2005 LGT rebuild with 450 hp target

[VAdanno]

I have a Legacy GT I bought new in 2004, and drove for 112,000 well cared for miles. Mostly stock, with just a set of Koni shocks and a Cobb Accessport at Stage 1. I was driving the car in a horrendous rainstorm, and drove into a puddle on the Austin I-35 access road. The motor sucked up water and hydrolocked. It bent a rod...time for a DIY rebuild!

 

History: I have built a number of road racing race motors, and thanks to the LGT forum, had the information needed to do my first flat four since a VW Bug overhaul 1.6L years ago. I decided the goal was 450 flywheel horsepower, and selected parts that would hold up at that level. I am working with Mike McGinnis of Innovative Tuning, and will be spending some time on the Cobb HQ dyno after the final tweaks are done. The motor has been running for 1500 miles, and came out once to chase down a light oil leak. It was just a seep from the rear oil separator cover and the oil pan, and I bought a new cover. I pulled the oil pan and re-sealed it. I used anaerobic sealer the first time for both parts, and used a light coat of Permatex RTV the second time around. No leaks!

 

Mike has me adding an AEM wideband UEGO AFR gauge kit to tune the engine. It's on the way, and I will install that and my VDO oil temperature gauge when they are delivered. The plan is to get it tuned the second week of December. I will update the thread with the dyno information. Thanks for everyone posting their experiences with the EJ25 engine. You made the research an easy process, and I look forward to driving it with a big jump in horsepower. Here's a list of the parts and some detail, along with some pictures of the rebuild:

 

Grimmspeed Cold Air Intake Grimmspeed EBCS Grimmspeed TMIC Tomei Equal Length Header COBB Accessport V3 002 COBB catted downpipe BNR Supercars 18g turbo Infamous Tuning oil supply line Deatschwerks 740cc side injectors (cleaned and flow tested at 800cc/min) Port Flow Designs Pocket Port & Polish; valve job GSC valve springs & titanium retainers Supertech valves (Inconel ex.) Moroso oil pickup Mahle 99.75mm 4024 alloy forged 9:1 pistons; .002 piston to wall clearance King Mains & rod bearings @ .002" clearance ARP head studs and rod bolts Southbend Stage 3 Endurance clutch & PP (rated at 450 ft lbs @ crank) Subaru 2007 single mass flywheel Subaru OEM case, machined with head plates by Scroggins Machine Subaru OEM rods, magnafluxed, checked for straightness, big & small end balanced Subaru OEM crank, magnafluxed & polished Subaru OEM 11mm oil pump Subaru TGV valves removed, housings ported Subaru OEM gaskets Subaru all new water and vacuum hoses Invidia Q300 3" stainless cat-back exhaust system Mishimoto turbo inlet silicone hose Mishimoto aluminum radiator VDO 340 degree mechanical oil temperature gauge AEM 100 psi oil pressure sensor AEM wideband O2 gauge and sensor Walbro fuel pump 255 lph, new OEM tank filters

[Max Capacity]

Have you thought about Blast Plates for the 5mt ?

[KingIkeLGT]

Are you getting tuned on pump gas or E85? I would think 740cc might be a little restrictive for your power goals, especially on pump. But I'm no tuner

 

 

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[VAdanno]

Have you thought about Blast Plates for the 5mt ?

 

I did some research about blast plates, and decided if I need a stronger transmission, I need a 6 speed. I don't do quarter mile or 0-60's, and may do a HPDE at COTA if (when) I get another job. Involuntarily retired for almost a year, so I'm watching my pennies. I keep selling off garage parts to pay for updates. Check the ads for a set of ARP head studs, Mishimoto throttle body hose, plus more!

[VAdanno]

Are you getting tuned on pump gas or E85? I would think 740cc might be a little restrictive for your power goals, especially on pump. But I'm no tuner

 

 

Sent from my iPhone using Tapatalk

 

Deatschwerks injector calculator says 738cc will generate 450 hp @ 80% duty cycle on pump gas. I had the injectors cleaned and they flow tested at 800cc, which calculates out to 485 hp. I should be good, but the dyno will be the final arbitrator.

[malvic]

Subscribing.

 

Big plus for Mike McGinnis of Innovative Tuning. He tuned my 05 LGT.

[VAdanno]

Mike is living in Austin, Texas now. He's using the Cobb HQ dyno for tuning in the evening and on weekends. I believe Mike is in Indy this week for the motorsports show.

[kzr750r1]

Looking forward to how this progresses. I'm curious about the cable tilt unit on your lift. Who makes that?

[Max Capacity]

Looking forward to how this progresses. I'm curious about the cable tilt unit on your lift. Who makes that?

 

 

Harbor Fright has a engine balancer for about $60.00. I have one like it from years back.

 

Its different then the one above.

 

Edited December 11, 2017 by Max Capacity

[xtea]

Deatschwerks injector calculator says 738cc will generate 450 hp @ 80% duty cycle on pump gas. I had the injectors cleaned and they flow tested at 800cc, which calculates out to 485 hp. I should be good, but the dyno will be the final arbitrator.

 

Thats at the crank. You need more for the wheels.

[traildogck]

I agree, I don't think those side feed are going to get you there.

 

When it comes to building your fuel and cooling systems...you want to be well with in the operating range, not at the limit.

 

I can't see, are you using the stock fuel pressure regulator and all stock fuel lines?

[traildogck]

I did some research about blast plates, and decided if I need a stronger transmission, I need a 6 speed. I don't do quarter mile or 0-60's, and may do a HPDE at COTA if (when) I get another job. Involuntarily retired for almost a year, so I'm watching my pennies. I keep selling off garage parts to pay for updates. Check the ads for a set of ARP head studs, Mishimoto throttle body hose, plus more!

 

I would still utilize those blast plates if I had an MT.

[kzr750r1]

Harbor Fright has a engine balancer for about $60.00. I have one like it from years back.

 

Its different then the one above.

 

[ATTACH]259442[/ATTACH]

Thanks Max. I already have the HF unit.

[VAdanno]

Looking forward to how this progresses. I'm curious about the cable tilt unit on your lift. Who makes that?

It's an Oberg TiltLift. I've had it for years...I bet I pulled the I-6 from my old 240Z race car 50 times using it. It worked great on the flat 4, though I did play around with mounting location for the ends until I got it right. I'm using it with a Harbor Freight 1 ton engine hoist...$99 special.

[VAdanno]

Thats at the crank. You need more for the wheels.

 

Right. I will be delighted to see 350/350 at the wheels. The reason I mention crank HP (and torque)...the Southbend Stage 3 Endurance is rated for 450 ft. lbs. at the flywheel. I'm using stock blueprinted rods with ARP fasteners, which should be reliable if I set redline at 7000 RPM's. I thought about buying some $500 Chinese rods (like Eagle or Crowers), but decided to keep in mind this is a road car, not a race car. The valves and springs are overkill, rated to 8000+, but the pocket porting should improve the flow from 5500-7000. Bigger heads, hotter cams, closed deck cases, stronger crank and rods, rotated turbo...it's easy to keep going down the slippery slope towards race car output levels. I keep chanting the mantra "it's a street car, not a race car" until those demons leave my head!

 

I'm waiting for the FedEx truck. Once my AEM wideband is delivered, I can install it and set up the tuning session. It's three days late...lowest cost supplier = slow shipping. I plan on tweaking the Q300 while I wait...I clearanced the center bearing support to clear the expansion coupler, but still hear a rattle where the exhaust is touching the body on accel/decal. It's quiet over bumps, though. Maybe I need to firm up the motor mounts? I already put in a STi trans mount.

[VAdanno]

I agree, I don't think those side feed are going to get you there.

 

When it comes to building your fuel and cooling systems...you want to be well with in the operating range, not at the limit.

 

I can't see, are you using the stock fuel pressure regulator and all stock fuel lines?

 

I am using the stock FPR and lines, and believe they will be sufficient to see 350 WHP. The dyno will tell me if I'm wrong. I added an oil temperature sensor in the back port of the oil galley (VDO sensor used by another flat four - VW - also M18x1.5), and will add an oil cooler if the OEM unit, combined with the Mishimoto aluminum radiator, doesn't keep both fluid temps in a safe range.

[kzr750r1]

Group N motor mounts in your future. Thanks for the info on the tilt lift.

[VAdanno]

Group N motor mounts in your future. Thanks for the info on the tilt lift.

 

I'm a little worried the NVH will jump using the Group N mounts. I pulled the exhaust yesterday, and saw where the center resonator was touching the driveshaft. I clearanced the resonator with a ball peen hammer, and adjusted all the connections to max out clearance. The right muffler is closer to the body, and I pulled the trim strip from the lower quarter panel near the muffler. I might take the muffler to a shop and modify the front mount. If I move the mount inboard, it should keep the rubber mount from touching the inner fender. I'd like to tweak both mounts, so both rubber mounts are leaned as far inboard as they can be. That should keep right to left motion at a minimum and max out clearance. The right tail pipes stick out about 3/4" more than the left, but trying to fix it might cause more problems than it cures.

 

eBay refunded my money from the vendor that never shipped my AEM UEGO. I ordered from another supplier, and I will confirm they get it out in today's FedEx shipment. I'm also doing the OEM BOV modification, tapping the vent hole and drilling a hole to vent to atmosphere.

[kzr750r1]

It will. But your not gonna have a bit of slop under heavy torque request.

[VAdanno]

It will. But your not gonna have a bit of slop under heavy torque request.

 

The exhaust hitting is after the flex joint, so stiffening the engine and trans won't address the problem. General OEM flex in the drivetrain is a new area to work on. Is there an option that improves the drivetrain motion without adding noise to a daily driver? I read some of the dogbones increase the sound of the starter into the cabin. I could deal with that, if the other 99.9% of my driving was unaffected in NVH.

[Max Capacity]

For my Q300, I got longer rubber exhaust hangers.

[MTBwrench]

Subscribed, I like what I'm seeing here.

 

Sounds like you're headed in the proper direction for damn near everything, which I'm not surprised given the past you described.I know people have mentioned it, but I'll add my (sort of detailed) $0.02:

 

-Fueling: Are you upgrading your pump as well? I didn't see mention if it. My guess is(with a pump) that you'll be just close to spot on for 450 crank HP. Perhaps a bit short. FWIW: with a DW65c pump, and 1000cc top feeds, I max at ~67% duty cycle with a 17.5psi boost peak. I have a VF52 and my AFR's are in the mid 10's. I'm also at sea level. All of that being said... I'm only making maybe ~300-320hp at the crank.

 

-Transmission: The reason everyone is urging caution is because of how unpredictably weak it can be. Subaru's 5 speeds tend to break whenever they feel like it when you start nearing 400whp. It can be on a launch, or just during any high torque application regardless of impulse(for you folks that have taken some physics). The issue is the shape of the case. The 5 speeds have heart shaped inner case profiles to allow the gearsets to reside side by side. When large amounts of torque are pushed through them, the case will flex radially from the gears allowing greater distance between the input shaft and counter shaft. This causes the gearsets to mesh improperly, and usually results in shattered gears, sheared teeth, or cracked input shafts. Blast plates keep the case from "blasting" outwards under high torque application and maintain proper gear mesh. They still don't help with shattered teeth though.

[kzr750r1]

Any change in one system the OEM design needs a look at all angles to ensure the entire system will last long term. I wasn't suggesting the motor mounts would fix the exhaust hitting. Good point about the blast plates. Even as a short term counter measure before a 6 speed is a good option to consider.

[VAdanno]

For my Q300, I got longer rubber exhaust hangers.

 

Longer won't help. The tight clearance will be improved if I move the right muffler forward. Best way to do that is cut the pipe on the muffler and shorten it by 3/4". If I try to bend the pipe that runs sideways on the car, I'm more likely to cock the muffler at an angle. No bueno.

[VAdanno]

Subscribed, I like what I'm seeing here.

 

 

-Fueling: Are you upgrading your pump as well? I didn't see mention if it. My guess is(with a pump) that you'll be just close to spot on for 450 crank HP. Perhaps a bit short. FWIW: with a DW65c pump, and 1000cc top feeds, I max at ~67% duty cycle with a 17.5psi boost peak. I have a VF52 and my AFR's are in the mid 10's. I'm also at sea level. All of that being said... I'm only making maybe ~300-320hp at the crank.

 

-Transmission: The reason everyone is urging caution is because of how unpredictably weak it can be. Subaru's 5 speeds tend to break whenever they feel like it when you start nearing 400whp. It can be on a launch, or just during any high torque application regardless of impulse(for you folks that have taken some physics). The issue is the shape of the case. The 5 speeds have heart shaped inner case profiles to allow the gearsets to reside side by side. When large amounts of torque are pushed through them, the case will flex radially from the gears allowing greater distance between the input shaft and counter shaft. This causes the gearsets to mesh improperly, and usually results in shattered gears, sheared teeth, or cracked input shafts. Blast plates keep the case from "blasting" outwards under high torque application and maintain proper gear mesh. They still don't help with shattered teeth though.

 

I installed a new OEM fuel tank filter and a Walbro 255 gph pump, so I think I have the fuel volume. Thanks for the explanation on the blast plates. Time for more research!