turbo choice.

[ka-t4u]

ok guys here is the deal, am on the tightest budget u could imagine, somehow i have achieved to obtain 3 different turbos, 2 t25, and a crazy t3, now i don't know any specs for any of them, one t25 came off a saab 9-3, i believe, very low millage, i pulled it apart and checked everything, it all looked good. it came off a 2.3 engine so it kind of makes sense, the scary part is that the inlet on the turbine is a tiny hole about inch and a half, the other t25 came off a ca, i think it would be to stupid to try since the ca is only a 1.8, cfm wise, and the t3 i a caterpillar (sorry if i misspelled), i believe it is a twin scroll, its been fully rebuilt but i dont have any specs at all, thing looks huge but when i measured the inlet on the cold side is like 2 inches so it might be sized properly, am not looking for huge numbers am trying to do 7psi of boost on a FMU. so what do u guys think?? if u where in my place what would u choose?? economy wise also am kind of concerned about mpg even though i know i can pretty much kiss them goodbye if i boost. thanks in advance.

[Lonismos14]

i would go with the twin scroll those turbos put out alo of power u should be ok on mpg its noticeable but not that much. you still should get like 25mpg

[Shift_Kouki]

i would go with the twin scroll those turbos put out alo of power u should be ok on mpg its noticeable but not that much. you still should get like 25mpg

Smart money says he's got an HX35 there... And that it won't be at all in its efficencey range at 7psi.

I'd use the T25 off the Saab's 2.3L engine. The other part of it is that the bottom mount turbo + using an SR downpipe will keep your build costs low. Where as a T3 setup is probably going to be a top mount and require a custom downpipe and jumping through some other hoops to get it all done.

[spank044]

I would have to believe the CAT turbo is more likely a Garret/AI unit. If you are going low boost, go with the CA T25 because the Saab turbo does not flow as much air as the CA turbo. So the CA turbo will have a little more power at the same psi. The CA was designed to have power and the Saab was used an economy setup for more MPG.

[Shift_Kouki]

I would have to believe the CAT turbo is more likely a Garret/AI unit. If you are going low boost, go with the CA T25 because the Saab turbo does not flow as much air as the CA turbo. So the CA turbo will have a little more power at the same psi. The CA was designed to have power and the Saab was used an economy setup for more MPG.

Please give me some numbers when you tell me the turbo for a 1.8L motor flows more air than the turbo for a 2.3L motor. -- Esp when were talking about putting the turbo from one of those engines onto a 2.4L motor.

[koukiFC]

i have personally ran a ca t25 on my ka. anything past 9 psi and its worth d!ck on our motors. however it will be faster than now and keep your budget down. 255 pump and your fmu on 8 psi and you can make fun power cheap.

[spank044]

Please give me some numbers when you tell me the turbo for a 1.8L motor flows more air than the turbo for a 2.3L motor.

This statement lets me know that you don't understand how turbos work or the trims, a/r, or even know how to read flow maps for these turbos. Please don't take this the wrong way but, you don't understand the effects of volume and pressure that play a predominate role in the production or power or efficiency. Please don't start a debate with me with statements like, "The bigger the turbo, the more power you get", because it is simply not how they work.

Different turbos on differently engine react differently. First you need to understand what effects trim, air flow ratio, and housing size have on the intake charge.

Without getting into too much technical detail, trim is the difference in size between the minor wheel diameter and the major wheel diameter. A smaller trim will have a quicker spool, but more back pressure in the top end causing power to peak sooner and even lose power if it it too undersized. On the other hand a larger trim with the same A/R will spool a few hundred rpm later, but be more efficient in the top end and make power to the red line. Next the air flow determines the efficiency of the housing. The turbine housing with a smaller a/r is going to spool quicker and be more efficient with higher air ratios, but a bigger a/r will feel and perform better in the top end.

So to make this short and sweet, 2 similar looking T25 turbos for two different engines can have vast differences in power production and where that production is made. So the application of driving is always the first question asked, where do you want to make the power in the rpm curve, and how violent do you want full boost to be?

The OP wants a low boost, quick response, sporty feeling turbo setup. So the CA would be the turbo of choice with what we know about his options.

Next we get way more technical discussing the exhaust gas flow and pressure difference between diesel and gasoline engines. The cat turbo may actually be the best choice for him. Most of the common CAT turbos were from the TO4E family so most likely he a 76 to 82 trim on the turbine housing with a .70 a/r and the compressor housing is gonna be a .60 or .70 a/r with a 50 trim wheel. That turbo will be spool quick and make 10 psi by 3000 rpm, but choke at the 6500 rpm range. I had a smaller TO4B on my KA and it was awesome for road racing since I was almost always on full boost, but it was terrible for drag. Now my turbonetics turbo had too big of turbine housing and didn't make boost until 5200 rpm, but it made 416 whp at 28 psi. That was a better drag setup that ran low 12's. My current HY35 hybrid is a balanced sectional of both. It has 15psi by 3700 rpm and will make way more than 40. Although the top end power at 25psi was only 347whp the car now runs in the low 11's because of the early power production and improved efficiency of the turbine housing.

OP, I hope this makes a little sense and helps you make a decision. If you could and you put the trim and a/r of the cat on here and maybe the model so we can get a better idea of the flow ability of that turbo.

[ka-t4u]

well thanks to all of u guys for your input, i really really appreciate it, please don't turn this into a, who knows more than who thread, obviously i know less than any1. i have a vague idea on all this stuff, I've tried to read and read but can never manage to fully understand the art of the turbos, i mean i know how they work and their purpose, but i cant never work out how to determine proper size, flow, etc.

i want to thank Spank 044 for sharing all that knowledge, now i wish i had any info on the cat turbo, but it doesn't say anything on it about the a/r, or anything else, I've been wondering if i can take some measurements myself and calculate it all but i don't know where to start, all that it has on it are part numbers or serial numbers, i would not know for sure.

i would love to use it because in the future when i can afford a nice ecu upgrade and tune and all that i could probably squeeze more power out of it, and i would already have the whole setup.

setting it all up on the car wont be too hard for me, i have some welding skills and i am a certified mechanic, so the setup doesn't really worry me, like i said i just want to make a choice.

i would love if you guys can provide me maybe with a formula or a web site, or some way of calculating all the information that i need, a/r, etc.

thanks to all again!!!

oh and by the way the Saab turbo is a TD04hl 15-t, dont know if that helps any. but just like to throw it out there.

thanks one more time!!!

[neverlift]

http://www.stealth316.com/2-turboguide.htm#tninfo on the tdo4

and hit the garrett site to figure ou how to calc the size/trim.

[ka-t4u]

thanks neverlift, and by the way what part of the sunshine state are you in?? if you don't mind me asking...

[neverlift]

thanks neverlift, and by the way what part of the sunshine state are you in?? if you don't mind me asking...

the part that fails

jacksonville, one of the worse places to live IMHO.

[ka-t4u]

lol you think jacksonville fails?? then where am at fails at everything, have you ever been to ft. myers?? cape coral?? i think the cop population down here is larger than the civilian population!!! lol

[neverlift]

lol you think jacksonville fails?? then where am at fails at everything, have you ever been to ft. myers?? cape coral?? i think the cop population down here is larger than the civilian population!!! lol

ok so in general florida fails

yeah we have more people than cops and not ALL of them are d!ck but 95% is pretty high. But the people here I'm 27 with 140/90 for blood pressure

[ka-t4u]

i feel your pain, down here is just a bunch of old people driving, and they have all the patience in the world, if you know what i mean, i mean i don't have the same blood pressure but am 19 so am pretty impatience for the only thing i have patience is my car and the girlfriend, but when am driving sometimes i get a little... young and stupid should i say?? and old people in front of me just p#*s me off.

well back to the topic, lets not keep talking smack about Florida, hopefully today later on or tomorrow i get to crack that cat turbo apart and calculate the trim and see whats up! thank u all for the support, and neverlift nice meeting you(sort of)lol, maybe one day in one of my many road trips i'll pass by Jacksonville and see whats up.
Modified by ka-t4u at 10:08 PM 10/3/2009

[ka-t4u]

alright guys am back with the trims for the cat turbo, alright acording to my calculations(thanks to the Garrett website) th trims are:

44 on the cold side, or compressor

73 on the hot side, or the turbine side

so what do you guys think?, too big?, too small?, maybe?, should i??

well again, thank you all for your input!!

[Patarach]

What model did you say it was a t3? If so 44 trim t3's are pretty small for a ka, its sound like it has the regular stg1 t3 turbine wheel

Just a question what was the actual inducer/exducer measurements?

[ka-t4u]

thanks for the input patarach, yes it is a t3 series turbo, and the actual measurements where:

compressor wheel:

inducer= 50 mmexducer= 75 mm

turbine wheel:

inducer=60mmexducer= 70mm

i dont know if i got the names right for the turbine side since the exhaust gases exit out of the "inducer" but i hope you guys understand what i mean.

again thanks for the input!!

[hannibal]

you got the trims right. Sounds like a T3 45 trim.

If so, thats small, but people use T25/28's.

BTW, youre thinking correctly about the exhaust. Inducer where the gas comes in (the larger side) and the exducer is where it exits (smaller side).

[neverlift]

lol that sounds like the size of my turbo. post a pic.

[ka-t4u]

so it's small?? great, i was affraid it might be too big, lol, i still think the hot side is a little big, but what do i know, its a twin scroll by the way, i would love to post up pics, but i still dont learn how to,lol and also i have the turbo all apart from taking measurements, i'll try to post them when i put it back together, also i would like to mention that on the compressor inlet, it has that feature like the hx35s where the whole inlet its 4 inches and it has like the side ports to feed the compressor wheel, i hope you guys understand what i mean, like it has 3 ports around the compressor inlet, again thanks for the input!

thanks!

[neverlift]

you need to open a photobucket account and load them there, then link us to them.

hmm IDK get some pics

[Patarach]

Did you actually disassemble the the entire turbo or just the housings? You have to make sure to mark the compressor wheel for re installation or its going to be hard on the bearings and eventually fail.

If I were you I would use the cat turbo assuming that you don't get a different one, but don't be surprised if your out of air by 5000 rpm, then again the t25 would probably be worse.

typically If your going to run a t3 on a 240 your going to want over 50 trim with 60 being the perfect number.

[spank044]

so it's small?? great, i was affraid it might be too big

Depending on what you re doing with it determines whether it is too small. The cat turbo will hit full boost by 3500 rpm and surge at 5800ish. Full boost will probably only be around ten pounds due to the restricted air flow of the compressor housing. The inlet on the compressor is designed for a silencer ring to be install to reduce the whistle from the turbo, but we all remove them because it is a cool noise. If you are just using it to add some low end power and not drag racing with it then it will be an okay turbo for your needs.

[ka-t4u]

well again thanks for all the input!!

so all in all,i think that we can all conclude that if i use the cat turbo, i'll be better of the using any of the other t25's correct??

again as i stated before am not looking for huge numbers, i am just looking for some extra power, the car is my daily, but maybe i'll track it once or twice, just for fun, and if i run out of breath by 5800ish i wont really mind, since it is only a stock rebuilt engine, and don't want it to be spinning all the way up there on full boost and all that pressure, plus thats where these engines seem to like to make all their power, now another question, i have performed the "dual exhaust cam"swap, so the duration is 248/248, will that change the way of the engine when i boost it? would it help? i definably felt the difference when i did it, but when i boost is it going to be good having it? or should i go back to the stock one?

just so you guys know and dont feel all worry or go crazy my setup is gonna be: the cat turbo(thanks to all of you guys), walbro fuel pump, 8:1 fmu, and 8 psi of boost(maybe lower also depending on your recomendations).

oh and also to clear things out, I JUST TOOK THE HOUSINGS OFF, i was aware of the danger of pulling the whole thing apart with the balance of the wheels and etc.

once again thank you guys, without your help it wouldd be so harrd to figure things out!!! .

i'll try to post pics later.

edit: forgot to add to the setup my greddy type rs BOV, and i'm still looking for wastegates.
Modified by ka-t4u at 11:51 AM 10/20/2009

[spank044]

Numbers wise everything looks good. I do recommend the 248/232 exh cam swap instead of the dual exhaust. In my car it spooled my HY35 quicker and had better throttle response. No official dyno numbers, but like most people on here I have a testing course through the industrial park around the corner for judging mods. Just to be extra safe I would get a rising rate FPR and set it at 46 psi.

[ka-t4u]

wow hold on, so you are saying 248 intake and 232 exhaust?? if so where do i get the 232 isn't that the intake cam? would you mind to enlighten me as to how that would work/works? also i have to research into the rising rate fpr, unless you don't mind explaining that too...

thanks spank044 you are like an infinite source of knowledge, if you had a school it would be awesome!!!lol

thanks again for all the input!!
Modified by ka-t4u at 1:00 PM 10/20/2009

[spank044]

The 248 is the S13 exh cam rotated four teeth and the 232 is a S14 exh cam used with the correct setup. The rising rate FPR is just a fuel pressure regulator that increases fuel pressure at a 1:1 ratio with boost. So for every psi of boost it increases your fuel pressure by 1 psi.

For this example lets say we are boosting 8lbs. The reason for the rising rate is because the boost raises your intake pressure by 8 psi and the fuel pressure acting against the would still be a constant 43.5 psi from the regulator so you would only have 35.5 pounds of fuel pressure. Now with the rising rate fpr you cancel out the boost because the fuel pressure also went up by 8 pounds to 51.5.

Now FMU's on the other hand raise the fuel pressure at different ratios to feed the need for fuel with the increased airflow from the boost.

Make sense?

[ka-t4u]

so if i'm digesting correctly, i should run a rising rate fuel pressure regulator instead of the fmu??, or (the other way i think i understood) replace the factory fuel pressure regulator with a rising rate fuel pressure regulator and still use the FMU. im leaning towards the latter version of my understanding, sorry for being so ignorant!! .

now another question to you is, i read in one of your sale threads that you tapped your block for the return line, instead of the oil pan, would you mind sharing how you went about doing that? because i am really interested in no having to drop the oil pan.

thank you so much for your help!!!

edit: by the way i did understand the principle of the rising rate FPR, and the reason for it, i am just confused into which one to use now.
Modified by ka-t4u at 1:23 PM 10/20/2009

[spank044]

You want to use the latter of your thinking. The reason for the non-oem FPR is so you can can have a more accurate fuel pressure and you can adjust it with a gauge. So all in all you should get a quality FPR and FMU and use both to get the most accurate and controllable fuel.

In order to tap your block for a return line you will need the oil pan off and the engine out of the car. My block has a 3/4" return and is tapped right behind the motor mount. You will need a 1/2 drill with the bits and taps in order to do it.

[ka-t4u]

never mind on the block tapping procedure then!lol, well seems like i have everything settled then!!, now i have a complete plan to boost my car!!

i want to thank everyone who helped me with all the information and opinions! specially: patarach, neverlift(for the info on how to do the calculations), and last but not least spank 044 for sharing all the wisdom, and point me in the right path!!!

thats why i love NICO!!!

thanks again guys!! you are all awesome!