TMIC Install, Boost Leak
 

Hey guys. I recently installed a tmic and it seems like I've got a boost leak but I can't pinpoint it. Would anyone who's good at this kinda thing volunteer to take a look at my car?

Rob

Would a spray bottle with soapy water help? I guess you'd have to find a way to pressurize the system though right?

Uninstall + reinstall might work, like rebooting a PC instead of trying to find the actual problem. :p It's real easy to kink up the hoses on that install.

I've reinstalled it 2-3 times :( I thought I knew what I was doing but maybe I forgot to reconnect something or punctured a hose that I keep looking over, I don't know.

What makes you think you've got a boost leak?

Yeah, but just incasae pressurize the system somehow and spray soapy water all over your IC piping and IC itself. You then should figure out where your leak is coming from.

It sounds like it. I can hear my turbo screaming much more than on the stock tmic. I asked other people who installed the same tmic and they confirmed this is unusual. That and inconsistent performance from the car.

I wouldn't know how to do this.

What are your peak boost levels? Is the boost fluctuating unusually?

Make sure the problem isn't just that the Y-hose for the boost controller/wastegate actuater is improperly hooked up or something.

I've had boost leaks at the intercooler before, but mine was kinda obvious:

http://www.seccs.org/gallery/Car%20P...03%20small.jpg

Sounded like a giant rubbery fart when the car came on boost.

Everything seems to be hooked up correctly. According to my accessport I see normal peak boost levels. I took some datalogging and am seeing normal numbers from that, as well. The numbers don't fluctuate either, though acceleration does. Hesitations and poor power, etc.


I'm thinking that the ecu is just having trouble compensating for the low back pressure of the new tmic, but I can't explain the noise.

Sounds like a hesitation problem, not a boost leak.

How much bigger is the TMIC then stock? What brand is the TMIC and why did you put it on?

Click the link. You want something that matches your IC piping diameter. Hook it up, pressurize the system, listen and use soapy water.

Also, check your intake pipe (the one that connects to your turbo) and see if that's loose.

You have a picture for everything.

fixed.

Yeah, Kevin's got it right. :lol:

Oops:
http://www.seccs.org/gallery/Car%20P...%20Endlink.jpg

That looks sticky:
http://www.seccs.org/gallery/Car%20P...%201_small.jpg

Isn't that supposed to be attached to something?
http://www.seccs.org/gallery/Car%20P...02%20small.jpg

What the hell's that been rubbing on?
http://www.seccs.org/gallery/Car%20P...06%20small.jpg

Oooh, burn!


That's not right!
http://www.seccs.org/forums/attachme...&stc=1&thumb=1

What cooked that!?
http://www.seccs.org/gallery/Car%20P...%20(Small).JPG

I don't have pictures of the rod-knock on my 2.0L block, or the shattered piston from the 2.5L block that replaced it. Nor do I have pictures of shreaded bearings and brake parts I've gone through. Or stripped lug nuts. Or the failed exhaust gaskets from years past. And I don't even know how to take pictures of a missfire. :lol:

And nevermind the pictures from my SVX's paint issues or the gallery of photos from the unfinished work on the WRX when I got it back from S-Squared.

Damn... my car's are piles, aren't they? :lol:

A custom tune is probably needed for a bigger TMIC.

At least reset the ECU. A custom tune is definately a good idea. Perhaps the ECU is freaking out because your new IC is most likely much more efficient in terms of flow.

Most aftermarket IC's will see a significantly smaller pressure drop. This could very well cause the boost control system to overshoot boost and result in wildly fluctuating boost levels which would feel like the surges you're describing. If you'd like to take some logs, I'd be happy to look at them for you and tell you what I think.

FYI, in general adding a bigger TMIC on a WRX with stock turbo won't result in any power gains even with a tune. I know this from experience ;).

Thanks
-- Ed

Thank you for your input, Ed. I just got ECU Explorer working on my car if you wouldn't mind if I used that. So I just capture a pull and then send you the captured file?

Kind of you to offer, thanks.
Rob

I log:

Engine Speed (RPM)
Ignition Timing (°BTDC)
Knock Correction (°BTDC)
Air Flow Sensor Voltage (V)
Manifold Relative Pressure (PSI)

I'd imagine that's all Ed needs logged on a 3rd gear pull to red line, but I'm only guessing.

Do I want the log that shows the min/current/max values or is there something else?

When you log, it captures real time data. What I do is right click a blank spot in the section where you see the realtime data and select, "Use Defrost Button to start/stop capture" or somthing like that. Then you turn your defroster on to start capture and turn it off to stop the capture. You can configure where you want your logs to be stored, %My Documents%/Logs, for example. Then just zip them up and email them to ed (at) eqtuning.com

Check your intake! I think that could be it.


Also, no point in resetting the ECU or needing a "re-tune". Unless I'm mistaken, evey ECU is in constant adjustment. More over, the TMIC isn't a drastic change.


and god damn Scott... god damn....

With a Subaru, resetting the ECU after any power mod is the right thing to do for performance and safety. Some learning is very slow if you don't.

Cody has it right. When an ECU is first reset, any learning and adjustments happen much quicker. Once the ECU "settles in" it takes a very large change and a lot of time for it to make any further adjustments. When adding just about any parts, a reset is recomended.

While an intake leak will cause a/f inconsistancies, it is not likely to cause boost fluctuation.

Thanks
-- Ed

Dude, seriously... you do not understand Subaru engine tuning whatsoever, and you have proven this over and over again on this forum. Please refrain from discussing EJ series engines and tuning until you do the research and learn how they work. I'm not trying to suggest that you're not smart enough to understand them, or that what you know about the 4G63 isn't highly useful, but what works for DSMs and Evos DOES NOT work for turbo Subarus, period. We've gone down this road before and I don't want to start arguing again, but when you post up in a novice engine tuner's thread with blatantly incorrect advice, I can't not say something. Please note that Ed gets paid to tune Subarus... and everything he says directly and absolutely contradicts you. Please consider that if you can't even be in the same ballpark with a professional tuner on your advice and comments, you should keep them to yourself.

Pulled a log this morning. Can I post it on this thread somehow?

If it won't let you post it directly using the attachment feature, just zip it first.

3rd Gear Pull

I took a look at your log. After the initial spike, your boost levels are on the low side. I also see signs of knock around 5k RPM, but this is a fairly common problem area on 91 octane. I'm assuming this is a Cobb map? I deffinately don't see anything that would exhibit itself as power surging. Could you try to describe in more detail under what conditions and exactly what you're feeling? Maybe you can log those conditions as well.

Thanks
-- Ed

Thanks, Ed!
 

Could this be attributed to our altitude or something else?

Yes, it is.

Not sure how to get more detailed. The car is slower than it was before the install in every condition. There was a bigger kick from the onset of boost before the install. There are also harsh hesitations at wot that pull power even more. This particular logged pull didn't feel too bad, though. I'll see if I can get it to misbehave and log it again.

I drove it around for a bit and it decided to run fairly smooth. Go figure. I'm still skeptical of a boost leak.

Anyway, I forgot to mention pertinent mods:
cobb ots stg 2
tbe
up
intake
turbo inlet
tmic with hoses
crank pulley

It sounds like doing a couple pulls gave the ECU a chance to learn in some knock correction and smooth out the power band. This generally means you should really consider a custom tune. Based on your logs, I would also deffinately recommend checking for boost leaks. Maybe try re-installing the stock TMIC and see if everything goes back to normal.

Thanks
-- Ed

Thank you, Ed. I asked a member from another forum to look at it and here was his response:

He mentions the high kc which corresponds to what you're saying, Ed.

So I guess back to my original question? Would anyone care to look at my install for any boost leaks/abnormalities?

What about the old spray-starter-fluid-on-the-vacuum-lines trick? I know it's a common way to search for vacuum leaks on N/A cars. You just spray it all over the vacuum lines and if the idle gets higher, you've sucked some of the starter fluid into a vacuum leak.

That response is on the ball for the most part. The only parts I don't agree with are his comments on boost. Running the same relative boost at elevation as you do at sea level will not necessarily work the turbo harder. You have to remember that this pressure is relative to atmospheric pressure. So at the same relative pressure, you're still running less absolute pressure than you would be at sea level, so you're not actually working the turbo any harder. You would be pushing less air at that relative pressure, but again that's just because you're running less absolute pressure, not because the turbo is less efficient.

We've shown this to be true empirically on Cody's car as it kept flowing more air and making significantly more torque right up to 17.5psi of relative pressure even at elevation without creating excess heat. You also don't need a helper spring to run these boost levels. The limiting factor here is not the wastegate actuator spring, but rather the stock boost control solenoid and restrictor pill. Using a 3-port solenoid, MBC, or even a smaller restrictor pill will easily allow you to run whatever boost you like without adding any helper springs.

My main question here is what boost were you hitting with the stock TMIC? If your boost levels are now significantly lower, I would deffinately look for a leak or start questioning the efficiency of the bigger TMIC.

I'm also concerned that the car seems to be making less power and had a rough power band upon ECU reset. To me this says that the ECU encountered some problem spots and had to pull timing in places where it didn't have to with the stock TMIC. Again, this could point to a leak or just a poorly designed IC.

Thanks
-- Ed

Interesting. I'll try that.


According to my ap it's hitting the same peak pressure and holding the same boost as with the stock tmic. I never had a chance to datalog before the install so I wouldn't know with regard to ecu explorer.


It is a TurboXS knockoff and many others have had success with it, especially after tuning, though maybe I got a bad apple..

What it seems is going on is that yes, the ecu is having to adjust quite a bit to cope with it but there is probably a boost leak going on. I can't get past the fact that my turbo got so much louder under boost when no one else's did.

The other people I refer to are here:
http://forums.nasioc.com/forums/show...9&page=1&pp=25
If you're interested in reading it skip to within 7 or so pages of the end.

The turbo deffinately shouldn't get much louder when swapping IC's. I would deffinately suspect a leak somewhere. Maybe the actual core is damaged?

I hope not :(

Update?

I haven't had the time to mess with it much. I planned on loading the cali 91 map to decrease my chances of any knock but I couldn't find my ap power cable to load the map on my ap.

If you need to borrow my cable let me know.

You should have been on the cali map already, since you're burning cali gas.

Thanks, Cody.

I would think it would be a pain in the ass, but have you considered putting your stock IC back on with your new IC hoses (if the new IC hoses fit the stock IC) to see if you still have boot leak ? (if you did , then you could probably rule out the IC itself, and if you didn't , then maybe its the IC itself)
?

I may need to do that. How disappointing :(

Any luck discovering the cause?

Thanks for checking in. I have been remarkably busy lately obtaining a job and just got one this week, fortunately, so I've been putting around until I can get things sorted out.

What I need to do:

1. Load cali base map
2. Get silicone gasket sealer to resolve possible leaks
or
Reinstall stock tmic until everything is sorted out and I have an opportunity to tune

UPDATE


I decided to do an experiment. Yesterday I picked up some Lucas octane booster (remarkably, I've had great success in the past with this product) from pep boys and poured it in the tank and filled up. Reset the ecu and drove around normally for 25 miles or so.

That night when the air was cool I found an open stretch of road and floored it 1st through 3rd and was immediately impressed. It pulled just like it was supposed to. A couple minor hesitations that are hard to feel unless you're really paying attention, which will hopefully clean up after loading the cali 91 base map.

This leads me to believe that with the stock tmic I was getting by on the standard stg 2 91 map but the aftermarket tmic just pushed the tune over the edge. So if I'm correct then the less aggressive cali 91 map should hold me over until I get tuned.

Right now I'm just trying to borrow Cody's AP power cable and we're looking into getting Ed down here sometime soon to protune.



-Rob