cut n' turn mod (2 Viewers)
- Thread starter concretejungle
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I think the improved clearance with horizontal orientation is worthwhile for anybody that deals with rocky trails.
I'm going with improved heat shielding regardless. I like to keep a cooler right behind the front passenger seat, where it can be reached while on the road. That puts it right over the cats, with the seat hardware in the floor providing a direct heat conduction path from underneath the truck to the cooler. In the meanwhile, in hot weather, I put a few 2x4s under the cooler.
I'm going with improved heat shielding regardless. I like to keep a cooler right behind the front passenger seat, where it can be reached while on the road. That puts it right over the cats, with the seat hardware in the floor providing a direct heat conduction path from underneath the truck to the cooler. In the meanwhile, in hot weather, I put a few 2x4s under the cooler.
- Thread starter
- #23
FirstToy said:
I'm sure Photoman has allready done this. ;p
- Thread starter
- #24
Rich, good point. I think that those who have done this mod and live in hot climate talked me into the fact that it's not too hot. IF it does, then i'll deal with a heat shield of some type. Right now, after a good long drive, the floor doesn't feel any hotter than before.
For those of you that have done this modification, is there any risk of the O2 sensors being affected by the heat from the welding?
lx450landcruiser
Moderator
The O2 sensors are further back and theres no prob from that. its a small cut and a fast weld. not much more heat then a hot exahust anyways.
mike
mike
Bambusiero
SILVER Star
I thinks Rich's #1 idea is better, with some enhancements. It will be much better to keep the heat out of the floor altogether if possible.
There is already sheetmetal (thin galvanized steel) shields screwed onto studs underneath the floorboard. Mud and so forth can't be too much of an issue.
What about this idea? Remove the existing shields. Add several layers (4 or 5?) of cut up space blanket to make a reflective shield sandwiched between the existing sheetmetal shield and the floorboard. Space blanket is aluminized mylar which is very good at reflecting infra-red radiation (heat) and can be gotten at any camping/hunting store, and is not expensive. Wrinkles and gaps between the layers will actually be a good thing. Fit will not be critical. It's very, very thin stuff. This will be an easy job.
Then, adding another sheetmetal layer on standoffs will enhance it even more. That layer will take the brunt of the direct heating, and the air gap between will allow circulating air to carry some conducted heat away. I suppose aluminum would be easiest to work with, and non-rusting, but steel is a poorer conductor of heat, and therefore a better shield. Maybe air conditioning/heating duct would be a good source of material. This part will be more work, of course.
There is already sheetmetal (thin galvanized steel) shields screwed onto studs underneath the floorboard. Mud and so forth can't be too much of an issue.
What about this idea? Remove the existing shields. Add several layers (4 or 5?) of cut up space blanket to make a reflective shield sandwiched between the existing sheetmetal shield and the floorboard. Space blanket is aluminized mylar which is very good at reflecting infra-red radiation (heat) and can be gotten at any camping/hunting store, and is not expensive. Wrinkles and gaps between the layers will actually be a good thing. Fit will not be critical. It's very, very thin stuff. This will be an easy job.
Then, adding another sheetmetal layer on standoffs will enhance it even more. That layer will take the brunt of the direct heating, and the air gap between will allow circulating air to carry some conducted heat away. I suppose aluminum would be easiest to work with, and non-rusting, but steel is a poorer conductor of heat, and therefore a better shield. Maybe air conditioning/heating duct would be a good source of material. This part will be more work, of course.
- Thread starter
- #30
e9999 said:
Super glue
I'm not sure, i wasn't there. I dropped it off at 8:00 and he was finished by 10:00. Welds look good and they do go all the way around.
lx450landcruiser
Moderator
i watched my guy do the welding, theres a reason these guys have exhaust shops they can weld at any angle, very very good welders. as for the space blanket idea, with ever solution there is a problem. i live in Az half the year and Wa the other half. if you do any driving in water (i.e. rain, water crossing ect..) waters going to get trapped in that material and rust your cats away at a much much faster rate then normal. Last i hear those cats cost a pretty penny. i thought about doing the exhaust wraps a year ago or so but after talking to others on the board here about rust issues i went against it.
mike
mike
- Thread starter
- #32
Have you ever delt with Mylar? That stuff is fragile as heck. Just a little nick and it tears to pieces.
http://www.thermotec.com/products/full/16500/16500.html is one such aluminized mylar fiberglass product to be used as heatshielding.
I'd love to see some sort of data on this so-called increase in heat to the pass floor. Anyone? Well then it's all conjecture as far as I'm concerned. There's no airflow data for under there that any of us have seen and low-speed/high effort wheeling is where you'll see the most heat and that heat os going UP no matter WHAT angle your catalytic converters are at.
A far more dangerous situation is what happened to me when I 'nudged' those cats and slightly bent the exhaust pipe UP so IT contacted the heat shield under the 2nd row pass seat, which was folded forward to accomodate my cooler. The heat shield became a heat-conductor and said cooler melted to the floor. Rotating the cats thereby reducing this occurance has resulted in cooler floors overall
Who's to say it's like that becuase of heat anyway? I'm probably frying some of the expensive platinum by having them turned like that...
Not trying to be a d!ck, I just like fact with my science...
A far more dangerous situation is what happened to me when I 'nudged' those cats and slightly bent the exhaust pipe UP so IT contacted the heat shield under the 2nd row pass seat, which was folded forward to accomodate my cooler. The heat shield became a heat-conductor and said cooler melted to the floor. Rotating the cats thereby reducing this occurance has resulted in cooler floors overall
Who's to say it's like that becuase of heat anyway? I'm probably frying some of the expensive platinum by having them turned like that...
Not trying to be a d!ck, I just like fact with my science...
Bambusiero
SILVER Star
Rich, I'm not suggesting putting the mylar next to the cat's themselves, but up next to the floorboards where it's just pretty warm, not HOT HOT. It's not extreme heat stuff at all anyway. The mylar wouldn't trap any water next to the cats because it wouldn't be next to them. However, it COULD trap drops just due to contact above the normal heat shields and eventually cause the shields to rust. Hard to say. I can't think of any kind of insulation that would NOT do that even worse though. I don't think being delicate is an issue. You'd just cram some layers up there and hold it in place by re-installing the normal sheetmetal shields. If it didn't come out so neat, well, no biggy.
That Cool It reflective silica blanket product that you pointed out is interesting. That might have some benefit closer to the cat, maybe right above it. On the other hand, I can see a thing like that actually acting like a sponge in wet winter weather and really cause a rust problem.
That Cool It reflective silica blanket product that you pointed out is interesting. That might have some benefit closer to the cat, maybe right above it. On the other hand, I can see a thing like that actually acting like a sponge in wet winter weather and really cause a rust problem.
Bambusiero
SILVER Star
tiorio said:I'd love to see some sort of data on this so-called increase in heat to the pass floor. Anyone? Well then it's all conjecture as far as I'm concerned. There's no airflow data for under there that any of us have seen and low-speed/high effort wheeling is where you'll see the most heat and that heat os going UP no matter WHAT angle your catalytic converters are at.
A far more dangerous situation is what happened to me when I 'nudged' those cats and slightly bent the exhaust pipe UP so IT contacted the heat shield under the 2nd row pass seat, which was folded forward to accomodate my cooler. The heat shield became a heat-conductor and said cooler melted to the floor. Rotating the cats thereby reducing this occurance has resulted in cooler floors overall
Who's to say it's like that becuase of heat anyway? I'm probably frying some of the expensive platinum by having them turned like that...
Well, toirio, it is conjecture, I'd agree. Seems reasonable though. Those things are REALLY HOT radiating surfaces. I'd rather sit over the top of them than sit ON them like what practically happened to you. Not a good deal at all! Agreed, I'll take "cooler floors overall" over crispy fried any day. As for scientific data, well, it probably exists, in katakana, in a dusty box under the desk of some Toyota engineer. You could write a letter to Toyota Customer Relations requesting it...
Bambusiero
SILVER Star
CUT n' REPLACE mod. - I've been considering the idea of just replacing the original cats instead of welding back in the old tired ones.
Reasons:
1) Some aftermarket units with appropriate flow rating are noticably smaller than the stock units, thus gaining additional clearence.
- The MagnaFlow 94106 (2 1/2" tube) has a body size of 4" thick x 6 1/2" wide x 9" long, plus 2" of tube at each end for welding.
- The front stock unit has a body size of 4 11/16" thick x 7 1/16" wide x 11" long, plus 5/8" of flange/tube at each end.
- The rear stock unit has a body size of 4 1/2" thick x 7 7/8" wide x 10" long, plus 5/8" of flange/tube at each end.
2) Who knows how much longer the originals will last? They've got 100K miles and 8 years on them. Could be 70K more miles, could be 10K.
3) I see the MagnaFlow 94106 priced at about US $56 each online. With shipping that would $130 or so additional cost over keeping the originals. Not too bad.
4) I would have the muffler guy weld them in with the middle somewhat higher than stock/straight, and without a flange between the 2 cats. That will allow the slider support arm to be fabricated up higher. I would put a flange at each end of the whole cat assembly.
Also, I would do something about improving the underframe tube position and smash resistance at the same time.
So many ideas, so little time (sigh).
Reasons:
1) Some aftermarket units with appropriate flow rating are noticably smaller than the stock units, thus gaining additional clearence.
- The MagnaFlow 94106 (2 1/2" tube) has a body size of 4" thick x 6 1/2" wide x 9" long, plus 2" of tube at each end for welding.
- The front stock unit has a body size of 4 11/16" thick x 7 1/16" wide x 11" long, plus 5/8" of flange/tube at each end.
- The rear stock unit has a body size of 4 1/2" thick x 7 7/8" wide x 10" long, plus 5/8" of flange/tube at each end.
2) Who knows how much longer the originals will last? They've got 100K miles and 8 years on them. Could be 70K more miles, could be 10K.
3) I see the MagnaFlow 94106 priced at about US $56 each online. With shipping that would $130 or so additional cost over keeping the originals. Not too bad.
4) I would have the muffler guy weld them in with the middle somewhat higher than stock/straight, and without a flange between the 2 cats. That will allow the slider support arm to be fabricated up higher. I would put a flange at each end of the whole cat assembly.
Also, I would do something about improving the underframe tube position and smash resistance at the same time.
So many ideas, so little time (sigh).
Bambusiero
SILVER Star
Oh, yeah, well there is THAT.
They have a family of units that claim "OBD II legal in California". They ARE bigger though. Also, there is an emblem on the the 94100 web page that says the same thing. What's OK in California, what's not? I don't really get it.
BTW. MagnaFlow is at www.car-sound.com
They have a family of units that claim "OBD II legal in California". They ARE bigger though. Also, there is an emblem on the the 94100 web page that says the same thing. What's OK in California, what's not? I don't really get it.
BTW. MagnaFlow is at www.car-sound.com
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