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I...I...I got Nothin
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Discussion Starter #1
I just read a post over on LS1.com. A guys buddy installed JBA shorties and claimed he went from around 303 rwhp to 337 rwhp. Are the GTO manifolds THAT restrictive?
 

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No way are they that restictive. I only gained about 10-12rwhp by switching manifolds. That is with a tune.
 

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Oh my f*ck!
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gtodoug said:
No way are they that restictive. I only gained about 10-12rwhp by switching manifolds. That is with a tune.
Somebody around here gained like 50HP going from stock to JBA's, exhaust, and dyno tuning. I'll try and find the post...
 

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Member #804
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I put JBA shorties on my silverado and they were a waste of money, probley made 5hp.
 

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13 year owner
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Well, I was running around 290 rwhp (tuning issues) and went to 330rwhp with Long Tubes and a tune.

All results will vary. Each car is different, each car reacts different to mods.

What I will say honestly is that a 34rwhp gain for shorties is definetely on the high side of things. But without knowing the conditions when he last dyno'd vs. now, other mods done, etc, it's hard to get a good handle on what happened.

If he dynoed right before he installed it and gained 34rwhp, then hats off to him.

As to whether or not the stock manifolds are a restriction? Yes. To some degree. They aren't bad as factory units go, but they are a compromise of sound level, packaging, material to accelerate light off of the cats, etc. Performance is just one of those other criteria. Whereas all these aftermarket units think of performance first, everything else second. :)
 

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This is the Dyno Chart of the pull made with the Headers, they also gave me a graph with the before and after on it that I will scan and post if you want to see that.




Like the rest of you, before we did the above pull they wanted me to drive the car for 15-30 miles to allow the computer to relearn air fule. When I did I had Tech with me and I looked over and said, "I don’t want to sound too overzealous, but I think I feel the power" Usually my desire for the power can trick me into thinking that its there when it isn't. The chart proves I was right! These JBA headers add power you can feel!
 

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13 year owner
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Please be aware that you've posted this now in several threads and some members don't care for the "spamming" in a generic sense. One thread that you started is sufficient.
 

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I...I...I got Nothin
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Discussion Starter #9
WHO!!! Me???
 

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Member #804
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so a GTO stock with only JBA headers is going to out dyno a GTO with long tube headers and tune?????
 

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Member #804
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2edybrd said:
I just read a post over on LS1.com.
LS1.com is like a tabloid magazine, havn't visited that site in years. No serious LS1 gurus go there either.
 

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I wished my JBA's added that much power. In conjunction with the Random tech dump pipes I picked up about 12whp. This was on my H/C car. More Kudo's to you for putting out those numbers though.
 
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