The T28 is one of Garrett’s older line of turbochargers while the GT25 (pictured above) is from the newer GT series of ball bearing turbos, both of these turbochargers have similar power ratings, and can both be had for around the same price, but how well do they deliver the power?

The GT25 turbo is a newer and more efficient design than the old T series, so they spool up quicker and being ball bearing the GT’s are more reliable and they are also the smallest dual ball bearing turbo in Garrett’s GT range where as the smaller units like the GT22 are only single ball bearing.

Both of these turbochargers are super responsive due to the small size and they spool quickly, you can feel the T28’s power coming on at 3800-4000 RPM but as the GT25 newer, more advanced and is a ball bearing you can really feel it coming on at 2500-3000 and pull strong all the way up to redline. Both of these being excellent street turbos for sport compacts.

The T28 is a journal bearing turbocharger rated at 250hp however some JDM manual S15’s and S14’s came in a ball bearing version which is rated at 260hp, they also came with different A/R’s on the turbine housing. Both turbo’s are oil and water cooled, even on the ball bearing version of the T28 the maximum safe boost you can run is limited to 15 psi, anything beyond this is outside of its efficiency range and all you would be doing is pumping hot air into the motor and you are more likely to blow a hole in the piston. Also be carefull on which T28 you buy as there are many versions, the SR20 has an 0.60 A/R housing and GTR version has a 0.42 A/R, if you plan on a single turbo setup then the GTR’s 0.42A/R will be useless as you will have no top end power and blow the turbo or your motor very quickly. You can’t really buy a T28 new but they can be picked up for around $500 second hand.

The GT2554r is dual ball bearing turbo that is rated at 270hp but has seen figures on mildly work SR20’s of 300hp and has a maximum boost pressure of 18-20 psi, which it a lot of boost for a small turbo, its super responsive and really spools early and not to mention its also highly reliable, brand new you can expect to pay around $1500 and it’s a bolt on upgrade so no messing aroud.

Again the turbo you choose should be depending on your mods and goals, if its only a street car with nothing but a pod filter and blow off valve then I would suggest the T28 as they are cheap and easy to find and make a great replacement if you have blown you T25, but if you plan on installing or already have supporting mods such as a larger intercooler, dump pipe and ecu/ tuning upgrades then the GT25r is certainly the turbocharger for you.

Tech Specs – GT2554r
RRP $1500
Max Psi: 18 – 20
Rated HP: 270-300

Tech Specs – T28
RRP $500 Second Hand
Max Psi: 15
Rated HP: 260