LGT_ Posted November 9, 2014 Share Posted November 9, 2014 Got a Legacy gt 5mt, SPT intake, turboxs bov, 3" catless dp, ap at stage 2. How much psi can i run safely? i hit peak at 19.7 and i dont want my turbo to blow. Please let me know How much is safe! Thanks Link to comment Share on other sites More sharing options...
iNVAR Posted November 9, 2014 Share Posted November 9, 2014 A mild spike, especially in cold weather, is fine. You're using an AP with an OTS map so there's nothing you can do about it anyway. The only way to rein in that spike is to get it custom tuned. Your SPT intake isn't "compatible" with the OTS Stage 2 map, BTW. The MAF needs to be rescaled. 19.7 does seem a bit high though, even for a spike. Under what conditions are you hitting that? You may want to get the LWG map. Shows the targets: https://static.cobbtuning.com/cobbtuningweb/site/maps/subaru/map_notes/SUBA_US_LGT_07-09.pdf Link to comment Share on other sites More sharing options...
LGT_ Posted November 9, 2014 Author Share Posted November 9, 2014 Cobb dosent have intake maps, not for 09. I actually just downloaded LWG stage 2 from cobb which lowered it to like 18.5 peak. I think ill be fine. Also how accurate is the ap Dyno? i got 308 whp and 355 tq Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted November 9, 2014 Moderators Share Posted November 9, 2014 Sounds like you AP Dyno is about 50 whp too high and 100 tq too high, lol. Recommend pulling the aftermarket intake unless you are going to get tuned for it. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
LatentWagen Posted November 9, 2014 Share Posted November 9, 2014 That OTS map (same one I'm on) is pig rich. You'd probably be "okay" on OTS with just the intake, but not for the long term... however, the boost spikes are something you need to sort out ASAP. Especially with a potentially leaner A/F ratio (because of your intake). LW's spec. B / YT / IG Link to comment Share on other sites More sharing options...
iNVAR Posted November 9, 2014 Share Posted November 9, 2014 Under what conditions (driving, weather, gear, etc.) are you spiking to 18.5 and or 19.7? Link to comment Share on other sites More sharing options...
keenster Posted November 9, 2014 Share Posted November 9, 2014 Isn't there problems with the spt intake because where the MAF sensor sits? It sits right in the middle of the bend causing a vortex or something like that causing the MAF to go screwy. Let me see if I can find it and if it relates to this.... Link to comment Share on other sites More sharing options...
mikeydrives1 Posted November 9, 2014 Share Posted November 9, 2014 about 18.5 on these VF's seem to be the sweet spot for power and still be conservative, however, their capable of running into the low 20s, which i wouldnt recommend for longevity. Link to comment Share on other sites More sharing options...
InTheBay Posted November 9, 2014 Share Posted November 9, 2014 Even 18.5 is bit high, when tuning with my old VF40 we saw huge flow restrictions that made increasing boost past 16lbs not have much effect. The compressor design is just too restrictive to flow enough air, regardless of pressure, to increase power. You need both pressure and flow for a real increase, you can max out one for your car, but you'll see diminishing returns without improving the other. See Ed's posts with graphs here: http://www.xtremeracingtuning.com/forum/viewtopic.php?f=40&t=535 There's a reason he doesn't push past 16. Link to comment Share on other sites More sharing options...
Max Capacity Posted November 9, 2014 Share Posted November 9, 2014 If your hitting those psi's, your tmic needs to be "bulletproofed" see BarManBean for his kit. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
LGT_ Posted November 9, 2014 Author Share Posted November 9, 2014 Im not spiking 18.5. With my lwg stage 2 im constant 18 psi. With regular stage 2 im spiking peaking 19.7. With weather at about 40 degrees ferinheight. I have no knock, and im at constant 14.7 afr. Runs perfect with no retard. im at 86k miles Link to comment Share on other sites More sharing options...
iNVAR Posted November 9, 2014 Share Posted November 9, 2014 Log it. I'd like to see this. Link to comment Share on other sites More sharing options...
Terbow Posted November 9, 2014 Share Posted November 9, 2014 Just before it goes boom! Link to comment Share on other sites More sharing options...
Energyblue98 Posted November 10, 2014 Share Posted November 10, 2014 Altitude has an effect on it too.. im going to take a guess and say that your high psi is due to a wrong restrictor pill. Order the oem restrictor pill for the vf46 and throw it on and see if it makes a difference. I had the opposite problem before because of the restrictor pill Link to comment Share on other sites More sharing options...
LGT_ Posted November 10, 2014 Author Share Posted November 10, 2014 what exactly is a restrictor pill? Link to comment Share on other sites More sharing options...
turbolgt Posted November 10, 2014 Share Posted November 10, 2014 Can anyone explain why my AP v2 would register an extremely high wtq whp on stock motor and a 5eat. Link to comment Share on other sites More sharing options...
iNVAR Posted November 10, 2014 Share Posted November 10, 2014 Because it's not an accurate measure of wtq or whp. End of story. Link to comment Share on other sites More sharing options...
compsurge Posted November 10, 2014 Share Posted November 10, 2014 Can anyone explain why my AP v2 would register an extremely high wtq whp on stock motor and a 5eat. There are too many assumptions on the part of Cobb to make a quantitative analysis of the performance gained. Unless Cobb magically know the mass of the vehicle and occupant, they will assume the average GVW of the LGT. In this case, acceleration and velocity are calculated from the car's vehicle speed sensor and plugged into the above calculation. Acceleration is likely determined from the VSS by dividing by time. A 10% error in mass is highly possible and will result in large errors. These errors will be exacerbated by other inaccuracies in the measurement of time, VSS, and the derivation of the VSS to find acceleration. If Cobb also neglects friction (possible), then you may see even larger errors introduced. Link to comment Share on other sites More sharing options...
Max Capacity Posted November 10, 2014 Share Posted November 10, 2014 what exactly is a restrictor pill? In the short hose off the nipple on the turbo outlet to tmic there is a pill with a hole in it, that black hose should have a white line on it. You can feel it if you squeeze the hose. http://people.csail.mit.edu/ilh/vacation/ In the back of the service manuals there is a picture of the vacuum system. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Energyblue98 Posted November 10, 2014 Share Posted November 10, 2014 He clearly has a restrictor pill or hed only be gettint about 13 psi. Im thinking its either the wrong pill or theres something sruck in it giving it more restriction Link to comment Share on other sites More sharing options...
LatentWagen Posted November 10, 2014 Share Posted November 10, 2014 He could also have a slight crack or tear in the hose to the WG actuator. WG doesn't see all the boost, and stays closed too long... It's happened to me before. LW's spec. B / YT / IG Link to comment Share on other sites More sharing options...
Energyblue98 Posted November 17, 2014 Share Posted November 17, 2014 updates? was it the restrictor pill? Link to comment Share on other sites More sharing options...
LGT_ Posted November 18, 2014 Author Share Posted November 18, 2014 I havent checked. I hold at 18 psi. its safe... idk why i should lower it Link to comment Share on other sites More sharing options...
Energyblue98 Posted November 18, 2014 Share Posted November 18, 2014 Theres a reason cobb has the tune set at 16.7psi.. Link to comment Share on other sites More sharing options...
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