Welcome to V8Buick.com.
Page 5 of 7 FirstFirst 1234567 LastLast
Results 101 to 125 of 151
  1. #101
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Quote Originally Posted by Storm1 View Post
    Keep in mind this is the way I purchased the car, and other that what I can confirm with my eyes, this is what I was told was done:

    350
    Mild crane cam and lifters
    Hooker super comp headers
    3" exhaust to mufflers - 2-1/2" out from there
    H pipe

    So... Good, bad or ugly? Overkill? Losing, gaining, neither?

    Overkill, but looks very nice and effective. Most systems out there will be either 3" or 2 1/2", and stepping down from 3" from header collectors to 2 1/2" tails is a good design. Helps with moisture evacuation and ease of fitment around the axle, and in no way harms performance on a combination such as this.

    H-pipe looks to be in a good spot, and would do more for acoustics than anything, but isn't hurting anything.

    Headers are doing all your scavenging work, and exhaust system is more than adequate.

  2. #102
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    If you apply the acoustic wave formulas to many commercially made "competition headers" you might find that they focus their benefit around the rpm range seen near the shift recovery rpm, keeping in mid how limited of a scope that 'customization' to an application can possibly be to a mass marketed product.
    I don't recall that specifically enough to say across the board if it still rings true but going through the catalogs and applying the educational analysis a couple of decades ago, along with conversations with the above mentioned header makers back then....at least that's how I recall it.
    Keep in mind that mass produced products have to fall within a demographic.

    The testing isn't so much to see 'if' the header does it's job so much as verifying the rest of your combination executes as well as YOU planned it to...
    ***this is the catch 22 of the whole discussion***
    There isn't a universal way to apply a profitable product being big box priced, and to further obfuscate the topic it all depends on your specific combination and how it all balances together.
    With that being said, just the math alone to engineer your total combo is well past the hobbyists full understanding and patience, lest they go on a years long expensive learning curve but without the track time of a superstock racer.
    So either guess, work with $omeone, buy whatever is on the market and live with the result, or apply 50+ year old engineering (still current) to get your starting point and steer it from there.

  3. #103
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    IME 3" collectors lose torque for small cube applications, but bear in mind that this is with fairly unrestricted systems.

  4. #104
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Shift recovery? Where have I seen this phrase and its importance mentioned before?

    (shhh, not too loud)


    Good stuff Tony. Thanks again!

  5. #105
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Quote Originally Posted by 8ad-f85 View Post
    IME 3" collectors lose torque for small cube applications, but bear in mind that this is with fairly unrestricted systems.

    I totally overlooked that aspect. Buick 350 headers have a 3" collector, so there is no real 'reducer' effect going on (when used with a 3" header pipe to mufflers).

    In which case, maybe the H-pipe is helping more here?

    I don't suppose it would be a day and night difference though, considering the rest of the combination.

  6. #106
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    I've welded in the reducers supplied with headers into the 3" head pipes and had been happy with the feel of things.

    [edit...anti reversionary is a huge question mark as the full wave reflections are generally taken advantage of in a more competitive world]
    Last edited by 8ad-f85; 01-11-2017 at 09:16 PM.

  7. #107
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Quote Originally Posted by 8ad-f85 View Post
    I've welded in the reducers supplied with headers into the 3" head pipes and had been happy with the feel of things.

    Hey, that's an awesome idea!

    3" to 2 1/2" reducer inside a 3" pipe would help to reduce reversion and create a harder draw.

    I knew about this trick using manifolds and head pipes prior to a crossover, so makes sense.

  8. #108
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    If you look at formula suggestions and compare visually with Burns or other top racing headers, it makes you want to subscribe to the theory that only one pulse at a time passes the collector merge. Not that it matters for a Buick or any other street car with restrictive exhaust.

  9. #109
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    Food for thought

    Maybe this will help you with your exhaust Flow Test on your flow bench
    This was written By Darin Morgan

    My personal opinion and from what I have learned about exhaust ports I have to say that small super fast exhaust ports make more power over larger high flowing exhaust ports except in the case of full exhaust systems such as Nextel cup engines. For some reason they like a slightly larger exhaust port but no where even close to what I would call large. Large and Small are ambiguous. In my book anything over about 110% of the valve area is large and anything under 105% of the valve area is very small but the exit velocity seems to play a role here as well. I try to adhere to the 105-108% in our pro Stock engines and it seems that I am not alone in my theory because many of the top notch heads I have seen are about the same or within about 2%. Another very big thing to consider in the tuning of exhaust ports is there sound or should I say the lack of sound. How smooth an exhaust port sounds and how quietly it can move the air are both very serious factors to consider. As the valve opens the sound of the ports should smooth up and get increasingly silent. The loudest portion of the exhaust flow on the bench is from .200 to .400 after that they should go increasingly silent with every lift increment. I have had exhaust ports that actually cracked and popped like fire crackers! With a little seat blending and chamber work I managed to smooth up the flow, gained a measly 2 cfm average and gained 26 horsepower and it still was not correct because the port was to big. The hardest thing I do is try and fix exhaust ports that are screwed up. Its much easier to fix intake ports!
    Like an intake port, an exhaust port can be made to flow a great deal of air, Just make it big.

    Some rules I live by.

    (1) Exit area = 105-110 % of the valve.

    (2) Exit air speed at a minimum of 300 and a max of 330 ft/sec mean.

    (3) Smooth silent flow by at least .400 lift and absolutely by .500 lift.
    [ it isn't cfm flow, it's airspeed. ignore the parts you don't think apply here]

  10. #110
    Join Date
    Jan 2007
    Posts
    1,402

    Default Re: Loss of torque with larger exhaust myth

    Good info. I've been concentrating lately on reversion theory as opposed to mass*velocity theory as it applied to long tube headers. The latter makes perfect sense with headers where you have a slug of exhaust moving down a tube long enough to pull a partial vacuum behind it when the port closes. Beyond that basic theory there are a whole lot of details but the average guy doesn't need to know very much of that beyond the effect on tube size and collector dimensions.

    But reversion theory is something else again. Here I'm not talking about the effect you get with shorty headers where the exit of the exhaust pulse before the port opens again creates turbulence in the collector and backflow up the tube, but rather the reflected pressure wave that results from hard surfaces like the baffle in a canister type muffler. In this case there is no actual flow back up the tube, or it might be more proper to say that such flow as does exist is very incremental, sort of like a wave on top of water where the water has very little motion but the wave travels nonetheless, and has power. Yet a pressure pulse still reflects off that hard surface and travels back towards the port, followed by a low pressure pulse or vacuum. We know for a fact that this occurs because a 2-stroke scavenger pipe could not work without this specific phenomenon. If you want to get into the specific physics of how it works, I suppose it has a lot to do with the compressibility of exhaust gasses. But the bottom line is that it does.

    My point is that this reversion theory has long been used by the makers of 2-stroke exhausts and is a proven science. I firmly believe that OEM's have known about this and used it for decades, and the advent of computer engineering analysis has allowed them to refine it to the point where that LT4 is capable of 650 streetable hp with the shorty headers we see in the photo. Without the specific header pipe and muffler used in the application it was built for I doubt it would.

    Reversion theory won't work with long tube headers. In those you have something like 6 ft of primary tubing between any two ports so every reversion pulse is divided by four. But in a log or shorty header that distance is shortened to the point where a low pressure reversion pulse which arrives at all 4 valves simultaneously twice per crankshaft revolution, can suck down any port that opens when it arrives. On our conversion cars I suspect we severely hamper our outputs by attenuating the reversion pulses and by causing them to arrive out of phase.

    This approach still does not appear to be as effective as long tube headers but obviously they are getting better at it, and if scavenger designers have to nerf their designs to keep from blowing up their engines there's reason for hope. I'd love to know what that LT4 makes with long tube headers.

    So in reversion design, the volume of the header pipe and the design of the muffler become all important. Much might be learned from expansion chamber exit and stinger theory.

    Jim

  11. #111
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Hmm, quite thought provoking! I'm going to have to chew on this for a minute. lol

    It's refreshing to see I'm in congenial company.

    It seems I'm on the right track then, I just need to increase my understanding of these waves and their ability to create a drawing effect. Maybe I'm looking at it from the 'wrong' angle? Or maybe it's just a different angle. Not sure yet.

    What we know for certain, no matter the semantics of communicating thoughts, is that the exhaust needs to move fast and draw as hard as it can, whether it be from 'scavenging' or using reversion waves (synonymous and/or part of the same phenomenon).

    Am I getting warmer?

    We saw (if that smashed up header video was watched) that short restrictions introduced into the path of exhaust flow didn't hinder the power output whatsoever, as many would intuitively suspect.

  12. #112
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Quote Originally Posted by 8ad-f85 View Post
    I've welded in the reducers supplied with headers into the 3" head pipes and had been happy with the feel of things.

    [edit...anti reversionary is a huge question mark as the full wave reflections are generally taken advantage of in a more competitive world]

    Reducing reversion is what I coined it, but maybe it would be understood as something else?

    As far as 'in the competitive world' I was never truly interested in making money off this stuff or trying to create something that could draw capitalism's attention to it, as I believe that money will always get in the way of a true solution, which takes a back seat when it should be behind the wheel. (((no no, we can't do that even though it makes it better, simply because it would cost too much, and this other way here is more profitable, etc. etc. so on and so forth)))

    Anyway, perhaps this short-lived restriction (which encourages velocity) has more to do with enhancing the reversion wave phenomenon and its negative draw effect on the gasses behind it, rather than physically limiting how much gasses actually pass back up the system toward the engine--or maybe both?

    Regardless, we know it works well with a manifold setup placed before the merge pipe/crossover.

    I suppose it would just boil down to refining it.

  13. #113
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    Reversion theory won't work with long tube headers.
    ???
    There might be some that disagree with that.
    The way I interpret the formulas is that the longer the pipe, the lower the rpm range the wave reflection works in.

  14. #114
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Quote Originally Posted by 8ad-f85 View Post
    ???
    There might be some that disagree with that.
    The way I interpret the formulas is that the longer the pipe, the lower the rpm range the wave reflection works in.

    This would be true in a 'general' sense, but is relative and dependent on engine displacement, gas release timing/duration, the actual time it takes for the gasses to reach the end of the tube vs engine RPM/timing (where will the first pulse wave be when the next one is introduced, indicating that it is dependent on RPM and cam timing/duration, among many other factors that would affect the 'scavenging' effect), and would indicate the synergistic 'sweet spot' on tube diameter and length, as well as collector dimensions to accentuate this effect.

    Volume and velocity (and the balance between these two) become crucial factors in determining how well something will work, and makes one realize there is sooo much more to all this than simply bolting/welding parts together to move a quantity from point A to point B (as you already know).

    Blast it all, I'm out of time again and wish I could move this thought process forward a bit more, but alas it must wait until next time.

    It'll give me more time to digest and maybe realize the areas that I may have overlooked or misinterpreted/misunderstood.

  15. #115
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    I guess I would ponder those thoughts in the forums that the Nascar and Prostock header designers and engine developers post in.
    Their headers are fairly long for 9-11,000 rpm levels.
    I wonder how sound travels in a high temperature and pressurized environment?
    I'd be curious if the merges and branches act as reflective points or if there's influence from the other cylinders.
    I imagine sound has a pretty good influence over distance if concussion from noise bombs are effective.
    Rhetorical thoughts, obviously.
    All good discussion so far.

  16. #116
    Join Date
    Jan 2007
    Posts
    1,402

    Default Re: Loss of torque with larger exhaust myth

    "Reversion theory won't work with long tube headers" Fair enough, that statement is not completely accurate. Of course it will work, but the effect will be diminished to the point where it is far overshadowed by the mass*velocity effect of the exhaust pulses coming down a long tube. The primary tubes very effectively isolate each port from one another so only 25% of each reversion pulse will reach each port, while each pulse is 25% of one engine cycle. In other words, each port provides one pulse but only gets back 1/4 of one reversion pulse in sync with its requirements. It would be true that some additional scavenging could be achieved that way and maybe that is the direction the next phase of exhaust development should go in, but while the two effects could be additive they are very different from each other in the way they work so it might not be all that simple.

    That's a direction I had not even considered.

    By contrast in the log manifold nearly 100% of the reversion pulse would be available to draw exhaust out of the open valve, but there is no or rather, very little benefit available from the mass*velocity effect. Can the system be designed to boost this feature? Maybe. I guess that is where these reversion cones might come in. I expect their exact dimensions and configuration could tailor them to operate in either the mass*velocity mode or the reversion mode, or perhaps they could benefit both. Quite a lot of unknown territory there.

    As for the sound, I consider that to be a manifestation of what is actually going on in the system more than a method of manipulating it, but maybe there's more to it than that also. At the very least another means of visualizing pulse propagation. Anyway fun stuff to think about, huh?

    Jim

  17. #117
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Quote Originally Posted by 8ad-f85 View Post
    I guess I would ponder those thoughts in the forums that the Nascar and Prostock header designers and engine developers post in.
    Their headers are fairly long for 9-11,000 rpm levels.
    Good advice. What are your conclusions?

    I wonder how sound travels in a high temperature and pressurized environment?
    I suspect you already know, since sound waves travel faster and farther (before dissipation) within greater densities and not at all in a true vacuum, because the waves are the effects of energy being transferred through particles (the more there is, the greater the effect because there is more to be acted upon). Temperature tends to increase or decrease density with the expansion or contraction of molecules, and so cooler would indicate greater density with compressible mass.

    EDIT: I just looked up some of this basic stuff to see how my memory was, and it turns out I was incorrect about how temperature affects the sound waves in a gas, which is not dependent on density, but rather the tension of the medium. Seems I need to brush up on my definitions among other things, but we still know that there are circumstances affecting exhaust gas travel outside of the readily obvious.

    There is, however, much more going on that simply these two aspects, with overlaying and intertwining effects either accentuating or counteracting others.

    I suppose we could discuss how photons (and in fact most, if not all matter) can behave both as a wave and a particle, depending on how it is observed, and can change location in timespace depending on whether or not it is observed (!) Wrap your brain around that. Scientists are still trying to figure that out to this day. There's a few 'theories' (remember the scientific vs layman semantics of the term 'theory') so far, but the pursuit of knowledge is always exciting for any inquisitive mind, and so the quest continues.

    The formation of stars starting off as compressed hydrogen (understanding how this happens is fundamental to the formation of everything in the universe, including ourselves...) and the nuclear fusion that triggers ignition under gravitational forces, then the gradual stabilization leading into main sequence shows how density, mass, and temperature can affect particles/waves and release of energy, but I fear this would be too in depth for the purposes of this thread--or would it?

    Just how deep down this rabbit hole do you wish to traverse, and is it applicable to this discussion? Mayhap...but this is only my limited understanding of things, and I can always be wrong.

    I'd be curious if the merges and branches act as reflective points or if there's influence from the other cylinders.
    I imagine sound has a pretty good influence over distance if concussion from noise bombs are effective.
    Rhetorical thoughts, obviously.
    All good discussion so far.
    Indeed sir.

  18. #118
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    I'm stating that both OEM and highly developed racing using different methods don't disprove each other.
    There's a reason each does what it does. The circumstances are completely different.
    It's well known that opening an exhaust valve into a pressurized factory exhaust system running a computer would have very different camshaft events than and general needs than an unrestricted one.
    I believe that people selling headers and engineers writing articles are applying already well known principles to an 'in between' area (OEM and top level racing), and describing their suggestions in an easy to understand, somewhat foolproof method.
    I don't think it was too difficult to engineer a 650 hp LS engine, many have been done with other platforms.
    I believe many other builders can get them more driveable than the typical hot rod engine.
    Someone has to get paid for that time.
    Basically in any midrange consumer market with competitive pricing a couple things happen...1. is the customer and builder basically have one shot to get it right and 2. if a builder already has an outstanding package that vastly exceeds the competition, how do you price it knowing that anybody REALLY good can buy it and duplicate it and therefore negate your exclusivity to it's development?

    So...off on a tangent we are, trying to figure out if the main point is collaborative learning, deciding on which aspects have more influence and when how to use them, or IF any discussed concepts are valid.
    The internet is a treasure trove of 'free info', with the reader trying to discern the BS and popular opinion from the real poop.
    Books are inexpensive, SAE papers are still cheap.
    Buying and trying parts are a bit more $$ but the user is rarely qualified to discern more than 'it works for me'.
    A decades long racing effort is more expensive yet...
    Paying a shop for their expertise doesn't sound too bad except that one can easily 'buy a bigger stick', lol.

  19. #119
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    This is all fun to me, but I've always been a proponent of working with what you have.

    This would include trying to understand what's going on and how/why things work, not so much to develop something that's already been done for other applications for a different application, since there is no point in trying to 'reinvent the wheel', but to apply this to the platform(s) on this forum (Buick 350's here, mostly), using what we already have as a baseline.

    This would include maximizing the efficacy of using exhaust manifolds and existing header designs through the rest of the exhaust system itself, and wouldn't necessarily be exclusive to the Buick 350.

    It would be far more cost effective to optimize the rest of the exhaust system when considering these things.

    Perhaps the discussion would be more appropriate and 'back on track' with this.

  20. #120
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    Always the over explainer here...
    As far as buying a bigger stick, consider the cost of paying a guy to kind of quick engineer a custom or altered current header to work with your already well planned out package and you'll quickly see that many more cubes, expert head or machine work would be a better starting point financially...which is why we don't see so much of this now.
    Anyone buy some Lemon's or ARH's lately? Not for Buick most likely.
    (then what you you put behind that?)

  21. #121
    Join Date
    Mar 2004
    Location
    Edmonton Alberta
    Posts
    15,464

    Default Re: Loss of torque with larger exhaust myth

    A good article about header designs... They pretty much sum it up when they say something to the effect of: "although THIS engine liked a certain header design better not all engines will".

    http://www.hotrod.com/articles/ctrp-...ader-dyno-test

    As I showed the pic of the tri Y header design on my car it certainly is a good idea that Mark designed into the build and with such a tight limitation on that one side of the car.

    Factors such as cost, reliability, performance, and difficulty to build all come into play but the very best performing parts may not be ideal over the long term for reliability.
    __________________________________________________ __________________________________
    My book called Small Block Buick Performance covering the V6, 215, 300, 340, and Buick 350 engines will be released soon.

    http://www.v8buick.com/forumdisplay....rformance-Book
    __________________________________________________ ____________________________
    1970 Buick Skylark Turbo 350 street/strip

  22. #122
    Join Date
    Nov 2013
    Posts
    1,615

    Default Re: Loss of torque with larger exhaust myth

    Gary, to your post #119...since it isn't practical to mass market such a custom product that can fit the need of the target demographic of such a niche brand, the car owner and/or shop is left to adapt what they know to the platform and decide what they want to make happen.

  23. #123
    Join Date
    Jan 2007
    Posts
    1,402

    Default Re: Loss of torque with larger exhaust myth

    Another data point to add to the discussion, one of the guys who recently built a 302 SBF conversion hit his target build HP goals exactly (400) using shorty headers (custom RV8 style). Looking at his exhaust system, he has 2-1/2" pipes and canister mufflers all the way at the end of the system, maximizing the reversion chamber volume. (The pipes go under, not over the rear axle so a bit shorter, and he has short glass pack cartridges just before the axle. Also an "H" tube.)

    I posted a question as to whether his mufflers have an internal baffle or are straight through type. There is no indication that he was knowingly building a reversion based system. Luck of the draw.

    The open end at the termination of a tube can also generate a reversion pulse but it would not be as strong as one reflected off a baffle. The rear end plate of the muffler could also generate a pulse. Also the glass packs will somewhat attenuate the pulse both ways. But the results do support the theory, and are noticeably better than that achieved with the more typical exhaust system. Makes me wonder if changing out the resonators on the MG-Roadmaster for canister type mufflers might improve the system, a cheap and easy mod. Perhaps we should do a before/after dyno test at the BritishV8 meet in Lewisburg next June. The results would be illuminating.

    I do think there would be a risk of placing the muffler too far back, particularly on larger cars. For instance, on a GS I doubt it would help and might hurt, to put the muffler back by the gas tank. At some point the phase shift is going to make the pulse out of phase with the valves again. But we really need far more data addressing this theory.

    That is why I felt the LT4 results might be relevant. Not because it makes 650 hp particularly, that has become considerably more commonplace. It's just that it is usually done with long tube headers. That is what I felt was relevant, that in this case it was not.

    I enjoy the deeper theoretical discussion but things like quantum physics and string theory are generally above the pay grade of most of us here, me included. Still, over time some of it does sink in. I'll make use of everything I'm able to.

    Jim

  24. #124
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Quote Originally Posted by 8ad-f85 View Post
    Gary, to your post #119...since it isn't practical to mass market such a custom product that can fit the need of the target demographic of such a niche brand, the car owner and/or shop is left to adapt what they know to the platform and decide what they want to make happen.

    I completely agree, though there is a factor of 'good enough' that can play into the entire package, weighed against cost and complexity, particularly when we already have a good foundation to work with.

    I've always said that worthwhile gains could be achieved with a properly designed and placed merge/crossover if the iron manifolds were to be retained. There are many universal units already mass produced that would achieve this when incorporated into an existing or pre-fabbed exhaust system, or even one that your local privately owned muffler shop could bend and fabricate.

    There's a good one here in Clarksville, TN (and another one I've used in Ashland City) who do such things, and will let you watch as they do it so you can point out what you want done (looking away from the mig welder when the welding is being performed, of course).

    For a G body Regal, a full dual exhaust 2" or 2 1/4" aluminized 14 gauge system starts at $250 for typical 2 turbos+system and goes up from there depending on the type of mufflers you want to use. This includes using the original transmission crossmember which requires the system to be brought over to the right (where the catalytic converter goes/went), and back over to go on either side of the drive shaft, which is much more involved than your standard dual hump crossmember.

    This type of arrangement provides an ideal circumstance where a scavenger "Y" pipe or universal "X" pipe could be used, or even a 2-in-2-out catalytic converter to keep it legal (using this car as an example).

    The floor pan is even recessed a bit upward to accommodate the dimensions of the cat in that area, as well as a heat shield (of course).

    The G body cars provide a myriad of muffler locations to choose from: one could put a 2-in-2-out straight through (or "X" pipe inside) magnaflow in place of the cat, there's room for two mufflers before the axle, and then there's space between the axle and gas tank for a transverse muffler (which is where most put the mufflers, including the 2-in-2-out transverse Grand National 2 1/4" pipe muffler), or any combination of the above.

    The G body will also accommodate pretty much any engine and transmission combination (including aftermarket dual hump crossmembers for use with headers), as well as better rear ends for more power, and have the Grand National suspension components among other upgrades to transform your generic G body car into a relatively inexpensive street machine, and are still relatively plentiful.

    There are also pre-fabbed 3" and 2 1/2" mandrel systems available for them.

    Using this as an example, one could use any sort of powerplant or combination to achieve a desired and satisfactory outcome, if they liked that bodystyle.

    The cars came in a variety of styles too, such as station wagon, El Camino style (which uses the wagon frame and rear bumper, among other things), as well as the sedans and coupes, including the SS Monte Carlo, 4-4-2 Oldsmobile, and Buick Grand National or T-Type cars.

    Making parts for this G body style (from 1978-1987), which would fit a pretty large market, which includes pretty much all GM cars (not just Buick), would be a wise investment.

    Many already have.

  25. #125
    Join Date
    Jan 2013
    Location
    Clarksville, TN
    Posts
    2,138

    Default Re: Loss of torque with larger exhaust myth

    Quote Originally Posted by sean Buick 76 View Post
    A good article about header designs... They pretty much sum it up when they say something to the effect of: "although THIS engine liked a certain header design better not all engines will".

    http://www.hotrod.com/articles/ctrp-...ader-dyno-test

    As I showed the pic of the tri Y header design on my car it certainly is a good idea that Mark designed into the build and with such a tight limitation on that one side of the car.

    Factors such as cost, reliability, performance, and difficulty to build all come into play but the very best performing parts may not be ideal over the long term for reliability.

    All good points, Sean!

 

 
Page 5 of 7 FirstFirst 1234567 LastLast

Similar Threads

  1. Myth or Reality, low backpressure=low torque
    By whamo in forum The Bench
    Replies: 33
    Last Post: 04-20-2013, 11:56 PM
  2. Warped Rotors myth
    By whamo in forum The whoa and the sway.
    Replies: 4
    Last Post: 04-01-2010, 10:59 PM
  3. Near zero loss exhaust system?
    By Vern in forum The Bench
    Replies: 6
    Last Post: 05-26-2005, 08:55 AM
  4. Larger exhaust what tips? Olds 442
    By Olds-BMX Geek in forum The "Other" Bench
    Replies: 2
    Last Post: 05-18-2005, 03:04 PM
  5. Exhaust: Only 6 HP loss over open hdrs
    By gotbuick in forum The Bench
    Replies: 4
    Last Post: 10-06-2003, 08:07 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Back to top