When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Do you know how much they benefitted you power wise?
On N/A setup, it wont be a whole lot. Our stock exhaust flows pretty darn well from the factory. Unless your stock manifolds are a restriction, it wont be a lot.
I have ceramic coated BBK long tubes, and they've been great. Before i had my cams, i had my car dynoed before and after with the long tubes on the same dyno. As far as power gained, n/a i gained 6 rwhp & 6 rwtq, on the 100 shot i gained 20 rwhp & 57 rwtq.
Your 4v may show some different results then out 2v's, but I'm not sure. As far as numbers, I've had people tell me that the Kooks are tuned quite different then others and always show 15-20hp more, but I've never seen those results in any tests. The few I've seen they all showed fairly even, and I believe the MACs may have actually had the best output.