THE TRUTH About The SUBARU STI RA Piston (MYTHS BUSTED!!)
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- Опубликовано: 7 авг 2020
- THE TRUTH About the SUBARU STI RA piston (MYTHS BUSTED!!)
We get down and dirty with a new 2019 Subaru WRX STI to finally answer the question that everyone in the Subaru community is asking: Did the type RA actually solve the infamous ring land failure?
We team up with our friends at NUR Performance and Drew, a professional tuner with years of experience building and tuning hundreds of Subarus.
Piston comparison
-RA Piston
-2008 EJ Piston
-CP Piston
-Manley Forged Piston
Comprehensive understanding behind ringland / ring gap failure
Explanation of how to properly calculate the appropriate ring gap according to the boost desired. 
Авто/Мото
Manley also recommends a larger ring gap due to it being a 2618 alloy, the piston to wall clearance is also larger on 2618 alloy as the piston is going to expand more when you get to operating temp and the ring gap is going to still close, not necessarily all the way but can still happen.
I’ve seen it before, Manley turbo tuff pistons, proper ring gaps, proper piston to wall clearance using the same formula in this video, and guess what happened? The customer still ran the car too hard on a improper tune and bent the rings and cracked a piston! Combustion temps, air temps, coolant temps, and tune will kill the engine the quickest as it’s a sure was to bend the rings or crack the pistons in the first place due to excessive heat in the cylinder.
Great video, but I think you barely scratched the surface on this and jumped to your conclusion WAY too soon. There are more differences between the 2 OEM pistons. You never covered the different alloys used, the different manufactures of the 2 pistons, note the difference in the ring land area. These are all different! Sure using the flame front theory as a form of abuse to this piston is great, but not that relevant when the newer piston design accommodates it. I’d like to see a part 2 on this where you guys reflect on everyone’s arguments in the comment section 👌🏻
Thank you so much for the feedback!! I really like that idea! I will see if we can make that happen for everyone!
I’d like to update my previous comment. I have recently ran a Type RA short block in my 2009 STI. Built W25 heads, 1300IDs, and a FP blue turbo pushing 25psi. Been driving it pretty conservatively yet enjoying the power from time to time. Well now, at 5500 miles, it recently developed heavy blow by and low compression on cyl #2 and #4. Pretty sure the pistons/rings are cracked/broken/worn. The original engine which made it to 160k miles, mostly stock, stg 2 tune never developed this issue. Really goes to show the threshold of limitations between the 2 engines. Hope my experience helps somewhere out there looking to use the type RA short block. Cheers 🍻
To much boost
@@steveracecars What did the failure wind up being?
@@steveracecars so how it ended?
Why do you guys not have more views?! Amazing content. I've got a 2019 STi and this made me feel MUCH better about pulling the engine with only 9K miles and swapping in a built shortblock. (450WHP build)
Thank you so much! Oh that's gonna be so awesome!! Good luck! keep us updated!!
Great video, I am trying to talk my friend out of getting his 2020 STi stock block with full cobb bolt on and tune into 400hp ranges.
I am gonna share this to him...
Thanks you very much!
Anytime! We really enjoyed making this! Yeah maybe shy away from 400 ranges stock block!
@@boxerbaddies BS bro the standard block can easy take 4/450 BHP just makes sure the tune is on point
@@boxerbaddies ej205 - stock block can take close to 500 hp = see got it rex - for ej 12,000 rpm 1,200 hp = no shit sherlock - betty subaru with a 5 speed ! ha ha ha !
This is the first video of yours that I watch... Would love to know IF, there is an updated version of this video Re: The "S209" STI.
Thank you...
Oooo that’s a good question! I believe they didn’t change anything in that block from the EJ257. Just an intake and tune from factory to squeeze out some more horses!
@@boxerbaddies And of course, the use of an HKS turbo, Rather than going the usual route of the IHI unit.
The originally announced the S209 with a forged piston upgrade. Later they recanted the statement after they reverted back the the “RA” piston because of cylinder scoring issues with the Forged pistons during testing.
The S209 also got a larger HKS supplied turbo and larger injectors from factory.
There is a whole documentary on YT from Subaru about it.
@@crxkid16 Yep, I have seen that Documentary. I believe it was a 3 part series if I'm not mistaken. Unless you are speaking about a different one.
@@Kiss__Kiss that sounds right. It was either 2 or 3 parts
Great video...but there is more that comes into play. Manley is forged and oem is cast so they will expand differently which is probably why the gap is different.
Was thinking the same, we also dont know the oem material composite on the rings, maybe there more heat resistant
@@FakhryH i have ordered a 2018 ra ej207 short block for my 2001 turbo forester everyday driver 28/60 garrett dual ball turbo ! 365 hp.
@@ronnieboucherthecrystalcraftsm my 02 WRX just spun a rod bearing, found all bits of metal in my pan when I drained the oil out. sucks really can't afford right now but there's a guy out in Carson City, NV will do a swap for $1500 labor on a RA EJ257 block
GREAT VIDEO! my thoughts were different about the type RA, but now I know the truth! I’m gonna have an ej25 engine rebuild soon. I’m doing some research about engine internals, so I can at the same time upgrade everything inside, need some help about main bearings, pistons, piston rods, rod bearings, piston rings, valves, spring valves, basically everything lol. I have no idea what brands to get. Just trying to build a daily driven car with a bulletproof engine. Taking advantage of the disassembled engine. I think would be a great time for upgrades, so when I decide to put more boost on it, it’s going to be prepared for that! ✌🏼🔥🤙🏼
Oh awesome!! That’s going to be so cool! Let me know if you need any help!
@@boxerbaddies Thanks buddy, I’ll let you know! I appreciate that ✌🏼🙏🏼
Ringland on #4 is often fuel related. The feeling system causes cylinder 4 to get the last of the fuel. Builders and tuners down here in Australia have noticed improvements in engine reliability when converting cars to parallel fuel rail setups.
Cylinder 3 gets shortchanged on fuel (without a parallel mod,) cylinder 4 has the least coolant flow (without the GetaDomTune mod.) Both mods are simple and inexpensive, and are IMO critical reliability mods on a turbo EJ, even at stock power levels.
@JulianHale shit sorry I did mean cylinder 3. I've already done the cooling mod to my car now looking to do the fuel mod. Parts look like they would cost about 1k down in Australia.
@@JulianHale i have had a ej257 that has been tuned for 280whp for 200,000km with no issues, just has arp head studs and a aos
@@fynpedersen5627 I wish
I’m on my 3rd oem block within 100km of stage 2 abuse
@@liambarrer220 jesus christ. just save up like $700 extra and get a IAG
Crack pistons and lifting a head is always a risk the more power people go for. I don’t think there’s any engine out there that is going to be 100% immune to that risk when being heavily modded for power. Pay to play, want more power spend more money to get stronger parts, and life support mods to provide sufficient cooling, oil delivery, and exhaust flow.
only with too big a turbo ! - BOOST is the killer .
1st time viewer, feeler gauge looks familiar, thought you might be in Fl. Then saw the license plate on the lift. Yep! Mine look like that! :-( I was surprised at the end gap requirement. Have to keep that in mind! Thanks!
I have an EJ22 with a non automotive plan, but do want to boost it for max take off of 300hp. Cruise under 180.
Welcome! Yup in Florida haha! Of course!! Thanks so much for watching!
@@bryanst.martin7134 awesome!! Sounds like a super fun build!
How about the material, is it the same? Any hardness test or destructive test to compare piston strength? Keep up the good job.
Great suggestion! I will have to address this in a future video!
hey guys, this was a pet project of mine years ago and I sliced and diced many oem failed pistons into sections, I lost all my data in a theft, but i had tracked this down to their not being enough meat in the ej25 piston crown where the valve pockets are made there is simply not enough material between the valve pocket depression and the ring land that cracks
if you take enough pistons that have failed you will see typically where they all fail, pretty close to a valve pocket recess ?
start cutting a piston through from just below the top ring and then start measuring the thickness of the material from the failed cracked ring land to the valve pocket recess, thermal expansion and movement help this along
to fix this from Subaru side they need to redesign the piston crown and fix those silly tight ring gaps
Yes! Love this! Cut the pistons into cutaways!
Oh this sounds super interesting!! Might have to try it out!!
I wonder if you widen the oem ring gaps and boost on a budget?
Yeah good video, but Subaru never claimed they provided the kind of reinforced pistons to throw gobs of extra ponies at it. Just a slight upgrade so the ponies it came with can run a little longer on a track day. Big difference
Definitely true! We were hoping the reinforcement would equate to the ability to push more horses! But they didn’t fix the ring gap 😭
@@boxerbaddies you can always run a little colder spark plug = cheap easy fix every one knows that ! do you ?
@@ronnieboucherthecrystalcraftsm and E85
Good info. Would a wider ring gap contributes to oil consumption? Thanks!
It definitely could! But as long as you gap the rings correctly for the application, you should over consume! Thanks so much for watching!
Everyone needs the cylinder 4 cooling mod.
It definitely helps!
won't you have "trapped" unburned fuel mixture in this area?
My first time seeing you guys but I’m doing research on the Type RA engine because I was thinking about getting one for a 2014 STI Hatchback. If I did buy the block RA and put forged internals into it, would it make it more reliable?
ABSOLUTELY! But you don't need an RA block for that! A regular EJ25 block will do!
@@boxerbaddies ok thank you lol, I just wanted a bit more power out of it was all and for it to be reliable and not just give out. Mostly looking to keep the engine totally stock though. I’d probably just do a different air intake (front mount) and exhaust.
Good content bro, keep it up
Thank you!! Will do! 🔥
Appreciate the support 🙏🏼 we’ve got some interesting plans developing, next couple weeks should be very fun
If I take out the rings from a Type RA shortblock and I hone them to give better clearance (lets say, the gap Manley recomends) .. am I having fixed some sort of the ringlands failure? ... woulf that make "my" type RA block more reliable?
still interested on the answer 👍
Why is there so many factors like ring piston gap and boost pressure? Evos can handle so much boost on stock block
They must have addressed all of this in their production. Subie definitely dropped the ball on this one!
Stock motors with stock ring gap thats been tuned and up the boost havnt had the rings gapped for that modification so it's running higher temps and that creates swelling of the rings now in a normal aplication this would be fine but because we are hotter they expanding quicker and they touch and have no where to go so the break and there you have rongland failure if you want to tune your car just save the money your about to waist anyway and do it properly
So much truth to this! Exactly what we have proven here!
have seen a few different bone stock ra blocks/stock heads/studs making 600whp on e85 w supporting mods
i came to the comments to post this, allegedly some have been rolling 6+months too
@@tstandsforturbo it’s definitely possible... as drew the tuner would say “just gotta keep the temps low”
@@boxerbaddies what’s a good range cylinder temp ?
@@JohnD0129 well, on the Subies we don’t really have a way of measuring direct cylinder temp. But using a combination of products to control oil temp, coolant temp, and using a colder combusting fuel like E85, you can keep your temps much lower than you would on pump gas.
@@boxerbaddies ahhh ok. I’m tuned on E85. I try to keep my coolant around 185. IAT low. I need to get a Oil Temp Gauge.
material difference? effect of detonation based on material? dimensions aren't the whole story.
This is true! Looks like a part 2 is needed!
RA they did not name it that for nothing - power and endurance !
thoughts on
getadom tune cylinder 4 coolant mod?
Levitation I’ve heard it can help! Not sure it’s enough to stop the big issue here. That ring gap is just naturally way too small 💀
My thought is it’s a waste of money. Better spending the money on a equal length header.
@@Dave-so7sf lol less than $100 vs $1000+ both probably beneficial.
1/2 way through and not a word of boost ! ow , it is all about how much boost your putting in = what sized turbo ! ra ej207 good for 400 hp - your block does not have the THICK walls ! google a picture and see ! large gap rings on subaru = see`s the ring gap to rotate to the bottom of the cylinder and causes oil use and bore wear and circle burn out`s see hydraulicing !
so if you leave the STI stock you wont have this problem?
The chances of this occurring are much less if you leave the car stock, however because of the original poor design, it may still happen.
Not true. Ours is stock with only 69k miles and cylinder 2 failed. It was not abused in any way.
can i use all INTERNALS and AVCS HEADS from a V7 STI JDM into a V6 STI RA block ?
Ooof this one I don’t have experience on. I wouldn’t be able to answer this for you!
the ring end gap was set up for proper level for the power they designed for - surprising concept. the smaller the better for blow by. once you start increasing the power and the corresponding heat load to the piston problem start popping up.....
no, they fail on standard power and boost
Let’s not leave out two more important factors.. not properly maintaining and thrashing it on a daily basis. Any engine is going to fail
@@hyltontiedt7485 Ours failed at 69k, completely stock.
Subaru don't know how to project an engine. They're since 1988 building EJs and won 6 WRC titles but they don't know how to do that. The people who knows everything is an youtuber...
Still junk
DON'T EVER QUESTION SUBARU THEY ARE FAR SUPERIOR THEN YOUR INTELLECT......do not pass 400whp please collect $12k EJ257 from factory Subaru
Than*.... Should check your English before you try and rag on someone's intellect.
@@boxerbaddies pretty dense of you to think he's attacking you. This was obviously a poor attempt at a joke.
@@MarkGamingTV I guess it was that poor of an attempt that I failed to realize it was a joke 😂
He made a Monopoly joke.