Okay, so I've got this guy who wants to get about 250 hp out of his 4EFTE. The engine is a stock turbocharged 1.3 liter making something like 145 hp. I figure that another 100hp is about a 66% increase in power, needing another 9 psi of boost over stock which I believe is 7 psi or so.

So, I assuming that we need around 15 psi total. Now, a 1.3 engine running at 7500 rpm (stock redline) and assuming an 85% volumetric efficiency (probably a little better than that), I figure that the engine consumes 145 CFM:

79 x 7500 x 0.5 x .85 / 1728 = 145 cfm

Now, if we're running 15 psi, the pressure ratio is a touch higher than 2.0. So, 2.0 x 145 = 290 which is the cfm under boost.

We have to convert the cfm to lbs of air per minute for most compressor maps, so going with a temp of 85*, 290 x .073 (weight of air at that temp and sea level) is about 21 lbs of air per minute.

So, looking at a T3 Turbo with a 50 trim, 21 lbs of air per minute and 2.0 pressure ratio is sitting right around 73%. On the other side of the map, assuming boost is made at 50% of max RPM (which is about 3750), then 10 lbs per minute is at 70%. Now drawing the line down to 20% of max airflow, around 4.5 lbs/min, it goes right along the 70% line and stays well inside the surge limit.



So it should look like this:


So, is this a good turbo and are my calculations correct? Or am I wrong somewhere? Is there a better turbo that you would suggest?

I think we'll end up using a "T28", one of these compressors with a T25 turbine.

 

i stopped taking math... if you have all this ---- planned out, do it.

 

I thought you were the one with the bad *** shop in the NE region? if you had a bad *** shop, why are you turning to a forum for help on your customers cars? tell your customer to come talk to us, and we will help him/her out.

and a 1.3 putting out how much power stock. i havent seen to many 1.3 ltrs putting out that much power stock.

 

LOL

 

Wow, 250whp on a T28 with a T25 turbine? 9psi on a T28/T25 is going to make a 66% increase which equals 105hp from your numbers. That's pretty impressive.
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ok..... is this a toyota starlet?

here are some #'s:

Engine : 4E-FTE, L4 1331cc EFI DOHC 16valve

Aspiration : Toyota ct-9 Turbocharger (CT-9A) Output : 133hp @ 6400rpm (100kw @6400rpm)

0-100 km/h (0- 60 mph) : 7.0 Seconds

Redline : 7,200 rpm

Boost Settings (Dual-mode Turbo) : 0.40bar (@6psi) @ LO setting 0.65bar (@9.5psi) @ HI setting


now i know that most of us do not know alot about this motor, as for internals, and how much abuse it can take, and how to compensate in fuel and timing for more boost pressure.

could the internals handle 15psi?
what kind of mgt is he using (or going to use)?
what are his goals for this car?

these things need to be considered, which i'm sure that you know. you could put a 70 trim on this bitch and it would make all the power in the world after 6000 rpm, but on the street it would suck ***!

so if you were to ask me...
i would say that a Precision sc50 would be a safe bet.
http://www.extremepsi.com/store/cust...cat=508&page=1

not that i'm underminding you or anything... but make sure that you know what you're doing before you start working on other ppl's cars. the reason why i'm saying that is because from what you origionally posted, you gave no background info on the setup. you just threw out #'s, and asked if this T28/T25 turbo would work. well of course it will work, but the real question is how well and for how long?

hope this helps!
mike

 

I think you burnt your bridges here already. Dont hate on everyone and then ask for help

 

i have also heard of the infamous "******"

and thats what this guy is.

 

Don't forget to check the A/R of the hot side too...If you go from a T25 to a T3, it will take ALOT longer to spool. The T3 turbine has a bigger housing. Find out what your A/R is for the turine on the factory turbo too, and calculate accordingly.
Oh, yeah...have you thought about a CT26, I don't know if the housings are the same or not. If they are, it would make you life alot easier. I know they used these on the turbo MR2's and the AWD Celica's...hope I helped