19psi to redline safe??
The other thing to consider is where the boost is being measured. If you are talking about the manifold, you are right. 18psi is 18 psi no matter how it gets there.
If you read the boost at the turbo outlet as I think the Evo does, then all things may not be equal. Larger turbos also usually have larger outlets and are also fitted with larger intercooler pipes. A larger cross section at 18 psi flows a lot more air than 18 psi with a small cross section.
You would see the difference at the manifold though, which also takes into account intercooler efficiency and several other factors that determine the final number.
If you read the boost at the turbo outlet as I think the Evo does, then all things may not be equal. Larger turbos also usually have larger outlets and are also fitted with larger intercooler pipes. A larger cross section at 18 psi flows a lot more air than 18 psi with a small cross section.
You would see the difference at the manifold though, which also takes into account intercooler efficiency and several other factors that determine the final number.
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Originally posted by TearItUpSports
Do we know what the compression difference between the two cars is going to be? That will make a huge difference on hp as well. The big difference is that in one car you have 2.5 l of 14.5 psi air, and in the other you have 2l of 19 psi air. Total amount of air wins.
The turbo comment is correct too. The same psi is not the same air flow in different turbo's. One thing though, is that I am not sure that the STI turbo is any larger than the Evo. In fact I think it is smaller. I don't believe though that it can efficiently reach 19 psi, so those who think you can just boost the STI are mistaken. It won't get there.
Once again though, both are awesome cars. You need to look at the whole package of each, because picking apart pieces will get you nowhere. If you can actually get one of these cars, you are going to be more than happy, and to those not getting them, it shouldn't be an issue.
Do we know what the compression difference between the two cars is going to be? That will make a huge difference on hp as well. The big difference is that in one car you have 2.5 l of 14.5 psi air, and in the other you have 2l of 19 psi air. Total amount of air wins.
The turbo comment is correct too. The same psi is not the same air flow in different turbo's. One thing though, is that I am not sure that the STI turbo is any larger than the Evo. In fact I think it is smaller. I don't believe though that it can efficiently reach 19 psi, so those who think you can just boost the STI are mistaken. It won't get there.
Once again though, both are awesome cars. You need to look at the whole package of each, because picking apart pieces will get you nowhere. If you can actually get one of these cars, you are going to be more than happy, and to those not getting them, it shouldn't be an issue.
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Originally posted by twdorris
I thought about ignoring this, but decided what the heck. 18psi on a 2 liter motor is 18psi on a 2 liter motor. As long as the two turbos aren't completely out of their efficiency ranges, they'll both fill 2 liters with the same amount of air at 18psi. Going from a decent sized t3/t4 running 18psi on my 4g63 to a t88 running 18psi on my 4g63 isn't going to add 400 hp. Displacement is the limiting factor there.
[edit]Upon reflection, I've decided I may have misread dmora's post slightly. If he's talking about the original comparison between 14.5 psi on a 2.5L motor to 19psi on a 2.0L motor, then his statement is at least partially valid. You have to consider displacement in that comparison and you have to consider turbo efficiency. But I still object to the t3/t4 at 18psi compared to a t88 at 18psi generating +400 hp on the same motor.[/edit]
Thomas Dorris
I thought about ignoring this, but decided what the heck. 18psi on a 2 liter motor is 18psi on a 2 liter motor. As long as the two turbos aren't completely out of their efficiency ranges, they'll both fill 2 liters with the same amount of air at 18psi. Going from a decent sized t3/t4 running 18psi on my 4g63 to a t88 running 18psi on my 4g63 isn't going to add 400 hp. Displacement is the limiting factor there.
[edit]Upon reflection, I've decided I may have misread dmora's post slightly. If he's talking about the original comparison between 14.5 psi on a 2.5L motor to 19psi on a 2.0L motor, then his statement is at least partially valid. You have to consider displacement in that comparison and you have to consider turbo efficiency. But I still object to the t3/t4 at 18psi compared to a t88 at 18psi generating +400 hp on the same motor.[/edit]
Thomas Dorris
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From: Frederick, MD
Originally posted by dmora
one turbos ability to make equal power at less boost pressure is a direct example of its efficiency at compressing and expelling an engine's given displacement.
one turbos ability to make equal power at less boost pressure is a direct example of its efficiency at compressing and expelling an engine's given displacement.
Originally posted by TearItUpSports
If you read the boost at the turbo outlet as I think the Evo does
If you read the boost at the turbo outlet as I think the Evo does
Thomas Dorris
Last edited by twdorris; Apr 13, 2003 at 06:56 AM.
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Originally posted by twdorris
FWIW, I don't believe the US EVO8 actually measures boost. I don't see a pressure sensor in the circuit diagram that would be useful for that. So it's either using a "duty cycle at RPM" table for the wastegate solenoid to "get close" or it's using airflow per rev with some guess at volumetric efficiency to calculate boost. Or, I guess, it could just be relying on system design limitations to naturally limit the pressure. In any case, I'm a little surprised to not see a useful pressure sensor going into the ECU.
Thomas Dorris
FWIW, I don't believe the US EVO8 actually measures boost. I don't see a pressure sensor in the circuit diagram that would be useful for that. So it's either using a "duty cycle at RPM" table for the wastegate solenoid to "get close" or it's using airflow per rev with some guess at volumetric efficiency to calculate boost. Or, I guess, it could just be relying on system design limitations to naturally limit the pressure. In any case, I'm a little surprised to not see a useful pressure sensor going into the ECU.
Thomas Dorris
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From: Chicago
Can som1 plz tell me what kind of turbo is in the evo then? The STi you guys said uses a T3/T4 or w.e.? What does the Evolution 8 use then? I'm sorry for my ignorance.. but just trying to understand.. 
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Originally posted by I4K20C
Can som1 plz tell me what kind of turbo is in the evo then? The STi you guys said uses a T3/T4 or w.e.? What does the Evolution 8 use then? I'm sorry for my ignorance.. but just trying to understand..
Can som1 plz tell me what kind of turbo is in the evo then? The STi you guys said uses a T3/T4 or w.e.? What does the Evolution 8 use then? I'm sorry for my ignorance.. but just trying to understand..
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From: Chicago
How about the Evolution 8..what does taht use then?
Basically waht i was wondering.. since the car came out was that.. I understand that if you use a small turbo.. you need to run higher boost to get the same power of a big turbo... So basically is Mitsubishi's turbo small or big?
B/c im guessing if the STi runs 14.5 (on some forum they said that was mentioned on the STi microsite when you dl the Pf article) then it has a big turbo....
Therefore if the E8 is running at 19psi i thought it had a small turbo.. but no1 would answer my question so i jus forgot about it.. maybe the question is dumb or something..lol... but i jus want to know..
btw thanks dlowman for helping...
Yeah so basically does the Lancer Evolution 8 use a big or small turbo?
Basically waht i was wondering.. since the car came out was that.. I understand that if you use a small turbo.. you need to run higher boost to get the same power of a big turbo... So basically is Mitsubishi's turbo small or big?
B/c im guessing if the STi runs 14.5 (on some forum they said that was mentioned on the STi microsite when you dl the Pf article) then it has a big turbo....
Therefore if the E8 is running at 19psi i thought it had a small turbo.. but no1 would answer my question so i jus forgot about it.. maybe the question is dumb or something..lol... but i jus want to know..
btw thanks dlowman for helping...
Yeah so basically does the Lancer Evolution 8 use a big or small turbo?
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Originally posted by I4K20C
Can som1 plz tell me what kind of turbo is in the evo then? The STi you guys said uses a T3/T4 or w.e.? What does the Evolution 8 use then? I'm sorry for my ignorance.. but just trying to understand..
Can som1 plz tell me what kind of turbo is in the evo then? The STi you guys said uses a T3/T4 or w.e.? What does the Evolution 8 use then? I'm sorry for my ignorance.. but just trying to understand..
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Originally posted by I4K20C
maybe the question is dumb or something..lol... but i jus want to know..
btw thanks dlowman for helping...
Yeah so basically does the Lancer Evolution 8 use a big or small turbo?
maybe the question is dumb or something..lol... but i jus want to know..
btw thanks dlowman for helping...
Yeah so basically does the Lancer Evolution 8 use a big or small turbo?
Originally posted by dlowman
The evo uses a twinscroll 16g turbo. Yes it is a smaller turbo and your assumptions are right the turbo on the sti is a bigger turbo.
The evo uses a twinscroll 16g turbo. Yes it is a smaller turbo and your assumptions are right the turbo on the sti is a bigger turbo.
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Originally posted by ShapeGSX
T3/T4 doesn't really denote any particular size.
The 16G isn't a small turbo by any means. It is larger than the stock turbos on most any other vehicle.
T3/T4 doesn't really denote any particular size.
The 16G isn't a small turbo by any means. It is larger than the stock turbos on most any other vehicle.
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