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My08 Hatch gtx3071R

5K views 23 replies 4 participants last post by  Pssyboost 
#1 ·
Hi Guys!

I am new too wrxtuners altho not new to subaru! :)

I dont know if i have a problem on my car so lets see if anyone can help me!

i have a 2008 hatch wrx and fitted new GTX3071 on and before i did the turbo the car was stuck on 170kw... Nothing made it better had stage 1 map on but the Kw was still the same. So went to a meet up with subaru members and one guy with same WRX as me has got 190kw claiming on 0.9 bar boost and tapers to .8 with a standard k04 turbo 550cc hes got a cold air intake and grimspeed boost controller he too was stuck on 170kw before the controller.

Now i tuned my car with the new turbo and i am making 220Kw at 4000 revs my boost is 1.16 then tapers of pretty fast
my injectors are maxed at 89% so not going to squeeze more out of them...

Does that sound right to you all? 1.1bar 220kw 550cc injectors? of should it give more...

Thanks all :)

P
 
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#2 ·
That's a great amount of power for such low boost pressures. Your car, if tuned well will run very safe and you have a ton of headroom to make a lot more power with the expected fuel upgrades if you wanted to. But, Your reliability will suffer going higher. My motor blew up on me with the setup below. I did have a vf39, close to maxed out and past its efficient area running at 19.5psi which is 1.34 bars.

To give you an example, I also have an 08 hatch ( Hell yeah another narrowbody!!) I have a fully built short block, full water to air intercooler, turbo back exhaust, EWG, boost controller, tgv delete and I'm pushing the vf39 into flamethrower mode at peak target boost being 22psi and it's currently tuned mild to run this setup safely and it will on this built motor and the water to air setup being able to cool the charge, but that's this turbo's limit.

I will go to something like an 18g with ball bearings and conservative tune to lower psi for similar boost figures as you and similar power, maybe a bit more until I'm creeping up on my fuel system limits.

Welcome aboard!
 
#3 ·
Thats awesome to hear.

I have read so much storrys on the internet about narrow hatch builds that failed and why it failed and then again some guys pushing out 350hp with standard internals.

My next step will be injectors and at the end of the year do my forge internals.
I am in a subaru club and they did tel me 1.3 bar is too much for the head bolts and will blow gasket. What went wrong with your car?


If any one else has any tuning storys post them :)
 
#4 ·
I'm fairly certain climbing a mountain pass in 5th gear. At least one of my rods went but I also noticed that on the same pistons the rings were coming out of the top of the piston.

I'm no engine expert but I'm thinking my rings expanded and closed the gap.

I was going about 75-80 up a steep incline for a good 10 miles and climbing another 10 or so leading up to the pass.

I went over all components and my tune, there was nothing else out of the ordinary.
 
#5 ·
I never heard about head bolts not holding so little psi. That's very odd. Once again, I'm far from an expert but most stage 2 tunes run in the 17-19 psi range. That's well above your pressure, but your turbo does flow more volume of air.

I'm on stock head bolts. Not only are they stock, they're also reused originals ( minus pre-stretching portion of the torque sequence)... No issues so far, I built the motor about two months ago or so and I've been abusing the car good after break in period.
 
#7 ·
1.5bar is only 21-22psi. you will not blow your head studs and gaskets unless there is already a problem with them and they are weakened. we run 21psi all day long if you have good gas. 1.7bar is around the max we see over here and still stay safe. over that you have a potential to blow.

you will definitely need new injectors if you are to push any more. 550cc is pretty limited. consider something much bigger like 1000cc and make the switch over to ethanol. im assuming you are aussie/nz since your speaking in bar and kw. depending where you are, i know you have access to E85. United E85 is very consistant im told and usually above 80% ethanol.

i would not recommend pushing 1.5bar on 98RON fuel. which is believe is the highest you get at the pump is it not?
 
#8 ·
Hi titter thx for reply. I live in south africa and our pump fuel is 95.... Thats really bad... I run a octabe booster to get some of the knock away at 4000revs at 13.3 iesh timing.

1.5 sounds very high for standard internals. What power are you guys making?

And i have a e95 supplier.

A tuner told me to use 5 liter e95 with our 20L 95 ron thats pretty good octane.
 
#9 · (Edited)
my appologies for my assumptions.

E95 + 95RON would be pretty decent mix

im currently pushing 20psi (1.4bar) through a stock VF36 on a stock EJ207 running 101RON fuel. sorry i do not know power figures, all my tuning is done on a track or closed course. headbolts were never an issue when i was doing my swap.

i will say this though, i am considering upgrading to a GTX3071R and i will be doing headstuds but im going to push over 1.8bar on ethanol. none the less, with a turbo that size, i personally would do headstuds before i really crank up the boost.
 
#12 ·
titter, do you mean head studs or bolts? I'm still running bolts, any experience on whether the above comment about bolts has any value?

I was planning on doing more motor work next year after snow melts and I can actually drive to my house. Might be a worth while upgrade while I"m in there if it's something that's needed.
 
#13 ·
btw I've toned down my tune quite a bit, but a few weeks ago, just to test out my Water to Air Intercooler setup I was trying to see how far I can push my VF39...

It was happily hitting 23psi and tapering off pretty quickly to redline without knock (I lowered my timing a degree or two for these tests... but I also made the target fuel a bit more lean to just over 11.4 at high load/high rpm cells)... That's 1.58bar and I run on 92 fuel which is the best I have here.

I started overloading the MAP sensor at this point, and upped it's max limit in the map to 5v (it's designed to throw a CEL if it goes above I believe 4.6v.... and it was fine after that but I have no logical reason to run the car like that, it was just testing... so I moved down to around 22psi target boost.
 
#15 ·
Dude, funny you ask that. I've been running the higher boost for a couple weeks and literally just on my way home about two hours ago turned down to my 19.5 boost profile and advanced timing to where it was before. It definitely pulls harder.

A part of the reason is that at 19.5 target, it's a smooth boost curve with a nice taper. Same goes for the timing map. At higher boost levels its more a boost spike to 22-23 and then a non- linear taper... So I have to pull timing in more cells.

I did not collect logs tonight. Because my maps aren't knocking and are safe I know what I can safely tinker with so I'm just watching knock and iam.

My main issue is with my EWG right now. It's opening under certain conditions, such as low boost. (i can hear a tiny bit of the sound and there shouldn't be) and high rpm and very low load like when tires spin in snow when using anti-lag but that's another issue. I have it plumbed with one line in bottom port in the bleed configuration... But I'm gonna run a second line and do the other config which uses the top port and keeps it shut. I'll have to redo wgdc so I'll play with timing more when boost is somewhat under control.
 
#18 ·
from what i have seen, 24-28 psi is the danger zone for oem headbolts & gaskets. i have seen failures at 24psi, but i have seen successes at 28psi. so i would say it boils down to your tune and how you drive.

pretty much anywhere 24psi+ you are gambling on oem headbolts.

what is your elevation where you are in south africa? that will play a huge factor into all of this. my information given is based on being at sea level (or close to it)
 
#19 ·
Just wanted to confirm what I said yesterday. I tuned down the car to 19.xx max target boost and increased the timing by quite a bit (basically to what it was before I cranked the boost. I could take a screenshot of the map). The car pulls significantly more even when it would spike to 22-23+ psi on my last attempt.

Now the big question.... more fuel? or more timing advance? I will play and report back at some point.

I also replumbed my wastegate in the configuration that has a T in one of the lines and uses both upper and lower ports on the WG. Miraculously I did not have to change my WGDC (TD works well enough to compensate)... however now I think my EWG is dirty as I can hear a tiny but coming out of the dump tube during idle. I tested by disconnecting both ports and it still lets some idle through, I think there's some built up carbon on the valve.
 
#20 ·
Use the EWG manufacture recommendation for vacuum line routing with a wrx/STi. Also are you using a 2port or 3port EBCS? Routing those lines will vary depending on your method of boost control. I know that some people need only the top port, while other need the bottom..it all varies and using the wrong config can actually cause tuning/drive-ability issues especially at higher boost/RPM levels.

Also do you have an aftermarket wideband o2? This will be one of your 3 most useful tools for tuning at this point, along with EGT and IDC. You don't want to be boosting 19PSI at 5k RPMs and have your IDC jumping to 90% even when your WGDC is keeping control. High EGTs will tell you if you can safely allow more timing adv, read up on that and you should be good to go, AFTER you confirm those lines with a tuner/manufacturer.
 
#21 ·
Robo, let's keep on topic of the original post, I had no intention of high-jacking the OP. I'll admit that I am far from expert at tuning (I have only been doing it for a year), however I have done it A LOT and have a very good understanding of what I'm doing at least on my setup. I also have an engineering background which helps. I'm just saying don't go assuming that everyone on here doesn't know what they're talking about ;).

I have very specific reasons for trying to run in the two port configuration over the other. I have a 3 port EBCS (you cannot run the configuration I am talking about on a 2 port). I also am well aware that you should taper towards redline (the VF39 does that on its own btw). I clearly said my max target boost is 19psi. I also do have a Wideband, and I do monitor IDC. I always monitor for knock and watch my AFRs. I also have RomRaider Logger up on a tablet in my dash at all times (I wrote a gauge mod for it and also have a very large font so I can clearly see at all times ;)) monitoring my car and I always pull over and tweak my tune if something is even slightly off. . Technically I do not even need a wideband on my year since I run my fueling above 11.2 and it's been tested for 32 bit ecus that although the factory wideband is far from perfect and has a limited range (11.2), it's pretty well inline with a standalone AFR gauge until its limit.

So yes having said all of that, I was able to push the VF39 to peak at above 23psi and obviously taper off to redline on a safe tune. I even had to bump up the max range of the MAP sensor to 5V instead of 4.6 as I was maxing it out at sea level. The purpose of those tests was specifically to test my WAIC setup to see if it's capable of cooling off the charge enough to run knock-free while the vf39 is pretending to be a heat gun at that point.... :nerd:
 
#22 ·
No worries here dude, just trying to help with some pointers on things that may seem silly at time (I know I do it occasionally). I've read plenty of threads about EWG tuning and which port to use for tuning, and no one wants to hear down the road their engine blew up.

Good looks on all that education and knowledge, you asked what you could try changing next (fuel vs timing) and I just wanted to let you know if you watch your EGTs that you can tell when timing as adv. too much as EGTs will rise noticeably. On the factory o2, yes they're off, and I like that you're using an aftermarket wideband, but there's too many threads about tuning using the factory o2...let's not add another lol. BTW I forgot you made a WAIC so I bet that does help.

I honestly kinda forgot what the post was for at that moment, but yeah back on track.
 
#23 ·
Robo, please, use real life experience to help people rather than what you read on other posts on the internet.

If someone blows up a motor by not plumbing up the EWG properly, it has nothing to do with how they plumbed it up (unless of course they did it wrong)... but rather that they went WOT without re-tuning their WGDCs. Changing ANYTHING in the boost control path in ANY way generally requires a re-tune of the boost maps which includes turbo dynamics (unless you're (randomly) super lucky or your TD is so aggressive that it's actually able to compensate for the changes).

There are two distinct ways to plumb up the EWG that will work regardless of the EWG or EBCS as long as it has two ports and the Boost Controller has 3 ports. Each has advantages and disadvantages. The reason I'm going with the specific configuration is because unlike using just the BOTTOM PORT (you called it top port which would actually cause your car to instantly overboost), the configuration that uses both ports has an advantage of putting boost pressure into the top port which helps keep it shut during spool up with a lighter spring.... in my case running a stiffer spring is not an option because even though the EWG starts to open at 15psi as directed by two springs (5psi+10psi) it still overboosts (not to mention will produce more boost toward redline than it should) because it does not open all the way at high load conditions. Therefore I only run a 10psi spring, which strangely enough under mediocre boost conditions (say5-10psi) causes it to open prematurely (even when WGDCs are being applied) even though it works WOT as expected up to redline. :nerd:
 
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