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

You hear a loud whistling noise followed by a BA XR6 turbo nailing past you, that’s Garrett’s ball bearing GT3540 working hard, the GT3540 has to be one of the best matched turbos to a production car since the CT26 on the MR2 and Celica, producing a nice 320hp with only 5psi of boost (on the BA – BF models, FG runs 9-10psi).

The housing and centre are standard GT35r Garrett gear, so anyone who thinks the GT3540 is unique then your dead wrong, Garrett doesn’t list the GT3540 as a turbocharger but the compressor housing and cartridge are identifiable to the GT35r, but the turbine housing is one of Ford’s best contributions to the turbo world, an internally gated 1.06 A/R 5 bolt housing, this is great if you want to upgrade a stock turbo on another car and keep it all internally gated for that stock appearance, a lot of people retrofit the GT3540 turbochargers to older cars such as the VL turbo or and RB25’s due the availability and reliability of the Garrett ball bearing turbochargers oh and did I mention the GT3540’s hp rating of 400hp – 600hp?

The stock wastegate isn’t much chop with only a 5psi spring and if you know the rule of wastegates you should only be running a maximum of double the spring pressure, so if you plan to use a boost controller to crank up the psi then you should only be using a maximum of 10psi, but fortunately Turbosmart has a nice solution for this, the bolt on WG75 wastegate for the GT3540 with interchangeable springs depending on your desired boost level, for the same price as an electronic boost controller you have have a wastegate and spring fitted for the stock appearance and less of a defect chance.

The standard Ford turbine housing is a 1.06 a/r so if you are planning to use the GT3540 on a smaller engine like an SR20 you might want to change to a .86 or .63 housing for better response and quicker power delivery.

RRP $1650

Tech Specs

Rated HP: 400-600

GTX3076r with 4″ anti surge compressor cover

The advancements of ball bearing and billet compressor wheels, did I hear someone mention garrets new GTX range of turbochargers?

Anyone who is looking at a faster spooling long lasting ball bearing turbo with power goals of 450HP – 600HP, then you just can’t look past the GTX3076r from garrett, featuring a billet compressor wheel with 11 full height blades that will spool around 500rpm quicker than the older GT3076r.

Now if you take a closer look at one of the older GT series and other similar turbos from the late 90s they run full heights next to a inner set of half heights, running full height blades will give a turbocharger a higher HP rating but you pay for it in lag due to the heavier compressor wheel, but this problem is solved by changing the wheel from cast to billet.

The new GTX3076r has a very similar flow rating and compressor map as the GT35r but with out the need for a larger A/R on the exhaust housing for the higher HP so it spools a hell of a lot quicker.

The GTX series of turbo’s are sold as a compressor cover and CHRA, so you will need to get your own turbine housing, the housings are the same as the old GT series in the case you are upgrading from a GT3076r then you are able to keep the same housing, but if buying new you do have the option of 4 bolt, V-band, twin scroll, internal gate, .63 A/R, 0.82 A/R, 1.06 A/R.

RRP $1600

Tech Specs

Rated HP: 640

After a few requests I have been looking into Kinugawa’s range of Turbos and the high flow kits they offer for the CT26

First off looking at these kits, they do seem reasonably priced for upgrading your stock CT26 to hold a bit more boost, although they don’t mention the fact that you will need to have your cartridge machined out to support the larger wheel, at the same time it would also be wise to have a rebuild and balance, after all there is no point in running 16psi on a high flow if your going to be pissing oil out of your seals.

Kinugawa mainly sell though eBay retailers and the title mentions a Garrett 60-1 wheel. Further looking into the kit, the supplied wheel is only listed as 60-1 wheel, and inspect the wheel closer you can see they have removed portions off the side of the wheel for balancing, which may I add high end manufactures have never been know to do, maybe a stock turbo but never with a quality after-market wheel have I seen these techniques used, all the big names such as KKK, Garrett & Holset machine small amounts off the bottom of the wheel so it will no affect its circumference. If you compare their photo of a stock wheel and Kinugawa wheel own you can tell that there wheel is cast not forged or billet. Adding together a cast wheel with what appears to be poor balancing techniques I would not trust this turbo spinning at 200,000rpm, if their wheel were to shatter you’re pretty much pointing a shotgun into your intake system.

The initial price of the kit is $200 for a compressor wheel and housing, a rebuild and balance will set you back around $450 and the machining will also cost around $100 odd dollars bring the grand total to $750~$800. I personally would not recommend this option, it does not seem worth the risk. If you want to High Flow a CT26 do it right and spend an extra $200 to have a Proper wheel fitted and I would also use a 57 trim wheel as EMS have done there own research proving it to be the best option of a high flow, or just upgrade the whole turbo depending on your power goals.

The notorious T67 Turbo from Trust / Greddy is hands down one of the more popular 750HP rated turbochargers due to its quick spool.

The T67-25g is a large hybrid turbo from GReddys T-power spec Turbos that are known for reliability despite the fact they are oil only turbo’s meaning they aren’t water cooled and also offer the great performance for the street and competition. The T67 is recommended for engine sizes 2.5L – 4.0L, has two exhaust housing options of 8cm & 10cm with V-band outlet and incorporates an extra large free-floating journal bearing with a large diameter center shaft for longer lifespan.

Garrett’s popular GT35r is the most comparable turbo to the T67-25g, in both size and hp rating but the T67 is more sought after as it’s known to spool up 500rpm faster that the 35r if you choose the 8cm housing, there has been some speculation that the T67 turbo is extremely laggy but its mainly due to the use of the 10cm housing, like all turbochargers you must choose the correct size housing as it will determine how much usable power, response and how streetable your turbo is.

Although stated that the T67 Turbo is for use on engine’s sized 2.5L – 4.0L, it is available in bolt on upgrades kits for 2.0L engines such as the MR2’s 3SGTE, matched on small engines it should only be used in high end performance as it will hit 20psi by 4500k and hold right through til redline.

The compressor housing has a 4″ inlet and 2.5″ outlet with slip-on connections, The ehxaust housings are divided T4 flanged with 3″ V-Band discharge. To sum it all up its a great alternative to ball bearing turbo’s as for the price of a decent ball bearing tubby you will get a whole bolt on kit with a T67 turbocharger.

RRP $2200

Tech Specs

Rated HP: 750

After getting numerous emails requesting a good bolt on upgrades for the WRX’s so they could ditch the TD04 for a better spooler. After a lot of searching and asking a few pro’s the most recommended and reliable option was the APS SR56. One thing was clear the WRX lacked top end power and the drives wanted a larger exhaust housing for a better power curve and APS built it.

The APS (Air Power Systems) S/R56 series of turbo is dual ball bearing, single entry, oil and water cooled turbocharger that is known as one of the best bolt on upgrades for the WRX STI, although its bolt on you will have to ensure you have the right oil & water lines as they differ between models.

A HP rating of 550 is a big claim when your not a very large manufacturer like KKK or Garrett, however if you search the WRX forums you will see few examples of 25psi by 4000rpm and STI’s hitting 500hp at 22psi with supporting mods. The element that stands out the most on this turbo is the wast gate, a Forge piston type actuator that is made from billet aluminum to higher temperatures.

When buy APS turbo make sure you choose the turbo that suits your application the best, while doing research I have seen one example of the SR56 being used as a stock replacement and only seen a 10hp gain on the dyno, that and also the S/R series are very similar in price.

RRP $3000

Tech Specs

Rated HP: 550

The Trust Greddy TD06-20g is a widely known JDM turbo that is commonly sought after for a pro street turbo upgrade with a max boost of 30psi and 450hp rating if your thinking of upgrading the turbo on your MR2, WRX or Silvia this little baby will certainty pack a punch.

The TD06 is a journal bearing, single entry, oil and water cooled turbocharger that is built my Mitsubishi and is recommended for engine sizes 1.8L – 2.2L in high boost applications.

Rated at a max of 450hp and flow of 640 CFM, the TD06 is amazingly similar to Trusts more popular T67 Turbocharger which is a modified TD06 to begin with, whilst the TD06 is rated at 550hp it’s more laggy compared to the TD06-20g due to the larger sized exhaust housing.

A particular advantage that the TD06 hold is the fact that it is available as an internal of externally gated turbo with different size housings available to suit different applications, however due the the fact that both Greddy TD05 and TD06 use 3 bolt turbine flange and dump pipe, it does limit them to fitment and usually means a custom manifold, down pipe or adapters are required, but for the price you pay and the reliability of the Mitsubishi manufactured and Trust / Greddy Design its worth it.

RRP $1400 ($300 Secondhand)

Tech Specs

Rated HP: 450

The CT15b Turbo is one of Toyota’s well engineered blow dryers capable of providing 400hp, It was designed purely for 1jzgte to eliminate the twin turbo setup without loosing response or power but it also improved the maximum torque by about 4% and is 25% more efficient than ct12 setups.

A stock CT15B is rated at 400hp / 225KW and once high flowed it can snap out 450hp / 270kw, the stock unit has a max boost of 16 – 17psi. It is common practice to see the CT15B high-flowed, one option is to use a 20G compressor and bore the comp cover to suit, this will give you he 50 -70hp increase and as the 20g compressor wheel is a better mapped for volumetric efficiency you will have one super responsive turbocharger.

It uses Toyota’s own flanges on the exhaust housing inlet and their 4 bolt rectangular outlet and incorporated a internal waste gate that will open a 6-8 psi depending on the year and model of car. Its not a twin entry and 90% if the CT15s run ceramic technology and are both water and oil cooled. Looking at the dimensions of the compressor and turbine wheels it is very similar to the CT20b and it probably is one of the best turbochargers Toyota has developed.

RRP $1200 ($300 Secondhand)

Tech Specs

Rated HP: 400/strong>

After doing research on Diesel Turbochargers, I was quite annoyed at the low amount of information available on Holset Turbos, and after having a read up on lots of forums such as dsmtuners I discovered there are a number of JDM car’s using them to upgrade their turbos.

Today I will start of with the Holset HX35 Turbo, This is in fact rare to be seen in unleaded applications due to the fact it was built as a Diesel Turbocharger. There are two variations the 7 blade compressor and the 8 blade compressor. Early versions of the HX35 flow 52lb/min and run a 56mm 8 Blade compressor, These are a popular upgrade for the RB25, whilst being a large Turbocharger it does push upwards to 500RWHP with the right modifications, one car on dsmtuners was seeing 20psi by 3500rpm, not that’s a pretty good achievement in a RB25 considering that a GT40r would hit 20psi at 4000rpm onwards but also seeing that the HX35 is in between a GT35r and GT40r the key to the fast spool is getting the right houseing to suit your setup of its welcome to lag city.

The later Version is also a 56mm compressor but is 7 blade wheel, the one less blade enables the HX 35 to flow 60lb/min, both versions have the option of a T3 flange turbine housing or Divided Twin-Scroll T3 flange housing and like most popular turbochargers you have the downpipe option of 4 bolt of v-band. The 7 blade coupled with the Twin-Scroll has been proved to throw down 600whp on modified cars.

Being built by Cummins the Holset HX and HY range of turbos have proven to be robust and supper our cause for high HP, if you can find one cheap it will be a worthwhile upgrade, the main thing to consider is that when you blow a wheel, shaft or bearing you may be in for a wait as parts are not the easiest to come by.
RRP $1300

Tech Specs

Rated HP: 500~600

Garrett’s GT40 just screams out potential when your glancing into the compressor inlet. Garrett has always done a great job at engineering turbo’s especially for the jap crew, however the GT4088r is a funny turbo because it’s rated at 370 – 650hp but it’s recommended for use on 3.5 – 5.0L engines, so it would be ideal for 6 cylinders or larger, I did find it funny that after doing research we found a lot of Honda boys running the GT40’s.

Again a straight forward set up like all Garrett’s mid range turbos, oil and water cooled CHRA, external waste gate, T4 flanged twin scroll turbine housing, it also does feature a ported compressor housing to increase protection against surge. Being such a large ball bearing turbo and for its price it certainly is a steal, great for any low RPM large displacement engines, but I would not recommend it on a Honda Civic.

RRP $1900

Tech Specs

Rated HP: 650