Well, without the helper spring the best I can do is 15.2 psi even with 89% WGDC. Going from 80-89% didn't affect max boost much if anything; target is 18.5 and I'm obviously pretty far off. SS/Doug/tuners/anybody, feel free to suggest some ideas for fixing this. Thoughts: * I know I can use a helper spring, but would like to avoid if possible * Can a TD04 adjustable actuator be retrofitted on a VF34? * If I use a smaller pill (the .9mm that came with the VF34) might that suffice, or will it only help boosting quicker on the low end? * Is it the stock boost solenoid that's not sufficient to bleed off enough air? * Would a Perrin or GM boost solenoid fix this?
might wanna try here. http://www.wrxhackers.com/forums/index.php board is kinda slow but pretty technical.
Copied from the other thread: I don't see a need for it. The ECU has plenty of shit to handle boost, and it's just a matter of putting the proper mechanical pieces in place. I will try the Vf34 (0.9mm) pill next. Alex, would you mind wiping out the posts not related to OpenECU in the other thread? Want to keep it as clean as possible and not specific to my issues/car.
have you been running the stock restrictor pill since u had the vf34? scott changed mine on the WRX even before i upgraded the turbo... i think its most likely thats the reason u arent hitting your desired boost
The Cobb 2.5 map requires the stock pill. That's why I've been running it; I did try the VF34 pill on the Cobb 2.5 map and spiked to 22 psi. Hopefully cranking the WGDCs down a bit and running the smaller pill will be all I need.
1. what are you using to measure boost ? I have a digital cal press gauge that i can check if you are reaching target psi 2. Where are you taking the boost pressure from ? 3. pressure test try the 0.9 orifice pil and see if you will reach target boost. Then after the pil there is a T and then a union (I) on the way to the boost solenoid, change the Union to a larger one and see if this helps. ( I have a couple of unions larger than stock you can try.
1. Relative manifold pressure off the ECU 2. See above. 3. If you're talking about boost leaks, keep in mind that I hit Stage 2.5 target boost all day long as long as I use the helper spring. Didn't think about the union -- if the smaller pill doesn't help (assuming I can find where I put those hoses) I'll try that.
if you had tried it and spiked to 22 psi then i suspect its the union. or you can play the combo game (hate 1 equation 3 unknows) combo: WG adjustment, Poison pill, T fitting and I union
If I can't find where I put the pill I'll do the 3/16 mod first and see if it helps. Any idea what size the stock t-fitting is? 1/4"?
OEM part T / I The oem T ID is a tad over 2.1mm (0.083") cars too damn hot to measure the Union (on car) If you need that let me know ill measure it tonight I have a T that you can have that had 3mm ID and can plug off the branch to make it a union I
Thanks; I'm going to try the union first since I have some fittings sitting around here. Will keep you posted!
BTW, make sure the hose from the turbo outlet to the boost solenoid does not have major bends or kinks.
Well, did the 3/16" union and hitting a solid 18psi on the gauge now; will datalog a bit later. :banana:
Also, Ming, I owe you a beer or two for suggesting the union. I had completely forgotten about that mod.
So just a 3/16" union rather than the factory piece? (having same problem with Cobb stage 2 best was 14.4 before the TMIC..best now is 15.4 after new TMIC)
Yes, just that. My WGDCs were still sky high (around 90% to hit target), so decided to swap pills as well. I had to get them down into the low 60s to keep from blowing past target boost after that. Gives me some headroom to play with for sure! Also, protip: make sure you stick the hose back on the actuator properly. Good thing I was being very cautious testing boost.
I didn't put anything in to compensate. The 3/16" mod allows more flow to the boost solenoid, letting it bleed off more air. The 0.9mm pill lets less air through from the compressor side. Both help do the same thing; let the stock solenoid handle a ported/polished vf34 within what it is capable of...
Yes, stock is around 1.1mm. Even with the 3/16 mod it was pushing too much air through; the stock solenoid couldn't bleed off enough.
If you dont want to change the poison pil. you can reduce the hose size or somehow restrict the hose goin to the wastegate (reduce the tube ID or put a flow control valve) multiple gates will give you better control of the flow/pressure. If you go to walmart or places where you can get fishing line (wire leader) crimps you can press one into the T and reduce the flow of the air into the WG
Stock is 1.3 on WRX's, 1.4 on FXT's, and 1.0 on STi's. If you ever need a 1.0 we keep a BUNCH in stock and they're $2.93 NOS jets, carb jets, machined orifices, etc are available. I have a whole kit full of different size restrictors, but they spilled and I don't know what size they are. If anybody on here has access to pin gauges, I'd swap them something for organizing my restrictors SS
what is happening when you change the pill size? What is to consider when changing from a 1.3 to a 1.0? What effect is this going to have on how the wastegate operates?
Thanks for setting me straight on the pill diameter; I had 1.1 and 0.9 written down from some NASIOC thread but I guess they weren'r right. crashtke: a smaller pill will let less pressure through to the actuator and boost solenoid; without tuning you'll likely see some spiking/overboosting.
^^^ Correct. *DO *NOT* CHANGE PILLS WITHOUT TUNING* It WILL cause spiking. Smaller is more boost, more response, and harder to control. We normally go with 1.0's... SS
SS: any idea what the VF34 comes with? Somebody said 0.9mm earlier but that might be wrong. Either way, it was sufficient to lower WGDCs a good 30%.