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Discussion Starter #1
Well I started my car and have a few small things to work out. Its a on3 FF kit on my 97 cobra. Looking to run around 20lbs of boost. I dont think I will be able to get the spings to hold that high.
Would it be best to set the springs around 12 to 15lbs and add a boost controler to adjust for the rest?
first turbo car so Im not realy sure what would be the best choice.

How would you do it?
 

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AMS 500 electronic is the ticket these days for street cars. But a Hallman Pro Rx manual boost controller gets the job done for a basic setup. Put the small spring in the wastegate first and work your way up to the larger springs
 

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Depends on your setup and goals for the car. A boost controller can effectively get you double the spring pressure. For my setup I run 12psi on the street tune so I have a 44mm wastegate with a 12psi spring in it and my eboost2 turned all the way down for that setting, then I have a second setting that turns it up to 18psi with the touch of a button, and I plan on no more than 20-22psi on this setup with some race gas or meth later.

Now on the other hand if its drag car and you want big boost all the time you could just add springs to get you where you want, either way would work some are more expensive than others.
 

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Depends on your setup and goals for the car. A boost controller can effectively get you double the spring pressure. For my setup I run 12psi on the street tune so I have a 44mm wastegate with a 12psi spring in it and my eboost2 turned all the way down for that setting, then I have a second setting that turns it up to 18psi with the touch of a button, and I plan on no more than 20-22psi on this setup with some race gas or meth later.

Now on the other hand if its drag car and you want big boost all the time you could just add springs to get you where you want, either way would work some are more expensive than others.

Is that the limit of a boost controller? 2 times the spring pressure? I have 7psi spring now and running 15psi, planning to go over 20psi in November
 

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Electric boost controllers can adjust HOW the boost comes in which for me is a key point to using an electric controller.
Now electric boost controllers also might pick up your spool time.
 

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Is that the limit of a boost controller? 2 times the spring pressure? I have 7psi spring now and running 15psi, planning to go over 20psi in November
Yes a standrad manual or electronic boost controller can effectively control double the spring pressure. You can push its bit more but risk having boost control issues (wavy boost curve, drops etc) and fatiguing the spring.

Its posibble to get more but you would need an electronic controller setup with a solenoid and run a dual port setup on the wastegate.
 

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Electric boost controllers can adjust HOW the boost comes in which for me is a key point to using an electric controller.
Now electric boost controllers also might pick up your spool time.

Yeah thats what I love about my eboost2. You can set gate pressure to keep the gate completely closed longer unlike a spring and manual controller where the gate starts opening slowly as you approach target boost. This improves spool time and low end torque.
 

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how exactly is an ebc limited to only 2x the spring...???

as far as the comment about the street vs drag car it makes no difference the ebc will always out perform a manual setup which is simply for budget. outside of that i don't see why anyone would ever use a mbc over ebc.
 

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An ebc with single solenoid running to the side port of the wastegate will only get you to roughly double the spring pressure just like a manual boost controller. Just as the mbc has a spring valve in it and you manual adjust spring pressure, the ebc solenoid valve has a max duty cyle % that is designed to get that double spring pressure as well. My old setup was a tial 38mm wg with a 9psi spring with my ebc set point at 100% dc it spiked to 20psi and leveled out around 18 the rest of the pull. If you want to push it more and maintain control the boost level effectivley you would need a dual port config. However this also raises the min boost you can run as it puts pressure on the top of the wg diaphram (thats normaly open to atmosphere) this helps keep the valve closed longer beyond what would normaly be possible with the solenoid regulating pressure to the bottom side and working against the spring.

On a drag car they build boost at the line on a 2 step or trans brake and maintain boost throughout the run so it doesnt matter wether you are just using springs, a manual or electronic bc since your always in boost. #### I've seen quite a few big turbo drag cars without a wastegate at all.

For a street car where your getting on it after cruising with no boost, letting off the throttle when shifting and rolling in and out the throttle etc you have periods of no boost thats where the ebc will perform better than a mbc since you can control gate pressure with the solenoid. Other than that they work the same and theory of operation is the same, its still the spring in the wg that does the work, one has a valve you adjust manualy and the other uses a solenoid to electricaly controll the valve to adjust boost reference.

There are pros and cons for both setups mainly cost you can get a good manual controller for $30-50, while the nice mulitfunction electronic controllers are $400+.

I personaly think an ebc is worth every penny and always run them but not everyone finds it necessary to spend the money on it.
 

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Discussion Starter #10
Well with my on3 FF4V kit, I removed the stock large red spring and put in the larger blue spring and the small yellow spring. What is the around about boost i should exspect to see out of these two springs.
The instrutions were not that good. In the first part is says to run one large spring and one small spring. Then it gives a list of combos.
Stock red 5to6
Add small yellow+2
Add larger red+4
Add larger blue +6
Now how can you had a large red to a large red or a larger blue to a larger red? So I have no idea what its going to make. Haha
 

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Not to hijack the thread but...

I have the aem ebc that hooks to the to and bottom port. I'm at about 65% duty cycle to hit 15psi on a 7psi spring. Does that mean i can push it to 22-25psi? Triple spring pressure
 

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Not to hijack the thread but...

I have the aem ebc that hooks to the to and bottom port. I'm at about 65% duty cycle to hit 15psi on a 7psi spring. Does that mean i can push it to 22-25psi? Triple spring pressure
No, not effecively anyway with a dingel side port conenction setup. The duty cycle is non linear as you increase it, every setup is different but when i got bove 75-80% on my controller it was barely adding anything, your still limited by the spring in the gate it still does all the work. You would need to T your pressure source and run a line to the solenoid input and bottom port of the gate, then run the solenoid output to the top port of the gate to get in that range with that small of a spring. This effectively "makes" your spring bigger since you have pressure in the top port now and allows much higher boost but will also raise the minimum boost you can run and you will have to reset all your controller settings.
 

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I meant it hooks to the top and bottom port. Its the aem tru boost.


No more posting when im half awake. Springs are cheap. I saw a 14.3psi spring for $10 on ebay. Guess ill get a couple of those
 

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LOL it happends, yeah with a dual port setup you should be able to get there. IMHO the best ideal is to get the biggest spring you can based on the minimum boost you want and then go from there to ensure you have the most accurate control.
 
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