can i run longtubes without a tune?
12-29-2010, 06:20 PM
#1
TECH Apprentice
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can i run longtubes without a tune? in the middle of installing longtubes. will my car run like crap if i dont get a tune? I've read that some people have had nightmares without a tune and some people are fine, we'll find out after i'm done. Also... everytime i disconnect the battery my car takes a few minutes of driving around to run/idle normal.. but i think that's due to the k&n cai i have though, correct me if i'm wrong. thanks.
12-29-2010, 07:27 PM
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in the middle of installing longtubes. will my car run like crap if i dont get a tune? I've read that some people have had nightmares without a tune and some people are fine, we'll find out after i'm done. Also... everytime i disconnect the battery my car takes a few minutes of driving around to run/idle normal.. but i think that's due to the k&n cai i have though, correct me if i'm wrong. thanks.
Last edited by C/Performance; 12-29-2010 at 07:45 PM.
12-29-2010, 09:44 PM
#8
You may wanna consider getting the LT4 knock module since it's less suceptible to false knock than the LT1 module. Because the metallic noise from the headers is similiar to that caused by spark ping, it causes the knock module to signal the computer that the engine is pinging, and then the computer retards the spark for no good reason. The LT4 module is less sesitive to false indications.
12-29-2010, 09:47 PM
#9
I think i read awhile back something about lengthening the stock o2's messed with the signal some how? Beleive it was in the same post that someone said that you can use OEM Corvette O2 sensors as they are long enough?
I could have been dreaming though, was awhile back when i read it.
I could have been dreaming though, was awhile back when i read it.
12-29-2010, 09:58 PM
#10
I think i read awhile back something about lengthening the stock o2's messed with the signal some how? Beleive it was in the same post that someone said that you can use OEM Corvette O2 sensors as they are long enough?
I could have been dreaming though, was awhile back when i read it.
I could have been dreaming though, was awhile back when i read it.
12-29-2010, 10:21 PM
#11
Even so, the dual cat CA-emissions cars were still OBDI, which didn't have rear O2s. Still dual cat, but only pre-cat O2s.
True story. The knock sensor circuit can also be sensitized in the tune.
Pretty sure it's the REAR Corvette LT1 sensors that use the longer harness. Info is pretty sketchy on them though...not sure if the harnesses are long enough to justify not needing an extension.
And manually extending the harness (via crimping, taping, whatever) instead of using extensions (which provide the least amount of resistance) has been known to jack with the O2 voltage. I saw this firsthand with hacked wiring on my brothers 97 LT1. SOME people get away with it, but using the extensions is FAR more reliable.
You may wanna consider getting the LT4 knock module since it's less suceptible to false knock than the LT1 module. Because the metallic noise from the headers is similiar to that caused by spark ping, it causes the knock module to signal the computer that the engine is pinging, and then the computer retards the spark for no good reason. The LT4 module is less sesitive to false indications.
I think i read awhile back something about lengthening the stock o2's messed with the signal some how? Beleive it was in the same post that someone said that you can use OEM Corvette O2 sensors as they are long enough?
I could have been dreaming though, was awhile back when i read it.
I could have been dreaming though, was awhile back when i read it.
And manually extending the harness (via crimping, taping, whatever) instead of using extensions (which provide the least amount of resistance) has been known to jack with the O2 voltage. I saw this firsthand with hacked wiring on my brothers 97 LT1. SOME people get away with it, but using the extensions is FAR more reliable.
12-30-2010, 12:46 AM
#14
Soooooo... this thread just prompted me to buy a set of O2 extensions. 
http://cgi.ebay.com/ebaymotors/ws/eB...1#ht_856wt_939
I lengthened my O2 wires years ago. I dunno if I'm having any issues with them or not, but my car is currently in the shop waiting to be dyno tuned for the new heads and cam that was just installed. Figured I'd go ahead and eliminate any possibilities of any problems by just purchasing some extensions. This is seriously the first time I've ever heard of possible problems by extending the wires.
http://cgi.ebay.com/ebaymotors/ws/eB...1#ht_856wt_939
I lengthened my O2 wires years ago. I dunno if I'm having any issues with them or not, but my car is currently in the shop waiting to be dyno tuned for the new heads and cam that was just installed. Figured I'd go ahead and eliminate any possibilities of any problems by just purchasing some extensions. This is seriously the first time I've ever heard of possible problems by extending the wires.
