Good idea / Bad idea

[tiorio]

Is this a good idea or a bad idea?

Shortening the downpipe to the catalytic converters to increase ground clearance.

Back story:

I live in CA so it's completely illegal to replace the cats with anything non-OEM. I'm doing a custom cat-back with a Magnaflow muffler so the mounting height won't matter. I figure I could shorten the downpipe to gain ground clearance but what are the downsides (heat maybe?) and would the trade-offs be worth it?

Just can't leave well enough alone...

 

[cruiserdan]

Since the fron cat is part of the front pipe I would approach modifying it with caution. If you mess it up and need to go back a new pipe is only $1,314.54

Shortening the front pipe could have an impact on cat function. I do not know how much of an effect it would have. Logic dictates that it would run hotter than the original design intended. I do not know the ramifications of that change.

 

[tiorio]

I suppose the question is a tad pedestrian to begin with.

I'm just really pissed off that by CARB regulations I can't IMPROVE the smog-cleanliness of my vehicle by installing a high-flow cat suitable for the motor/vehicle. No shop will do it ($25,000 fine or something like that) and I wouldn't pass visual with one cat instead of two. So I'm stuck with the OEM cats. Good intentions, stupid law.

Anyway. I guess I'll just deal with the cats hanging down like the nuts on a horny squirrel. Dumb cats. Dumb squirrels.

???



-Todd

 

[cruiserdan]

What about back-to-back aftermarket cats?

It does seem dumb to me. What should matter is what comes out the tail pipe, not how it got there.

 

[GXO]

move to colorado or portland like all the other californians

 

[Asiarider]

Why are there so many different state laws in the USA. Are there no federal laws guarding this?

Mike

 

[alia176]

For what it's worth, you can have a muffler shop turn them so they lay flat horizontally to give a little bit more clearance!

 

[RavenTai]

[quote author=Asiarider link=board=2;threadid=10542;start=msg94868#msg94868 date=1074955299]
Why are there so many different state laws in the USA. Are there no federal laws guarding this?

Mike
[/quote]

there are federal laws governing emissions on new cars but checking on them after the sale is up to the state or even county. usually only areas with poor air quality require inspection, California is the worst, in Georgia the only the 13 county Atlanta metro area requires emissions checks, and they just check what is coming out the tail pipe on older cars (>26 year cars are exempt) and on OBD-II cars they just scan for codes, AFIK no codes = pass emissions ut I have not gone lately my '01 silverado is exempt because it has >8500# GCVW

 

[Jonathan_Ferguson]

what would removing the Catalytic Converters actually not make the ECU work correctly?
How does an Australian 1FZ-FE get around this?

Anyway had a look at the Exhaust Manifold and looks to have equal length pipes(Or very close to). Then goes into a Straight Through type Silencer then into a very big Reflective(Commonly refered to a Turbo Muffler) type Silencer and then there's the Resonator.

 

[Asiarider]

[quote author=raventai link=board=2;threadid=10542;start=msg95062#msg95062 date=1075003651]
there are federal laws governing emissions on new cars but checking on them after the sale is up to the state or even county. usually only areas with poor air quality require inspection, California is the worst, in Georgia the only the 13 county Atlanta metro area requires emissions checks, and they just check what is coming out the tail pipe on older cars (>26 year cars are exempt) and on OBD-II cars they just scan for codes, AFIK no codes = pass emissions ut I have not gone lately my '01 silverado is exempt because it has >8500# GCVW

[/quote]

Thanks for the info. I think the USA is so huge that this must be decentralized.

Mike

 

[tiorio]

Ah! Roll 'em 90 degrees, a stroke of genius! Any ramifications to THIS course of action?

Oh, and Dan, the shop that chooses to break the law and install the inline cats is subject to the $25,000 fine for the first offense and revocation of the Bureau of Automotive Repairs license (cannot do business anymore) for the second offense. OUCH!

Thanks!

 

[landtank]

Last time I read this idea I had a concern on mounting sliders. Most designs locate a brace that goes between the cats at the flange. I'd think that by rotating the flange it will now be in the way of that brace. I didn't get a responce last time either way, but I'd make sure if sliders where in your future plans.

 

[xl715]

Putting the cats closer to the exhaust manifold would make them hotter, however cats need heat to work efficently or 'fire-off' however, if toyota calculated the amount of heat produced from the motor and placed the cats distance accordingly, moving them closer could in theory burn them up by running too hot. On the other hand, a lot of vehicles now incorperate the cat into the exhaust manifold bolted right to the motor, 94 celica is this way and makes finding a header imposible!! Would be a crap shot to how much inpact to the life of the cats moving them would play, however they would fire-off sooner which i would think cal emissions would like!!

 

[semlin]

heat in the passenger floor pan is another issue. It gets pretty hot down there with cats in the stock position so I'd be careful about moving them up. Put your hand down there after a good long drive.