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Stratified peak boost values.

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asdfsafd
#1
What do you see with your car on the stock turbo?
They've bumped mine up to 27. I've seen it as high as 27.3psi. I'm a bit concerned. Thoughts, experiences?
 


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Hawthorne, NJ, USA
#2
I've seen 26.4 psi as my highest reading but that is the highest I have seen so it could have been higher. From what I've heard that the high psi isn't something to worry about since its when and how long it comes on for but maybe others can give a more direct answer.
 


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New Castle
#3
Not sure if I've topped 27. But I can easily get 26.5-26.8 on my 4.0 tune with the aggressive throttle mapping. On my older 3.x tune, I top out in the 25s. Been running them for about 7k miles, mostly city driving. No issues as all.

As others will mention, I wouldn't worry too much. Stratified isn't looking to damage any motors.
 


kivnul

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#4
For your peace of mind though, ask them to cap it at around 26. They can play with timing to compensate somewhat.
 


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Dublin, OH
#5
I have seen 27.6 on my 4.0 tune and I'm a bit concerned. I called them but did not get to a tuner. The girl that answered the phone (I forgot her name) put me on hold for a minute and came back and told me not to worry about it because that was not a sustained number. I am really thinking of having my tunes modified to cap them at 25 psi. My earlier versions were just over 26, and I was a bit worried then. This almost 28 number concerns me a lot.
 


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Alexandria
#6
26 or 27 psi is nothing to worry about. I am at about 50k miles and have been running about 30k+ with boost spiking between 27-28 psi and have seen 29 a few times.
 


danbfree

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#7
I have seen 27.6 on my 4.0 tune and I'm a bit concerned. I called them but did not get to a tuner. The girl that answered the phone (I forgot her name) put me on hold for a minute and came back and told me not to worry about it because that was not a sustained number. I am really thinking of having my tunes modified to cap them at 25 psi. My earlier versions were just over 26, and I was a bit worried then. This almost 28 number concerns me a lot.
The issue would be overspin if you were at 27+ when you are over 5000rpm, don't worry about spikes much lower in the RPM range. Next time you have a chance to do a full pull, watch what the boost is once you hit 5000 RPM if it's 26+ then email Stratified and let them know, but I HIGHLY doubt it, those guys know their stuff. I bet you are WELL under 25 but the time you hit 5000 RPM... Just saying as an example of how to show how safe it really is, the stock turbo can't really even do that anyway...
 


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#8
The issue would be overspin if you were at 27+ when you are over 5000rpm, don't worry about spikes much lower in the RPM range. Next time you have a chance to do a full pull, watch what the boost is once you hit 5000 RPM if it's 26+ then email Stratified and let them know, but I highly doubt it, those guys know their stuff. I bet you are WELL under 25 but the time you hit 5000 RPM.
I think you are thinking of aftermarket turbos. The stock turbo doesn't have issues with overspinning. It also drops pressure the higher you rev. At 6k rpm you may be near 20 psi but it will be dropping fast at that point.
 


danbfree

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#9
I think you are thinking of aftermarket turbos. The stock turbo doesn't have issues with overspinning. It also drops pressure the higher you rev. At 6k rpm you may be near 20 psi but it will be dropping fast at that point.
I was thinking that with a tune you never know how it might be pushed but clearly with a known commodity in Stratified it's not like they would ever push it past safe levels anyway... I was trying to give an example of how you can show how it's actually quite safe at upper RPM's as I agree with you, stock turbo can't really do that anyway.
 


OP
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Thread Starter #10
But what is considered "sustained?" If I floor it at 3K RPM in 6th, it will sit at 27psi+ for much longer than in 3rd. And if I'm driving uphill, that's definitely a lot more load for a much longer time than doing straight line 3rd gear pulls.
 


danbfree

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#11
But what is considered "sustained?" If I floor it at 3K RPM in 6th, it will sit at 27psi+ for much longer than in 3rd. And if I'm driving uphill, that's definitely a lot more load for a much longer time than doing straight line 3rd gear pulls.
But that is because of gearing you are sitting in that RPM band below 5500 longer, where it can easily handle that boost... it's only when it's boosting above 26 PSI when you are above 5000 is when you should be concerned. It's not a matter of engine load, it's a matter of the turbo over spinning, which is pretty much impossible with it's small diameter openings... Now will you get extra heat being at 27 PSI? Yeah, you will, but with all the safety checks in place it's allowing it to boost that high because it's determined your heat levels aren't excessive and it's trying to meet targeted torque... This is my take anyway, anyone feel free to jump in if anything I said sounds wrong...
 


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#12
I have been on these forums for a while and never seen anyone talk about over spinning the stock turbo. Also you wont ever see 27 psi at rpms above 4.5k. Yes that is a lot of boost but it isn't a problem. The fiesta has a good motor and gear box. Use a reputable tuner and you shouldn't have any issues. I have done plenty of 6th gear pulls but also realize if I'm going to be running up a hill I should shift down if i want to speed up. The point of this post was to ask if 27 psi was safe and the answer is yes. The guy that started talking about over spinning doesnt have much experience on this platform. From what I have seen you cant over spin the stock turbo. There is no way through tuning to get more boost out of it at higher rpm. It's a small turbo and falls on its face after 5.5k rpm. Another point is that stock turbos are not failing on these cars and are very cheap to replace at $2-300. There are stock frame turbos (x-37 and x-47 look it up) that will run 25+psi to over 7k rpm. No one has engine troubles doing so. It's still a reliable car. Those turbos if pushed for higher boost can be over spun trying to maintain 27 or 28 psi.
 


danbfree

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#13
I have been on these forums for a while and never seen anyone talk about over spinning the stock turbo. Also you wont ever see 27 psi at rpms above 4.5k. Yes that is a lot of boost but it isn't a problem. The fiesta has a good motor and gear box. Use a reputable tuner and you shouldn't have any issues. I have done plenty of 6th gear pulls but also realize if I'm going to be running up a hill I should shift down if i want to speed up. The point of this post was to ask if 27 psi was safe and the answer is yes. The guy that started talking about over spinning doesnt have much experience on this platform. From what I have seen you cant over spin the stock turbo. There is no way through tuning to get more boost out of it at higher rpm. It's a small turbo and falls on its face after 5.5k rpm. Another point is that stock turbos are not failing on these cars and are very cheap to replace at $2-300. There are stock frame turbos (x-37 and x-47 look it up) that will run 25+psi to over 7k rpm. No one has engine troubles doing so. It's still a reliable car. Those turbos if pushed for higher boost can be over spun trying to maintain 27 or 28 psi.
While just about any turbo, but our tiny stock one, can overspin, ours simply can't even flow enough air to make that happen, it was a bad example, I digress... but the stock turbo can start heating up much faster past 26, but if it's pulling 27 it's only because the system is allowing it because it's safe... so yes,, all that matters is that 27 psi is safe if it's actually pulling it, a reputable tune and the ECU wouldn't allow anything bad to happen. If anything pulling 27 means everything is actually working really well and in trying to meet called upon torque levels it's pushing for more boost to meet that, 26 is not a hard limit, but a soft one in Stratified tunes.
 


felopr

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JD
#14
good ol turn the wastegate to eleven and control it with etc angle. I would love to see a log
 


A7xogg

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#15
good ol turn the wastegate to eleven and control it with etc angle. I would love to see a log
I'll have to pull mine up but it cuts throttle till like 3300 rpm or so then it holds wot and makes more boost at 4500 than 3k
 


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