Why Would Anybody Get Get The GReddy TT Over The ATI SC ?
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From: NYC
<I lost you here. Most of the boost at high RPM = Linear. Exponential would mean as the RPM doubles, from say 1500 to 3000, boost quadruples. That is the pattern of most turbos, isn't it? Correct me if I'm wrong. I just don't think the ATI can have a linear relationship with RPM AND have an exponential boost pattern.>
Sure they can - both the ATI and any turbo use centrifugal compressors, which build boost exponentially to shaft speed. Turbos are driven by exhaust, so given enough exhaust and a properly sized turbo, they zing right up to their max as fast as they can. Usually with a good system they hit max speed somewhere in the lower rpm range (say...3000 rpm). That spool up time is known as turbo lag. Centrifugal superchargers do the same thing, except the shaft speed is proportional to engine RPM. If you want to limit your ATI supercharger to 7 psi, you're going to want that centrifugal compressor to be geared to spin fast enough to produce 7 psi at *redline*. So for instance say you're looking at a boost gauge in your 350 with ATI at redline. You'll see 7 psi. You let your rpms drop in a linear fashion, the ATI slows down linearly, but since it has a centrifugal type compressor, your boost will drop alot quicker. Hmm, dunno if this is clear, let me 'make up' some numbers to illustrate some boost patterns:
RPM turbo psi ati psi roots psi
1000-----0--------------0----------6
2000-----4--------------.5---------7
3000-----6--------------1----------7
4000-----7--------------2----------7
5000-----7--------------4----------7
6000-----7--------------7----------7
They all have tradeoffs.
ATI - Simple setup and install, easy to place in cramped engine compartments, efficient compressor can make alot of peak power, BUT peak power comes in late, no low end power.
Turbo - Efficient compressor makes alot of peak power, no parasitic drag, more power earlier on than ATI, BUT produces alot of under-hood heat, much more complicated install and management system. More potential to blow up your motor.
Roots Supercharger (or other positive displacement type) - Produces power RIGHT NOW, BUT harder to fit (many sit on top of the engine, no room), and not nearly as efficient of a compressor - i.e. say 7 psi is the max you can run on a turbo or ATI supercharged 350 before detonation, well a roots/screw type would probably heat the intake charge too much at 7 psi and blow the engine - would have to run it at maybe 5 psi, producing less power. Also the hotter intake charge means it produces less power at 5psi than a turbo/ATI at 5psi.
Anyway the 'exponential' boost curve of turbo's and ATI type superchargers is just the nature of the centrifugal compressor. That's just the way it is.
Hope this makes more sense,
Brad
Sure they can - both the ATI and any turbo use centrifugal compressors, which build boost exponentially to shaft speed. Turbos are driven by exhaust, so given enough exhaust and a properly sized turbo, they zing right up to their max as fast as they can. Usually with a good system they hit max speed somewhere in the lower rpm range (say...3000 rpm). That spool up time is known as turbo lag. Centrifugal superchargers do the same thing, except the shaft speed is proportional to engine RPM. If you want to limit your ATI supercharger to 7 psi, you're going to want that centrifugal compressor to be geared to spin fast enough to produce 7 psi at *redline*. So for instance say you're looking at a boost gauge in your 350 with ATI at redline. You'll see 7 psi. You let your rpms drop in a linear fashion, the ATI slows down linearly, but since it has a centrifugal type compressor, your boost will drop alot quicker. Hmm, dunno if this is clear, let me 'make up' some numbers to illustrate some boost patterns:
RPM turbo psi ati psi roots psi
1000-----0--------------0----------6
2000-----4--------------.5---------7
3000-----6--------------1----------7
4000-----7--------------2----------7
5000-----7--------------4----------7
6000-----7--------------7----------7
They all have tradeoffs.
ATI - Simple setup and install, easy to place in cramped engine compartments, efficient compressor can make alot of peak power, BUT peak power comes in late, no low end power.
Turbo - Efficient compressor makes alot of peak power, no parasitic drag, more power earlier on than ATI, BUT produces alot of under-hood heat, much more complicated install and management system. More potential to blow up your motor.
Roots Supercharger (or other positive displacement type) - Produces power RIGHT NOW, BUT harder to fit (many sit on top of the engine, no room), and not nearly as efficient of a compressor - i.e. say 7 psi is the max you can run on a turbo or ATI supercharged 350 before detonation, well a roots/screw type would probably heat the intake charge too much at 7 psi and blow the engine - would have to run it at maybe 5 psi, producing less power. Also the hotter intake charge means it produces less power at 5psi than a turbo/ATI at 5psi.
Anyway the 'exponential' boost curve of turbo's and ATI type superchargers is just the nature of the centrifugal compressor. That's just the way it is.
Hope this makes more sense,
Brad
Last edited by brad1972; Oct 16, 2003 at 01:51 PM.
Re: Are you kidding me?
Just for Clarification notices,
the US spec PE R&D has NOT blown ANY engines. i believe whosdady is referring to the Top SEcret Turbo kit in which they blew ~3 VQs in japan.
again the Power Enterprise Twin turbo kit has NOT blown any engines during our R&D processes and we hope to stay that way..
thanks
the US spec PE R&D has NOT blown ANY engines. i believe whosdady is referring to the Top SEcret Turbo kit in which they blew ~3 VQs in japan.
again the Power Enterprise Twin turbo kit has NOT blown any engines during our R&D processes and we hope to stay that way..
thanks
Originally posted by whosdady
[Then I proceeded to explain that the PE kit has blown engines. [/B]
[Then I proceeded to explain that the PE kit has blown engines. [/B]
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From: OC
Not to sounds like an @$$ or anything but I dont think I would want a turbo that hasnt blown an engine...
Cheston you know i agree with most of your threads but, I want someone that has blown an engine, I want someone who has tested and played around so much that they have made mistakes... I think it shows that something wasnt just put together to meet a demand... (not sayin that this is what PE is doin) but I'm sure that they want to get a kit out as soon as possible... anyways I want someone who has thought everytihng out and racked their brains on how to make it better... also this would give us some indication as to what the limits of the internals (if it is internal failure and nothing else) are on that system...
-non
not complainin about any systems just sayin it would inspire more trust in my eyes and I dont think that you will have as many problems with the first batch of kits sold to us... as some kits are running into problems
Cheston you know i agree with most of your threads but, I want someone that has blown an engine, I want someone who has tested and played around so much that they have made mistakes... I think it shows that something wasnt just put together to meet a demand... (not sayin that this is what PE is doin) but I'm sure that they want to get a kit out as soon as possible... anyways I want someone who has thought everytihng out and racked their brains on how to make it better... also this would give us some indication as to what the limits of the internals (if it is internal failure and nothing else) are on that system...
-non
not complainin about any systems just sayin it would inspire more trust in my eyes and I dont think that you will have as many problems with the first batch of kits sold to us... as some kits are running into problems
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From: Central Jersey
Blowing an engine isn't always a sign of true expertise. It's a sign of hubris, which is not always a good thing. PE shouldn't be faulted for not ruining an engine, just as Top Secret shouldn't be faulted for demolishing 3. It's two different paths to a similar goal. Little bit of string theory.
Last edited by 350zdanny; Oct 16, 2003 at 03:47 PM.
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From: OC
Re: Are you kidding me?
[i]
Please, we are talking about a Z that will hit 500-550rwhp, as OCG35 mentioned, not 370 rwhp with two baby turbos. Give me some examples of small turbos that can hit this number and turn on before 3.8K rpm. Then tell me that they hit full boost before 4.2Krpm. Its not going to happen, especially with this car. I have had two small turbos (modified stock supra twins) produced 410rwhp at 4.5Krpm and the turbo came on at 3.2rpm. I have had one medium sized turbo SP63, produced 515rwhp at 4.8Krpm and started at 4.0Krpm. I have a s/c (ATI procharger) producing 368 rwhp at 6.8Krpm. Granted it doesn't put out nearly the amount of boost I am used to, but it does boost instantaneously. That has to count for something. In a street race that may be the difference between a win or a loss. I have given you my opinion after personal experience, having had all three types of FI. What have you had and how do you base your opinions? [/B]
Please, we are talking about a Z that will hit 500-550rwhp, as OCG35 mentioned, not 370 rwhp with two baby turbos. Give me some examples of small turbos that can hit this number and turn on before 3.8K rpm. Then tell me that they hit full boost before 4.2Krpm. Its not going to happen, especially with this car. I have had two small turbos (modified stock supra twins) produced 410rwhp at 4.5Krpm and the turbo came on at 3.2rpm. I have had one medium sized turbo SP63, produced 515rwhp at 4.8Krpm and started at 4.0Krpm. I have a s/c (ATI procharger) producing 368 rwhp at 6.8Krpm. Granted it doesn't put out nearly the amount of boost I am used to, but it does boost instantaneously. That has to count for something. In a street race that may be the difference between a win or a loss. I have given you my opinion after personal experience, having had all three types of FI. What have you had and how do you base your opinions? [/B]
now as for your instantaneous boost your a little off man, i dont know its just funny it has already been said that the turbo rpm range at max boost is wider, its a given, now your SC is goin to make a lot less power mid range although it does have the advantage, if only for a split second, down low... but if you really want to talk races why not race me... I've got much less HP then you do... well at least I would think with the procharger and all... I would like to demonstrate my point with me being underpowered you should literally walk away with a victory by far(with your logic) but being as my power curve is a little different should be worth watching
Re: Re: Are you kidding me?
Originally posted by nonmature
ok first off you need to calm down and... look at all the parts out now for the Z it has been proven to put down over 300 with only NA mods... also none of these mods(or at least most) will need to be changed when you go with a turbo or SC now you are going to sit there and tell me that 2 18g turbos will not be able to make 550 rwhp on this engine???? come on also I dont think these are going to spool that slowly either I would expect VERY GOOD response with that kits boost and it is upgradeable to well over what you have stated... and as I have stated before I dont want to trust somebody who has blown an engine in development... I want someone who has found all 99,000 ways that something doesnt work...
now as for your instantaneous boost your a little off man, i dont know its just funny it has already been said that the turbo rpm range at max boost is wider, its a given, now your SC is goin to make a lot less power mid range although it does have the advantage, if only for a split second, down low... but if you really want to talk races why not race me... I've got much less HP then you do... well at least I would think with the procharger and all... I would like to demonstrate my point with me being underpowered you should literally walk away with a victory by far(with your logic) but being as my power curve is a little different should be worth watching
ok first off you need to calm down and... look at all the parts out now for the Z it has been proven to put down over 300 with only NA mods... also none of these mods(or at least most) will need to be changed when you go with a turbo or SC now you are going to sit there and tell me that 2 18g turbos will not be able to make 550 rwhp on this engine???? come on also I dont think these are going to spool that slowly either I would expect VERY GOOD response with that kits boost and it is upgradeable to well over what you have stated... and as I have stated before I dont want to trust somebody who has blown an engine in development... I want someone who has found all 99,000 ways that something doesnt work...
now as for your instantaneous boost your a little off man, i dont know its just funny it has already been said that the turbo rpm range at max boost is wider, its a given, now your SC is goin to make a lot less power mid range although it does have the advantage, if only for a split second, down low... but if you really want to talk races why not race me... I've got much less HP then you do... well at least I would think with the procharger and all... I would like to demonstrate my point with me being underpowered you should literally walk away with a victory by far(with your logic) but being as my power curve is a little different should be worth watching
the TDO5-18g is good for 420rwhp per turbo. thats 840 to the wheels. I think does turbos are good enough for any application. More then what the block can do. so, like you said I wouldn't call them small. As for your race I have seen the ati walk a z06 vette, so even if he missed a gear he would blow the doors off your car unless you get a turbo kit.
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From: OC
Re: Re: Re: Are you kidding me?
Originally posted by spazpilot
the TDO5-18g is good for 420rwhp per turbo. thats 840 to the wheels. I think does turbos are good enough for any application. More then what the block can do. so, like you said I wouldn't call them small. As for your race I have seen the ati walk a z06 vette, so even if he missed a gear he would blow the doors off your car unless you get a turbo kit.
the TDO5-18g is good for 420rwhp per turbo. thats 840 to the wheels. I think does turbos are good enough for any application. More then what the block can do. so, like you said I wouldn't call them small. As for your race I have seen the ati walk a z06 vette, so even if he missed a gear he would blow the doors off your car unless you get a turbo kit.
and just to say this for the debate... I know all of us here are all talkin about Power this and Power that but a lot of the time you will get beat by an exceptional driver not the better car... I would say if you plan on autocrossing or drag racing (or any kind of racing) your Z go take a performance driving course... one of the best investmants you can make is improving your own skillz... will this help you when bobby and dick pull up next to you in a zo6 when your comin home from work... probably not but it will help you when your actually racing when it matters... I know guys who have raced all their lives and I bet they could beat some of the people driving the ATI SC'd Z's on an autocross course with a stock Z
-non
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From: British Columbia, Canada
I'm probably going to go with a SC since I don't have an extra 5k CDN to burn. I do like the idea of a SC that can be deactivated if need be. Anyone ever watch the movie " Madmax " with Mel Gibson?? Well the car he had in that movie had a blower which he activated by a push button. I'm thinking since gas was such a huge cost in the movie it was more of a gas saver than anything but it did look cool. The only reason why I don't see this being built is reliability but it would be a nice feature to come with a SC.
Yielar
Yielar
i can see where you are coming from non- about 'not blowing' a motor to see the phyiscal limitations...but then you have to weigh in the risks involved. everything that hasnt been tried before has an inherient risk (think ECU devlopment, cam research. etc)
that is where engineering analysis and projections lead to sound engineering assessments and goals. no point in Technos blowing my motor for the sake of just doing so to find that ultimate number... we know the phyiscal limits of the engine. some ppl/companies choose not to believe what is widely known and approach the peformance envelopes cautiously... Top Secret attempted from the top down approach, which typically isnt the wisest thing to try first hand. but hey... what ever float's their boat... one of the main reasons why i have a spare VQ35, for the sole chance that Murphy comes into play so i dont have to call foul and try to find another motor... dont get me wrong , this kit was no way a 'slapped together' kit to meet a demand...its undergone severe hot weather testing and load tests while it was a prototype.. and u know and i know, for the projects that i do... its gotta be tested and done right...
probably one of the main reasons greddy's kit isnt out yet.. they're just probably double checking some figures... why rush?
that is where engineering analysis and projections lead to sound engineering assessments and goals. no point in Technos blowing my motor for the sake of just doing so to find that ultimate number... we know the phyiscal limits of the engine. some ppl/companies choose not to believe what is widely known and approach the peformance envelopes cautiously... Top Secret attempted from the top down approach, which typically isnt the wisest thing to try first hand. but hey... what ever float's their boat... one of the main reasons why i have a spare VQ35, for the sole chance that Murphy comes into play so i dont have to call foul and try to find another motor... dont get me wrong , this kit was no way a 'slapped together' kit to meet a demand...its undergone severe hot weather testing and load tests while it was a prototype.. and u know and i know, for the projects that i do... its gotta be tested and done right...
probably one of the main reasons greddy's kit isnt out yet.. they're just probably double checking some figures... why rush?
Originally posted by nonmature
Not to sounds like an @$$ or anything but I dont think I would want a turbo that hasnt blown an engine...
Cheston you know i agree with most of your threads but, I want someone that has blown an engine, I want someone who has tested and played around so much that they have made mistakes... I think it shows that something wasnt just put together to meet a demand... (not sayin that this is what PE is doin) but I'm sure that they want to get a kit out as soon as possible... anyways I want someone who has thought everytihng out and racked their brains on how to make it better... also this would give us some indication as to what the limits of the internals (if it is internal failure and nothing else) are on that system...
-non
not complainin about any systems just sayin it would inspire more trust in my eyes and I dont think that you will have as many problems with the first batch of kits sold to us... as some kits are running into problems
Not to sounds like an @$$ or anything but I dont think I would want a turbo that hasnt blown an engine...
Cheston you know i agree with most of your threads but, I want someone that has blown an engine, I want someone who has tested and played around so much that they have made mistakes... I think it shows that something wasnt just put together to meet a demand... (not sayin that this is what PE is doin) but I'm sure that they want to get a kit out as soon as possible... anyways I want someone who has thought everytihng out and racked their brains on how to make it better... also this would give us some indication as to what the limits of the internals (if it is internal failure and nothing else) are on that system...
-non
not complainin about any systems just sayin it would inspire more trust in my eyes and I dont think that you will have as many problems with the first batch of kits sold to us... as some kits are running into problems
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From: OC
Originally posted by Chebosto
i can see where you are coming from non- about 'not blowing' a motor to see the phyiscal limitations...but then you have to weigh in the risks involved. everything that hasnt been tried before has an inherient risk (think ECU devlopment, cam research. etc)
that is where engineering analysis and projections lead to sound engineering assessments and goals. no point in Technos blowing my motor for the sake of just doing so to find that ultimate number... we know the phyiscal limits of the engine. some ppl/companies choose not to believe what is widely known and approach the peformance envelopes cautiously... Top Secret attempted from the top down approach, which typically isnt the wisest thing to try first hand. but hey... what ever float's their boat... one of the main reasons why i have a spare VQ35, for the sole chance that Murphy comes into play so i dont have to call foul and try to find another motor... dont get me wrong , this kit was no way a 'slapped together' kit to meet a demand...its undergone severe hot weather testing and load tests while it was a prototype.. and u know and i know, for the projects that i do... its gotta be tested and done right...
probably one of the main reasons greddy's kit isnt out yet.. they're just probably double checking some figures... why rush?
i can see where you are coming from non- about 'not blowing' a motor to see the phyiscal limitations...but then you have to weigh in the risks involved. everything that hasnt been tried before has an inherient risk (think ECU devlopment, cam research. etc)
that is where engineering analysis and projections lead to sound engineering assessments and goals. no point in Technos blowing my motor for the sake of just doing so to find that ultimate number... we know the phyiscal limits of the engine. some ppl/companies choose not to believe what is widely known and approach the peformance envelopes cautiously... Top Secret attempted from the top down approach, which typically isnt the wisest thing to try first hand. but hey... what ever float's their boat... one of the main reasons why i have a spare VQ35, for the sole chance that Murphy comes into play so i dont have to call foul and try to find another motor... dont get me wrong , this kit was no way a 'slapped together' kit to meet a demand...its undergone severe hot weather testing and load tests while it was a prototype.. and u know and i know, for the projects that i do... its gotta be tested and done right...
probably one of the main reasons greddy's kit isnt out yet.. they're just probably double checking some figures... why rush?
-non
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From: North Jersey
Originally posted by zland
Here is my opinion:
If all you want is about 370rwhp, both the ATI SC and Greddy can do it. The cost advantage is to the ATI as you stated.
The advantage of the TT comes if you plan on boosting more and going for 500+ hp. To do this, you would be replacing internal parts in the motor thus adding to the cost you stated above which is already expensive. The TT allows more flexibility to boosting the system compared to the ATI (which you could possibly go from 7 lbs boost to a 9 lb boost pulley).
It appears companies like Greddy are going for CARB certification (smog legal) thus the low hp gains as posted. This will make it appeal to a greater market yet allow a stage 2 upgrade which would include internal mods as I mentioned.
Maybe if Greddy included a warranty on the entire motor, it might make more sense for the added cost. At this point, the ATI covers the SC parts under warranty thus the several people on this forum that have blown motors do not have a warranty on their motor. I would suggest you select a first rate installer/tuner if you are going ATI unless you have money to burn so to speak.
I think what you need to do is decide what your goal is. If you want your Z reliable, you might want to go NA and add up to about 45hp more as the Mossy Nissan Z has done. Another route in this hp range is the Stillen SC with a complete motor warranty. Again, these are for relativitly modest hp gains.
If you are willing to take more of a "risk" with your motor and want your car to go beyond "peppy", than the ATI SC is going to give you 365-375 rwhp. Most people have not had problems but a couple have. Do some research on this and decide for yourself if it is a tuning issue.
If you want large amounts of hp, then TT is the way to go. There is a debate on what this VQ motor can handle as far as hp goes. This is not a cast irn block etc thus I am sure we will see some motors get blown up trying to pusch the 500+hp barrier. If you want that much hp and can afford to risk damage to your motor, the TT seems like a perfect option for you.
If taking a risk bothers you, keep your car stock and hopefully get 200K miles out of it. If you want to reduce your risk, drive it stock for another year, let all the TT and SC kits come out, be installed on others Z's and then decide which is best based on their experiences.
Jeff
Here is my opinion:
If all you want is about 370rwhp, both the ATI SC and Greddy can do it. The cost advantage is to the ATI as you stated.
The advantage of the TT comes if you plan on boosting more and going for 500+ hp. To do this, you would be replacing internal parts in the motor thus adding to the cost you stated above which is already expensive. The TT allows more flexibility to boosting the system compared to the ATI (which you could possibly go from 7 lbs boost to a 9 lb boost pulley).
It appears companies like Greddy are going for CARB certification (smog legal) thus the low hp gains as posted. This will make it appeal to a greater market yet allow a stage 2 upgrade which would include internal mods as I mentioned.
Maybe if Greddy included a warranty on the entire motor, it might make more sense for the added cost. At this point, the ATI covers the SC parts under warranty thus the several people on this forum that have blown motors do not have a warranty on their motor. I would suggest you select a first rate installer/tuner if you are going ATI unless you have money to burn so to speak.
I think what you need to do is decide what your goal is. If you want your Z reliable, you might want to go NA and add up to about 45hp more as the Mossy Nissan Z has done. Another route in this hp range is the Stillen SC with a complete motor warranty. Again, these are for relativitly modest hp gains.
If you are willing to take more of a "risk" with your motor and want your car to go beyond "peppy", than the ATI SC is going to give you 365-375 rwhp. Most people have not had problems but a couple have. Do some research on this and decide for yourself if it is a tuning issue.
If you want large amounts of hp, then TT is the way to go. There is a debate on what this VQ motor can handle as far as hp goes. This is not a cast irn block etc thus I am sure we will see some motors get blown up trying to pusch the 500+hp barrier. If you want that much hp and can afford to risk damage to your motor, the TT seems like a perfect option for you.
If taking a risk bothers you, keep your car stock and hopefully get 200K miles out of it. If you want to reduce your risk, drive it stock for another year, let all the TT and SC kits come out, be installed on others Z's and then decide which is best based on their experiences.
Jeff
all depends on what you are going to use the power for....some ppl want boost all the time, some only like having it when the turbo's "spool up" when you rhomp on it. most of it is preference and cost
-ESP
-ESP
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From: Arlington, TX
Originally Posted by JETPILOT
The voices in my head tell me that a one week ban is in order. If I only had the power!
JET
JET
Yea, lets teach that douch bag a lesson!!!
BTW, the bulb on my DLP burnt out the other day so I have no other form of entertainment.
