Proper header for odd fire PVR

[Kenny_Z]

I'm trying to wrap my head around the headers you're talking about building. From what I gather you're talking about taking an exhaust port from the left and having it exit the right collector and vice versa? The tubs would have to pass through the area currently occupied by the crossover pipe but then how do you get the remaining exhaust tubes to equal that length? Anything I imagine has a huge mass of pipes that just doesn't fit in the engine bay. Unless you aren't worrying about the equal length on the tubes running from side to side and the remaining pipes.

I've seen headers like this built for other engines. I want to say either Ford or Dodge, I can't remember exactly. I know they are a pain to install in a bay that would hold an entire Delorean. I couldn't imagine trying to stuff something like that into such a small area while leaving room to reach the oil filter and starter.

Of course I could be completely wrong with my thought process.

[stevedmc]

This is quickly becoming a Robertson situation. I'm out of here.

If this was Bill he would have either been put on timeout or would have been banned by now. I don't think it's him.

[EarlHickey]

You're on the right track, however, the idea is to have the leading and lagging slugs, on each bank, hit their respective collector at 120 degrees apart.

This does not require a gt40 flat crank v8 snake display.... nor will such a pipe have equal length primaries. See the bgn header, sans crossovers and note the impressive dyno chart with its amazing torque curve reflecting stellar volumetric efficiency even with heads I can assure you are very mych inferior to the dmc's heads.


How much torque does a normally aspirated four stroke engine make when it attains 100% volumetric efficiency? The answer is an absolute.

I'm trying to wrap my head around the headers you're talking about building. From what I gather you're talking about taking an exhaust port from the left and having it exit the right collector and vice versa? The tubs would have to pass through the area currently occupied by the crossover pipe but then how do you get the remaining exhaust tubes to equal that length? Anything I imagine has a huge mass of pipes that just doesn't fit in the engine bay. Unless you aren't worrying about the equal length on the tubes running from side to side and the remaining pipes.

I've seen headers like this built for other engines. I want to say either Ford or Dodge, I can't remember exactly. I know they are a pain to install in a bay that would hold an entire Delorean. I couldn't imagine trying to stuff something like that into such a small area while leaving room to reach the oil filter and starter.

Of course I could be completely wrong with my thought process.

[delornut]

Header design in most street applications must cover a wide range of driving applications and end up being a compomise but they're not rocket science either. As a rule of thumb longer pipes give better low end torque while shorter pipes work better for high rpm's. Collector diameters and designs vary depending on displacement along with several other things. The available space for routing the headers figures into the equation and in the end there probably is no perfect way for a header design in the DeLorean that will offer the most at all levels of driving. I know that DMC Houston had their headers designed to match the flow characteristics of their head modifications and cam grinds. I can't speak for the other offerings but I'd guess the differences between them are small for every day driving. I'm not sure what Earl is getting at here as he's offered no details, only generalities that hint at his having a technical backgroud. I'm not knocking him, only wondering where he's going with this.

Bruce Benson

You're on the right track, however, the idea is to have the leading and lagging slugs, on each bank, hit their respective collector at 120 degrees apart.

This does not require a gt40 flat crank v8 snake display.... nor will such a pipe have equal length primaries. See the bgn header, sans crossovers and note the impressive dyno chart with its amazing torque curve reflecting stellar volumetric efficiency even with heads I can assure you are very mych inferior to the dmc's heads.


How much torque does a normally aspirated four stroke engine make when it attains 100% volumetric efficiency? The answer is an absolute.

[Kenny_Z]

How much torque does a normally aspirated four stroke engine make when it attains 100% volumetric efficiency? The answer is an absolute.

You got me, my brain is already fried with network and IP information. I can't fit anything else in here

I do understand the concept better though. The engine is an air pump and incorrect exhaust flow angles can choke it. Makes sense.

[EarlHickey]

Header design in most street applications must cover a wide range of driving applications and end up being a compomise but they're not rocket science either. As a rule of thumb longer pipes give better low end torque while shorter pipes work better for high rpm's. Collector diameters and designs vary depending on displacement along with several other things. The available space for routing the headers figures into the equation and in the end there probably is no perfect way for a header design in the DeLorean that will offer the most at all levels of driving. I know that DMC Houston had their headers designed to match the flow characteristics of their head modifications and cam grinds. I can't speak for the other offerings but I'd guess the differences between them are small for every day driving. I'm not sure what Earl is getting at here as he's offered no details, only generalities that hint at his having a technical backgroud. I'm not knocking him, only wondering where he's going with this.

Bruce Benson

From the beginning, I'm sure I stated I don't want or need any catalytic convertors and I can certainly see how having to fit them, which most people would desire and require, would eat up a bit of precious space. I merely asked who offered headers for these cars so I could see for myself if anything offered appeared acceptable. As we agree on them not being rocket science, it doesn't take the eye of a NASA engineer to eyeball one and get real close to seeing for which ranges it's been optimized and how much fuel it will waste in the process of driving conditions outside those operating ranges..... without ever seeing a single dyno chart.

If I were to fit cats, I'd likely just have them in the area the popular systems use for the muffler and use less muffler. I already said I was ok with hooligan sound pressure levels although that's not preferred.


Kenny, at 100% VE, an engine makes 1 ft.lb. of torque per Cubic Inch of Displacement. This is why mere peak numbers only leave out lots of very desirable information for a street driven or even rally type car.