[Liesjemt]

Thanks for posting masterbB,

It sounds to me that he was asking for people to check their installs...

Exactly.
I am no expert on exhaust. But I consider the guy who did the install one.
So when he told me that he thought this was a potential hazard I listened.

Looking at your ‘pics the box seems to be sitting a bit higher from the pipe than the two cars I’ve seen in person.
Those installs were done by different techs at two different shops on different dates.
Since both of them hung low it seemed pretty likely that other installs out there would too.

[TrevorS]

Originally Posted by Liesjemt

Thanks for posting masterbB,


Exactly.
I am no expert on exhaust. But I consider the guy who did the install one.
So when he told me that he thought this was a potential hazard I listened.

Looking at your ‘pics the box seems to be sitting a bit higher from the pipe than the two cars I’ve seen in person.
Those installs were done by different techs at two different shops on different dates.
Since both of them hung low it seemed pretty likely that other installs out there would too.

This isn't a question of an "exhaust" expert, it's a question of the function of that box and its susceptibility to heat. My installation was done by myself and I deliberately positioned the pipe outlets for what I consider a conservative spacing from the fascia (I absolutely don't want damage to the fascia). The spacing from the box is a natural fallout. The 1/2" measurement from the fascia to the outlets came from the exhaust vendor, I asked!

So, I know nothing about what any particular shop does in installing the exhaust, I can only presume these are less conservative then I. I do know that I have yet to experience a vehicle misbehavior, let alone one that can be attributed to the exhaust. However, what is clearly germane is the exact function of that box and its contents and their reaction to externally sourced heat. I'm hoping to learn more about that.

PS. I deliberately performed the install so that the bolted connections would be relaxed (minimum twisting and other tensions) -- this may also be a factor in the clearance from the box. That is to say, I first installed the catback pipes, and then hung the rear pipes from the rear supports before tightening any of the coupling bolts.

[masterbB]

you really think an exhaust shop doesn't know how to tighten a bolt or how close an exhaust should sit from the "fascia." dude just leave it at more research should be done about the black box, which im pretty sure is the evap box. If you work for speed element and your sad that i had a problem with your exhaust big deal. i love this kit and really could care less.

[TrevorS]

I don't know what you're talking about and I have absolutely nothing to do with Speed Element (outside of having been a customer May 2008). But I do know that if I'd wanted to position that pipe closer to the box, I could have.

Those installers may be professionals (meaning they are paid for their work), but that doesn't mean they'll be as careful with your car as they would be with their own -- they're on the clock and they just bang through the job. My guess is what happened in both your cases is they exactly aligned the flanges and bolted them one by one. Then looking at the result they or you see the driver's side pipe is very near the box. The solution is simple, there's a fair amount of adjustment available in those flanges. It needs to be made use of. I bought the same pipe set you did, yet it appears I have a different result.

Apparently the full name of the box is "Evaporaative Canister". I'm used to it being referred to as the "Charcoal Canister". This is its function:

"An evaporative canister is part of the evaporative system that is within the emission system. Hydrocarbons are a form of pollution that gasoline releases as it evaporates or after is is burned. While fuel is stored inside the tank, fumes build up and are retained inside this canister. The canister contains charcoal that absorbs the hydrocarbons. When the engine is started, a valve opens that allows fresh air to come in and purge the fumes (hydrocarbons) into the air intake and then into the combustion chamber for burning. I understand that more hydrocarbons are released into the atmosphere by leaving your fuel cap off, than what comes out of your tailpipe while the engine runs. If there is a leak anywhere in the evaporative system, such as a bad hose, canister leak or leaving the fuel cap loose, the check engine light will set."

So, knowing that, I'm wondering why it being heated along one corner would interfere with the ability of the car to run or start, and apparently the heat wasn't great enough to distort the plastic. I just took this photo from underneath to try to clarify how much of the box is actually over the pipe, and it clearly is just the corner.



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You know, the problem you described sounds a lot like vapor lock! The flushed content of the canister dumps into the intake ahead of the throttle body, so the worst it can do is to temporarily enrichen the air fuel ratio (even with heat being applied to one corner of the canister) -- I don't see how that would result in your described symptoms. On the other hand, vapor lock would prevent the fuel from flowing normally and can cause the engine to stumble and fail to start.

You said it wasn't hot weather, how often did that happen?

[masterbB]

it happened to myself twice. i did not go to the exhaust shop that liesjemt spoke of. i went to my friends custom shop and was there during the whole process. i was also at the muffler shop for the install of my club members exhaust. he has not experienced any problem seeing that the shop made a custom bracket and heat wrap for his evap box.
just trying to warn people of a possible problem with an easy solution

[TrevorS]

Well, it certainly is an interesting problem you experienced! Am I right in thinking that when the engine wouldn't start, it had been previously running and then shut down for a fairly short time (not enough time for the engine to cool all that much)? When the wrap was applied, is it also either intentionally or inadvertantly shielding anything else down there? Any of the lines or hoses maybe?

[Liesjemt]

I have a Tsudo exhaust myself that I think I bought from Speed Element (E-bay back in 2006) which I’ve never had a major problem with.
I think they’re a great product for the price.

It really is interesting that your install turned out so differently from the other two.
Can anyone else post pictures of how close the pipe and box are to each other on their ride?
I’m curious how much variation there is.

Perhaps it all just comes from the tweaking on the install like you suggested?
As you said you started from one end versus the other; could that alone really affect the height difference so dramatically?

I also wonder if perhaps there was a slight variation in design between different batches of the exhausts? Both of ours were ordered pretty close in both time & distance so probably came from the same lot.

My last guess is that perhaps the cars themselves have a slight variation in the clamp holding the box.
I notice your box seems to be held nice & level to the ground.
Both of ours were drooping at a slight angle BEFORE any changes were made. This droop brought it closer to the pipe. Maybe Scion had different batches of the bracket with some beefier than the others?

Again, I apologize if I came off as Chicken Little, but seeing how close the plastic box was to the very hot pipe on BOTH our cars it seemed pretty scary. That’s why the wording on my earlier post was more alarming. Then I did a little more searching to see if any of you had burst into flames or whatnot. Since I didn’t find any evidence of that I tried to use less frightening wording in this thread, but I did want folks to go stick their heads under the car to see what was going on.

[TrevorS]

Originally Posted by Liesjemt

Perhaps it all just comes from the tweaking on the install like you suggested?
As you said you started from one end versus the other; could that alone really affect the height difference so dramatically?

I also wonder if perhaps there was a slight variation in design between different batches of the exhausts? Both of ours were ordered pretty close in both time & distance so probably came from the same lot.

I probably had two advantages. One was that I'm used to doing my own work on cars and I'm really loath to pay someone else if I can avoid it ! Together with that, I tend to take my time and mentally review what I'm doing and how it looks. (Unfortunate side affect is I'm kinda slow .)

The other thing is I had previously read a post by another Tsudo owner who was wondering if he needed to wrap the box. It was in a different forum, and I didn't think his box was so very close, but I had yet to do my own install, and I didn't know the answer. In any case, reading that post sensitized me to the issue before doing my own install.

Thinking of the pipes and installation. The usual last step would be to hang the driver's side rear pipe and bolt it to the passenger side. On the surface, no big deal, however, it just so happens all the pipe installed before that one bend toward the passenger side of the car, this tends to rotate them clockwise looking from the rear. The last pipe on that side is also pulled clockwise by the weight of the resonator. If all those pipes are bolted together before the drivers pipe is hung and bolted, that bolted in twist will cause the drivers side pipe to lift towards the box.

In my experience, whenever you have a multi-piece assembly to install, it's appropriate to fit it before final fastening. Much the same with a engine valve cover or wheel lugs or fender etc. You can't just fully install one bolt and expect everything else to align properly. The approach I took was to hang all the pipes starting at the cat (running in the bolts, but not tightening at all). When basically satisfied, again starting at the cat, I final tightened the bolts (with a little final tweaking at the rear).

Originally Posted by Liesjemt

My last guess is that perhaps the cars themselves have a slight variation in the clamp holding the box.
I notice your box seems to be held nice & level to the ground.
Both of ours were drooping at a slight angle BEFORE any changes were made. This droop brought it closer to the pipe. Maybe Scion had different batches of the bracket with some beefier than the others?

Anything's possible, but I wouldn't think it probable. I suspect it more likely a tilt in the drivers side pipe due to bolted in twist is causing the box to look tilted -- a trick of the eye.

Like I said earlier, I know I could have installed my pipes for significiantly less clearance from the box. For example -- on that last flange (driver side pipe), I know I didn't center the bolts through the holes (nor the flange before it). I located them to help bias that pipe as far as I could away from the box -- that's what I mean when I say there is a range of adjustment available at each flange. It's limited, but in combination, it's enough. Yes, one can simply bolt them all together and not worry about the final fit, but I think that's a mistake.

Originally Posted by Liesjemt

seeing how close the plastic box was to the very hot pipe on BOTH our cars it seemed pretty scary.

The pipe will definitely get hot after a while (it takes time), but I would reserve "very hot" for the manifold and pre-scuba piping ! The vast majority of the exhaust heat has already been absorbed and radiated via the first cats and huge center cat/resonator with further help from the piping before the split. It's getting reasonably tame in the divide by two final exhaust. Sure -- hand's off, but not as bad as all that !

Thought I'd post a photo of the original prototype install and my own, SpeedElement appears to have a tad more down slope than mine towards the driver side, but I don't think they're that dissimilar (unforunately, his photo is off center and that results in eye tricks again). I think if Tsudo were to counterclockwise rotate one of the nearer to cat flanges just a tad, the issue would be that much less likely, but I really don't think there's a substitute for hanging the pipes before tightening the bolts. It's just not a good idea to leave the fit to chance.



Oops! According to SpeedElement's thread, the above photo is actually of the production pipe set. Sorry about that !

[TrevorS]

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FWIW -- I was talking to another fellow regarding the warm engine stumble and fail to start behavior, and we're definitely agreed that wouldn't result form heating the charcoal canister. In fact, the result would be at worst to enrich the mixture, which makes the engine more responsive, not less.

The only way I can explain your experience is vapor lock -- the implication being the fuel tank located pump isn't producing enough pressure to overcome the vaporization affect of heat applied to the fuel line. This suggests either the pump is not performing properly, or exhaust pipe proximity requires shielding for the fuel line from the pump, but not for the "Evap" canister.

As i said, an FWIW, but the diagnosis is far more likely than the problem being due to heating of the charcoal canister -- far more likely.