Sperry's exhaust leak and melted timing cover from the RFR Trials event

[MPREZIV]

Lemme know! I can bring any "oddball" tools you might need, and not have as well!

[sp00ln]

That should NOT effect your boost... that is so minor.

And map sensors dont measure the exhaust pressure - they measure the intake manifold pressure. Every fuel injection car has one. I doubt you have anything measuring your exhaust pressure.

If you think its your MAP sensor messing up, you have a boost leak. Time for a boost leak test!

[Kevin M]

First off, if you had heard Scott's car, you would not be arguing whether or not that leak was costing him boost. Second, he didn't say that the car is directly measuring exhaust gas pressure, he said that the car uses MAF and MAP to determine engine load, with which backpressure varies more or less linearly. Lastly, his MAP sensor is perfectly okay, and he has no boost leaks, because if either was the case the car would be running extremely rich and acting all kinds of weird. Please, please stop trying to diagnose Subaru engine maladies over the internet.

[Dean]

With complete disregard of Kevin's request not to diagnose engine problems over teh Interweb, That is a shot muffler bearing if I ever saw one!

I bet he ran low on exhaust fluid, and the sucker just blew out due to lack of lubrication...

Shit like that can get you in trouble, or worse, her pregnant.

[Ezdno]

Damn...just goes to show you that muffler bearings do run out of fluid....just like the blinkers! Running out of blinker fluid could permanently throw the earths orbit out of whack.

[sperry]

Originally Posted by sp00ln

That should NOT effect your boost... that is so minor.

And map sensors dont measure the exhaust pressure - they measure the intake manifold pressure. Every fuel injection car has one. I doubt you have anything measuring your exhaust pressure.

If you think its your MAP sensor messing up, you have a boost leak. Time for a boost leak test!

You must have x-ray vision or something to see the hole in the pipe that's behind that braided steel. Trust me, the leak is *plenty* big enough to limit my boost. See that junction between the up-pipe and header? I've had simple gasket leaks there that will kill the boost... what I've got now is an outright *hole* in the pipe... with the car running you can put your hand near the flex and it's like a friggen blow drier blowing hot air!

As far as the "exhaust pressure"... who measures exhaust pressure? Wastegates use the manifold pressure as the feedback loop parameter. When the turbo is making too much manifold boost, the wastegate opens reducing the force on the impeller, which lowers the boost. With a MBC, the manifold pressure simply reaches a point where it can bypass the ball/spring in the MBC, which allows the pressure to vent to the wastegate control valve which opens the wastegate. An EBC just adds a computer that monitors the manifold pressure and opens a valve to operate the wastegate depending on the boost. At no point is exhaust pressure measured.

The only exception might be on a cheap external wastegate that has a simple valve that opens at a pre-determined pressure level like a BOV. But even in that case, there's no sensor monitoring the exhaust pressure.

[sp00ln]

Originally Posted by sperry

As far as the "exhaust pressure"... who measures exhaust pressure? Wastegates use the manifold pressure as the feedback loop parameter. When the turbo is making too much manifold boost, the wastegate opens reducing the force on the impeller, which lowers the boost. With a MBC, the manifold pressure simply reaches a point where it can bypass the ball/spring in the MBC, which allows the pressure to vent to the wastegate control valve which opens the wastegate. An EBC just adds a computer that monitors the manifold pressure and opens a valve to operate the wastegate depending on the boost. At no point is exhaust pressure measured.

Exactly. I wasn't saying anything measures exhaust pressure, understand my posts. I was just questioning why you think an exhaust leak like that would limit your boost when boost control has nothing to do with the exhaust after the turbo. However, I do recognize my mistake as where a WRX's up-pipe is pre-turbo, correct? I assumed it was a downpipe by the picture And as far as me questioing the "exhaust pressure" maybe post #62 should ring a bell. Oh, and I do have x-ray vision, that's why my wallet says "bad-ass mother fucker" on it.

And be sure to let me know when you fix it. I am curious to see if it'll correct your boost problem.

[sperry]

Originally Posted by sp00ln

Exactly. I wasn't saying anything measures exhaust pressure, understand my posts. I was just questioning why you think an exhaust leak like that would limit your boost when boost control has nothing to do with the exhaust after the turbo. However, I do recognize my mistake as where a WRX's up-pipe is pre-turbo, correct? I assumed it was a downpipe by the picture And as far as me questioing the "exhaust pressure" maybe post #62 should ring a bell. Oh, and I do have x-ray vision, that's why my wallet says "bad-ass mother fucker" on it.

And be sure to let me know when you fix it. I am curious to see if it'll correct your boost problem.

I must have mis-read your post #61... I thought you were asking what that car used to read manifold pressure... to which the reply is "the MAP sensor".

I've got a new up-pipe on order, I should get it around Monday or Tuesday... same time I should get the new timing covers. I went with the Bosal up-pipe. It's a flex pipe, but it's also got head shields on it like the stock unit. That should help a little with the underhood temps... but probably just a little.

[cody]

Are heat shields as/more effective than a good ceramic coating?

[sperry]

Originally Posted by cody

Are heat shields as/more effective than a good ceramic coating?

I gotta think properly engineered heat shields are better than coating both in heat protection, and lifespan (which is why they're used OEM)... but they take up a bunch more space, cost more, and add a further failure point for rattles and the like.

To be honest, I'm a bit nervous buying an aftermarket exhaust pipe w/ a heat shield, but I don't have the time to get something jet coated, so I'm giving it a whirl.

[cody]

Crucial UP's are ceramic coated and usually in stock.

[sperry]

Originally Posted by cody

Crucial UP's are ceramic coated and usually in stock.

Neither Gruppe-S, MJP, or SubyDude had anything in stock w/ a flex joint (Helix was my 1st choice). The Bosal is getting dropped shipped via SubyDude.

IIRC, the Crucial pipe is non-flex, and coated inside and out. Not having heard any real information about the quality of the pipe, plus the fact that I'm attempting to use it to mate an aftermarket turbo and headers, I'd rather not take the risk of a rigid pipe that will probably leak at the gaskets and may end up flaking ceramic coating through my turbo in a year. Plus it costs like $50 more than the pipe I ordered.

[cody]

Correct, it is non-flex and coated inside and out. Litterally hundreds of people are running them on their cars at wrxfanatics and the only leaks I've ever heard of are from people neglecting to retorque after a heat cycle. Now that the Cu-Seal copper gaskets (also available from Crucial) are anieled (sp?) retorquing is less necessary, but still cheap insurance.

I run it and fitment was perfect. It also comes with Worth studs which are supposedly indestructible but one of them needs to be flipped or it will sometimes keep the DP from going all the way back on.

Anyway, I guess it's a moot point.

[Nick Koan]

I think the fitment concern isn't with the uppipe, but with the aftermarket headers and the uppipe. Yeah, both are supposed to fit just fine at stock points but you never know how close it'll really be with two aftermarket pieces.

[cody]

True, true.

[sperry]

Originally Posted by cody

Correct, it is non-flex and coated inside and out. Litterally hundreds of people are running them on their cars at wrxfanatics and the only leaks I've ever heard of are from people neglecting to retorque after a heat cycle. Now that the Cu-Seal copper gaskets (also available from Crucial) are anieled (sp?) retorquing is less necessary, but still cheap insurance.

I run it and fitment was perfect. It also comes with Worth studs which are supposedly indestructible but one of them needs to be flipped or it will sometimes keep the DP from going all the way back on.

Anyway, I guess it's a moot point.

I've got both an aftermarket turbo, and headers. The chance that they're both in stock-enough locations for a non-flex pipe to line up just right is pretty slim... hell it takes some careful torqueing just to get the *flex* pipe to match to the headers.

Having had a solid pipe in the past, and had a ton of leak issues (to the point where I went through like 9 different gaskets and eventually had Vishnu replace my pipe w/ a flex version), I'm going to just stay w/ a flex unit.

Edit: Yeah, what Nick said.

[cody]

That's too bad Scott, because if what Nick hears is true, you'll be replacing that thing every few years. I guess that's not terrible for a track car though.

[Nick Koan]

It really depends on vibration and movement. I think in that sense, daily drivers have it worse for flex pipes because they make the same repetitive motions over and over again, where as the track sees more extreme movement, but not in a repetitive way (and not every day either).

On one hand, Scott'll maybe have to replace the flex every few years, where as he could go through a number of non-flex pipes before he even finds one that works. I'd go with the flex in Scott's case as well, if it were my choice.

[sperry]

Originally Posted by cody

That's too bad Scott, because if what Nick hears is true, you'll be replacing that thing every few years. I guess that's not terrible for a track car though.

If I'm spending $200 every 2 or 3 years on an up-pipe, it's just a drop in the bucket. I spend like $1000/season on brake pads and rotors as it is. As long as the pipe doesn't fail every other event, I'll be totally happy.

[cody]

Originally Posted by nKoan

I'd go with the flex in Scott's case as well, if it were my choice.

Yep, sounds like it's a necessary evil.

[sperry]

Okay, I split this out of the RFR Trials event thread to bump an update.

On Monday, Cory and I attacked the car w/ the intent of swapping the timing covers. We got about halfway done, but were foiled because the sever underbonnet heat rendered the right-side exhaust cam gear bolt fused. We were actually slipping the timing trying to torque it off! According to Cory's tech friend at Subaru, that's not all that unusual, and the normal solution is to simply shatter the timing gear and replace it. So, we stopped for the night, Tuesday morning I put in an order for a new gear and bolt at Lithia.

Wednesday came, and good ol' Don at Lithia called me... my parts were in a day early! So after work, Cory, Matt and I were back at it. This time we used Cory's 2 foot long chain wrench to hold the gear, and put a big ass breaker bar on the bolt and got it loose... of course the chain wrench ruined the gear, but at least we didn't have to take an air hammer to it. Things looked good to go. We swapped the rear timing cover, and started reinstalling all the gears.

That's when we noticed, one of the idler pulley bolts was stripped out in the block. Like *way* stripped out. Stupid grade 8 bolts into an aluminum block. Looks like someone either cross threaded it, or simply over torqued it. I don't believe Gruppe-S would have ever had that pulley off, so I have to think it was screwed up by S-Squared when they originally assembled the motor. And instead of fixing it, all they did was goup a bunch of thread locker on it.

So, we started looking into tapping the hole for a larger bolt. We got the tap, the replacement bolt... but as if turns out, we needed to drill the hole larger, which is something we just wouldn't be able to do w/o pulling the radiator and A/C condenser, which would require an r134 collection setup. So, instead we retapped for the factory size bolt to clean up the few threads that were left, then got a longer bolt and reinstalled the pulley into the virgin threads deep in the hole. It seemed to snug up pretty well, so I think we'll be okay.

By now Matt had left, so it was up to Cory and I to descipher the marks we put on the timing belt. It was actually more of a PITA that I expected, but in the end the belt was on with the crank and all cams properly aligned.

Cory had to bounce, so I finished up installing the belt guides and outter timing covers, then the I/C pipe we had to remove, the radiator fans, and the coolant lines. And when I was done I only had one spare bolt left over! (Seriously, I had one of the center timing cover bolts left over, but I had a bolt installed in every location that was listed in the service manual... how does that happen!?)

I crossed my fingers and started up the motor, and aside from the massive up-pipe leak I've still got, the motor seemed to run correctly.

So, if SubyDude/Bosal ever get their act together and get my my up-pipe today or tomorrow (should have been here on *Tuesday*), I'll make it to this weekend's autocross.

[cody]

Sheesh, that's a lot of surprises for one week.

[JC]

Originally Posted by sperry

which is something we just wouldn't be able to do w/o pulling the radiator and A/C condenser, which would require an r134 collection setup.

Taking the radiator out takes like 15 minutes and I removed my motor without disconnecting the A/C condenser so I don't see why you would have had to?

Glad to hear it's all back together.

JC

[sperry]

Originally Posted by JC

Taking the radiator out takes like 15 minutes and I removed my motor without disconnecting the A/C condenser so I don't see why you would have had to?

Glad to hear it's all back together.

JC

Drill + drill bit is about 12" long. Even w/ the rad out, we couldn't have fit it in there to drill out the hole. We would have certainly needed to remove the A/C condenser, and possible the intercooler.

[bruspeed]

No fun dude, I have done timing belts on our cars, Lame. Hope everything is back in black for this weekend.

*crosses fingers for Scott*