| Has anyone tried running a GT25 turbo? After figuring out proper turbo sizing for our engine, it seems that the GT25 is smack in the middle of what that size should be. To put it in perspective: Stock is a TB02/22. I guess with today's names it would be a "2220" (remember that these names are usually derived by the turbine wheel and the compressor wheel. Hence a GT2530 has a GT25 turbine and T3 compressor) The JWT Sport 500 is about the same size as a stock turbo, with slightly larger wheels. It has a T25 turbine in a stock sized housing. It's roughly a "2520" The old Garrett T28 has a T25 turbine and T3 compressor. Therefore it is the "T series" ancestor of the newer "GT series" GT2530 And as mentioned before the HKS 2530 has a GT25 turbine and T3 compressor. The stock sized turbos such as the JWT Sport 500 have great spoolup and good power, but leave a little bit to be desired in the top end. They're also T series instead of GT series so you could gain a little efficiency if you went with a newer GT series design. The larger turbos such as the GT2530 and Sport 700 make great top end power but are too laggy for my taste. The newer GT series design sure helps but it doesn't change the fact that they're oversized for our car. Much of their top end power will never be realized on a street driven Z but the lag will always be there to nag you. This brings us to the GT25. It's slightly larger than the Sport 500 but smaller than the 2530. Its turbine wheel is a 25 size like both the Sport500 and 2530. However, like the 2530 it has a newer GT25 series turbine design in the proper housing, unlike the Sport500 with its older T25 turbine in a smaller housing. On the compressor side it has a 25 size wheel which is in between the T2 wheel of the Sport500 and the T3 wheel of the 2530. The compressor/turbine set is a matched design by Garrett so you know the performance of the compressor and turbine work well together. On paper at least it seems like it would work great with ball bearings and the proper spec housings. So has anyone tried these, or would this turbo be the same or similar to what's already marketed, such as the JWT 530's and GMS 550R? Just something to ponder on a calm day at work. Any input is appreciated.
 |
