T3 vs. T25 turbo

[03MSPRO]

ok, I know 6 psi using a T3 is not the same as 6 psi using a T25.
Does anyone know what 6 psi using a T3 is equivalent to using a T25?

[Micah]

shot in the dark, maybe 10psi

I have no clue, just a guess - you should ask the vendors - or maybe read a book by corky bell - I heard that book can make anyone an expert. (lol)

[jersey_emt]

9.55524 psi.

[azian6er]

^^ are you jking? I dont know you so i dont know if you are or not....

[jred321]

you need a compressor map for each to tell for sure. there are different trims and compressor sizes that make for different flow characteristics within the t3 and t25 line, so you'll need to know specifics to tell for sure.


oh yea, micah, i'm sure to be buying some of your awesome products in the near future.
next time learn who you are commenting on before saying things. i used corky as a reference to support my claim, since he tends to know what he's talking about. i agreed with that before reading the book, but had no actual support until then. what experts or theories do you have to supporting your claims, other than saying that it's good?

[03MSPRO]

I am asking because the Flying Miata kit is supposed to be very reliable using a T3 boosting 6 psi so I want to put the same kind of CFM on my engine and I assum it will be just as reliable or more since the car has just a rich AF ratio.

[jersey_emt]

Originally posted by azian6er
^^ are you jking? I dont know you so i dont know if you are or not....

LOL yeah I'm joking...I have absolutely no clue.

[MazdaSpeed0020]

Well I believe that the T3 is a bigger turbo correct? So I would think that with a bigger turbo pushing the same psi it would feel like you are running at 10 psi on the T25.

[03MSPRO]

My GUESS is around 9 psi.
Some guy posted his dyno plot of his MSP boosting 8 psi with no other mods it made very similar results are the FM kit boosting 6 psi.
If I had the specs on both turbos, I am sure I could figure it out exactly.

[jred321]

ask fm for a compressor map, i'm sure they have one

[perfworks]

Originally posted by jred321
ask fm for a compressor map, i'm sure they have one
Jred is correct.
You will need to evaluate the various compressor maps for the turbos. BUT they are two completely different designs. The T25 is garrets new GT series that is replacing all the prior units soon.
But to answer the question, A base T3 can support up to 300hp. The T25 is rated for 260hp. I like a little larger turbine for increased exhaust flow characteristics. a good .63 T3 stage III wheel and standard comp housing is good for 350+ hp easy and efficiently. The T25 is reaching its max efficiency around 16psi and 265-270 hp. Thats concidering you have the proper EMS to back up the claim

[Micah]

Originally posted by jred321
you need a compressor map for each to tell for sure. there are different trims and compressor sizes that make for different flow characteristics within the t3 and t25 line, so you'll need to know specifics to tell for sure.


oh yea, micah, i'm sure to be buying some of your awesome products in the near future.
next time learn who you are commenting on before saying things. i used corky as a reference to support my claim, since he tends to know what he's talking about. i agreed with that before reading the book, but had no actual support until then. what experts or theories do you have to supporting your claims, other than saying that it's good?

I've never even read the book, no immediate plans to either. I'm sure the book is great - just the only books I read right now are for M$ and Cisco Certs.

We're in the process of having the authorized vendor status transferred to MPNicks account since he has been on the forums more often.

[Micah]

but don't worry, you can still look forward to me acting like a jack-ass

[Micah]

Originally posted by perfworks
Jred is correct.
You will need to evaluate the various compressor maps for the turbos. BUT they are two completely different designs. The T25 is garrets new GT series that is replacing all the prior units soon.
But to answer the question, A base T3 can support up to 300hp. The T25 is rated for 260hp. I like a little larger turbine for increased exhaust flow characteristics. a good .63 T3 stage III wheel and standard comp housing is good for 350+ hp easy and efficiently. The T25 is reaching its max efficiency around 16psi and 265-270 hp. Thats concidering you have the proper EMS to back up the claim

I think you once told me that also a turbo could be pushed past it's efficiency limits for more HP - but that the gains would not be the same. Am I remembering this correctly?

You've got the knowledge - help a brother out.

[jred321]

you can push a turbo past it's efficiency limits, but once past them you are heating up the air more, so the power will not increase at the same rate it does before this point.

[perfworks]

Originally posted by Micah
I think you once told me that also a turbo could be pushed past it's efficiency limits for more HP - but that the gains would not be the same. Am I remembering this correctly?

You've got the knowledge - help a brother out.
The increase in Hp output from the engine will depend mainly on its volumtric efficiency NOT turbine efficiency. They are two different things also. There is only so much an intercooler can do. At that point the only option is to increase the compressor housing. Are you negating it then with the restrictive exhaust housing? Probably.
Our conversation long ago was the ability of the stock or modified engine to process more air then it would normally. Cylinder filling would have to increase thru advanced or radical cam profiles, etc etc. There is alot to it.
Turbo charging just raises that volumetric efficiency earlier in the rpm band. It is the ability to maintain a quality charge that gives you increased power thruout the band

[03MSPRO]

Thanks for the info guys. I am debating wheather ot not I should void my warranty by increase the boost to a safe level (~9 psi). I already instell the boost gauge. I might just get the exhaust firts and see how that feels before rasing the boost level.

[boostaddict]

Not that I know anything about this but can someone check my logic here.

If you are running the same pressure, intake temperature exhaust backpressure and rpm then the two would be the same.

Pressure is the same

I'm assuming a T3 would have less backpressure

What the intake temp was and what rpm it would be able to reach the desired pressure on a given engine are what the question really is. Correct?

This is what the map tells us?

Anyone who knows: Can you give us newbies an idea what A/R and Trim are and what bigger/smaller numbers mean.