Thread: Holy Sheet!!! New Turbo!! Videos on pg 4!

^^ The wheels are quite different aerodynamicly but they seem get pretty similar hp results. The greddy has a slightly bigger turbine wheel and the garrett a slightly bigger compressor.

I reckon the greddy has more of that turbo boost hit whereas the garrett is a bit smoother in the way it comes on.

My info tells me a td05sh-18g is rated at 400hp and is generally oil cooled but i see some on ebay now that are water and oil cooled which i would love to try.

The gt2871r is oil and water and rated at 420hp for the 56trim .86 which is probably the more similar turbo to the greddy debatable though i guess.

I reckon they are both the best allround turbos availble for these engines.

i would definitly say if the greddy td05sh-18g is journal bearing and not DBB like the gt2871r,the journal bearing is going to fall short of the boost response and full spool, and boost start unlike the dual ball bearing which i feel from expierence is going to be significantly better over the journal bearing unit, personally my car made 300whp and almost 300wtq @ 10lbs with the gt2871r .86AR full boost at 3600rpm @ 10lbs, the boost is almost instantanious, boost start extremely low around 1500rpmstart 3600rpm full boost and pulls throughout the band till redline. i really think the larger AR on the 2871r is optimal for high outputs, i have put 17lbs on my setup before, and it was completely unbelieveable on the highway.

they are definitly both great turbos, esp if you are upgrading from say a t25/t28 ball bearing or not, both gt2871r and greddy and going to be a major upgrade in both power and response

What do you mean itll fall short in boost response, full spool, and boost start. How does a turbo fall short in "full spool"? Im not understanding what your saying...

I think he means that the ball bearing will be more efficient than the journal bearing

been in both 2871r 56 .63 and t518z 8cm

t518z wins imo, more responsive, and when boost kicks in it kicks in a lot harder, feels like a lot more torque

there is a lot more to a turbo than just bearings buddy, in fact the drag caused from bearings is pretty minimal when you compare to wheel design, lightweight materials used on the wheels, trim sizes and soo forth. Remeber that the t518z is very different to the mitzu td05 18g, trust have put a lot of research into their turbo's and chose to keep it oil cooled for a reason

a t518z does have a bigger ex wheel, however it is an 11 bladed design as apposed to a 10 blade that is used in the gt serries. So they are pretty equivalent in size really

How is a td05sh 18g different to a t518z? From what i have seen they are the same turbo?

Can you tell me how they are different? Because this just sounds to me like the guys that were claiming a hks gt-rs is different compared to a gt2871r 52trim which are clearly pretty much the same turbo except one has an hks badge.

I agree with you about ballbearings they arent the be all and end all of how a turbo responds.

I doubt its only oil cooled because they put more research into it that just doesnt make any sense. If i get a choice over an oil cooled t518z and an oil and water one its not a difficult question which one im going to choose.

correct im talking about the differences between spool with a ball bearing verse journal bearing turbo, ball bearing turbos can be up to 1000rpm faster in full spool and spool sooner in the RPM band depending on the AR. the drag isnt going to be extremly noticable, in fact you probably wouldnt notice the drag, BUT the rpm difference in spool is what sets dbb apart from just journal bearing.

ball bearing turbo are also going to bring in power sooner in the rpm range which might be boost for people with larger AR and dont want to sacrafice a short rpm band for the larger AR so they go with the ball bearing to get a slight edge on having a larger turbo.

im not saying ball bearing are ''all be all'' but they are efficent in boost response and full spool, i have had journal and ball bearing and i agree that the ball bearing do have somewhat of a smoothe spool, as my 2871r the spool is hard but its seemless its not a on off type boost response, its a seemless booth response and that i like not sure on others.

Nobody is saying they are different. The T518z is part of greddy's "compact line" from reading on there site. The compressor housing itsself looks smaller as weve already mentioned here. The Real 18g's housing is huge and has a 3" velocity stack built into the turbos intake. Also the turbo is indeed Oil cooled only. Why did greddy do this? So that the turbo could be installed easily on cars without stock turbo's for there kits. There are actually advantages to being oil cooled only...

Anyway, I have driven a built SR20 with a 2871r @ 20psi and all ill say is that they feel the exact same except my turbo feels like it has more tq at 20psi. They may start spooling at different times. But at 3500rpm i also have 10psi. 7lbs comes in right at about 3000-3200depending on how hard i hit the gas and what gear im in. I also have full spool by 3800 no matter what. The 18g pulls hard all the way to redline also.

do you know exactly how much power you are putting down at 20psi? jw. i definitly feel turbos are application specific and not just application specific but also opinion specific, some people like large turbos some people like small turbos, just really depends on how your setup like it which equates to how it feels to you driving it.

ok the wheel sizes are slightly different, not by much but they are, defiantly. Now i have also heard that blade angles and metal used are slightly different, but i cant confirm this. But the t518z is based o the td05 18g. This is not like hks and garret where they are the same turbo and garret basically outsourced some rnd with the benefit of hks having exclusivity for 5 years

here is a couple reasons why oil cooled is better, keep in mind greddy recommend an oil cooler with their turbo's.

1, at track days you dont have a hot turbo warming your coolant.
2, less lines to leak and go wrong
3, less problems caused by contamination in coolant
4, water cooling is is not needed unless going ball bearing as ball bearing turbo's wont accept as much oil due to their design