Mximus

1. could someone please explain to me the befits of a ball bearing turbo over a normal turbo. I know that the spool is faster but is there anything else?
2. also what is the difference between the dry and wet floating bearing on a turbo and what does each do?
3. how does trim affect a turbo (smaller and larger trim)
4. and my last nagging question, what does a larger and smaller a/r have on the function of both the turbine and compressor side of a turbo?

ive read the stickies several times along with many other threads but have yet been unable to dig any information up on this subject. any help would be greatly appreciated cause this whole turbo plan is quite a long and complicated design and fabrication process as many of you know. thanks again!

subs1000w

you named the only benifit of the ball bearing turbo the cons are higher price and cant rebiult them have to replace complete centersection= more $$$

wet or dry is not the bearing but the center section (where the bearing are)

wet = water cooled + oil lubricated

dry = oil cooled and oil lubricated

trim is simple bigger the trim the more air it will flow but that doesnt mean get the biggest one. you need a trim right for your engine size and power goal

A/R is also pretty simple and applies to both turbine and compressor the bigger the # the slower to spool but the more air the will flow (less restiction)

look over this chart and it will give you a general isea of how the sizing works for engine and power needs also it gives recomended trims and A/Rs

http://www.racetep.com/turbomatrix.pdf

Mximus

thanks, i appreciate the help!

Mximus

so what would you say is better, a watercooled turbo or an oil cooled. it seems to me that the watercooled turbo would be better so the oil wouldnt heat up so much, but it would also make it more complicated. let me know what you guys think.

subs1000w

the advantage of a water cooled turbo is that theres no need to "turbo time" or let the car idle for 30-60sec before turning the car off (to prevent oil coching which is when the oil in the turbo gets baked onto the shaft because there is no oil flow when the car is off) thats why most OEMs use water cooled turbos but for simplicity generally a "dry" centersection is just fine

SPiG

iTrader: (7)

Just about all of the questions can be answered at Garretts Turbo Tech, especially 101 and 102.
http://www.turbobygarrett.com/turbob...ch_center.html

|Bijan|

iTrader: (12)

good info