One commonly discussed subject is that of low-mount turbocharger options for the SR20DET Silvia. Indeed there are quite a few options out there, but I thought I'd make an attempt at drawing a picture of some of my findings over the last few years in industry.
In this article we'll strictly address the line of Nissan Silvias in the 2.0L turbocharged variety (the most commonly modified one). Whether it be for the thick-skinned 13, old-famed 14, or fast-maturing 15; the low mount turbo for the SR20DET is a strategic option for those chasing a quick and nasty power upgrade, with as little fuss as possible.
Before we begin, just a few acknowledgements to a few peers who have been my teachers, guides and mentors. Thanks to Chea of Powertune Australia for his undying passion and untiring inquisitive spirit who is always on a personal mission to perfect the turbocharged injection engine.
Also, a warm thank you to Sunny, my old, grumpy and curious friend who for years has endured my incessant questioning. Along with him, thank you Kemp (STR8E180) also of Powertune Australia for his ever fervent pursuit for maximal performance in street-car modifications. To you two guys, I also say thank you for building me a "Super Duper".
Without you all, this article would not have come about so detailed.
We'll be comparing several notable factors that stand out to comparing these turbos. They are:
Price: Rough price on these turbos brand new and second hand if available
Affect on performance: What performance changes can be expected
Ease-of-fitting: Testing how close it is to being a true 'bolt-on' turbo
Construction: Materials and/or manufacturing process used
Pros: The good
Cons: The bad
Common Demographic: Common buyers of this turbo
I'll aim at covering the market-share of tried, tested and proven turbochargers, so although there may be a list of turbochargers which suit the testing criteria, if you don't see it here, it's because it's not something I've seen a lot of - thus can't really comment on.
All tests were carried out with SR20 Silvias that are at what I have affectionately dubbed, "The Stage 1 Level of Modification". A Silvia at Stage 1 generally means it reps a fmic, full turbo-back exhaust, boost controller, fuel pump upgrade, injector upgrade aftermarket ECU, Z32 AFM (or MAP sensor) and a tune - AKA "The usual mods".
Onto the comparo.
The Comparo
Garrett GT2560R A/R 0.64
Also known as "The Jap spec turbo" (Sorry Kenji), or the "T28BB," this turbo came factory standard with Japanese delivered S14s and S15s. It's a popular choice for many Silvia owners who didn't have this turbo on their cars from factory (ie all S13s and all Aussie spec S14s and S15s).
Sure enough against the tiny T25 that came with all S13s, it's a an upgrade. However, this guy is not much of an upgrade when compared to its S14 and S15 journal bearing counter-parts.
Many gurus will argue that the ball-bearing variant will spool up quicker and make a little more power than the journal-bearing version. However, I'm yet to find a single soul who can pick the difference between either turbo when measuring in-the-seat-of-the-pants experience - because I can't.
This turbo is a popular choice because you can get away with fitting it to a factory SR20 Silvia without having to retune it (not that it's a good idea). Furthermore, it's cheap. You can pick one up second for a couple of hundred bucks max, or brand new for about $1400.
Price: Approximately
$1400 brand new or $200-$400 second hand
Affect on performance: Approximately 200rwkW on a Stage 1 setup @ 18psi on pump fuel. Response as standard.
Ease-of-fitting: Direct bolt on. Recommend braided line kit.
Construction: Cast aluminium front housing, cast iron rear housing, forged aluminium compressor wheel, steel turbine wheel, steel ball-bearings.
Pros: Cheap, an upgrade when compared to the standard S13 T25.
Cons: Not
much of an upgrade at all.
Common Demographic: Those looking to replace their damaged standard turbo.
Garrett GT2860RS A/R 0.64 or 0.86
Named affectionately as the "Disco Potato". The story behind the odd nomenclature originates from the U.S of A. Many moons back when this turbo was first developed, it was tested on a poo brown Nissan Sentra.
Although it only put out a meager 209kW at the wheels, the judges were highly impressed by its torque and lack of turbo lag. The poo brown Sentra would dance like it was 1999, earning the name "The Disco Potato". The turbo immediately adopted the name of the car it was tested on and has been known as the Disco Potato since.
This turbo was once a favoured upgrade for the SR20DET Silvias. It was a direct bolt-on replacement, relatively cheap and although didn't offer gigantic power upgrades, certainly did (and does) provide a big torquey kick in the pants.
A lot of people got into the habit of strapping this onto their setups without a tune. I remember one of the first 180SXs I had ever test driven and considered buying repped a Disco Potato with no tune. Oh memories.
One common mistake I've come across is this turbo being mistaken for the GT2871RS or GTRS listed below. Comes in both 0.64 and 0.86 A/R, both which are popular.
An energetic little turbo that will provide plenty of fun to those who don't demand massive power.
Price: Approximately
$1400 brand new or $800 second hand
Affect on performance: On the 0.64 rear housing - Approximately 200rwkW on a Stage 1 setup @ 18psi on pump fuel. Increased torque and response from the standard turbo. Very snappy.
On the 0.86 rear housing - Approximately 220rwkW on a Stage 1 setup @ 18psi on pump fuel. Higher torque but lower response from the standard turbo.
Ease-of-fitting: Direct bolt on. Recommend braided line kit.
Construction: Cast aluminium front housing, cast iron rear housing, forged aluminium compressor wheel, steel turbine wheel, steel ball-bearings.
Pros: Cheap, an upgrade when compared to any standard Silvia turbo.
Cons: Not a large power upgrade.
Common Demographic: Those looking for a little extra excitement from the standard setup.
Garrett GT2871R A/R 0.64
HKS GT-RS A/R 0.64
Trust T518Z A/R 0.64 (Journal bearing only) (tiny bit more power and torque)
The GT2871R is commonly mistaken as the above mentioned Disco Potato. If you know how or why this came to be then I would love to hear it!
This turbocharger once used to (and still does to a degree) dominate online forums as being one of the best or most highly rated turbochargers for a street-driven SR20DET Silvia. Being (at the time) the largest low-mount, true-bolt-in turbo solution, it's not hard to see why.
However, compared to the standard unit, the turbo is a little on the lazy side and although offers a decent power upgrade, is often criticized for not justifying the amount of lag it introduces (All the tease, none the squeeze). This is particularly apparent in the 0.86 rear housing (heaven knows who or what convinced those poor souls to purchase this already laggy turbo in a 0.86!).
Overall, a tease. The GT2871R has a bark that is a lot more impressive than its bite.
Note: The T518Z is a journal bearing turbo and generally sees slightly higher power figures than its ball-bearing counter-parts. Because of such a small difference in testing criteria, I feel it's appropriate to bundle these turbos together.
Price: Approximately
$1500 brand new or $1100 second hand
Affect on performance: Approximately 225rwkW on a Stage 1 setup @ 18psi on pump fuel. Similar torque to the Disco Potato with a significant decrease in response from the standard turbo.
Ease-of-fitting: Direct bolt on. Recommend braided line kit.
Construction: Cast aluminium front housing, cast iron rear housing, forged aluminium compressor wheel, steel turbine wheel, steel ball-bearings (except for the T518Z).
Pros: Popular. One of the larger true bolt-in, low-mount turbos
Cons: Teaser, all the promise, none the delivery. Overrated.
Common Demographic: Those who wanted the promise of power and response in a low-mount turbo before the advent of the GTX2863R. Those who didn't want to make the modifications for a GT(X)3071R.
Garrett GTX2863R A/R 0.64
The Garrett GTX2863R is a recent addition to the market and is positioned to replace Garrett's ageing GT2871R. Sporting the GTX format means that this turbo reps a billet compressor wheel and 11 intake fan blades instead of the traditional 6.
A very promising turbo which has seen some great results so far, this turbo is very snappy. It offers much quicker response than the GT2871R and more power. However, it's not a true bolt on turbo kit.
Modifications to the intake pipe (if not a custom intake pipe) and hot-side intercooler pipe are needed to fit up to this turbo.
I'd like to think that this is the turbo that every GT2871R owner expected when they bought their turbos. It offers both power and response. When performing, it is sure of itself and delivers power confidently.
Price: Approximately
$1500 brand new
Affect on performance: Approximately 240rwkW on a Stage 1 setup @ 18psi on pump fuel. Increase in torque not too much decrease in response from the standard turbo. 270rwkW on E85 with the right supporting mods (exhaust manifold, 1000cc injectors).
Ease-of-fitting: Not a true direct bolt on - requires modified or custom intake pipe. Recommend braided line kit.
Construction: Cast aluminium front housing, cast iron rear housing, billet compressor wheel, steel turbine wheel, steel ball-bearings.
Pros: Significant power upgrade from factory. Responsive. New.
Cons: Not a true bolt on turbo.
Common Demographic: Those who may have wanted a GTX2871R but held out.
Precision 5130
Now here's one that's really fresh off the press. Manufactured by Precision Turbo and Engine from Hebron Illinois, this unit is exclusive only to Powertune Australia and Rotormaster in Sydney Australia. Although it may have only entered the market recently it already boasts some impressive results.
Currently, it's the most power-productive, low-mount, direct bolt-on turbo that is available for the SR20DET Silvia. Being a true bolt means that any Silvia sporting its standard turbo can upgrade to the Precision 5130 without any modification needed to the intake pipe, hot-side intercooler pipe, dump pipe and exhaust manifold.
So far this turbo has made 260+rwkW on 98RON in an S15 with a complete standard engine (Stage 1 setup) and 320+rwkW on the same setup on E85. There was still more in it on E85 however the fuel pump in that setup would not push any more fuel - It was only a Walbro 255Lph after all.
(On that note, ensure you have a read up on my fuel pump comparo to find out why the Walbro 255Lph fuel pump wouldn't be a good choice for this turbo).
I'm still yet to see what this turbo is capable of when pushed harder. So, if there are any takers out there who are keen to see how far this turbo can go, drop me a line.
Price: $1888 brand new
Affect on performance: Approximately 250rwkW on a Stage 1 setup @ 18psi on pump fuel.
320+rwkW on E85 with the right spporting mods (stage 1 with 1000cc injectors and E85 ready fuel pump).
Ease-of-fitting: Direct bolt on. Recommend braided line kit.
Construction: Cast aluminium front housing, cast iron rear housing, billet aluminium compressor wheel, steel turbine wheel, steel ball-bearings.
Pros: Significant power upgrade from factory. Responsive. Largest low-mount, true bolt-on turbo available on the market
Cons: Rare. Price changes according to exchange rates (can be a pro too)
Common Demographic: The power-hungry experimenter.
Super Duper
This here turbo is a bit of a surprise entrant. It's only the third of its kind to have ever been crafted and of the three that exist, none are exactly the same. So although it's not available in commercial quantities, because it's an experiment that I'll be getting involved in, I thought to add it to this list.
Dubbed the "Super Duper" by its creator(s), this turbocharger is in its other forms, a completely low-mount, bolt-in unit. Of course the one you see here is reps a V-band rear housing which was a request by yours-truly for the want of externally gating the turbo.
One of the other instances of this turbo went off to achieve a punchy 280rwkW on 98RON on a standard motor with drop-in cams. I'm wanting to see what it's going to do on E85. I'll write on results as they happen.
Price: Custom jobby
Affect on performance: 280rwkW on a Stage 1 setup with drop-in cams on pump fuel.
320+rwkW expected on E85.
Ease-of-fitting: Direct bolt on. This one in particular requires a new v-band dump pipe.
Construction: Cast aluminium front housing, cast iron rear housing, forged aluminium compressor wheel, steel turbine wheel, steel ball-bearings.
Pros: Very significant power upgrade from factory. Responsive. Largest low-mount, true bolt-on turbo available on the market.
Cons: Rare. Doesn't officially exist.
Common Demographic: The power-hungry, low-mount extraordinaire
Garret GT3071R A/R 0.64
Garrett GTX3071R A/R 0.64
Not to be taken lightly, the Garrett GT3071R or GTX3071R turbos are by no stretch of the imagination a simple and true bolt-in turbocharger for the SR20DET. In fact, this turbo is much more commonly found in the high-mounted position when strapped onto an SR20DET.
The only reason why this turbo even features in this comparo is because it has countlessly been "forced to fit" the low mount role by the will of power-addicted owners with a penchant for clever ingenuity.
This unit will low-mount with the help of a custom-fabricated aftermarket exhaust manifold. A modified or custom dump pipe will need to be fabbed up, as would an intake pipe and your hot-side intercooler pipe. Additional to this, the engine mount will need some "modifications" made with an angle grinder. Definitely not a bolt-on turbo.
The relative costliness and requirement for lots of modifications, this setup defeats a lot of the purpose of choosing a low-mount turbo in the first place (cheap and easy). However, with the trade of repping power levels starting at 250rwkW on a Stage 1 setup, it's not hard to see why it attracts a lot of fans.
Price: $2,200 brand new
Affect on performance: Approximately 250-270rwkW on a Stage 1 setup on pump fuel.
330+rwkW on a E85.
Ease-of-fitting: Not a direct bolt on - requires new intake pipe, custom exhaust manifold, hot-side intercooler pipe, custom dump pipe, braided line kit.
Construction: Cast aluminium front housing, cast iron rear housing, billet aluminium compressor wheel, steel turbine wheel, steel ball-bearings.
Pros: Significant power upgrade from factory. Largest low-mount option available for the SR20DET.
Cons: Pricey. Not a simple bolt on - lots of modifications required.
Common Demographic: The ones who can afford it.
In summary
|
Affordability |
Affect on performance |
Ease of fitting |
Thumbnail |
| GT2560 |
 |
 |
 |
 |
| GT2860RS |
|
 |
|
 |
| GT2871RS/GT-RS/T518Z |
 |
|
|
 |
| GTX2863R |
|
 |
|
 |
|---|
| PTE-HP5130 |
|
|
|
 |
| "Super Duper" |
|
|
|
 |
| GTX3071R |
|
|
|
 |
This chart pretty much wraps up my thoughts and experiences on the range of low-mount SR20 options I've had the pleasure (and often displeasure) of working with over the last several years in industry.
Hope this write-up was able to clarify a few things for you my discerning reader. If you have any questions about this write-up, then please do leave a comment below.
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Low-mount turbo
