Project YOLO: The Quest for 100 HP per Liter
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I'm going to have to go with 2'' primary's also. Even the gm ls3 cnc exaust ports are way to big for 1-3/4 od tubes. They just came in today.
I'm going to have to go with 2'' primary's also. Even the gm ls3 cnc exaust ports are way to big for 1-3/4 od tubes. They just came in today.

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Yes, we did. Well, we can definitively say that 2" headers are too much for an NA setup. I gained 1hp and lost 8lt-lbs. Through the curve, the loss is significant. For instance, at 2700 w my 1 3/4 headers I was at 420ft-lbs; w/ my 2" headers I'm now 350. Drivability is still great, and this cam is swallowed up w/ these heads. A bigger bump stock will be the next move. Currently it's at 555/482.
Stepped headers would have been best, 1 3/4" to 1 7/8". I bet you would have picked up hp/tq everywhere. 2" are just plain too big unless you have much bigger cube setup or high boost.
I would take them off, sell them, and get some stepped 1 3/4" to 1 7/8". That would nag me all to hell knowing I took a huge leap backward.
I would take them off, sell them, and get some stepped 1 3/4" to 1 7/8". That would nag me all to hell knowing I took a huge leap backward.
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Yup, yup! God only knows what stepped headers would run on vettes! Our headers are already a kings random.
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I would take them off, sell them, and get some stepped 1 3/4" to 1 7/8".
Please refresh my memory JP.....what is the sizing and configuration of your exhaust after the collectors to the tailpipes (size, x or H, etc)? Do these headers have merge collectors?
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