HP manifold performance

[tallhair]

Installing headers and replacing the ported 906 heads with ported 915s got me almost a full second of my ET in the 1/4 mile. 69 RR with 451, auto trans. Who know how much improvement was due to the head change, and how much was due to the header installation. I know they both helped. Don't know what the guy on tv was thinking, but headers have always been a great way to increase power and torque.

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And I was using open exhaust with the stock 69HP manifolds, as well as with the headers.

did you have header pipes running off those manifolds or just open manifolds? I've always thought they would crack if run open

 

[Herr_Poopschitz]

I've read that smaller pipe diameter headers are actually better for torque on a street cars RPM range than larger diameter and that larger diameter ones like 2" reduce torque and allow back pressure at lower RPM ...

Depends on cam timing events.

Backpressure is the enemy.

 

[bee71]

Anyone on this thread that wants to sell their stock bb manifolds please pm me.

 

[Mr.SpeedFreak]

I haven't run my car yet, but I have my 440 in place with Hedman Hedders, and I sometimes wonder if the same people complaining about headers burning plug wires etc are the ones that expect to just throw them in without any foresight and have nothing go wrong. :shruggy: I just did some research beforehand on issues people talked about, took steps to avoid them, and it looks like everything should be fine. (Good set of custom cut plug wires, stainless wire sleeves (not on in this pic), wire retainers, remflex gaskets, exhaust studs instead of bolts, flexible oil dipstick). No issues changing spark plugs with a wobbly joint on the socket. Clearances are real tight around the steering box and stock starter, but they're cheap hedmans, it seems TTI's would be better but these work for me for right now. Changing the starter would suck, but I was able to install my transmission and starter with the headers hanging on the studs, so it's not impossible.





Again, my car is not running and I don't have dyno sheets or personal experience with the comparison, so I can only really speak on fitment and install. But it seems like the concensus is pretty clear, and it only makes sense that better exhaust flow will translate to better performance and more power.

Mark from GYC is also the guy who puts backseat/trunk partitions in backwards and dips the wrong end of the lower control arms when he does the cosmolene, so I wouldn't necessarily put all my stock in what he says.. lol.

 

[Xp29h]

I dvr the show so I can fast forward past his parts!
I have heard the same conversation for years! I think these post are definitely right. Headers for those performance situations. My thought when I saw the show was he was trying to push people into keeping the original manifolds because he said they were taking them off and scrapping them. Therefore driving the prices up on the ones that remain. Which is true on prices however, no way am I convinced that manifolds do the same as headers as he stated..

oh oh yeah one more thought.. Speaking of starters.. On my 69 charger with 383 h code, most headers I've looked at require a mini starter. I haven't found a set yet that can use the regular starter. Maybe still out there?? Haven't finished looking either. I haven't done the change over yet to headers but it's on the list for this car.

and I have changed a starter with headers in the cold rain! My 73 charger years ago died in the parking lot at a golf course where I was working. It poured all after noon! It was late fall. It sucked!

 

[Mr.SpeedFreak]

I dvr the show so I can fast forward past his parts!
I have heard the same conversation for years! I think these post are definitely right. Headers for those performance situations. My thought when I saw the show was he was trying to push people into keeping the original manifolds because he said they were taking them off and scrapping them. Therefore driving the prices up on the ones that remain. Which is true on prices however, no way am I convinced that manifolds do the same as headers as he stated..

oh oh yeah one more thought.. Speaking of starters.. On my 69 charger with 383 h code, most headers I've looked at require a mini starter. I haven't found a set yet that can use the regular starter. Maybe still out there?? Haven't finished looking either. I haven't done the change over yet to headers but it's on the list for this car.

and I have changed a starter with headers in the cold rain! My 73 charger years ago died in the parking lot at a golf course where I was working. It poured all after noon! It was late fall. It sucked!

I'm not 100% sure if it's the same for 383's but my Hedmans required the stock starter, actually had to repair a primary where a guy was bashing the hell out of it to try and fit a mini starter.
Man that must have sucked in the rain!

 

[Xp29h]

Im still looking at all options on headers. Maybe I'll find a set that doesn't need the mini for the 383. If there are any suggestions, I'm certainly open.. Oh did I mention I'd have to go inside every 10 minutes or so cause I couldn't feel my hands.

 

[boneheadsGeTeX]

My car had headers , my dad installed when he put it back together, he said the heat from the them was burning up the starter, he put a high dollar starter cooked it, so he put the manifold s back on..it killed the power,, it a 440 dont know the cam but its got alot of overlap, msd, holly and 3in pipes,he said it need the headers,,, I was thinkin about a heat sheild?, guess ill have to pull the motor to get headers back on? Heat rap tape? Id like to know what yall thinking

 

[ZR9B]

Do the coated headers really control the under the hood heat very well??

 

[lewtot184]

Do the coated headers really control the under the hood heat very well??

the exhaust manifolds on my r/t run at 700f+. the tti headers on my '65 run 350f. the r/t's engine runs hot and the '65's engine never gets hot. both have the same size radiator.

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My car had headers , my dad installed when he put it back together, he said the heat from the them was burning up the starter, he put a high dollar starter cooked it, so he put the manifold s back on..it killed the power,, it a 440 dont know the cam but its got alot of overlap, msd, holly and 3in pipes,he said it need the headers,,, I was thinkin about a heat sheild?, guess ill have to pull the motor to get headers back on? Heat rap tape? Id like to know what yall thinking

try some tti's. no need to pull the motor to put them in.

 

[70rr-brian]

I dvr the show so I can fast forward past his parts!
I have heard the same conversation for years! I think these post are definitely right. Headers for those performance situations. My thought when I saw the show was he was trying to push people into keeping the original manifolds because he said they were taking them off and scrapping them. Therefore driving the prices up on the ones that remain. Which is true on prices however, no way am I convinced that manifolds do the same as headers as he stated..

oh oh yeah one more thought.. Speaking of starters.. On my 69 charger with 383 h code, most headers I've looked at require a mini starter. I haven't found a set yet that can use the regular starter. Maybe still out there?? Haven't finished looking either. I haven't done the change over yet to headers but it's on the list for this car.

and I have changed a starter with headers in the cold rain! My 73 charger years ago died in the parking lot at a golf course where I was working. It poured all after noon! It was late fall. It sucked!

I have ceramic TTI's 1 7/8ths on my stroker (496 from a 383 block) and a full size starter.