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Larger turbo vs stock turbo at higher boost?

Jerickson88

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#43
The DV and wastegate are separate parts. By replacing the stock DV, you are putting on a more efficient part for performance. Basically, the electronic valves are like light switches. On or off. The vacuum valves are like dimmer switches, and boost pressure/vacuum determines how bright the light is.

And it may not be that there’s one better than the other in the aftermarket world, it’s just that the programming for the stock one sucks.
 


danbfree

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#44
The DV and wastegate are separate parts. By replacing the stock DV, you are putting on a more efficient part for performance. Basically, the electronic valves are like light switches. On or off. The vacuum valves are like dimmer switches, and boost pressure/vacuum determines how bright the light is.

And it may not be that there’s one better than the other in the aftermarket world, it’s just that the programming for the stock one sucks.
But I thought a tune would fix that part of it? Yeah it's understood that the DV is a factory recirc BOV while a WG controls the boost output right at the turbo, definitely 2 parts to the equation. Sound like I should start with a DV+ to prevent leak in the first place to keep the turbo running efficiently and take my time considering options from there... Thanks for all your input!
 


danbfree

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#45
Yeah, stumbled on that yesterday, I am just wondering what is so custom about the Tune+ one... Someone on the FB group says his came in a 14 psi spring box and when asked was basically told by Adam to not worry about it, it's definitely setup right, but then the customer said if he could do it all over again he would just go with a 7 psi one for a stock turbo, he had too much partial throttle issues and is now running a hybrid... So Adam isn't real forthcoming about what is so special about his, I can understand not giving away company secrets but seems he really pumps this up as the very next upgrade to do right after intercooler but doesn't provide a lot of details... between the cost of the part and his fairly expensive tuning I'm not sure that's the route I'd go... So I'll chill for now on the idea and I'll see what Jason with Dizzy comes up with.
 


Jerickson88

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#46
But I thought a tune would fix that part of it? Yeah it's understood that the DV is a factory recirc BOV while a WG controls the boost output right at the turbo, definitely 2 parts to the equation. Sound like I should start with a DV+ to prevent leak in the first place to keep the turbo running efficiently and take my time considering options from there... Thanks for all your input!
Look at that or Turbosmart options. They have electric or vacuum.
 


Quisp

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#50
Yeah, stumbled on that yesterday, I am just wondering what is so custom about the Tune+ one... Someone on the FB group says his came in a 14 psi spring box and when asked was basically told by Adam to not worry about it, it's definitely setup right, but then the customer said if he could do it all over again he would just go with a 7 psi one for a stock turbo, he had too much partial throttle issues and is now running a hybrid... So Adam isn't real forthcoming about what is so special about his, I can understand not giving away company secrets but seems he really pumps this up as the very next upgrade to do right after intercooler but doesn't provide a lot of details... between the cost of the part and his fairly expensive tuning I'm not sure that's the route I'd go... So I'll chill for now on the idea and I'll see what Jason with Dizzy comes up with.
Mines 11psi. The springs are color coded .
 


A7xogg

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#52
Huh, there is a new For Sale post that says their Tune+ WG is a 10 psi... anyway, I'm either gonna do a 7 with the stock turbo or just save to upgrade the turbo itself.
the wastegate i thought gaveme more power than switching to my e30 tune. basically its the only bolt on that makes power
 


danbfree

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#53
the wastegate i thought gaveme more power than switching to my e30 tune. basically its the only bolt on that makes power
And this was Tune+ version and their tune? This would be the same thought process as Adam as well, what he says on his site being the 2nd most important mod after IC, that's why I'm so curious now.., Because others have basically said it either helps from 4-5k RPM or the stock turbo is still too small for that to help, as is usually the case, the truth lies somewhere in the middle, Adam's very generic charts only show "after" results, not before...
 


A7xogg

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#54
And this was Tune+ version and their tune? This would be the same thought process as Adam as well, what he says on his site being the 2nd most important mod after IC, that's why I'm so curious now.., Because others have basically said it either helps from 4-5k RPM or the stock turbo is still too small for that to help, as is usually the case, the truth lies somewhere in the middle, Adam's very generic charts only show "after" results, not before...
This was a tune + wastegate, so it was a 11psi wastegate. A 7 or 11 psi wastegate is perfect for stock turbo. I used jstperformance for my tuning (which I highly recommend). My logs on datazap show morr boost through the rpm(2-4 psi more), lower and flat wgdc, and a higher air flow meter reading (2-3 more). Tuning took a little bit but just s couple more than regular tuning. Took an hour and 10 minutes for install so to me it's worth it a few times over
 


M-Sport fan

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#55
But I thought a tune would fix that part of it? Yeah it's understood that the DV is a factory recirc BOV while a WG controls the boost output right at the turbo, definitely 2 parts to the equation. Sound like I should start with a DV+ to prevent leak in the first place to keep the turbo running efficiently and take my time considering options from there... Thanks for all your input!
The GFB DV+ was the very first performance mod I did, along with, and at the same time as, the CP-E RMM. ;)
 


danbfree

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#57
This was a tune + wastegate, so it was a 11psi wastegate. A 7 or 11 psi wastegate is perfect for stock turbo. I used jstperformance for my tuning (which I highly recommend). My logs on datazap show morr boost through the rpm(2-4 psi more), lower and flat wgdc, and a higher air flow meter reading (2-3 more). Tuning took a little bit but just s couple more than regular tuning. Took an hour and 10 minutes for install so to me it's worth it a few times over
Thanks man, will definitely keep this in mind... do you know if you were a good 10 HP more then since it's clear you like it? :)
 


danbfree

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#59
Usually every 1 lb/min of more air flow is 10 hp
Whoa, so 20-30 more HP? That's pretty substantial... you see guys ask if they can hit 250 HP on a stock turbo but this mod never gets mentioned as a way to get there... well, with this mod and e30 that looks to quite attainable... BUT, the problem is the more you mod and help the stock turbo, the more it has that absolute donkey kick of sudden torque, with just e30 and drop in I'm already having issues with wheel spin in 2nd gear... I can see hybrids as more than for just more power, but smoother powerband as well.
 


OP
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Thread Starter #60
In plain English, is there a cheap solution to increase boost by a bit?

And how much can the boost be increased on a totally stock ST, without the ECU triggering all kinds of error codes?
If I can just install some valve (spring or other mod) of a few tens of dollars, without a tune, and gain even +1PSI extra without a tune, it would be worth it (I hope).

I understand running higher pressure can destroy the Turbo.
I'm barely ever taking my car over 4k RPM anyway.
I just love the turbo kicking in, when I surpass the 2.5k RPM. And usually pull it to 3.5-4k RPM before shifting. Occasionally 4.5k RPM.
I don't see myself changing that.
Adding a few PSI of boost, will hopefully add to the acceleration effect around that RPM range.
 




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