Boost Controllers

[NJMR2]

Can someone please explain to me how excactly manual and electronic boost controllers work, I know they regulate the wastegate, but what parts do i excactly need and which brand would you recomend. Thanks

[JekylandHyde]

The wastegate opens based on boost pressure depending on the spring rate inside it.
A 10 psi spring in the WG will open the WG at 10 psi and hold your boost steady.

A manual boost controller (typically a ball and spring) just adds restricition to the vac line feeding the wastegate. The more pressure required to move the restriction, the more boost you are going to run. So if you have a 10 psi spring in your WG and you put a MBC in the way and set it at 15 psi ... the WG never sees the boost until it hits 15 psi.

The EBCs work the same way except they use a solenoid (or two) to impede the boost flow to the wastegate.

I highly recommend the Blitz Dual Solenoid unit (BLitz DSBC).

[TRD2000]

hey jeff what would happen if we upped the boost a couple of PSI on a stock engine, kept it just under the fuel cut.

i don't want to do anything to this engine, most stuff can wait till the new one, but i don't think it takes much to up the boost by just a couple of psi, so it might be worth it. i can't raise it much or i have to deal with the fuel cut.

[JekylandHyde]

Stock boost is 7 ~ 11.8 psi.
Fuel Cut is 12 psi.
There isn't really any room to up it.

The most boost I would recommend running on the CT26 is 15 psi. Under no circumstance would I go over that.

I race at 24.5 psi on the stock engine, but I amtuned for it, use race fuel and water injection.

[MR2turbo93]

What about being tuned for per say 17psi, will the stock turbo hold up? Thats what they say in here anyway. http://www.mrcontrols.com/primers/power.htm

[JekylandHyde]

Where does it say on there that the stock turbo will hold up to 17 psi? I think you should reread that article a bit more carefully.

It does say "With the addition of three simple, inexpensive devices, this can be safely increased to 15psi for a gain of nearly 10rwhp per additional pound of boost."
and
"After doing this, you can expect to be producing approximately 200rwhp. First, you need an accurate boost gauge to be sure that you are not boosting above 15psi."

It does not matter what you do to the engine or anything else, the CT26 is out of it's efficieny range above 15 psi; therefore, you are drastically increasing risk for very little gain in power.
It's not worth it. If you want big power and you want big boost, you need a bigger turbo.

[MR2turbo93]

It says you can take the CT26 up to 16 psi with a larger intercooler not 17 i made a mistake.

[JekylandHyde]

You might notice that it says you might see another 5 rwhp.

You might notice that I said above:
"you are drastically increasing risk for very little gain in power."

[TRD2000]

i'm with Jeff, i wouldn't want to go above 15 on the stock turbo, it's ceramic, put too much load on it and you'll hear the blades make their way down your exaust with a puff of black smoke... game over. not worth it for minimal gains...

[MR2turbo93]

lol true , i only thought it was ceramic everywhere but the US

[MR2Driver]

The CT20B is, not our CT26's

[TRD2000]

mmm so you guys got steel turbines in the ct26? like the us supra?

[91 Celica St]

how does the boost controller work witha 4agze supercharger...basically the sam way right...i know how on a turbo it works but i have little to no exp w a supercharger

[JekylandHyde]

As far as I know, the amount of boost from a supercharger is fixed, not adjustable.

If you want more boost from a supercharger, you need to get a different pulley for it.

[91 Celica St]

yeah i knew that but the only thing i didnt get is why a gyuy w an ae 86 rolla w a 4agze had a boost controller on it...meh it coulda been a turbo timer w an lcd screen but im not sure

haha im using ta 4agze tat i got and putting the head from my 4afe on it

ima have a 4afze...w my near stock ecu running stock boost on the supercahrger...haha

how much boost did the 4agze supercharger run stock?