Engine Choices

[BrandonDrums]

Phil, you should know as well as anyone else no race car resembles the car it came from outside of a dedicated nascar frame. Just accept that it won't look pretty with a 6 speed just as many race cars don't always look pretty. 6MT is overkill for anything but what you want to do with it. I just don't see the justification to change up the chasis to make the 6MT look pretty.

Even so shouldn't you consider a 5 speed case with swapped gears just for the weight? Having that heavy 6 speed really far back isn't going to help weight distribution. I know you have a PTWR you want but PTWR isn't everything. Will a 2000 pound car with 400HP going to react anywhere near the same as a 4000 pound car with 800hp? That lower weight alone is going to make a huge difference in the corners you can't make up any other way no matter how much power you throw at it.

This is my point^^^

The FFR 818 Chassis isn't made to utilize the 6 speed. People are upset about that. But there's no need to be for all the reasons above and more. Be happy with the 5 MT because that's all this thing will support without some major PITA modding and frankly it's not worth it for all those reasons. I'd rather discuss engine choices, tuning, turbos, intercooling, etc. etc. than keep having every thread about engines or power etc. get derailed by someone saying how crappy the 5mt is and that FFR has shot themselves in the foot for not leaving room for it when there's dozens of reasons why the 6mt is a bad choice and a topic we should leave behind for now. I just want to talk about the car at this point.

So, engine choices...

[RossLH]

Engine choices....well if its up to me, EJ22T or big port EJ207, either way its going to be built. 5MT is fine--it may not be able to handle AWD too well, but it'll be fine running only 2 wheels. That will also be built.

I guess my concerns revolve around rotated turbo kits and front mount fitment. How is all that going to work?

[Canadian818]

What about the '08 & up legacy 6spd? Is it just as big and heavy as the sti tranny?

[Draco-REX]

What about the '08 & up legacy 6spd? Is it just as big and heavy as the sti tranny?

yes.

[Steve91T]

I know it's a little bit different, but sometimes I wish my 97 Camaro was a 5 speed. And actually, for the track, a 4 speed is nearly ideal. With less area under the curve, the 5 speed will be plenty on the track. The only time you'd want a 6th gear would be for long distance highway stuff.

[Etos]

This is my point^^^

The FFR 818 Chassis isn't made to utilize the 6 speed. People are upset about that. But there's no need to be for all the reasons above and more. Be happy with the 5 MT because that's all this thing will support without some major PITA modding and frankly it's not worth it for all those reasons. I'd rather discuss engine choices, tuning, turbos, intercooling, etc. etc. than keep having every thread about engines or power etc. get derailed by someone saying how crappy the 5mt is and that FFR has shot themselves in the foot for not leaving room for it when there's dozens of reasons why the 6mt is a bad choice and a topic we should leave behind for now. I just want to talk about the car at this point.

So, engine choices...

The 6mt will fit. The mounting points are the same. It'll just stick out past the bumper most likely. It's just an overkill solution with a bunch of downsides. A 5mt with stronger gears, case bolts and maybe a brace(someone made some a few years back) would be more then enough to handle any power you can make out of an EJ. It's a whole lot better then getting stuck with 6mt gearing, weight, cost, etc.

Engine choices, god the sky is the limit. We can sit here for 100 pages about what engines you can go with. Personally for the everyday joe smoe any factory engine will be great. At 1800 pounds even the EJ251/253 will be super nice. The fact that it's not much more to get into WRX 300hp area is icing on the cake.

[evo818]

I agree, with not having a ton of knowledge on modding a subaru engine I'd rather get some good info on that. I plan on using the 06 - 07 WRX motor like FFR has in the chasis right now. While I have the engine out what are some worthwhile mods to do? I know intake and exhaust and IC plumbing will be different so I'm looking for more like cams, injectors, head work, etc. type of mods. Obviously a good tune is already on the list.

Thanks

[Draco-REX]

I agree, with not having a ton of knowledge on modding a subaru engine I'd rather get some good info on that. I plan on using the 06 - 07 WRX motor like FFR has in the chasis right now. While I have the engine out what are some worthwhile mods to do? I know intake and exhaust and IC plumbing will be different so I'm looking for more like cams, injectors, head work, etc. type of mods. Obviously a good tune is already on the list.

Thanks

What are your power goals?

[evo818]

I'm looking for a good safe reliable number. From what little research I've done probably in the 320 - 350 range.

[Draco-REX]

I'm looking for a good safe reliable number. From what little research I've done probably in the 320 - 350 range.

A lot of people do that with the stock heads and cams.

The stock setup is pretty good for having 90 degree intake and exhaust exits. But any stock head will benefit from some massaging. For your goals, I wouldn't worry about oversize valves or crazy cams. You might find some mild cams, but you usually don't see them until someone wants crazy power.

TGV deletes, injectors, and a smooth inlet are good to do while the engine is out and the intake manifold is off. The inlet won't get you much, but it's such a pita to do with the intake manifold on that you might as well do it while the engine is apart in case you want to do it in the future.

I would probably just freshen up the block, but I'd stay away from forged pistons if this will be a daily driver. No point in dealing with piston slap and rebuilds if you don't have to.

The header and up pipe will likely be the same. So that would be a good time to do those too since you'll have beter access to the bolts on the turbo. Equal length headers will get you a little more power, but make it sound more like a regular 4 cyl. nequal length will preserve the subaru rumble if you want it. And don't go too big on the up-pipe diameter or it'll kill your spool. MadDad has a good header/up combo.

And external wastegate is something that might be a good idea, but until we get a good look at the final chassis and exhaust arrangement, we won't know what the clearances are like. I think a regular dump tube could work, but it'd be pretty noisy right behind your right ear.

Once the first 818s are out it'll be interesting to see if they might benefit from an NA intake manifold. But that's something for the future.

[evo818]

Good info. I definitely want to keep the unequal length header as I love the subaru rumble and I'll have to research the TGV delete more. What about BOV's? Is it worthwhile to port and polish the throttle body or intake manifold?

[AVIONX]

A PPG gearset is around $4k but with all the upgrades (speedo gear, interlocker, upgraded 5th gear syncro hub) you really need, it's $5k plus and don't forget you'll need to upgrade the differential at $800-1200. You could easily be hit $6k where 6 speeds are readily available for $3k to $3500 with shifter parts.

Thanks,
Philip Grabow

Wow. You people must be made of money or this thing must be so bad that a 400WHP car with 2WD and an open diff it blows the first time you dump the clutch (like IRS on a Cobra mustang with slicks) Otherwise you could just keep a pile of 5 or 6 low mileage trannys stacked out back like cordwood for about half the price of a PPG gearset. Not to mention removing/replacing a tranny takes about a 1/4 of the time and 1/10th of the talent are remove/rebuild/replace.
Matt.

[Draco-REX]

Good info. I definitely want to keep the unequal length header as I love the subaru rumble and I'll have to research the TGV delete more. What about BOV's? Is it worthwhile to port and polish the throttle body or intake manifold?

Being MAF-based, an atmospheric BoV is a bad idea as it vents already metered air. Stick with a BPV. The stock BPV is good for 25lbs or so.

I'm planning to experiment with a BPV restrictor on my WRX. Depending on the results I might do that on my 818 also.

Any air pathway can benefit from smoothing, but you're chasing fractions at that point.

[PhilElement]

Phil, you should know as well as anyone else no race car resembles the car it came from outside of a dedicated nascar frame. Just accept that it won't look pretty with a 6 speed just as many race cars don't always look pretty. 6MT is overkill for anything but what you want to do with it. I just don't see the justification to change up the chasis to make the 6MT look pretty.

I'm Ok with the back of the transmission hanging out and I've mentioned this. I'm hoping with the "Race" version they are making the body will have more overhang at the back.

No one should be offended I want this and want this for others also as I know it's the best move for high power. I'm trying to get what I want and if FF is going to prevent a 6 speed from fitting at all so be it. For all we know it does fit, just sticks out the back. Has anyone confirmed this?

Even so shouldn't you consider a 5 speed case with swapped gears just for the weight? Having that heavy 6 speed really far back isn't going to help weight distribution. I know you have a PTWR you want but PTWR isn't everything. Will a 2000 pound car with 400HP going to react anywhere near the same as a 4000 pound car with 800hp? That lower weight alone is going to make a huge difference in the corners you can't make up any other way no matter how much power you throw at it.

Upgrading a 5 speed box with a front diff and a gearset is something I've done before and I don't want to go there again given how good the 6 speed is for $3k. The weight split isn't everything and a little extra weight back there is going to help the car hook up the HP when substantial downforce isn't available.

As for power to weight ratio and performance we've touched on this some and aero drag will be a problem with a lower power car regardless of the power to weight ratio. At 400 HP it's going to be very fast no doubt! Why wouldn't you want more though? I'm not saying it makes sense but we build 600-800HP Subarus all year long for customer that don't race but very occasionally or never. You have some that will want the 818 to be an affordable and fast car, and then you'll have our customers who could by a GTR or a Z06 but prefer to tinker and build up a car that is not only ridiculously powered but makes absolutely no financial sense. It's a toy, a means to happiness that you cannot put a price on.

I've also studied many cars around VIR (it's a pro track so lots of data) and nailing down lap times based on power to weight ratio is really tough. You have 2500 lbs 850 HP Ganassi Nascar COT pulling 1:55 laps, you have 1200 lbs Juno V6s with 395 HP pulling 1:56s
juno-race-car-ss3.jpg
, and you have my 3200 lbs Subaru at 600 HP pulling 1:56 laps times.

No one including me is telling anyone they can't or shouldn't use a 5 speed.

[PhilElement]

This is my point^^^

The FFR 818 Chassis isn't made to utilize the 6 speed. People are upset about that. But there's no need to be for all the reasons above and more. Be happy with the 5 MT because that's all this thing will support without some major PITA modding and frankly it's not worth it for all those reasons. I'd rather discuss engine choices, tuning, turbos, intercooling, etc. etc. than keep having every thread about engines or power etc. get derailed by someone saying how crappy the 5mt is and that FFR has shot themselves in the foot for not leaving room for it when there's dozens of reasons why the 6mt is a bad choice and a topic we should leave behind for now. I just want to talk about the car at this point.

So, engine choices...

Blowing this out of proportion and for some reason taking it personally. Build the car you want no one it telling you otherwise.

[BipDBo]

6 speed, 5 speed, whatever.

By the direction Subaru seems to be heading, it won't be long before all of the potential donors have CVTs.

[PhilElement]

Ok I'm moving off the 6 speed, let's drop it.

I think the best engines (of course your budget will determine how you go) but if you can score a 2005-2009 Legacy GT you've got one of the best engine and transmission combos plus a better ECU to tune. These 5 speeds are much stronger than the 02-04 WRX. If a good deal comes up on a wrecked 06+ WRX those also have the 2.5 motor and strong 5 speed. The 2009+ WRX is underrated and comes with a strong turbocharger!

What to watch out for on high mileage WRX 02-04 with EJ205. Most of high mileage (70k+) WRX EJ205 motors that come here for build up have cracks in the heads. Sometimes you don't see it until you clean up the carbon but the cracks extend from the spark plug hole into the intake or exhaust port. Valves are usually recessed and the seats pretty worn. The open deck blocks are good and reliable but keep it to 400 HP or less as cylinder walking on track cars can be an issue with high coolant temps. At 400 ft/lbs the rods can buckle also. In some cases picking up a high mileage engine that needs so much work, rebuild, heads replaced or serviced, high mileage turbocharger, etc. in the end may cost more than trying to score a newer engine that doesn't need much work.

The 2.5 (EJ257+) with good tuning even the cast pistons are plenty strong and we've proven that racing our car at 500 whp for an entire time attack season with no failure. They also have some better parts such as stronger rods, better oil pan/baffling, and overall the heads hold up really well to high mileage. You'll still likely need a valve job at 70k plus but we are not seeing the heads crack. Bad tuning or even off the shelf mapping can result in cracked pistons at any power level and neglect can result in oil starvation. Do not buy an engine or car that has rod knock!!!! In most cases the damage runs through the heads and the engine is scrap because the owners don't pick it up quickly enough.

Thanks,
Phil Grabow

[fateo66]

Ok I'm moving off the 6 speed, let's drop it.

I think the best engines (of course your budget will determine how you go) but if you can score a 2005-2009 Legacy GT you've got one of the best engine and transmission combos plus a better ECU to tune. These 5 speeds are much stronger than the 02-04 WRX. If a good deal comes up on a wrecked 05+ WRX those also have the 2.5 motor and strong 5 speed. The 2009+ WRX is underrated and comes with a strong turbocharger!

Thanks,
Phil Grabow

05 Wrx's are still the EJ205 Phil

[Xusia]

I think the best engines (of course your budget will determine how you go) but if you can score a 2005-2009 Legacy GT you've got one of the best engine and transmission combos plus a better ECU to tune.

Hey Phil, thanks for the good info. Question: Which engine does the 2005-2009 Legacy GT have - the EJ205 or the EJ257?

[Evan78]

Hey Phil, thanks for the good info. Question: Which engine does the 2005-2009 Legacy GT have - the EJ205 or the EJ257?

EJ255.

The wikipedia article is helpful: http://en.wikipedia.org/wiki/Subaru_EJ_engine#EJ255

[Xusia]

Ahh, OK. That's the engine I had sorta decided on previously. Didn't know it also came in the Legacy. Now I have more options to find one! Thanks!

[PhilElement]

Some years of the EJ255 have higher compression but it's essentially strong with the same potential as the STi motors. I typically lump the EJ257-255 in the same category even though there are differences in the cooling jackets for heads, gaskets, EGR.....

Yes, oops on the 05 WRX I'll change that. The 05 WRX and honestly it could also be the 04 WRX have different heads than the early EJ205. These heads do not have the smaller EJ205 valves or shim over bucket setup. They have the same size valves as the STi, have shimless buckets, could have better castings, but are not AVCS.

[BrandonDrums]

Engine choices....well if its up to me, EJ22T or big port EJ207, either way its going to be built. 5MT is fine--it may not be able to handle AWD too well, but it'll be fine running only 2 wheels. That will also be built.

I guess my concerns revolve around rotated turbo kits and front mount fitment. How is all that going to work?

Yeah, with all the pics of the FFR test chassis it's probably too early to tell if there's going to be room along the body to get FMIC piping anywhere but underneath the car. There's as much if not more room in the engine bay than a standard impreza along the sides just because there aren't strut towers to deal with or the firewall behind the engine. However, the space in front of the engine is nearly non-existant from what I can tell. Once we see the body on the chassis we can determine what type of intercooler setups are possible...

I do miss my EJ207, much smoother than the EJ205 in so many ways, if I build another engine I'm considering stroking a 207 to 2.2 myself.

[Draco-REX]

I don't see a FMIC as feasible. That's a LOT of volume to charge up. I'm thinking a rear-mount with electric fans might be the better option for the 818.

[Evan78]

Plus there will probably be less frontal area to share with the radiator than say a full size sedan.

[BrandonDrums]

Blowing this out of proportion and for some reason taking it personally. Build the car you want no one it telling you otherwise.

I've been on this forum since February and all any new members seem to talk about is 5mt vs. 6mt when there are literally hundreds of threads already on the topic including a couple where Dave Smith himself says the 6mt won't fit the chassis. Of course I'm annoyed but nothing personal bro ;-)

Ok I'm moving off the 6 speed, let's drop it.

Deal!

[BrandonDrums]

.....TGV deletes, injectors, and a smooth inlet are good to do while the engine is out and the intake manifold is off. The inlet won't get you much, but it's such a pita to do with the intake manifold on that you might as well do it while the engine is apart in case you want to do it in the future.

I would probably just freshen up the block, but I'd stay away from forged pistons if this will be a daily driver. No point in dealing with piston slap and rebuilds if you don't have to.

The header and up pipe will likely be the same. So that would be a good time to do those too since you'll have beter access to the bolts on the turbo. Equal length headers will get you a little more power, but make it sound more like a regular 4 cyl. nequal length will preserve the subaru rumble if you want it. And don't go too big on the up-pipe diameter or it'll kill your spool. MadDad has a good header/up combo.

And external wastegate is something that might be a good idea, but until we get a good look at the final chassis and exhaust arrangement, we won't know what the clearances are like. I think a regular dump tube could work, but it'd be pretty noisy right behind your right ear.

Once the first 818s are out it'll be interesting to see if they might benefit from an NA intake manifold. But that's something for the future....

all very great info! I have forged pistons on a DD, on one hand I love it as I don't fear ringland failures like most 2.5 guys. On the other hand, it sucks waiting for your car to warm all the way up before driving every single time... especially in the winter. All in all, if you're going to have a big turbo on a DD car, an EJ250X will last longer with forged pistons than without as long as you let the car warm all the way up before driving it at all. Some guys say just not to get onto boost until it's warm, honestly it's better not to drive it period until it's warm. Otherwise at 50 or 60k you'll have lost compression from the out of round or 'egged' out cylinder walls. I'm hoping for at least 100k before I have to go back to the machine shop and drop in new slugs...still cheaper than a new block I say...

[Draco-REX]

Some guys say just not to get onto boost until it's warm, honestly it's better not to drive it period until it's warm.

This. Loose pistons are loose pistons.

The only forged setup I'd consider for a street car is the RalliSpec block. Lots of people have commented on it's minimal piston slap. I'm not sure which pistons they use, but they have somehow got away with much better cold tolerances than you find with most forged pistons.

[armstrom]

Just a thought... for those who live in Europe I wonder if the diesel subaru boxer engine/tranny would fit... I know there's talk of a high MPG diesel variant based on the TDI powertrain but if the diesel subaru will "drop in" then we might see a diesel variant sooner than we think Considering the boxer diesel gets about 42MPG (combined) in a legacy sedan (while the old 2.5L NA gas engine is lucky to get 27MPG on the highway) Might make for some good economy.
http://www.boxerdiesel.com

-Matt

[BrandonDrums]

Just a thought... for those who live in Europe I wonder if the diesel subaru boxer engine/tranny would fit... I know there's talk of a high MPG diesel variant based on the TDI powertrain but if the diesel subaru will "drop in" then we might see a diesel variant sooner than we think Considering the boxer diesel gets about 42MPG (combined) in a legacy sedan (while the old 2.5L NA gas engine is lucky to get 27MPG on the highway) Might make for some good economy.
http://www.boxerdiesel.com

-Matt

I'm fairly certain it would drop right in. As the addage goes, Subarus are like leggos and I believe the diesel engine inevitably has the same subaru housing that should mate to most subaru transmissions. However, I don't believe it's a turbodiesl, just a N/A :-(

[RossLH]

Being MAF-based, an atmospheric BoV is a bad idea as it vents already metered air. Stick with a BPV. The stock BPV is good for 25lbs or so.

I'm planning to experiment with a BPV restrictor on my WRX. Depending on the results I might do that on my 818 also.

Any air pathway can benefit from smoothing, but you're chasing fractions at that point.

The problem I have with the stock BPV is the response time. It holds boost well, opens right on time, and takes half a lifetime to shut. It is not at all difficult to beat the stock BPV to the shift, and its no fun when that happens.

When it comes to the BPV, Forge all the way. They took the best design out there (stock) and made it better. Faster response, adjustable spring rate (comes with a spring/shim kit), and honest to god leak free.

[shinn497]

Out of curiosity, would an EJ207 still make sense in cali? I am confident that it could pass inspection, but I'm wondering if it would rev high with only 91 gas. I'm thinking an E85 tune might be a solution.

[Draco-REX]

The problem I have with the stock BPV is the response time. It holds boost well, opens right on time, and takes half a lifetime to shut. It is not at all difficult to beat the stock BPV to the shift, and its no fun when that happens.

When it comes to the BPV, Forge all the way. They took the best design out there (stock) and made it better. Faster response, adjustable spring rate (comes with a spring/shim kit), and honest to god leak free.

Nothing wrong with an aftermarket BPV. Just as long as it's a BPV not an atmospheric BoV.

[RossLH]

Nothing wrong with an aftermarket BPV. Just as long as it's a BPV not an atmospheric BoV.

BOV's venting to atmosphere really isn't that big of a deal (a little afterfire never hurt anyone), the main issue comes when they leak, and most do. Unfortunately, most aftermarket BPV's leak too, which is a rarely addressed issue. The Forge BPV is the only one I've seen tested that didn't leak.

[Draco-REX]

BOV's venting to atmosphere really isn't that big of a deal (a little afterfire never hurt anyone)

Except for the cats burning that extra fuel and melting. There's also the way it'll make the back end of your car look like a diesel. Then there's the risk of washing down your cylinder walls with fuel.

Fouled plugs

Carbon build up which leads to knock

Best to just stick with BPVs.

[Etos]

BOVs are fine. They just need to be set to the right application. Stock everything, not a good idea. But if you use manifold pressure for tuning rather then MAF then it's fine. GFB makes an excellent BPV/BOV that can be switched between them.

Point being when you start doing heavy mods, BOV are fine when installed right and actually preferred. That way it's not a nightmare routing the air back through post maf, and pre turbo.

On the other side of the coin, BW with their EFR found a way to make BPV awesome and perform better by putting the BPV right on the turbo to help it spool between shifts.

[RossLH]

Except for the cats burning that extra fuel and melting. There's also the way it'll make the back end of your car look like a diesel. Then there's the risk of washing down your cylinder walls with fuel.

Fouled plugs

Carbon build up which leads to knock

Best to just stick with BPVs.

I agree with sticking with BPV's, but 3 of the effects you described are being pretty dramatic. Burning cats? Yeah thats an issue. The other three....well thats just not gonna happen, and if it does, there's a bigger culprit than the BOV. The actual amount of fuel dumped during each BOV opening event is rather minimal--running an AFR below 11 produces more dramatic effects in the long run.

Again, not arguing that BOV's are a good idea, I'm just being realistic about the effects.

BOVs are fine. They just need to be set to the right application. Stock everything, not a good idea. But if you use manifold pressure for tuning rather then MAF then it's fine. GFB makes an excellent BPV/BOV that can be switched between them.

Indeed, speed density and BOV's can go hand in hand. By the way, GFB valves are known to leak. Definitely not a piece I'd recommend.

[Xusia]

I'm trying really hard to follow the conversation (and learn), but the number of acronyms is getting out of hand. I'm pretty sure MAF = Mass Air Flow, and NA or N/A = Normally Aspirated. Based on the context, I'm guessing BPV = ByPass Valve, and BOV = Blow Off Valve (did I get those right??). But GFB, BW, EFR, WTF?!?

[Etos]

I'm trying really hard to follow the conversation (and learn), but the number of acronyms is getting out of hand. I'm pretty sure MAF = Mass Air Flow, and NA or N/A = Normally Aspirated. Based on the context, I'm guessing BPV = ByPass Valve, and BOV = Blow Off Valve (did I get those right??). But GFB, BW, EFR, WTF?!?

GFB = go fast bits, company that makes BPV/BOVs among a few other things
BW = Borg Warner, huge turbo charger company. More well known in the OEM world
EFR = engineered for racing series turbos that BW just released recently. It's the cats meow of high performance turbo charging.
WTF = What the freak :P

[RossLH]

I'm guessing BPV = ByPass Valve, and BOV = Blow Off Valve (did I get those right??)

Bingo, difference being (at least in how I use the terms) is BPV's recirculate, BOV's vent to atmosphere.