Boosted influence

[wtdash]

Per my Sig, I recently joined the EJ22T world. I have an MBC set @ 14psi, and a vrg3/Vikash designed FCD.

I've noticed that when climbing hills that would cause the 4EAT to downshift to 3rd or 2nd w/the NA EJ, the turbo kicks in for a few secs (the boost climbs to 10+ briefly) and car just keeps climbing in OD - torque is a cool thing!

Well, this turbo surge isn't so welcome when there's a 1/2+" of snow/ice between the tires and asphalt while climbing. I've never taken my Subies for a spin, and don't want to in mixed company.

Although still in my turbo initiation, it appears that shifting down to 3rd mitigates the turbo's influence. Being TC (tech challenged) I'm guessing there's less load on the engine, so the turbo doesn't spool??

Would an EBC also be an answer? Since it would prevent PTFB?

[subydaddy]

Hey, I don't have an answer to your EBC question, but I will try and help.

A cheap alternative that, i'm running, to an EBC is a stock boost selenoid with your MBC. I know it's not the same, but with the money I spent on my car and the money I make, it's good enough. Anyways, I wired that up to an SPDT switch so when you push your button the selenoid opens and closes (duh i know). Then run your tubing from turbo inlet to the wastgate through this selenoid with your MBC T'd in connecting the tubes on either side of the selenoid together. When the selenoid closes you run MBC PSI. When Open you run wastegate pressure. Mine is around 14/9 and I have the same turbo/intercooler set up you do.

Also, if you manually downshift to 3rd and press the manual button on the shift knob is doesn't down shift from there and is supposed to be better for driving in the snow. My legacy takes a full two seconds of front wheel spin before the back tires kick in. Unless I mash my foot down quickly and get the power light to come on. Which I typically do rather than wanting my nose heading for the nearest sidewalk or car.

I'm sure I'm not the only one out there that knows this and I know more people will chim in and help you, especially with your initial question. haha, sorry, I think I've had too much to drink to night and need to either stop drinking or stop typing.......

[wtdash]

Thanks for the info....do I understand correctly that you use the SPDT switch for low boost (slippery conditions) and high boost (full traction)?

I'll have to look into that, too.

As far as your delay, that sounds just like mine did before I filed down the grooves on the rear hub..doesn't require removing the tranny - just the rear housing. I've also hear of the VSS causing this too.

Here's a Linky


Post # 21 shows pics.

[subydaddy]

Wow, You my friend have been more help to me then I have to you. Thank you. I had no idea this website even existed let alone that I could fix my AWD delay. I figured that's just how it was in 1992.

As far as the SPDT switch. I don't believe it's required, but for my application it was needed. All the boost selenoid needs is a 12v signal to power it on and it either opens or closes, I forget. But combined that with an on/off switch in the cab and you can quickly change to high boost setting.

I picked up a used boost selenoid from an STI for I think $35 shipped (to Alaska) and I drive around 99% of the time at wastegate pressure anyways. I don't feel the need for speed very often anymore, I think just knowing it's there is what really does it for me.

Thanks again for your help. If what I'm trying to say isn't painting a clear picture (it usually doesn't) just pm your email address and I'll send you a beautiful ms painted picture of hooking up the selenoid and the MBC.