Ok guys this is a hot topic and has erupted in the past. So lets try to keep it civil and I personally apologize If I came on to strong in the past and pissed some people off.

What are the limitations of our engines? What is the maximum psi our engines can RELIABLY hold with and without stand alone engine managment. My car is currently at 6psi and out of tune. I am taking it to my tuner so he can tune it on the dyno but I am cautious on the max psi I should go up to? What are your guys suggestions?

What do you think our rods can handle?Pistons?Head gasket?

Thanks again all of your suggestions will help

 

I guess the difference would be how fast the boost builds up with the different turbos, right?

 

No one has really ran a turbo on a 3rd gen Protege that I know of, so no one knows hehe. Linux has a MP3 with N2O, and he blew his engine, so I dunno if we can handle lots of boost or not. Me personally, I would run 6-8 daily, 10 max with just a FMU/Regulator and pump, and maybe 12-14 with a standalone with stock internals. Anything over 14 I would change out the con rods and pistons and headgasket.

 

Yes the compressor size is a very crucial thing to consider when one talks about how much boost an engine can handle...a small turbo(14B)will flow much less CFM at 15PSI than a large turbo(20G).

 

Linux confirmed that his ZEX system was installed incorrectly after talking to the ZEX techs. We need much more R&D on our engines before we will see a pattern of parts breakage. One or two people isn't enough to establish a pattern, IMHO. You have no way of knowing whether the part weakness was in that particular engine, or due to improper installation or tuning of aftermarket parts. When many people report problems with the same parts of the engine when using established products, then you get reliable information.

 

As for my turbo its a mitsu 16g

 

Spoolin I have been in close contact with Knight turbos and ATS turbo out of oregon. Both of them have boosted the F series engines and the are reliable where you have it no 5-7 PSI of boost. Both of them have told me in detail that it will run 10 but not reliably both of them said that when someone ran 10 about a year later both of them got calls about cracked pistons. As long as you keep the boost between 5-7 you will be fine...BTW how does the 6 PSI feel? I'm about to put my turbo kti on this weekend and that is what i'm planning on running. Oh yeah The stock fuel pump also is beign highly stressed at those HP levels...I would suggest getting an inline. MSD has a pump that is made by Bosch that runs about 90 dollars through summit...very good idea considering your setup. Happy Boosting.

 

Sounds like we are starting to get into another Probetalk convo here Boost is Boost you can only flow the same CFM at the same boost no matter what the turbo.....the difference is the efficeincy of the compressor. At 15 PSI a T25 and T4 will flow the same CFM its just the T4 is much more effiecent thus blows out cooler air and makes more HP. It is impossible by the laws of physics to have the same amount of Pressure flowing a different amount of air in the same diameter piping. If you saw this then you are saying that a larger turbo under the same PSI creates mass which my friend is impossible...Theory of Mass Conservation I believe. Mass can neither be created nor destroyed.

 

You've never read a compressor map, have you?

You can have the same pressure flowing different amounts of air, if the compressor is bigger or smaller. A T66 can pressurize alot more air effeciently @ 15psi than can a 12A Mitsubishi turbo. You could get into the arguement that you might be able to make the 12A flow as much mass flow as a T66, but we're assuming Et values of greater than 60%--these arent roots blowers ya know...so Mdot=ro*a*v is true, but lets be practical here, not live in a theoretical world that doesn't take into account real life.

Mass flow is more important than CFM, because a chemical reaction couldn't care less about the volume of stuff there, just how many molecules there are to work with.

I'd recommend Maximum Boost by Corky Bell for the Turbocharger newbie. Excellent info to clear up misconceptions that are present here.

 

I still go with Bryan Pendleton on this one.......you cannot have more air in the same space under teh same pressure in the same type of gas it defetes the laws of physics.....get a 6" diameter tube by 12" long and fill it with one pressure and try to put more air into it without increasing the pressure...and yes i have heard of compressor maps...i'm nto an idiot. I am saying you cannot put more air into the same space under the same pressure without raising the pressure.

 

Yes, you can put more air in a tube at a fixed pressure. If I took Oxygen down to ~50K and filled a with it, there would be alot more O2 in there than a 2"x 15" tube filled with room temperature oxygen. You see my point? Just CFM doesnt matter, because it doesnt account for density @ a given temp. This is where effeciency tries to compensate, but ideally we'd like something like moles per unit of time.

Please, ask Bryan about this, he'll back me up I'm sure.

 

ok i understand that I was saying at a given temp. I know that with more temp come less dence air and lower temp more dence air I was trying to get that through in my first post in being a more efficient compressor and discharging cooler air. sorry I was at work and my brain was cut off.

 

Thanks for the schooling Pink

 

Ha you guys are funny!!!!!!
Well back to my question....thanks chdesign I think I will stay at the 8psi mark for now. I do have a high flow inlinee pump. As for 6 psi it feels nice. I only drove it once and its out of tune but it sure does sound sweet.

 

Thanks spoolin I got my downpipe back today and my intercooler along with the bracket i made so if i can find the fuel fitting I need my setup shoudl be in this weekend.