There have been 3 Generations of this turbo.
What you have is in fact a PT71 GTQ turbo. The 71 means it has a 71mm inducer compressor wheel and in this case it is the first generation Borg Warner billet compressor wheel. The 80 means it has an 80 trim GTQ turbine wheel. Hence the 7180 number. The GTQ turbine wheel was a re-machined Garrett turbine wheel, modified to specifically fit inside the standard T4 bearing housing. Those notches you see in the compressor wheel are balancing notches that BW used when they balanced the compressor wheel at their factory. The second Generation had the same Borg Warner compressor wheel, but the turbine wheel changed to our HP series HPQ turbine wheel. At that time, the part number changed to 7168. 71mm compressor wheel and 68mm exducer turbine wheel. When we brought out the HP series turbos, our part number structure also changed. Instead of the last two digits meaning the trim of the turbine wheel, it changed to the exducer of the turbine wheel. The third and final Generation of this turbo, is what we sell today. It features our latest CEA billet 71mm compressor wheel that we manufacture and the HPQ turbine wheel.
The turbo you have is rated to support 880 flywheel hp when maxed out and has pushed TSM class legal Buicks into the 9.00's. When the HP series turbos came out, the previous GTQ series units were discontinued. This was back in early 2007. Also, just so you know, it would not be cost effective to try to upgrade this unit to current 7168 specs, as there is nothing that could be re-used for the conversion. When it's all said and done it would wind up costing you more to upgrade it, than buying a new 7168 turbo.
This is why you see people selling off their used 71 GTQ turbos. With regards to your setup, if you are trying to make 750-775 rear wheel hp, this turbo would work nicely with the T4 housing. As long as it doesn't leak or have an excessive shaft play or show any signs of the compressor wheel rubbing the compressor cover, you should be good to go.
Hope some of this helps.
Patrick
