Headers?

[Tim W]

Iv been using Gibson headers. They arnt what I would call cheap but they are stainless and ceramic coated. Not to mention a lifetime warranty. They bolted right up to my factory y pipe

 

[PlayingWithTBI]

I have the same Summit Racing headers as @kennythewelder too only mine are the G9015 with the A.I.R. ports for emissions, as well as the JBA mandrel bent "Y" pipe (better flow than the OE pipe and collector) to 3" high flow cat and 3" - 3 chamber muffler. Sounds throaty but not too loud.

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[Kenton Danielson]

I have to throw my 2 cents in on this. Exhaust header design & fabrication has been a big part of my "automotive life" for many years. I studied the science & talked to several of the best header builders in the country. I had the most visited web page on the internet for header design & fabrication for several years, the page is long gone now but it sparked a rapid rise in enthusiast building their own headers and many more web pages with good info on the subject.

Having said that, shorty headers are NOT good at ANY rpm. They are better than factory manifolds but are designed strictly for convenience of installation and to meet smog laws. A 4-1 header will outperform a shorty header at ALL rpms. A WELL designed & built 4-1 header will far outperform any shorty header at all rpms AND focus your largest gain where you want it for YOUR application. A well designed & fabricated 4-2-1 header will make a much broader torque curve than a 4-1 header but not as much peak power-perfect for a truck. There are NO good 4-2-1 headers on the market these days. I cut up a Dougs Headers 4-2-1 to look inside and was appalled at the way it was slapped together. THIS is what a good 4-2-1 header looks like, note the long primary & secondary lengths to build torque and are within 1/2" in length, the merged collectors are a must to make good power, the venturi collector at the end is a real bonus too. This header was built for my little modified BMW 4 cylinder and it worked much better than the popular store bought 4-1 header that was on it. It worked so well I had to retune the megasquirt EFI which increased torque, HP & mileage (when I kept my foot out of it).

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I run the summit racing shorties on my '94-I lived in CA and they have the CARB exemption. I didn't have to cut flanges or anything, just blast them, rinse with acetone & spray with 3 coats of VHT then drive gently for a bit to cure the paint well. They look like brand new after nearly 100k miles. I no longer live in CA so they will be taken off and Patriot Headers H8059 (about $250 raw) will be going on this summer. These are 1 5/8" primaries but 1 1/2" would work better for torque on a truck. I may saw off the collectors and install merged venturi collectors so I leave less power on the bench than necessary but these collectors aren't too bad.

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Ken

 

[kennythewelder]

Just click the link to my post about exhaust.
https://www.gmt400.com/threads/exhaust-explained-by-engineer.46397/

 

[Kenton Danielson]

Seen it before, he got most of it right & it's a good start for someone that needs to start learning about headers/exhaust. There is MUCH to learn on the subject. Engineers don't know as much as the scientists that literally wrote the book on exhaust design. Scientific Design of Intake and Exhaust Systems by Phillip H. Smith and John C. Morrison ISBN #0-8376-0309-9. Pretty dense stuff and good read (if you like science & math). I interviewed Ed Henneman, Jere Stahl, Vince Roman & Mark Lelchook for my articles. All are VASTLY more experienced at header design & fabrication than anyone at Magnaflow. I LOVE Magnaflow products but they are a production facility that cuts corners to keep costs down. I learned a TON from them, the MAIN thing is that ALL off the shelf production headers are a compromise for fit & performance. The key is to understand those compromises and do your best to minimize them for YOUR application. Or, buy the equipment & develop the skills to build your own without compromises. I'm old and getting lazy these days so those Patriot headers above will do on this truck.

ken

 

[Emagnisalb42]

Hey y’all! New here. I’m working on redoing my 89 k2500. I’m new to this and my exhaust is rusted through. I saw on JC Whitney where they have mid length headers, is there any merit to those or are they something to shy away from. Link to page included.
https://www.jcwhitney.com/details/C...heyenne/8_Cyl_5-dot-7L/F3131508.html#plpslot2

 

[JCribb]

I have shorty summit racing “brand” which is reboxed flowtech headers. Ceramic coated, and almost four years old come April ‘20. No complaints, no leaks

 

[Hutchinson]

I slapped on a pair of Hedman Hustler race headers - long tubes. I called Hedman and asked them to install two O2 sensor bungs, on inner side/ 45 degree angled up. Also did the EGR delete/ cover plate,... so didn’t have mess with augmenting the headers for EGR,....plus it keeps the soot outta your intake. Gotta say, that upgraded MPFI spider works better than that old poppet style (stock).
If your installing a new motor in a truck, don’t buy the ceramic coated headers,.... the new 383 smoked the ceramic off mine (in spots),...

 

[Schurkey]

Doesn't the ceramic coating have to be "cured" by intermittent warm-ups? Fire the engine, run briefly, shut off, wait, fire the engine, run a little longer, shut off, wait...repeat a few times?

 

[Tim W]

My ceramic coating is fine on my gibsons. I mean they are not as shiny but the coating still there