J.films Posted September 25, 2016 Share Posted September 25, 2016 Hey guys Just wondering how much boost can you put through your stock plastic intake manifold Ive got a 2005 legacy GT AT with a SteamSpeed STX 67+ Turbo and a COBB short ram intake filter and a CNT top mount intercooler. Link to comment Share on other sites More sharing options...
WahooNo2 Posted September 25, 2016 Share Posted September 25, 2016 Welcome. How much did you want to push through? Is your car tuned now? How much power did you want to make? How long did you want the current engine and drivetrain components to last How many miles are on the current engine? Link to comment Share on other sites More sharing options...
Max Capacity Posted September 25, 2016 Share Posted September 25, 2016 45psi I think the real question is...how much will the stock pistons hold. I see your new here...if this is your first turbo car...you have a lot to learn. You can blow one of these things up pretty easy if you don't know what your doing. Who did the tune on your set up. You shouldn't need much more than 20 or so psi for a reliable DD. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
WahooNo2 Posted September 25, 2016 Share Posted September 25, 2016 http://legacygt.com/forums/showthread.php/plastic-lgt-intake-manifold-problemsi-anyonei-anyonei-142933.html I found a post similar to your question. The intake i believe is made of nylon or glass reinforced nylon by the look and feel of it. It should be good for many psi over the stock and dd needs. Other parts will likely fail before the manifold fails. Link to comment Share on other sites More sharing options...
battelready Posted September 25, 2016 Share Posted September 25, 2016 Depends on the tuner. If you dont have supporting fuel mods ( which you should for that turbo) max like 17-18. But with mods you can go from 18-24 on that turbo. Also the AT needs to be beefed up deff for that turbo. Your plastic manifold is good for what ever you would ever need it for unless you go sti turbos. I bought an auto be more involved in my uninvolvedness . 200k+ Club If you can't blind them with brilliance, baffle them with bullshit. My high mileage turd. Link to comment Share on other sites More sharing options...
J.films Posted September 26, 2016 Author Share Posted September 26, 2016 Welcome. How much did you want to push through? Is your car tuned now? How much power did you want to make? How long did you want the current engine and drivetrain components to last How many miles are on the current engine? I was looking at running 14psi of boost but my car is not tunned yet and i wanted to get 300hp out of my engine. my car has done 110,000 miles Link to comment Share on other sites More sharing options...
J.films Posted September 26, 2016 Author Share Posted September 26, 2016 Depends on the tuner. If you dont have supporting fuel mods ( which you should for that turbo) max like 17-18. But with mods you can go from 18-24 on that turbo. Also the AT needs to be beefed up deff for that turbo. Your plastic manifold is good for what ever you would ever need it for unless you go sti turbos. what fuel supporting mods do you recommend? Link to comment Share on other sites More sharing options...
coldsoda Posted September 26, 2016 Share Posted September 26, 2016 what kind of compression / leakdown numbers is your engine showing right now? That'd be the first thing I'd check before aiming for "300 hp". the stock intake manifold is FAR from the first bottleneck in your quest for more power. do you have a tuner yet? These are really questions that should be answered by that person - finding a reputable tuner is KEY to a reliable subaru. Link to comment Share on other sites More sharing options...
Max Capacity Posted September 26, 2016 Share Posted September 26, 2016 what fuel supporting mods do you recommend? You'll need bigger injectors and a fuel pump. I'm guessing you don't have a Cobb AP either. you can contact http://www.tuningalliance.com/home.html or PM them from here. Mike is one of the best tuners with these cars. He's had my wagon happy at 21-psi for close to 90,000 miles. KEEP you car OUT of Boost until its tuned. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
battelready Posted September 26, 2016 Share Posted September 26, 2016 What max said Sent from my E6683 using Tapatalk I bought an auto be more involved in my uninvolvedness . 200k+ Club If you can't blind them with brilliance, baffle them with bullshit. My high mileage turd. Link to comment Share on other sites More sharing options...
Tuning Alliance Posted September 26, 2016 Share Posted September 26, 2016 I would get your car tuned sooner rather than later, can't be running that turbo and other mods without proper tuning. Shoot us a PM and we can get you setup on the right path. -Brian (tnx max/battle for the recommendations) Contact us for all your tuning and performance parts needs! Etuning the legacy community since 2008! Follow us on FACEBOOK | INSTAGRAM [sIGPIC][/sIGPIC] Link to comment Share on other sites More sharing options...
RWebb Posted September 26, 2016 Share Posted September 26, 2016 Its not about boost its about CFM. 18psi on a stock turbo and 18psi on a 44lb turbo are 2 very different CFM.... Link to comment Share on other sites More sharing options...
magnusonsubie Posted September 27, 2016 Share Posted September 27, 2016 I was looking at running 14psi of boost but my car is not tunned yet and i wanted to get 300hp out of my engine. my car has done 110,000 miles Don't be so dead set on numbers as much as having a car that is fun to drive. what fuel supporting mods do you recommend? Like Max said, upgraded pump, injectors, I'd probably do a topfeed conversion for the tuners sake as everything I've seen the topfeed injectors are far more consistent than the stock sidefeeds and aftermarket side feeds what kind of compression / leakdown numbers is your engine showing right now? That'd be the first thing I'd check before aiming for "300 hp". the stock intake manifold is FAR from the first bottleneck in your quest for more power. do you have a tuner yet? These are really questions that should be answered by that person - finding a reputable tuner is KEY to a reliable subaru. All of this. Get a tuner you trust. I personally use Cryotune and his E-tuning services which he just started offering again but I know there are others like Max with good experience with TA. Its not about boost its about CFM. 18psi on a stock turbo and 18psi on a 44lb turbo are 2 very different CFM.... ALL OF THIS!!! You went pretty crazy right off the bat asking about how much boost you can push through the plastic intake manifold. These cars aren't just a 12v cummins that you can throw a bigger turbo on, crank up the fuel screw and throw 35 psi into. These are super picky precision engines that must be tuned properly and accurately to get the best reliability out of. 2005 Vader Wagon Material Tests on Ringland Failure Piston I should have held off and purchased a wagon instead of the spec.B Link to comment Share on other sites More sharing options...
Max Capacity Posted September 28, 2016 Share Posted September 28, 2016 What was that old saying from a few years back...in before it blows up... OP give us an update? 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Brettaminer Posted January 29, 2022 Share Posted January 29, 2022 ok so i am really tired so i had to double check to make sure i wasn't missing anything and i'm almost pretty sure i have not... so far noone has answered the question and i am wondering the same thing. how much psi can the stock turbo safely handle? (and everyone quit looking so deeply into it. you're all making it way more complicated than it should be.) not trying to sound like too much of a dick. i'm just super tired and irritated. regardless. how much pressure can the stock turbo handle? stock. it's stock. completely stock. no tune. no pro-tune. no tuning of any kind and no mods. no addons. just completely stock. i want to push it as far as i safely can that is not going to do any damage or require any upgrading. (hopefully someone still reads and/or checks this. i didn't look at the date on the post or any of the replies.) Link to comment Share on other sites More sharing options...
Pleides Posted January 29, 2022 Share Posted January 29, 2022 (edited) How much can the stock VF40/46 handle in terms of PSI? About 20 PSI before you might notice the turbo starts to separate. The VF46 on my car didn't make an appreciable amount of boost more at 18 PSI than it did at 17 PSI, so the efficiency of the turbo really would have you stopping at around 18 PSI, and most stock fueling setups will run out of steam above 17. That is, assuming you have an aftermarket downpipe installed. If you don't, don't turn the boost up at all cuz you'll blow your cat up. Oh, and you WILL have to tune it. Your car will blow up if you run more boost without more fuel. Edited January 29, 2022 by Pleides Link to comment Share on other sites More sharing options...
Max Capacity Posted January 29, 2022 Share Posted January 29, 2022 The stock limit will be the plastic tmic. It will begin to separate at the crimps. at about 18psi. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
All_talk Posted January 29, 2022 Share Posted January 29, 2022 All stock engine with all stock parts can handle stock boost. Any changes that will increase power (like raising boost) will require a tune. These engines do not have headroom like turbo cars of the past, they are tuned lean for mileage and emissions and will not tolerate more boost without adjusting the tune. First mod for these cars is a tune. Link to comment Share on other sites More sharing options...
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