Crawford Performance FMIC Front mount intercooler Deatschwerks DW65C Injector Dynamics ID1000 Motive TGV delete GrimmSpeed MotoIQ Project Gen 3 STi

MotoIQ Project Gen 3 STi Crawford Performance FMIC front mount intercooler turbosmart clamps

Project Gen3 STi - Fueling and Intercooling

by Wes Dumalski

You may have heard the expression 10 lbs of shit in a a 5 lb bag before. Well I am fairly certain the origination of that statement came from the first person to try and remove the intake manifold from an EJ25 and work on the systems surrounding and underneath! In our quest for more power and greater reliability we dive into the bowels (the heart would be the engine) of the boxer motor to upgrade our fuel system, improve the intake and intercooler efficiency and well… To reduce the amount of useless crap tucked in to the engine bay. 

In our last installment we explored power production and gave our impressions of the Turbosmart internal wastegate and BPV. During that testing our datalogs revealed 100% injector duty cycle and as such we had to limit boost in the interest of motor preservation. Let's face it, the late model EJ25 is not known for being the most robust motor and we certainly did not want to press our luck without having proper fuel. We began to research injector options and other items that we could improve while we were "in there" and what could be a relatively simple (as easy as the EJ can be) 2 day install quickly turned in to a several week process of re-doing damn near every hose and wire loom in the engine bay. Because we will soon be testing a GTX turbo we certainly wanted headroom within our fuel system for whatever power we chose to make. If we chose to push 400 or 500 horsepower on pump, race or the corn we did NOT want to have to upgrade the fuel system a second time.


ID000 Injector Dynamics 1000CC MotoIQ Project STi


We turned to our friends at Injector Dynamics immediately for their ID1000 injectors. As the name implies these injectors flow 1000CC's at 3 bar and have some of the most consistent spray patterns we have ever seen supporting data for. They are more than capable of supporting our power goals and despite their large size should allow us to maintain perfect idle and drivability characteristics.

In addition to the injectors we felt compelled to supplement the fuel pump and for that we chose what is quickly becoming the default pump from DeatschWerks in their DW65 model. This 265LPH pump supports all fuel types and for our application is a drop in replacement. While we were consulting with Tony Palo from Injector Dynamics regarding our fuel system he introduced us to Lance Lucas of Cobb Tuning Surgeline. Lance explained that Cobb was releasing a new "fuel damper delete" kit for the 08+ STi's and that it simply was a MUST HAVE piece.

If the air pump and all of those completely pointless systems were not enough Subaru thought it good to incorporate a damper and regulator that would allow fuel to be returned pre-regulator under certain conditions. This results in a very bad lean hesitation during tip in at about 2500-3200 rpm's that is a problem for nearly every stage 1-3 car. Some people claim to be able to "tune it out" but the reality is that it is mechanical in nature and the best way to get rid of it is to get rid of IT; the BS regulator that is. Cobb supplied us with a prototype kit that would allow us to replace the OEM quick connect fuel lines from the firewall and replace the existing FPR and assembly with one from the GD chassis STi.

Another item that we shook our head at were the Tumble Generation Valve's within the riser's between the cylinder head and the intake manifold. These valves are designed to open and close to improve emissions and in the end the simply create another restriction within the inlet and another mess of wires and ancillary garbage on or around the intake manifold. On our Gen 2 STi Howard from Technosquare deleted these by porting out the stock pieces however we chose a slightly different route. Our friends at Turn in Concepts made us aware of a composite riser made by Motive Autowerks that would not only eliminate the TGV but also serve as a means of isolating heat from the intake manifold. Essentially you are taking an all metal assembly and placing a composite spacer in the middle to reduce the amount of heat transferred from the cylinder head to the intake manifold.


Motive TGV delete Turn In Concepts Motive Autowerks composite TGV eliminator risers.

Seeing as how we had to remove the intake manifold to replace the injectors it made perfect sense to install these while we were at it. Two other items that could be done "while we were in there" came from our northern friends at Grimmspeed. Knowing we would need better control over boost we chose to use their 3 port electronic boost control solenoid and because the fuel lines would be torn apart at the fire wall this was the PERFECT time to install their Master Cylinder Brace. I know I know, that has NOTHING to do with fuel and air systems… Well if you object to us including this part in this installment you can suck it because there is NO WAY we would ever try to install this part with the OEM fuel system in place. That is NOT a shot at Grimmspeed, rather it is a statement in support of our introduction regarding too much fecal matter in tight confines. Last but in no way least we also decided that the top mount intercooler needed to go. As we make way for more power and taking the STi to the track we felt it imperative to drop kick the top mount inter heater to the curb in favor of a Crawford Performance front mount.


Crawford Performance FMIC front mount intercooler Ghymkana

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Monday, May 19, 2014 1:56 AM
Aren't 1000ccs a bit too small to be used with corn fuel and a 3076 ? You might run them at high duty and have no marign left. I have not tuned subaru engines so i can't say if it makes sense to compare, but on nissan 1.8 and 2.0 turbo engines, 1000cc is on the small side for anything higher than 1.6/1.8bar, with e85.

Now all you have to do is ... change them to 1600 ... which requires another disassembly, but will really be worth it :p i have been running e85 for years now, and will never go back.

Monday, May 19, 2014 3:41 AM
One argument for retaining a recirculating blow off valve is for vehicles which retain the airflow meter for the load source. Deleting the blow off valve can cause the car to run rich and stall on throttle lift off, particularly if the driver clutches in, as the air rushing backwards past the airflow meter gives a false reading. The same happens when an externally venting blow off valve is fitted, where metered air is vented from in engine intake tract, causing a rich condition, and if the spring in the blow off valve is quite soft, it will induce unmetered air when the engine is running in vacuum, causing the car to run lean. Yes these issues can be masked in a tune, but unless running an MAP sensor or throttle based tune, why introduce problems that compromise drive ability.

As for not much proof of surge affecting turbo life, this may be true - but when you think that in the case of a plane turbine engine, they can live bird strikes, mass water induction, but surge can destroy them.

Also a massive congratulations on being so honest on how stupid it is to work on many of the systems on a subaru motor.

Monday, May 19, 2014 6:56 AM
Just so you know, the FSM mentions leaving the TGV housings on the manifold for removal. :) The only thing I did different from how Subaru says, is I left the power steering pump in place and unbolted the AC compressor bracket and moved it when I needed to.
Dusty Duster
Dusty Dusterlink
Monday, May 19, 2014 11:24 AM
I install a BOV just so I can get that "PSSSSssh" sound when I close the throttle. But I'm a recovering riceboy.
Monday, May 19, 2014 11:50 AM
Crousti, it's a GTX3067R :) Should flow round about 49lbs/min, so a fair amount smaller than the GT3076R which does around 56lbs/min. The goal was for best street response meaning minimal lag and transient penalty for a sizeable power gain.
Wes Dumalski
Wes Dumalskilink
Monday, May 19, 2014 6:40 PM
Thanks for reading everyone!

Crousti - As Khiem pointed out we are using a stock location 3067 NOT a 76. As such the ID1000's should be adequate. If we find they are not they always have the 1300's out now.

CMW_Nathan - There is a lot of dialog on both sides of the fence relative to a bypass, bloww, or no valve of any kind. We honestly approached this with an open mind and installed the FMIC as shipped from Crawford. I can tell you that it is really FUN to hear the sounds the turbo is making. That said I would really like to test the difference in wheel speed between the different possibilities. That will honestly be a difficult test to achieve but we have been discussing that and if it comes to fruition, rest assured, we will share the results. Thanks for appreciating our honesty, I really detest the layout of the EJ unless I am working on the exhaust manifold... The rest of the car is actually very easy to work on and the engine isn't HARD per se, just tiem consuming to do things cleanly. I have done a lot more cleaning up since this install during the turbo prep. that we will share in the next article.

Eric - I mentioned that the proper technique is to leave everything attached in the article. I have removed the IM on at least one other Subaru and have followed the FSM regarding the removal since this install. With that said I would NEVER re-install it the way the factory does. I can now take my intake manifold off in about 15 minutes and it has proven VERY handy already on more than one occasion.
Friday, May 23, 2014 4:17 AM
What type of clamps are those in the opening picture?
Marty Staggs
Marty Staggslink
Saturday, May 24, 2014 12:32 AM
Murray Constant Tension clamps
Sunday, May 25, 2014 7:26 AM
Thanks Marty!
Wes Dumalski
Wes Dumalskilink
Sunday, May 25, 2014 9:21 PM
As Marty pointed out they are the Murray constant tension clamps available from Turbosmart. We will go in to more detail abotu the clamps and 2 other items from Turbosmart in our next installment.
Saturday, August 23, 2014 8:22 AM
Any updates?
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