I have a header question.
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Instructor
Joined: Jul 2011
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From: MoVal California
I have a header question.
so i have been thinking about some headers for my 90 c4, i have a 6 speed and i was interested in just some short headers since i have a after market exhaust in the car at the moment(came that way when i bought it) but it seems that i can only run short headers since the cats are right under where the headers bolt into the exhaust it self. now my questions are, what is a good short tube header? and is there one that is ca smog legal? well i look forward to your replies and thank you for your time. 
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Joined: Nov 2011
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From: Budd Lake New Jersey
I too have a 90 and headers are a great way for a nice flow, this was the first thing I did, First off, go long tube its so much easier(and ull probably spend thesame amount of money on shortties when you fabricate the pipes after the flange, 2nd be prepared to deal with replacing the dipstick, its a pain, ull have to remove the ERG if u dont have the air injection(that'll be removed too) U can punch a hole in the bottom left header for 02 sensor, but id recommend u get 2 cats, put one after the header on both sides with a nice set of muffler eliminators n u should be ok 
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
I think that the shorty headers from Edelbrock, Doug Thorley and JBA are CARB-legal, but you still need to have the cats in place.
Longtube headers are a non-no as will any attempt to remove or relocate any emissions devices as long you want the car to have plates.
As for the cats, those will have to stay and I'm sure that CARB rules say they have to be in the same position as stock. Even aftermarket cats are hard to get. There are CARB-approved main cats, but they are expensive and are for the stock-style exhaust only.
Of course cat-back systems are legal and they do help some with improved performance and sound.
I have read about certain areas in CA where emissions sniffers are placed alongside freeway on ramps to detect excessive emissions on acceleration. There is a camera with the equipment that takes a pic of the license plate and you get a ticket in the mail.
Longtube headers are a non-no as will any attempt to remove or relocate any emissions devices as long you want the car to have plates.
As for the cats, those will have to stay and I'm sure that CARB rules say they have to be in the same position as stock. Even aftermarket cats are hard to get. There are CARB-approved main cats, but they are expensive and are for the stock-style exhaust only.
Of course cat-back systems are legal and they do help some with improved performance and sound.
I have read about certain areas in CA where emissions sniffers are placed alongside freeway on ramps to detect excessive emissions on acceleration. There is a camera with the equipment that takes a pic of the license plate and you get a ticket in the mail.
Thread Starter
Instructor
Joined: Jul 2011
Posts: 108
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From: MoVal California
I think that the shorty headers from Edelbrock, Doug Thorley and JBA are CARB-legal, but you still need to have the cats in place.
Longtube headers are a non-no as will any attempt to remove or relocate any emissions devices as long you want the car to have plates.
As for the cats, those will have to stay and I'm sure that CARB rules say they have to be in the same position as stock. Even aftermarket cats are hard to get. There are CARB-approved main cats, but they are expensive and are for the stock-style exhaust only.
Of course cat-back systems are legal and they do help some with improved performance and sound.
I have read about certain areas in CA where emissions sniffers are placed alongside freeway on ramps to detect excessive emissions on acceleration. There is a camera with the equipment that takes a pic of the license plate and you get a ticket in the mail.
Longtube headers are a non-no as will any attempt to remove or relocate any emissions devices as long you want the car to have plates.
As for the cats, those will have to stay and I'm sure that CARB rules say they have to be in the same position as stock. Even aftermarket cats are hard to get. There are CARB-approved main cats, but they are expensive and are for the stock-style exhaust only.
Of course cat-back systems are legal and they do help some with improved performance and sound.
I have read about certain areas in CA where emissions sniffers are placed alongside freeway on ramps to detect excessive emissions on acceleration. There is a camera with the equipment that takes a pic of the license plate and you get a ticket in the mail.
but i never heard about the freeway sniffers... those might be in LA since that place is literally gray and purple and smells like tijuana(no offense) 
but yeah, ill check with those names that your brought up with then.. thanks all! 
Le Mans Master
Joined: Jun 2000
Posts: 6,461
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From: Ypsilanti MI
Cruise-In 10-11-12 Veteran
St. Jude Donor '09-'10-'11-'12-'14
I have an LT1 not an L98, but I just finished (almost) a JBA shorty install, and while it fits nicely and looks great, I am not sure it is worth the close to 80 hours i have wrapped up so far 
(I am a perfectionist, so I have spent hours on little details here and there). At this point, both headers are on, passenger cat is back on, and plugs and wires are on. I still need to reinstall the drivers cat after removing some broken studs, and install the cat back.
(I am a perfectionist, so I have spent hours on little details here and there). At this point, both headers are on, passenger cat is back on, and plugs and wires are on. I still need to reinstall the drivers cat after removing some broken studs, and install the cat back.
Thread Starter
Instructor
Joined: Jul 2011
Posts: 108
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From: MoVal California
thats cool. yeah i was just wondering, idk what i have, i hear from many, but some say i have a L99 and some says i have a LT1 idk though, i have a 90 convertible. someone here will be able to answer me on it. but yeah, right now i am doing a head gasket job and about half of the engine is off, and i was just wondering about short headers because i took the stock ones off to get to the bottom head stud bolts. but is there is difference to the headers between the years? i mean, in some ways my engine looks like the 92 and up and the 89 and down... well i hope someone can give me answers, again i like to thank you in advance and i look forward to hearing your replies.
