CT20 turbo overboost Options

[Island_Racer]

How capable are these turbos at surviving pressure above 18psi. Ive heard "hot air" etc...but i have a water injection system....i can clamp the signal and tune beyond the 18psi fuel cut but what other than hot air should i be concerned about? and do you think the water injection can cover that?

[Smaay]

sure the turbo had less restriction allowing for more boost to be made, however at 20psi the turbo isnt efficient. Like you said in the first post, its just pushing hot air. I cant think of a metaphor to relate it to.

lets say you take 10psi through a small turbo its moving X amount of CFM. then you install a large turbo and boost the same 10psi. its going to be moving Y amount CFM. another example is water flowing through a straw and a garden hose. both at 10spi but the hose is moving much more volume. So when you beyond the efficiency range. its the same amount of volume in the garden hose but now its flowing through a larger pipe. there is wasted air in that volume.

[Island_Racer]

sure the turbo had less restriction allowing for more boost to be made, however at 20psi the turbo isnt efficient. Like you said in the first post, its just pushing hot air. I cant think of a metaphor to relate it to.

lets say you take 10psi through a small turbo its moving X amount of CFM. then you install a large turbo and boost the same 10psi. its going to be moving Y amount CFM. another example is water flowing through a straw and a garden hose. both at 10spi but the hose is moving much more volume. So when you beyond the efficiency range. its the same amount of volume in the garden hose but now its flowing through a larger pipe. there is wasted air in that volume.

I think youve gotten a little confused about what I'm saying man. Im asking....can the ct20 turbo actually hold 20 psi for extended periods...i understand that it wont stand in any of the efficiency islands...but will it surge or choke at 20.....and can i use the water injection system to bring the air temps back down. If you look at the parts list for my car, u'll see the only thing left to do is buy a larger turbo (just wanted to push this one really really far...just to see what it does)

I know i could very easily buy a gt30 or t series, run 16psi on that and make way more power....but im just choosing to use the ct20 out of curiousity...

This post has been edited by Island_Racer: Mar 25, 2015 - 1:55 PM

[3WayStunna]

sure the turbo had less restriction allowing for more boost to be made, however at 20psi the turbo isnt efficient. Like you said in the first post, its just pushing hot air. I cant think of a metaphor to relate it to.

lets say you take 10psi through a small turbo its moving X amount of CFM. then you install a large turbo and boost the same 10psi. its going to be moving Y amount CFM. another example is water flowing through a straw and a garden hose. both at 10spi but the hose is moving much more volume. So when you beyond the efficiency range. its the same amount of volume in the garden hose but now its flowing through a larger pipe. there is wasted air in that volume.

I think youve gotten a little confused about what I'm saying man. Im asking....can the ct20 turbo actually hold 20 psi for extended periods...i understand that it wont stand in any of the efficiency islands...but will it surge or choke at 20.....and can i use the water injection system to bring the air temps back down. If you look at the parts list for my car, u'll see the only thing left to do is buy a larger turbo (just wanted to push this one really really far...just to see what it does)

I know i could very easily buy a gt30 or t series, run 16psi on that and make way more power....but im just choosing to use the ct20 out of curiousity...

Sure you could do it and it would work swimmingly. But why? Just because you can do it, does not mean it makes sense to do it. Reason being is that you just aren't making any more power to risk running your turbo like that. You are better off getting the Gt series turbo and pressing on from there.

[Island_Racer]

sure the turbo had less restriction allowing for more boost to be made, however at 20psi the turbo isnt efficient. Like you said in the first post, its just pushing hot air. I cant think of a metaphor to relate it to.

lets say you take 10psi through a small turbo its moving X amount of CFM. then you install a large turbo and boost the same 10psi. its going to be moving Y amount CFM. another example is water flowing through a straw and a garden hose. both at 10spi but the hose is moving much more volume. So when you beyond the efficiency range. its the same amount of volume in the garden hose but now its flowing through a larger pipe. there is wasted air in that volume.

I think youve gotten a little confused about what I'm saying man. Im asking....can the ct20 turbo actually hold 20 psi for extended periods...i understand that it wont stand in any of the efficiency islands...but will it surge or choke at 20.....and can i use the water injection system to bring the air temps back down. If you look at the parts list for my car, u'll see the only thing left to do is buy a larger turbo (just wanted to push this one really really far...just to see what it does)

I know i could very easily buy a gt30 or t series, run 16psi on that and make way more power....but im just choosing to use the ct20 out of curiousity...

Sure you could do it and it would work swimmingly. But why? Just because you can do it, does not mean it makes sense to do it. Reason being is that you just aren't making any more power to risk running your turbo like that. You are better off getting the Gt series turbo and pressing on from there.

O yeah man, i have intentions at some point of going to a more capable turbo....like i said, i just happened to accidentally boost to 21psi on the dyno one day and saw that at like 4900 rpm the engine produced 315whp (graph fell off because i stopped accelerating when i saw the 21psi) which is like 30whp more than what i usually make at 16-17psi ...am i wrong to just be curious how much it wud happen to make if i fulfilled the conditions to prevent knock (especially since i have meth injection)...not saying i wanna run that as a daily setup...just wanna kno if the bearings, turbine wheel, shaft etc will survive a pull or two to 7000rpms at that boost....

This post has been edited by Island_Racer: Mar 26, 2015 - 11:04 AM