Category Archives: TMIC

Ej20, EJ257, Subaru, TMIC, Transmission, Turbo, WRX

Motor Mount install for Subaru Impreza WRX/STi

Motor Mount install for Subaru Impreza WRX/STi:

This how-to is based off a GR, but the concepts should be similar to a GD. I’m not sure how different the front subframe is or how it might interfere with the install.

Here is a selection of stiffer motor mounts:

Group-N motor mounts:

Group N Subaru Motor Mounts Set! Legacy Gt, Sti, WRX See Listing for Fitment!

Perrin Performance motor mounts:

Perrin Performance Motor Mount Kit Subaru WRX/STI 02-14

Torque Solution motor mounts:

Torque Solution Engine Mounts: Subaru Wrx Sti 2002-2016

I’m making this as a response to so many people saying that motor mounts are a terrible install. I think they’re cake, and I want to show why. I had originally installed the Tigwerks motor mounts, but their NVH was a little much for my tastes so I went to Group Ns, and that’s where this install was born (my second time through). I’d do it again and could accomplish the whole process inside of two hours with mandatory beer breaks.

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Ej20, EJ257, exhaust, STi, TMIC, Tuning, Turbo, USDM, WRX

Uppipe WRX upgrade FAQ

Aftermarket Uppipe FAQ for WRX/STi

Uppipe: The primary purpose of an aftermarket uppipe is to remove the catalytic converter housed within the stock unit. This serves two purposes: to increase horsepower and decrease turbo spool time.

uppipeaftermarket
Uppipe: The primary purpose of an aftermarket uppipe is to remove the catalytic converter housed within the stock unit.

HP gain is around 10HP. This figure is highly debated as different manufacturers use different dynos with different cars with different levels of mods. Dyno Proof Example. The general consensus for turbo spool time decrease is boost will occur around 500 RPM sooner.

Is an aftermarket uppipe a performance or reliability mod? With regard to swapping over from a catted uppipe to a catless uppipe, it’s both. Need some evidence of the reliability? View this link.

Which manufacturer is best? This topic is highly debated. There have been no reported consistent “bad” uppipes on the market. Obviously, there may have been bad pipes sold, but not enough to report as “bad” overall.

What uppipe metal material is best? Uppipes are made from mild steel, stainless steel (304 & 321), cast iron, and inconel. There is no irrefutable evidence that one material is better than the other. Obviously, corrosion levels are higher with mild steel (coated or otherwise) and cast iron. Corrosion on cast iron, due to it’s thickness and material qualities, is more resistant to corrosion damage than mild steel. In terms of heat retention, the best material is inconel.

Which uppipe construction method is best? Uppipes are either solid or flex. There is no irrefutable evidence that one design is better than the other. The thought process is that a flex pipe will reduce the chances of leaking. Practical application has shown that correct installation plays a bigger role than the uppipe construction.

What is the cheapest uppipe? Gut your stock uppipe. Instructions. Gutting your stock uppipe can have the same benefits as using a more expensive aftermarket uppipe. Dyno Proof.

Which uppipe has the best gains? There is no irrefutable evidence that any uppipe has better gains than another. The consensus, if there is one, is they are all within 1-2 HP, gain wise, of each other.

Where do I buy an uppipe?

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AWD, Ej20, ej20G, Intake, Intercooler, JDM, Legacy, Rally, Subaru, TMIC, Tuning, Turbo, UK, wrc

Legacy: 1989-1994 Subaru Legacy (BC/BF) GT/RS

Prior to the Legacy RS turbo, Subaru had never enjoyed the experience of distributing a genuine performance car. Of course, there had been the 4WD turbo RX and Vortex, but neither could crack 10 seconds for the 0-100km/h sprint – although they were very reliable. The RS was the gun version of the first Legacy series released in 1988 and discontinued in 1994. The RS (Rally Sport) model was aimed squarely at world rallying, with many of its components and concepts carried over to the dominating Impreza WRX.

Legacy: The BC/BF is unique in having an Air - Water intercooler with a front mounted radiator for optimal cooling. The bonnet scoop only provides cooling to the turbo. While later model legacy's have all used air to air intercoolers.
Legacy: The BC/BF is unique in having an Air – Water intercooler with a front mounted radiator for optimal cooling. The bonnet scoop only provides cooling to the turbo. While later model legacy’s have all used air to air intercoolers.

The center Viscous LSD on the MT models initially starts out with a 50/50 torque split, front and rear, and will up the ratio towards the end with more traction. The manufacturer doesn’t give a final figure, so the max split is either 65/35, or could even venture as high as 95/5, since the A/T model has a different system that is marketed at a 65/35 maximum split. A higher ratio would explain some of the handling characteristics at the limit. The rear differential is also a Viscous LSD model.

The BC/BF is unique in having an Air – Water intercooler with a front mounted radiator for optimal cooling. The bonnet scoop only provides cooling to the turbo. While later model legacy’s have all used air to air intercoolers.

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Ej20, ej20G, EJ257, JDM, TMIC, Tuning, Turbo, USDM, WRX

Turbo: STi/WRX VF Series Turbocharger breakdown:

Turbo: STi/WRX VF Series Turbocharger breakdown:

IHI VF Series
The numbering on both the VF turbos are for reference purposes and not necessarily indicative of its ‘performance’. On GC8/GF8 WRX STi, the VF turbos have gone ‘smaller’ from VF22 to 23, 24, 28, 29 while the release of the New Age STi GDB saw the introduction of a new breed of VF turbos with a bigger compressor wheel namely, VF30, VF34, VF35 for example. The previous VF turbos (VF22,23,24,28,29) have been ball bearing cored while the later ones (VF30, VF35) are Divided Thrust Bearing type core, with the VF34 being a Ball Bearing.

IHI VF22
(455cfm at 18.0psi, 250-325whp, Bolt-On)
The VF22 has the largest potential for peak horsepower. In other words, in the IHI model range, the VF 22 supports the highest boost levels. With its significantly increased turbine housing, the VF22 turbo is capable of producing upwards of 310 whp* on an EJ20. The downside of this turbo is the older center cartridge design and larger compressor housing, which makes for slower spool up but more top-end than the other VF series turbos.

This turbo is the best choice for those who are looking for loads of top end power. The top end power however, does not come without a cost. The VF22 spools significantly slower than the rest of the IHI models due to the larger P20 exhaust housing and is much less suited for daily driving than some of the other models. Although the largest VF series turbo, the VF22 is not quite optimal for stroked engines or those who wish to run more than 20PSI of boost.

The VF22’s compressor is rated at 35 lbs/minute. The VF22 was designed with the EJ20 in mind but because it has the biggest turbine in the IHI family it can be use on the EJ25 with a slight increase in performance. The VF22 is good for around a realistic 300 to 315 WHP on a 2.0L. The IHI VF-22 turbo is the largest of the VF-series turbos.

VF22: The IHI VF-22 turbo is the largest of the VF-series turbos.
VF22: The IHI VF-22 turbo is the largest of the VF-series turbos.

IHI VF34
(440cfm at 18psi, 250-325whp, Bolt-On)
The VF34 is nearly identical to the VF30, with the same exhaust housing and compressor. However the VF34 goes back to the ball bearing design, and in doing so achieves full boost approximately 500RPM sooner than the comparable VF30. The VF34 is the most recent IHI design and as such costs slightly more than its counterpart.

Top end performance and maximum output are identical to the 30. The VF34’s compressor is rated at 35 lbs/minute but the turbo suffers from the same turbine restrictions found with the VF30. The VF34 was designed with the EJ20 in mind and will not have the same performance on an EJ25. The VF34 is good for around a realistic 290 to 305 WHP on a 2.0L.

VF34: The VF34 was designed with the EJ20 in mind and will not have the same performance on an EJ25. The VF34 is good for around a realistic 290 to 305 WHP on a 2.0L.
VF34: The VF34 was designed with the EJ20 in mind and will not have the same performance on an EJ25. The VF34 is good for around a realistic 290 to 305 WHP on a 2.0L.
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anti-lag, DCCD, EJ257, exhaust, idiots, Impreza, Intake, Intercooler, Ringland, STi, TMIC, Tuning, Turbo, USDM, WRX

Engine Management For Subaru WRX/STi

 

Why do I need engine management?

 


Consider your stock engine management for just a moment. Your stock engine control unit (ECU) is a very complex piece of circuitry that calculates hundreds of variables every second. All of these variables rely on inputs within a + or – range. When you modify your vehicle, these values change. As long as the changes are within the values the ECU expects to receive, your engine runs fine. Once the values are exceeded, the ECU is programmed to compensate to return the values to normal levels.

A typical way of engine management is to use a Cobb Accessport.
A typical way of engine management is to use a Cobb Accessport.

This is a layman’s explanation of how your stock ECU can actually work against you when modifying your vehicle. This also explains why modifications can feel great once they are bolted on but the butt dyno results seem to fade over time. This is due to ECU compensation.

What is the first step in finding what engine management I need? Finding a tuner. The Tuner FAQ will help with the general rules of finding a good tuner. Remember, it’s always better to have a custom tune vs. a plug and play or “staged” map. Always defer to the tuner’s advice as to what to choose as ultimately he will be the one to provide custom support. Discuss your goals and budget and your tuner should set you on the right path. If you are a “plug and play” kind of person, review the options below and decide for yourself along with input from locals in your regional forum and the car parts review forum.

What will engine management do for me? Generally speaking, engine management optimizes several engine functions to create more horsepower and efficiency. The stock ECU is designed to ensure your car runs fine and monitors the engine’s output parameters. Utilizing an aftermarket engine management solution takes this to the next level.

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AWD, gc8, Prodrive, STi, Subaru, TMIC, Turbo, UK, wrc, WRX

Prodrive GC8 WRX Special Editions

22B “Type UK”

In late 1998, Subaru UK officially imported 16 22Bs (described below), and passed them on to Prodrive for modification. The UK cars differ from the privately imported 22Bs, not just in their 3 year factory warranty, but with revised gear ratios more suited to UK roads.

This was achieved by changing the final drive ratio from 3.9 to 4.44 to lengthen the gearing. Cosmetically, the car got the headlights from the ‘99 model, UK rear light clusters and driving lights (not fog lights!) were fitted where the normal 22B has blanking plates. From the back, you can tell you’re looking at one of the rarest cars in the world by the “Type UK” and “Prodrive” stickers. The price was £39,950, and demand for the cars was overwhelming.

The rear of a Prodrive 22B Type UK.
The rear of a Prodrive 22B Type UK.

Interestingly, Subaru UK were not able to put their 16 cars through the Single Vehicle Approval scheme because the maximum of 50 privately imported 22Bs had already been registered in 1998. Consequently the Type UKs were registered in 1999. The cars do not meet European Type Approval regulations for noise and emissions.

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EJ257, Intake, Intercooler, STi, Subaru, TMIC, Turbo

Turbocharger: How to choose a Turbocharger

Turbocharger: How to choose a Turbocharger for your Turbo Subaru:

In order to make an informed decision when purchasing an aftermarket turbocharger, the consumer needs to avail themselves of the different types of turbochargers first. To this end, we will discuss the various types of turbos on the market. These are just the basics of turbo information though. Please do not confuse this as the main source for turbo information as there are many other factors to an informed turbo choice such as compressor maps, matching the turbo to your displacement, etc. For the best advice, please consult an experienced turbo vendor and/or your tuner.

A regular turbo is, in essence, a pump that forces air into your intake system. The end result is a denser air charge that will produce more power vs. naturally aspired vehicles. The only downside is that more power produces more heat, and the engine’s internal components must be properly suited towards turbo charging. Upgrading this unit to a larger one is the easiest route in terms of time, trouble, and expense. Common upgrades for all turbocharged Subaru models include the VF-30/34/22 and 16/18/20G.

A twin scroll turbo is designed to be used on an equal length exhaust set-up. By internal turbo design and having all the exhaust gases enter the turbo at the same time, this allows the turbo to spool faster vs. an equally sized regular turbo. This is a very important point as many people are confused by the marketing hype of twin scroll set-ups. When comparing a twin scroll turbo that will flow say 500 cfm vs. a normal 500 cfm turbo, the twin scroll should see full boost sooner. So if there are two suitably sized turbochargers, with one being twin scroll and one regular, the twin scroll unit may be your best choice if you do not mind the extra exhaust expense and prefer faster spooling.

This type of turbocharger requires more expense than a simple upgrade though. The biggest concern is the use of an equal length header, proper uppipe design, and the possible use of a different oil pan to accommodate the new twin scroll exhaust piping. Quirt Crawford of Crawford Performance recently did some testing on a GT32 twin scroll turbo Legacy to test the theory about the importance of exhaust flow to a twin scroll unit. When he switched from the correct equal length header and uppipe to a traditional unequal length header and normal uppipe, he saw degradation in turbo response by 750 RPM. This should be word to the wise to anyone who thinks they can avoid the expense of the correct exhaust components and still see the quicker spooling benefits of a twin scroll turbo.

Another consideration is the change in exhaust tone. An equal length header required in a twin scroll set-up sounds entirely different than an OEM or aftermarket unequal length header. To fans of the familiar boxer rumble, equal length headers are just not an option. It may sound silly, but for many, this reason alone is enough to keep them from buying a twin scroll turbo.

A rotated mount turbo is any turbo that’s physical size prevents it from fitting in the stock location and must be mounted at a slightly different angle. Most of the turbos that fall into this category are of the larger variety. Many require custom piping, a front mount intercooler, external wastegates, custom tuning, tumble generator valve deletes, and other technical or expensive upgrades to support it. Most would consider this type of turbo to be outside the scope of the average do it yourself person and should be farmed out to a professional or at least utilize one of the kits supplied by various manufacturers.

As well, many feel that when going this route, strong consideration should be given to fully built motor, or at the very least, forged pistons. Rotated mount turbos produce large amounts of power and though there is no magic horsepower number for switching to forged internals, the larger rotated mount set-ups seem to be commonly used on built motors.

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Ej20, EJ25, EJ257, Intercooler, STi, Subaru, TMIC, Turbo, USDM, WRX

Header Aftermarket Turbo Subaru FAQ

Header Aftermarket Turbo Subaru FAQ

The primary purpose of an aftermarket header on a turbocharged Subaru is to remove or replace the stock exhaust manifold with a better flowing unit.

An Agency Power Stainless Steel Header for a EJ257
An Agency Power Stainless Steel Header for a EJ257.

HP gain is 15HP and 20TQ. This figure is highly debated as different manufacturers use different dynos with different cars with different levels of mods. It also varies because some headers incorporate an uppipe into their design. This makes it nearly impossible to compare the gains of a header without an uppipe vs. a header with an uppipe.

Which manufacturer is best? This topic is highly debated. There have been no reported consistent “bad” headers on the market. Obviously, there may have been bad pipes sold, but not enough to report as “bad” overall.

Where can I find headers?

Subaru WRX STI Header Prosport Unequal Length Stainless Steel Header

Perrin Subaru STi /WRX Header Equal Length Big Tube

AP WRX/ STI Stainless Steel Unequal Length Header w/o Uppipe

Invidia HS05SW1HDR Racing Header for Subaru WRX STI/Legacy GT

Agency Power (AP-GDA-175) Unequal Length Header, Stainless Steel

Perrin PSP-EXT-050 04-08 STi /LGT/FXT/06-08 WRX (06+ WRX requires modification to oil cooler) Header (02-05 WRX Requires STi Oil Pan)

TOMEI 193082 Headers

What differences are there with headers? The main difference is exhaust piping length. Headers are made to be unequal length or equal length. Unequal means the piping on the driver’s side of the engine will be longer than the passenger’s side. Equal means the piping length is equidistant from the engine outlet to the header outlet for all piping.

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