Just thinking outloud here for someday (probably a year or two at least) down the road. My Hooker LT coated headers are beggining to corrode and not look as good as they once did. This gives me an opportunity to do something I should have done when I re-built the 383 and put the D1SC in, and thats change out the Hooker 1 3/4 LT's for some Kooks 1 7/8 headers. I am guessing this will probably net me another 10 RWHP or so over my Hookers, and better yet, since they'll be stainless, they will last forever.

My problem is this; my tune from Bryan Herter is sound, and I need to find how far off my tune will be (if any) if I change the headers up to some better ones (basically going from the 1 3/4 primaries to the 1 7/8 primaries, along with changing the Hooker Y-pipe out for a Kooks one). Basically I am asking if I will benefit from a new tune after this is done, or not.

 

I don't think it will affect your tune very much. I also don't think you will gain any noticeable HP. My Pacesetters are looking pretty bad too. I was wondering if those stainless are coated and how much engine bay heat they will create. Also with bigger primaries how easy will plug access be.

 

Well, I already know plug access will be better. As far as heat goes, I doubt theres any noticable difference to be honest. The only way to make a noticable difference would be to heat wrap the headers, but even then it will still be hot under the hood from the blower.

The biggest concern I have with all this is really if I could get away with it and not have it throw off my tune. My tune is perfect, and I don't know that I am willing to not only put new headers in, but then get everything "re-tuned" on account for it.

 

Ben, if your tune was done on a dyno (as I'm sure it was), then I agree with Steve and don't think the motor will require additional tuning. Changing primary sizes from 1-3/4" to 1-7/8" may change the torque curve of the motor slightly, but probably won't net you any noticable gains.

Jethot does offer a more durable coating that is recommended for exhaust parts, but it isn't as appealing to the eye as their standard exhaust coating. It has a much more dull, gray look to it.

 

My Hookers were JetHot coated, but it was years ago, and the coating is shot, and the corrosion is starting to take place. It's just a valid excuse for me to think about going with some bigger and better headers that would be more ideal for my setup. I should have just done them when I went boosted in the first place, but was concerned with too many other things at the time and didn't even think about the smaller primaries.

So you think going to a 1 7/8 header won't throw off the tune?

 

Yes it will throw off the tune... and by a long shot to some degree. Most of the horsepower gains you get with headers, you get them out of the tune.

 

I contacted my tuner (Bryan Herter of PCM's for less) and he said it would barely change anything, and that having it re-tuned would do little (if anything).

I consider Bryans experience in this field to be exceptional, so I'll probably just stick with his advice.