Hey guys , my son reminded me of a trick we used to use back a long time ago. Just wanted your opinions. Last year I went from a small 1 5/8 to 1 3/4 tube header TTI to a large for the INDY heads W2 big tube headers. The car went almost a 10th slower off the trailer. I jetted the carb up some and got my time back but couldn't help but wonder why such a difference. Anyway fast forward to tonight and my son reminded me of the old header collector extensions we used to put on and mark with a wax pencil to cut at the melt point. How about opinions on weather I should give this a try and do you think it will help ?? I was really hoping that those expensive TTI ILL fitting headers would have made a big improvement in my setup and they never did.
I have a 422 ci X Block with a 652 roller cam and INDY 360-1 heads on it. It runs pretty good but I really thought the headers would have made a pretty good difference.
I can’t imagine on 422 inches a 1.875 tube is too big. I’d start with a 24 inch extension and trim it down from there. If you are running more than a couple degrees of split on cam timing the big headers will kill it. The correct size headers hate big intake/exhaust duration splits. It kills everything in the middle. Also, wide for the combination LSA’s with a bigger header kills mid range power. At your displacement and heads I’d think 111 is as wide as I’d go.
All of this stuff has to work together. I’m not 100% sure from your post if you now have TTI headers or if you took them off for something else. If they are TTI headers their collectors suck poop through a straw. I’ve complained about it several times to them, but they say I’m the only one complaining about them. Unless it’s just a street car and I have to use TTI headers I cut those junk collectors off and buy slip on collectors.
That also has another benefit. You can cut the flanges so you have three pieces per side, plus the slip on collectors. Makes it much easier to get the headers on the car. I’ve asked TTI to make their collectors slip on, but they say they don’t make a true “race” header, except in the description it says “race” header IIRC.
Just my .02 and that’s way more than it’s worth.
