Ya Sokar.... it seems thats the case hey I guess it is safe to say we are no experts on all the detailes but we have been there and done that....welll um I guess I could say that, you have a sx again and will be rebuilding it plenty..... again:lol:
RBSX....if you still bothering to read this pathetic stuff, if you decide to use a standard Garret T25 or T28 made in the old days specs and you want to boost 1 bar, at least ask the turbo experts to ad a 360 digree thrust bearing when you rebuild the turbo.....it helps to prolong it's life.
Exactly....I am only talking about the exhaust wheel, all compressor wheels are made from aluminum, I have never heard of a copressor wheel shattering whithout something hard going through it and causing the shatter, I have seen many bent blades because off bearing falior and bent shafts.
Aluminium? The blades are made of aluminium?Holy shit.The blades are NOT made of aluminium!!!!!
Ok,not trying to be an ass,but i mean really!
The rest is correct. Study the compressor maps of the turbo in question to see it you will be operating it in it`s efficiency range. Boosting the stock T25 to 14 PSI is just stupid. All heat and no gain.
Just some backup for the pathetic comments that I posted, something from GOOGLE....
Compressor wheel breakage also can occur from foreign object material although not as frequently as turbine wheel damage. Sometimes pieces of the air cleaner will break loose and go through the compressor. There also have been instances where hose connections fail and pieces of rubber or wire reinforcing from the hose get into the compressor wheel. Again, carelessness in allowing nuts, bolts, washers, rocks, rags and even screwdrivers to get into the intake systems will cause compressor wheel failures.
Modern commercial vehicle turbochargers are subject to very high loads due to the wide range of applications they are used in. In many cases where there are extreme loads, a compressor impeller made of an aluminum alloy determines the service life of the turbocharger. In particular, material fatigue can result from extreme loads, especially when the loads are cyclical loads occurring at low frequencies. This phenomena is also known as low cycle fatigue (LCF).
The rest is correct. Study the compressor maps of the turbo in question to see it you will be operating it in it`s efficiency range. Boosting the stock T25 to 14 PSI is just stupid. All heat and no gain
I don't know what you are carrying on about.....the first quote I made was in response to your earlier remarks on compressor wheels shattering.....
The second quote was in his response saying the wheels are not made of aluminum, the compressor wheel and blades from the standard garret T25 and T28 are made from aluminum unless modded otherwise. Please.... I am not speaking about other turbos made 10 years later or the ones built now.....
I don't have the flow chart....I don't need it to say what I said earlier,I never recommended that the T25 can boost or must boost 14psi reliebly, I did boost that but I do not recommend it as I said before. I recommended 0.8(12 psi) as the most it can relieble...and then I did not say that is right and that is the way it is....that was my opinion.
Come on....what do you not get or understand.....?
Lets smile on this pathetic thread theres mine
Last edited by Draco on Tue May 27, 2008 12:15 pm, edited 1 time in total.
I work at a place that has departments that do quality control on metals so I just double checked with them before I replyied, And I’m sorry to tell you that aluminum almost any metal will fail catastrophically when pushed beyond its limits, if you had worked much with aluminum you would have noticed how easily it fractures and tends to crack also Steel / aluminum and other metals after being place through extensive thermal cycles tend to get brittle and fractures\fatigue over time.
Now I am going to ask you a question, you are using a 12 year old turbo lets say a T25, OK and its been through millions of thermal cycles ,yes its had a couple of rebuilds but the wheels have not been replaced.
Now you need more power so you increase the boost pressure to get those extra pounds of air so now the shaft speed increase from lets say 10000rpm a minute to 13000 rpm a minute the increase shaft speed is because the wastgate stays closed longer before the required pressure is reached but now because of the increase boost there is also increase heat around the exhaust house and this is made worse because of the t25 small .48 A/R step-up so now the cartage is taking more heat hence the failure of over boosted units as the seals start to give out also increased oil breakdown the turbo is also working a lot harder to produce said boost increasing the temperature of the air supplied …
Above this the tip speed and centrifugal force of the compress/expeller wheels are increase producing a more stress on the metals involved making it more likely that there will be a catastrophic failure, now lets make things worse still the t25 small .48 A/R housing will suffer from huge boost spikes even when the set pressure is reached this is because of the small wategate and the increased pressure around 3 times boost pressure between the manifold and turbo because of the incorrectly sized housing this will further more increase the shaft speed stressing the metals even more that’s why a older SR20 has a T25g with a .64 A/R exhaust housing
Now I know you are happy that you proved the blades are made from aluminum but I don’t really care, because even if they thought they where made of titanium or freaking adamantium you are still stressing them beyond the sensible capabilities secondly the increase flow of the t28 will allow it to pressurize the piping more efficiently making it more practical at the set sensible boost level but then again check the flow charts on this one.
Thirdly, I don’t care if you think the internals are the same, The “Fact” is a T28 will flow more air then a T25 that a fact unless it a special Garret unit and you can Google why.
Dude if an endless "E-thug" battle makes you feel like you have your Sx back then I’m happy I could help but this was a waste of time and it stupid stuff like this that warps the truth and stops us from helping people and that’s what a forum is for
Turbo wise? I need to brush up again but the if I remember correctly the RB25 has a very nice unit, But the rear bolt pattern does not match out down pipes.
I work at a place that has departments that do quality control on metals so I just double checked with them before I replyied, And I’m sorry to tell you that aluminum almost any metal will fail catastrophically when pushed beyond its limits, if you had worked much with aluminum you would have noticed how easily it fractures and tends to crack also Steel / aluminum and other metals after being place through extensive thermal cycles tend to get brittle and fractures\fatigue over time.
Good for you, thanks for the useless info, when presisely does this happen, how much boost, what temp, what revs, how long does it have to perform like this for this to happen....what is the limits of a T25 comressor blade and wheel, have thay tested it are we speaking about aluminum in general or a turbo impeller :shock:ask them to test it and post all the detailes so I can have my facts straight next time...
Now I am going to ask you a question, you are using a 12 year old turbo lets say a T25, OK and its been through millions of thermal cycles ,yes its had a couple of rebuilds but the wheels have not been replaced.
You are assuming again friend....assumtions are the mother of all F*ckups aint it, but I'll comment futher when I see your works quility control department tests on a 12 year old turbo compressor wheel
Now you need more power so you increase the boost pressure to get those extra pounds of air so now the shaft speed increase from lets say 10000rpm a minute to 13000 rpm a minute the increase shaft speed is because the wastgate stays closed longer before the required pressure is reached but now because of the increase boost there is also increase heat around the exhaust house and this is made worse because of the t25 small .48 A/R step-up so now the cartage is taking more heat hence the failure of over boosted units as the seals start to give out also increased oil breakdown the turbo is also working a lot harder to produce said boost increasing the temperature of the air supplied …
These parts are made for operation to about 100 000 rpm and tempriture to 1200 digrees farenhight.....thats pretty tough don't you think and still they mention broken hard parts that cause wheel shatters....I am sure if you are gonna run it on 100 000 rpm for a whole hour or maybe less it will burn up and shatter....maybe but I will wait for your quiality departments test before I commit to a theory
Now I know you are happy that you proved the blades are made from aluminum but I don’t really care, because even if they thought they where made of titanium or freaking adamantium you are still stressing them beyond the sensible capabilities secondly the increase flow of the t28 will allow it to pressurize the piping more efficiently making it more practical at the set sensible boost level but then again check the flow charts on this one.
I am extremely happy that I proved what I know, again I will wait for your quality dep. tests before I comment, ask them to do it on the same size titanium as well
Thirdly, I don’t care if you think the internals are the same, The “Fact” is a T28 will flow more air then a T25 that a fact unless it a special Garret unit and you can Google why.
I don't need to Google, I know the flowwwww is better....again it seems you think I disputed this.....why,is it the pink bunnies that told you this...?
Dude if an endless "E-thug" battle makes you feel like you have your Sx back then I’m happy I could help but this was a waste of time and it stupid stuff like this that warps the truth and stops us from helping people and that’s what a forum is for
OOOOOO that makes sense...I did this because of my endless pain of selling my sx , I do agree, you are wasting my time, I could have given other people my opinions by now....
PS. relax dude, I was just doing this cos I injoyed reading how you get all defensive and agrevated, lets help the dudes, thats what I say,relax it's all about the flowwwwwww
Alu Alloy,and Alu is two totally different things!
I agreed with all you have said Draco,except the part about the Alu compressor blades.
>> My reasoning. I have seen what happens when Alu when it gets too hot: Form a picture # Blink# 1 standard motorbike silencer.Place standard motherbike silencer on Rotary exhaust.Drive around for a few minutes.See the alu breaking apartt bit by bit.It didnt melt or anyhting weird like that,if fisically broke apart.
The rest : It is not a healthy idea to overstress a Turbo!!! I have seen what happens when a turbo lets go some years ago.
Ya Sokar.... it seems thats the case hey 
are we speaking about aluminum in general or a turbo impeller :shock:ask them to test it and post all the detailes so I can have my facts straight next time... 
