08 LGT Spec. B. 400/400 whp/T Build Help/Suggestions?

Hey all, there are numerous build pages with numerous opinions, facts, situational components to meet people's standards etc... However, as this is my very first "big boy" build, I wanted to get people's opinions on things I might be forgetting, or changes they would make to the build and I would like to hear reasons why.

 

First off, the build I am about to list I am well aware can make more power, but I am very much a believer of buying it right, buy it once, and I don't want anything to be pushed to its limits so I can get more out of it later if I wish, and increase its reliability in the process, so here it goes.

 

As of right now, I have an 08 Legacy GT Spec. B, with 131xxx miles on it. All it currently has on it, and has had for the past 40k miles or so, is a GS CAI, with an Invidia Q300 CBA. Currently Pro E-tuned from Dave at Cryotune Performance which was more than an amazing experience working with those guys, they're awesome. Stoptech Street/Race pack Brake Pads, along with StopTech Cryo Rotors. These haven't been on for more than 10k miles and I believe will be perfect for this setup, along with a set of Pirelli P-Zero All Season Plusses, (245/45/18) Also I have an Exedy Stage 1 Organic Race HD Clutch that is capable of handling up to 472lbf⋅ft. This setup has been perfect for a DD, but I am wanting much more out of it now, and I am well aware of the jump I am making. Also due to me having the notorious bulletproof 6-speed trans, I will be keeping it completely as is until there are more than the 5 rare instances of something terribly wrong going with this setup.

 

Here goes.

 

1. RalliSpec's StreetSpec EJ-25 Shortblock~ $2995 (Reason I am going with this one instead of IAG stage 1 block is they use OEM 257 Rods from earlier years, and JE Pistons which would do more than what I need, but the Rallitec Block happens to be cheaper, use Manley pistons (2618 material which I happen to have more experience with.) and forged rods. Between the combination of Forged Rods compared to OEM, Manley Pistons compared to JE, and a cheaper price, this is the route I am most likely going to choose.

 

Quick Summary, contains

• salt bath nitride hardened crankshaft running in King XPG race-series bearings.

•Connecting Rods SouthAmerican 4340 Forgings with a H-Beam Design.

•ARP 2000 Rod Bolts, (Would like to have Studs, but oh well, these will definitely do.) Rod's of this quality usually aren't found in Short blocks under 3k anyways, (Not that $2995 isn't 3k lol.)

•Manley Pistons with 2618 Material matched to the bores.

•All block hardware including pin access plugs, covers, and the rear main seal is included.

•According to RalliSpec. "This short block is warrantied against defects during the initial startup period." Which is nice.

 

2. ID 1050x Injecors~ $520 Not much to say here, could go 1300CC, but don't need them for what I have planned, maybe in the future.

 

3. AEM 320 LPH E85 Pump~ $115

 

4. AEM Electronics Adjustable High Capacity Fuel Pressure Regulator~ $131

 

5. Cobb's Flex Fuel Package~ $800 (Contains Ethanol Sensor Kit, and the Pressure Sensor Kit.)

 

6. Torque Solution Top Feel FRails~ $150, Probably not needed but doing the whole fuel system anyways, figured might as well.

 

7. Perrin's Turbo Inlet~ $283.

 

8. Perrin's MAF Hose~ $89

 

9. Turbo, here is the fun part, I thought LONG and hard about this, who wouldn't? I'm deciding to go with a GT3076R, plenty of quick spool time, plenty of power, plenty of reliability, and will allow a little bit more room to grow in the future if I wish. Also, the big pro is it's one of the cheaper turbos, and it's a ball bearing turbo for the quicker spool. $1106

 

10. AVO's Front Mount IC/Kit, $899 Could definitely go Grimspeed Top Mount, but between the advantages of Front Mount, and it is so sexy, just gotta go with this option instead, PLUS it's cheaper!

 

11. Cobb's Tuning Boost Solenoid~ $115 Not much to explain here, they all do the same. Just choose your favorite brand Ig. Or allow your OCD to take over?

 

12. Uppipe/EWG~ Grimspeed and Turbosmart 38/40mm EWG 2 Bolt Coated Uppipe Wastegate Kit~ $702

Now we get into a bit of territory where I'm unsure and might need a bit of help. Not sure if this is my best option or not, or if there are cheaper options that will do a perfectly fine job of what I am needing to do.

 

13. Crawford Single Chamber AoS V2 Kit~ $356 IAG or Crawford, can't go wrong with these two.

 

14. Cusco Rear 21mm Sway Bar~ $216 I actually have been rolling around without a swaybar for about 6k miles because we broke the bolt and I was too lazy to go get a new one because I knew I would probably be doing this soon LOL. Let me tell you... Squiiiiirley on 2nd gear slide turns

 

15. Cobb's Short Throw 6MT shifter Along with their Shifter Bushings. ~ $215/$40 ($265 total.)

 

16. Downpipe Invidia Catless Divorced Wastegate~ $316 This and the UpPipe/EWG I may need some help with, I think I want to go Catless, I'm prepared for the smell, and the raspiness, but I do however see that there are multiple Invidia Catless models FOR THE MANUAL Trans and would like to see if anyone knows the differences between all of them and if anyone has any objections as to why I should change my downpipe choice.

 

17. Subaru 2.5l Oil Pump 11mm~ $200. Not sure if I should go get the 12mm or bigger if anyone has any recommendations would be much appreciated.

 

18. NGK Iridium Spark Plugs 2309~ $44.80, Figured might as well do these while doing all the other crap.

 

All of this comes up to a Subtotal of around $9302.80. I am well aware I can do a 400whp/400torque build for much cheaper but as I said I am trying to do this right, and do this once, hence why I am sharing my build to see if anyone can think of anything I am crucially missing or anything that I should change, this is my first post so apologies for it being such a long one. As I said, Cold Air intake, CBA, brake pads/rotors/clutch are all already done along with quite a decent set of tires, though I will probably be changing those soon. I await everyone's thoughts, thank you all so much!

Looks like a good build list to me. I assume there's other 'typical' things you're aware of that aren't listed here, like machine work for your heads, timing components, gasket kit, etc.

 

Only thing I'd add from personal experience is either a fuel pump hardwire kit, or a DIY rewire. I recently started running out of pump running a 320 w/ ID1050s on an E85 tune way before I should have, with a smaller turbo than you're after. Turns out the pump was only getting 10ish volts instead of the 13.5V, with the culprit being voltage drop across the wiring as well as some through the fuel pump controller. I ended up at 13.1V at the pump after a rewire and leaving the controller alone.

 

I was pointed to this thread for the fuel pump wiring, great resource:

 

https://legacygt.com/forums/showthread.php/fpcm-wiring-upgrade-relay-staying-switched-w-key-off-242295.html?t=242295

Sure you want to go EWG for a street car? They can be pretty loud and annoying unless your going for boy racer noises all the time. If so, I’d opt for having the dump tube routed back into the DP downstream to make it more civil. Cobb Surgeline here in town offers that option and its not very expensive to have your DP modded to accept this. I know it’s a bit more expensive but I’d strongly suggest going with the ETS front mount, the overall package; build quality, engineering, etc it’s just top notch. I’ve just seen too many guys deal with constant fiddle farting with their FMIC over the years chasing boost leaks due to fitment issues with other brands, AVO included. Regardless of what you choose, swap in Murray Constant Tension clamps instead of whatever clamps you kit comes with, it will help to keep all your pipes on securely. Even if your state doesn’t have emissions, please don’t go catless. Your only leaving a teeny bit of power on the table and eliminating the stink as well as not douche-ing the environment. Also running Rallispecs street spec shortblock in my track car, but with upgraded rods and 4032 Cosworth Pistons instead. It’s been solid for me, you should be fine.

Modifications

- Cobb SF Intake

- Mishimoto Induction Hose Kit

- Blouch TD06-440XT 10cm^2 Turbo w/ HPD Turbine Billet Wheel

- AVO Top Mount Intercooler

- AEM Electronics 340lph Hi Flow In-Tank Fuel Pump

- Aeromotive Fuel pressure Regulator

- Injector Dynamics Side / Top Feed Conversion Line Kit

- Injector Dynamics ID1050X Fuel Injectors w/ Top Feed Fuel Rails

- Stage 2 long block from an '06 STI that had previously dyno'd 470whp

- Forged CP Pistons - 99.75mm 8.2:1 Compression

- Carillo Rods with ARP Rod Bolts

- B25 Heads

- Mishimoto X-Line Performance Aluminum Radiator

- Mishimoto Radiator Hoses

- Mishimoto Racing Thermostat

- Grimmspeed 3 Port Electronic Boost Controller

- Grimmspeed Lightweight Underdrive Pulley

- NGK Iridium LFR7AIX Spark Plugs, 0.028" Gap

- IAG Unequal Length Header & Uppipe

- Invidia Catted Downpipe

- SPT Catback Exhaust

- Cobb Access Port with Custom Tune from Dotson Tuning

 

This netted me 362hp/369tq at the wheels. I’ve since upgraded to the Grimmspeed TMIC. Tuner said the AVO TMIC was my bottleneck. Should be able to squeak out a little more power. Injectors were at 65% duty cycle, so Tuner said both the turbo and injectors had more in them. This is on 93 Octane by the way.

 

 

Sent from my iPhone using Tapatalk

Looks like a good build list to me. I assume there's other 'typical' things you're aware of that aren't listed here, like machine work for your heads, timing components, gasket kit, etc.

 

Only thing I'd add from personal experience is either a fuel pump hardwire kit, or a DIY rewire. I recently started running out of pump running a 320 w/ ID1050s on an E85 tune way before I should have, with a smaller turbo than you're after. Turns out the pump was only getting 10ish volts instead of the 13.5V, with the culprit being voltage drop across the wiring as well as some through the fuel pump controller. I ended up at 13.1V at the pump after a rewire and leaving the controller alone.

 

I was pointed to this thread for the fuel pump wiring, great resource:

 

https://legacygt.com/forums/showthread.php/fpcm-wiring-upgrade-relay-staying-switched-w-key-off-242295.html?t=242295

 

Ah, was not aware that, that could be an issue, thank you for the advice!

And yes, indeed I am aware of the machining costs, decided not to include services/labor in this page as I just wanted strictly hardware since those are purchases that people can change recommendations on, but unfortunately, services are universal. HG kit is already ordered, along with a new water pump/timing belt so I don't believe I am forgetting anything there. What is the average cost (I know this fluctuates greatly on many variables.) on having your stock heads resurfaced?

Sure you want to go EWG for a street car? They can be pretty loud and annoying unless your going for boy racer noises all the time. If so, I’d opt for having the dump tube routed back into the DP downstream to make it more civil. Cobb Surgeline here in town offers that option and its not very expensive to have your DP modded to accept this. I know it’s a bit more expensive but I’d strongly suggest going with the ETS front mount, the overall package; build quality, engineering, etc it’s just top notch. I’ve just seen too many guys deal with constant fiddle farting with their FMIC over the years chasing boost leaks due to fitment issues with other brands, AVO included. Regardless of what you choose, swap in Murray Constant Tension clamps instead of whatever clamps you kit comes with, it will help to keep all your pipes on securely. Even if your state doesn’t have emissions, please don’t go catless. Your only leaving a teeny bit of power on the table and eliminating the stink as well as not douche-ing the environment. Also running Rallispecs street spec shortblock in my track car, but with upgraded rods and 4032 Cosworth Pistons instead. It’s been solid for me, you should be fine.

 

Pretty sure I want to go an EWG for this car as plans are for this to be a track car soon as this is just the beginning stage for the first "power level" that I want to do, so it is more of a long term investment.

 

As far as the FMIC goes, I was looking at the AVO or the TurboXS as I heard the quality of the core is overall very good, and fitment can be fixed by trimming the bumper, I figured manual labor on my part was worth saving the $500-700 (depending on details I chose from ETS.) from buying the ETS FMIC although I do understand it is the #1 option for these cars.

 

As car as the downpipe, the only reason I was going catless was just me being greedy for the price more than anything, so I suppose there is no real excuse for me other than just trying to save money. At least I'm honest

Modifications

- Cobb SF Intake

- Mishimoto Induction Hose Kit

- Blouch TD06-440XT 10cm^2 Turbo w/ HPD Turbine Billet Wheel

- AVO Top Mount Intercooler

- AEM Electronics 340lph Hi Flow In-Tank Fuel Pump

- Aeromotive Fuel pressure Regulator

- Injector Dynamics Side / Top Feed Conversion Line Kit

- Injector Dynamics ID1050X Fuel Injectors w/ Top Feed Fuel Rails

- Stage 2 long block from an '06 STI that had previously dyno'd 470whp

- Forged CP Pistons - 99.75mm 8.2:1 Compression

- Carillo Rods with ARP Rod Bolts

- B25 Heads

- Mishimoto X-Line Performance Aluminum Radiator

- Mishimoto Radiator Hoses

- Mishimoto Racing Thermostat

- Grimmspeed 3 Port Electronic Boost Controller

- Grimmspeed Lightweight Underdrive Pulley

- NGK Iridium LFR7AIX Spark Plugs, 0.028" Gap

- IAG Unequal Length Header & Uppipe

- Invidia Catted Downpipe

- SPT Catback Exhaust

- Cobb Access Port with Custom Tune from Dotson Tuning

 

This netted me 362hp/369tq at the wheels. I’ve since upgraded to the Grimmspeed TMIC. Tuner said the AVO TMIC was my bottleneck. Should be able to squeak out a little more power. Injectors were at 65% duty cycle, so Tuner said both the turbo and injectors had more in them. This is on 93 Octane by the way.

 

 

Sent from my iPhone using Tapatalk

 

440XT was one of my top 3, maybe 4 choices for turbo choice, and quite often made my number one as I was swapping my mind back and forth, but I just had my heart set on going with a Garret, how is it holding up for you? any issues, or things you don't like about it that you wish you would have known about before?

Ah, was not aware that, that could be an issue, thank you for the advice!

And yes, indeed I am aware of the machining costs, decided not to include services/labor in this page as I just wanted strictly hardware since those are purchases that people can change recommendations on, but unfortunately, services are universal. HG kit is already ordered, along with a new water pump/timing belt so I don't believe I am forgetting anything there. What is the average cost (I know this fluctuates greatly on many variables.) on having your stock heads resurfaced?

 

Last time I had it done, I paid $475 to have both heads cleaned, decked, pressure tested, and valve guides and seals replaced. I'd do at least that if you're planning to run these heads for a while. Particularly, the machinist noted that exhaust valve guides on our heads tend to almost always be worn out of spec on higher mileage heads. I trust that shop's advice, they do a lot of Subaru heads for Boost Controlled Performance here in Michigan.

 

About to do another pair of heads with those guys, will post an updated estimate, but should be in the same ballpark.

Edited August 10, 2020 by awfulwaffle

Didn't see headers on your list but worth considering. The STI fuel pump control unit might be a more straightforward solution than hardwiring your pump. I too have a 440xt and about to go flex, we'll see how close to 400 I end up.

^^ For me, the lion's share of the voltage loss was in the wiring, not the FPCM. Your mileage may vary, though

yeah, if I remember the thread correctly the STI FPCM is only good for about 1v increase but gets it into nominal range. We'll see soon when I get around to installing all this Flex and new injectors.

Didn't see headers on your list but worth considering. The STI fuel pump control unit might be a more straightforward solution than hardwiring your pump. I too have a 440xt and about to go flex, we'll see how close to 400 I end up.

 

EL Headers are definitely to come.in the future. Unfortunately budgeting money aside for unexpexted surprises during the installatiom/tuning process is more of a prioriy at the moment.

EL Headers are definitely to come.in the future. Unfortunately budgeting money aside for unexpexted surprises during the installatiom/tuning process is more of a prioriy at the moment.

 

Always good to have some extra money stashed for a rainy Subaru day!

Pretty sure I want to go an EWG for this car as plans are for this to be a track car soon as this is just the beginning stage for the first "power level" that I want to do, so it is more of a long term investment.

 

 

 

As far as the FMIC goes, I was looking at the AVO or the TurboXS as I heard the quality of the core is overall very good, and fitment can be fixed by trimming the bumper, I figured manual labor on my part was worth saving the $500-700 (depending on details I chose from ETS.) from buying the ETS FMIC although I do understand it is the #1 option for these cars.

 

 

 

As car as the downpipe, the only reason I was going catless was just me being greedy for the price more than anything, so I suppose there is no real excuse for me other than just trying to save money. At least I'm honest

If you want to go catted with one that passes emissions instead of dealing with swapping a factory dp on all the time I was reading 5250 Motorsports blog up in Longmont area and they do a quality downpipe custom aftermarket for about $650. To me, not having to keep another downpipe around and having to go through the hassle to cheat emissions is worth it. I buy stuff from Dave at Cryotune also and I've got an 08 spec b as well and first time I talked to him on the phone he emphasised to not go catless because they are cracking down, this was pre covid though.

 

Sent from my Pixel 3 using Tapatalk

EL Headers are definitely to come.in the future. Unfortunately budgeting money aside for unexpexted surprises during the installatiom/tuning process is more of a prioriy at the moment.

 

hopefully you don't end up spending it on a burnt exhaust valve on cylinder 4!

if you are running on the track with that combo, do you have a radiator swap in mind?

Also, if you decide to autocross, you're pretty much guaranteed to be in SM or higher class.

The murray tension clamps will ease your connections, especially as popping a hose loose is a common end of track day occurrence.

 

Rallispec's warranty will have specific criteria, however, you'd be well served to check everything you can before assembling the long block. If buying the block from Rallispec, why not have them tap it for studs and be done with it?

 

don't see the gasket set, timing belt, crank pulley, etc on your list.

if you are running on the track with that combo, do you have a radiator swap in mind?

Also, if you decide to autocross, you're pretty much guaranteed to be in SM or higher class.

The murray tension clamps will ease your connections, especially as popping a hose loose is a common end of track day occurrence.

 

Rallispec's warranty will have specific criteria, however, you'd be well served to check everything you can before assembling the long block. If buying the block from Rallispec, why not have them tap it for studs and be done with it?

 

don't see the gasket set, timing belt, crank pulley, etc on your list.

 

Koyorad SC radiator is already in there about 5k miles in. Gasket set, TB and CP are all in the order with the short block. And the Studs they offer for with the short block are extremely expensive to have them do. Would much rather purchase the studs and do it myself if i were to do that.

Spending arp $ on bolts instead of studs seems overkill for little return. That said, Sgt.Gator had a few comments on how to get a torque on them.