Header collectors - extensions, X-pipe or nothing.....

Right now I have a set of 2" primary Super comps, 3.5" collectors with turn downs on the ends to keep the exhaust off the floor boards. Would I gain anything if I extended the collectors with straight pipe or would an X pipe help any??. I'm also interested to hear of any new or old school little detail tricks that you guys might have tried that did or didn't work when it comes to finding a little HP. I've got a list of things that I would like to do to the car now that I'm running in the Super Pro class, but I can only do it as my wallet allows.  This winter paint is the priority, I hate the color of my car...LOL...Mid plate will happen, new front Strange struts, new SS race valves in the heads and a victor intake. Of course there is more on my list but it just sounds too expensive to put it all out there at once...   

throw a methanol carb on it and watch the magic happen......

I made a set of 17" collector extentions for the 466 in my ole Maverick. It was suppose to be an old school trick back in the day. Don't remember any BIG diff. but, I liked the sound better. 

I was told to put the extensions on, draw a line down the side with crayon - make a run and cut the pipes off where ever the crayon stopped melting....old school speed shop owner told me this. No ethanol or blended fuels available here anywhere.

damn Id move lol.

damn dble post sorry

I heard that Wilson's might sell a supreme pump gas with up to 10% ethanol but all the pump says is "may" contain ethanol. Bio diesel and blended fuels don't seem to like our winters, the city bus fleet tried a small blend of bio diesel and it cost them more money in repairs than it was worth so they stopped. I'm running 60/40 pump and av gas, she seemed to like more AV gas. I'll try 50/50 next time and maybe one tank of straight AV to see if it picks up or loses any. My engine is 10:1, straight AV might be overkill? This is what I love about drag racing, so many things to try at each race until you sort you car out....if ever LOL

Ive been sorting mine out since '87

Your on the long term plan ....LOL

They are all long term always looking to go faster and faster and faster  I am still working on mine to get it close to what I want. I shot for one ET time I get to it I am ready to make it a little faster, but I am like you just have to do a little at a time as money lets me. I have cut over 2 sec. off the 1/4 mile time before this new engine with changing to the truck and 460 I had in it. I want know how much I cut off the best time of 6.72 1/8 and 10.80 1/4 until I get my trans built now as the stock c6 could not handle the new 552 but did get my best speed 127.73 out of it with the slipping c6.

I added 45* turn outs with some cheap speedway motors mufflers it did not hurt my et or help, my headers are 2" with 3 1/2" collectors I run methanol so I needed to get the exhaust out from under the truck. It sure helped with the deafening sound in the cab for sure plus got the heat from out from under it also.

Building a rollerized c6 is near the tops of my list, might happen this winter. My trans works great so I would make it the spare. I have 3 more BBF C6's here to use.

fwiw I have a little info.....

This smallblock turd, its got a big ass cam ground for nos, 3" stroke deal....... no torque havin pos.

no chip on the t brake open exhaust 3400 rpm max, granted this is a 1 7/8" tube 3.5 collector, collectors are real short.

I just put full exhaust 3.5 " all the way back to the rearend, and used a set of Magnaflow 3.5 race mufflers....... it goes 4300 now.

Im gonna add an H pipe tomorrow and see what that does.....

I'm curious to see how the H pipe affects the deal. Im picking a 95 GT tonight to inspect the bottom end of the 347 and install some new AFR cnc'd heads. This thing worked good before, can't wait to see what the AFR's do for it. It belongs to my best friend, my cousin and myself are all in for the little project this week in the evenings in my shop.

didnt fool w the h pipe, tons of other stuff to do before I take it and im not gonna have time to screw with it.

Doesn't that always happen LOL

i read an article about collector extensions in hotrod or some similar magazine. the author extended the collector 18" and did a dyno pull and compaired it to the first run with the collector hooked to normal exhaust.

i dont remember the size of the tube at the collector or the pipe it down sized into, but his results were a slight drop in low rpm power around 4-5 hp up too like 1800 or so, then his mid range increased across the board by around 7-15 hp.
i just saw all the books i bought while stations in iraq, but they are still in storage. i might try to browse and find it and link it.
that might be why the h pipe is so useful, because of the collector extensions (and of course the cross pipe equalizing back pressure might help down low.
the x-pipe is all top end from what i have read. ive never run one tho. the crossing over helps with scavenging.

its been a few years since i read the article so the details elude me. but its interesting to read things like that.

Me too, if I have time this winter I'd like to try and fab up a cross member that would allow for a 3.5" X pipe. Worth a try and it would get the noise a little further back too.

I tried a set of 18" collector extensions on my 13 second 460 powered comet .I couldnt believe it picked up 5 tenths .I had so much more low end torque this really helped my 60 foot times .I didnt mark the collector extensions and cut either .I just bolted them onto my crites headers and went with them .Collector extensions can be bought for less than $50 Try them you might like em !

I might have to try this at the next race! LOL I will if I can squeeze the time in.

BigRigTech wrote:Building a rollerized c6 is near the tops of my list, might happen this winter. My trans works great so I would make it the spare. I have 3 more BBF C6's here to use.

If your future includes a three speed automatic transmission, try a quality built C4. I believe you will find an amazing amount of performance.

Dave.

I was looking at that but I'm going to stick with my C6 stuff, I don't have much invested in it and it works great. A C4 swap would cost a fair bit with an ultra bell, new TC, shield and a built tranny. I can rebuild my C6 for $500-600 and it will last forever. I have 3 spare BBF C6's here for parts as well. I would put the money into a set of good heads instead. My C6 was built 15yrs ago strictly for racing and it still works awesome now. The racer I got it from told me the worst thing he ever did was ditch his 466/C6 combo in favour of a 514//glide....he's blown up two engines since that time and the old 466 was trouble free....lucky guy eh? LOL

I was looking at that but I'm going to stick with my C6 stuff, I don't have much invested in it and it works great. A C4 swap would cost a fair bit with an ultra bell, new TC, shield and a built tranny. I can rebuild my C6 for $500-600 and it will last forever. I have 3 spare BBF C6's here for parts as well. I would put the money into a set of good heads instead. My C6 was built 15yrs ago strictly for racing and it still works awesome now. The racer I got it from told me the worst thing he ever did was ditch his 466/C6 combo in favour of a 514//glide....he's blown up two engines since that time and the old 466 was trouble free....lucky guy eh? LOL