Ive read and heard about different turbos being used on the YB engine, so Now i want to make a thread where people can add rolling road graphs inc spec and their opinion of their turbo, Would help many people out.
A simple explanation of different turbos to my knowlege
T25 fitted to the small turbo escort cosworths, this turbo isnt used by many as it runs out of puff at the high 200's, quite a rare turbo.
T28, this is good for low 300's and is a good small turbo that comes on boost very early, But very rare as was only fitted to the 67 rouse cosworths, Once again not many people use this turbo as for the money its easier and more sensible to go for a t34.
T3, The original turbo fitted to 3 door and sapphire cosworths, good for around 320bhp( give or take a few bhp) Turbo gives a good kick and is responsive, cheap to buy and many around
T34 is the turbo fitted to big turbo escort cosworths, Which can be bought 2nd hand for £300-500 on average, All round good turbo,Punchy and reliable, Theres 3 different variations of turbo housings, .48, .55 and .63 ( .63 being the biggest)
.48 will max out @ 370bhp so ive been told by msd as james has proven this, the .48 is a good punchy turbo which comes on boost early and produces good figures!
You can get around 380/5
.55 is the mid range, rare turbine housing
.63 Is the biggest size of housings, ive been told once again by MSD that this housing is good for 400-420 on a standard engine.
Standard engine with a t34 wouldn't see 400 without compromising turbo life expectancy big time and deffinately wouldn't do 420 unless the engines had some serious work
T4, This is a alot bigger turbo than the above, getting rare to find now days, the T4 was fitted to the rs500 from standard, Its good for 500-550bhp, But is a laggy old brute compared to a t34.48 for example, Many people used to use this back in the 90's as there was no variant to make over 450-500, How ever now days we have the....
Gt30 range of turbos, starting with the
Gt3071r and Gt3076r, These turbos are costly new, ranging from £900-1100, Theyre direct bolt on and are good for 500bhp, the difference in the 71 and 76 are the size of the compressor housings, The 76 will make more power than the 71, Theyre good for 450-500+bhp Plus maintain drivabilty, mark shead from MAD mapped a car on a gt3071r and managed to make 2.2bar of boost by 3700rpm!
The difference between 3071/3076 is the size of the compressor wheel also, its a bit bigger 
Moving along from the GT30 range are GT35's
These are turbos that are similar to the gt30's, but are for alot more power, 500-700,I havent really looked into these much as ive never thought about over 500bhp, But theres quite a few options for these, example a gt3582r is good for 600-630 bhp, capable of over 2 bar bar,they can make this by early 4000 rpm.
Cheap chinese turbo's Like TO4E and T70...
The TO4e is a cheap turbo, good for 400-450bhp, The turbine housing is similar to a t3, .50 and the compressor a t4, these turbos Can be ok but are nothing compared to the build quality of a garret.You can pick these up for as little as £150 new.
T70, good for 600 bhp, its a cheap alternative of a gt35 but once again misses quality, you can pic these up for £200
Ive also seen Kkk27 turbos and other variations used on the YB engine, this isnt a proven guide, its just a rough estimate of what i know to my knowlege, as i asked at the top of my thread i would like graphs and spec please, and what your car drives like and what your opinion is, this would be great and would help me and others out
If theres anything you want me to change please say and il edit!
cheers!