find an auto with turbo builds boost way sooner than a manual..
You get way quicker 60Ft times with an auto as well..
Much more consistant times..
Given that drag racing is a time thing! It takes time / load to build boost...
GOOD post !! Good to see some different tech even if it has been done before....
You get way quicker 60Ft times with an auto as well..
Much more consistant times..
Given that drag racing is a time thing! It takes time / load to build boost...
GOOD post !! Good to see some different tech even if it has been done before....
RedPhoenix
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Good info... The main reason I am doing the centrifugal is lack of tools to go roots or turbo... without dropping big bucks on getting someone else to do it.
cjsupra90
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C'mon Matt, we all know that its really because you need some advantage to beat Jake and Sean and me soon too..... LOL J/K....... Although I have a feeling that all you'll are going to need quite a bit more to keep with me cause I have a feeling that in Im gonna end up going TT soon after the engine is finally in the car....
Ok sorry, back on topic now....
Ok sorry, back on topic now....
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