i have looked high and low for a new set of headers for my 90 Bronco 4.9L... are there no current producers out there? i have checked all the obvious sources (hedman-borla-edelbrock-hooker-dynomax-flowtech-gibson-pacesetter) and more... i dont really want to have a set made up at the local muffler shop, but as a last resort, maybe...

anyone point me toward a source for a set of headers?

 

Hedman, Hooker, Dynomax, and Pacesetter all make headers for the 4.9. Check summitracing.com

 

Well man, there is only one source that makes 4.9 EFI specific headers and that is cliffordperformance.net .

To save some bux, you might wanna get a set intended for a carb application (all the popular header companies have them) and weld in the O2 bung and do something about the emissions down tube.

Im gonna be as hoenst as I can be here though, on a stock engine, your not gonna see a noticable increase on the efi engine, by adding headers.

 

I gained 8mph in the 1/4 mile on a stock engine when I added headers.

 

if you would care to share your personal experience (all details appreciated) with adding headers to the '4.9L inline 6' (EFI or NOT) i will thank you in advance... thank you kindly

 

You are going to get a lot of the same responses I think. I added a header to my 78' six and it woke it up quite a bit. I would do it again. My truck wasn't fuel injected though, I also added a offy dp and 390cfm carb so it was more than just the header....but like I said, it was def. an improvement.

I used the Hedman Header and it did require some trimming to bolt up properly. The frame also had to be notched a little bit. The starter was a pita to get in, the exhaust that I had made cost about $300 but it sounds awesome. I have had to redo the header/intake a couple of times do to leaks.....it's hard to get those things tight up against the block!!

I don't know, on a daily driver I wouldn't probably mod it up. The efi manifolds are pretty good, I don't think you'll notice nearly the difference that the carbed trucks will. Let us know what you choose to do.

 

if u do a search on the site u will find countless posts about headers.

 

Headers should respond to a carb engine much better than an efi.


Doesnt change my opinion silver streak. What does you rig weigh with you in it, what was your before mph?

 

I see in your old posts you managed a 73mph quarter with headers, so your previous best was 65mph.


Rough vehicle weight estimate of 4000 with driver (I also used 3800), in either case, your suggesting you gained between 40 and 50 hp at the crank around 35 at the wheels.


Impressive but I sure as hell didnt see that kinda improvement from my header addition (EFI engine).


I noticed more going with true duals, no cats off the exhaust manifolds. When I added the headers a year or two later, it was a big let down. Suppose everyone has a unique expereience though.

 

It went from 65 to 73 like you said. There is no way in hell it gained 40-50 hp though. Maybe 25-30 at the crank. It doesn't take much power increase to make a large performance improvement at the speeds these trucks run at. Also consider that the torque improvement for a 30 hp gain would be 60-70 ft-lbs in the rpm range we're running in. That makes a lot more difference than the power increase.

 

I came to my figure with a simple quarter mile to horsepower calculator, accuracy wasnt so much important as consistancy of the formula. I used 3800 and 4000, both cases came back with the above results.

I can agree with the concept of where the hp occurs and its affect on torque, however, I still believe the major increase in hp/tq came from the less restrictive exhaust piping, not headers (on the efi engines), grande scheme of things it doesnt matter but Im sticking to it, for now.

You ever put any more effort into your custom efi intake, think you described it as spagetti? Just thought of that for some reason, thought Id ask, still like to see some pictures of it.

 

The formula you are referring to is qustionable at best if it's the one I'm thinking about. I believe it says mph=(hp/weight)^(1/3)x234 or something real close to that. It is fairly accurate in the 12-14 second range, but go haywire when outside of that range. It also assumes perfect vehicle setup and hp and tq approximately equal for an engine that peaks around 5500 rpm.

I had a high flow exhaust on the truck before the headers. It had a 2.5" straight pipe with gutted cats and no muffler before.

That intake is still sitting on the shelf. I haven't had time to mess with it, but I will get it on there eventually.

 

Yeah, as previously stated, that formula sucks at determining actual HP/TQ at the wheels or crank, I was using it to deterimine your claimed gains, its seemed consistant.

I still gotta say, I just didnt feel it, with what your describing, it should have been noticable.



Whats your take on the thread "injectors on my 93 f150"? A fella states hes running 19 lb/hr injectors, stock fuel psi, reset the computer to relearn. You ever run your larger injectors at stock 4.9 psi?

 

To be honest, you really can't feel it on mine either. It feels like you're driving a tractor around, but on the clocks it shows a lot of improvement. It actually felt slower for the first few hundred miles because the computer was so far out of its confort zone. It was really a turd initially. I was very disappointed even though a power increase wasn't why I put them on. I just needed a new exhaust pipe and Ford wanted $600 for the front cat and pipe assembly. Headers were more economical. As a general rule, you will never feel anything less than a 10% gain. I've driven several of these trucks and can't say that I can tell a significant difference in any of them unless they are geared differently.

I looked at that thread briefly but didn't read it all. I'm sure I've tried it but I don't remember how it worked. I'm happy with my current combination and will probably not go to anything else. I did try some 24 lb injectors with the AFPR and was able to get 8 mpg on the highway and the truck trailed a cloud of thick black smoke in town. Bigger injectors are definitely hard for the cmputer to compensate for.

BTW, when I said that intake was on the shelf I wasn't talking about it figuratively like I wasn't working on it. The intake is built and is physically sitting on the shelf waiting to be tested. I also have a single plane upper to try out. Just gotta find the time.

 

Now were coming to a common understanding.

Thats why I keep telling people dont do it (efi). No real SOTP feel. Im not gonna say the total exhaust redo wont make a slight difference, thats not what Im saying, Its just not likely people are going to take it much further than headers on the efi, once they run their buddy again and still get beat...haha. Besides, once a person realizes how the efi work and what needs to be done to make it work efficiently with mods, it something I think should be approached as a complete upgrade. Id rather they save their cash, see the big picture, then mod the hell out of that thing... if the idea of a standalone efi controller doenst intimidate them or the price of a repgrogram of the ecm. Now if I were convinced everyone that asked that question was a die hard inline fanatic, and not someone looking to turn their six into a hopped up v8, my answer would be, go for it.

Hey, I was the hardhead (still am), everyone said, dont, I had to see it for myself, here I am, the nay-sayer. Viscious cycle. Not everyone is gonna see a couple seconds off your quarter, and still being over 17 or whatever it was, as a good day, although, in reality, it is very good.



Tell me more about that single plane intake. Id sure like to see pix of either, hint hint.

I often wondered how either a single carb or dual carb intake would work with and elbow adapter and a couple throttle bodies. I was close to adapting two throttle bodies to the stock intake, it was a tight fit but rough measurements seemed to show it would work...ran into some issues and lost interest in it...even sold the turbo I had for it....made a profit, cant complain.