No hating or flaming at all. Discussion is the source of good ideas. The only way to find the truth is to be skeptical and prove out the theory. There's nothing wrong with heated discussion as long as it doesn't get personal as blake is starting to do, unfortunately. I mention my degree for credibility and background. You've done the same many times blake. By the way, I'm 31 and have been working in ballistics and thermal solutions for 7 years. I can direct you to my SAE papers and thesis if you'd like to PM me.

I've asked a number of times and no one has shown a dyno sheet or acceleration improvement to me. That's all I'm looking for. I've done flow simulation out of curiosity and Yaw did experiments and neither shows flow improvement. Prove me wrong and I'll accept it.

In the link you posted, you state that the water going around the inside of a riverbend (as an example of air going around a 90 degree bend - not accurately analogous) is high pressure, but you also to claim it's faster than the water going around the outside. You use the example of cars going around a bend, and how the inside one, covering less ground, goes 'faster' according to you because it emerges from the turn first.

The car example is flawed, as two cars going the same speed through such a bend would demonstrate that result. The car going around the outside covers a greater distance than the one on the inside - that is why the inside car emerges first. Furthermore, the car example fails to take into account that, in a river bend, water can only go as fast as the water in front of it. The water on the outside, covering a greater distance, has water getting out of its way faster than water on the inside, allowing increased velocity.

Just as your example is flawed, so are your statements about fluid dynamics. While you assert that water going around the inside moves faster and has a higher pressure, Daniel Bernoulli, who's work has been widely accepted by the scientific community for a few years longer than you've had your degree, tells us these cannot both be true.

If what you postulated was true, carburetors wouldn't work. Higher speed fluid results in a pressure drop, not increase.

From my experiences with fluid dynamics I say you're right about the pressure, wrong about the velocity. Since you've a master's and I have but a humble engineering degree I'll bring in a chart of velocity vectors modeled from data from river meander research by J.F. Friedkin, 1945, at the US Army Engineer Waterways Experiment Station, to back up my assertation:

http://www.ntnu.no/~nilsol/cases/meander/vec2.jpg

Notice the velocity is greater at the outside, not inside, of the bend. (green = riverbed velocity, black=surface). If velocity is greater at the outside of the bend, your claim that water moves faster around the inside is incorrect. If you can be wrong about basic waterflow dynamics, is it not possible that you are also wrong about your presumptions concerning Pineapple's racing sleeves?

:rolleyes: The combustion event in an internal combustion engine is no more an explosion than a wildfire running up the mountainside is a "controlled explosion." Except for the fuel source, they are exactly the same kind of physical process. How can you call a wildfire an explosion? That's why you can't characterize the controlled burn in a rotary or piston engine an explosion...

Carl, this 6 month old baby has turned out to be a high maintenance girl already...between wiffey's crazy hours at Sears and juggling the 4 year old boy, I can't even work on my cars except to keep them going...:(...realizing how things are going, I've sold the white '68 Pro-Street Firebird to a close friend and also dumped the '84 GS that was my main ride so I could finish Furious the way I wanted to. Now, all that's hit the bricks, even finding an hour or two to play on the 'Net has become a rarity....I drop in just to see what's going on, but I can't even process my pics and post to update my own little thread buried deep in this corner...the only thing that keeps me sane is thought that I could have been living in Florida....:cool:

I'm not trying to get personal, but you *are* attacking my credibility. I have told you that I have personally seen proof positive of the benefits of the inserts. You are calling me a liar and basing this conclusion entirely on your apparently tenuous grasp of the subject...a theory that does NOT reflect reality. I could understand if you were simply skeptical and reserving judgement but, instead, you have stated flatly that they do not work...an accusation I find unacceptable from a professional who should know better than to jump to conclusions with no practical experience to back up the theory. You have crossed the line from skepticism to condemnation, which should shift the burden of proof to you.

Did you asked Pineapple Racing for proof before launching off on your condemnation of the product? What you are saying -- particularly because of your apparent professional expertise -- is, to my mind, defamation. Rob lives and dies by his reputation and chickenshit accusations by someone claiming expertise can harm his business.

BTW, I sure hope you are not trying to use a flowbench on rotary engine ports! That is a dead end, as the dynamics are totally different than anything you could possibly simulate. Rob has a flowbench, which he uses for piston engine heads and manifolds, but he and just about everybody else who've been in the field for 20+ years concluded long ago that they are next to useless for determining port flow on rotary engines. The proof is in years and years of trial and error; stacks of timeslips, dynocharts, laptimes, etc. Again, when the theory and reality conflict, the *theory* must be discarded. Rob has 20+ years experience and a thriving business built upon his reputation; you have a degree and no experience. Even if I hadn't seen the proof, I'd side with him *every* time.

i've met rob, i've also talked to him over the phone many times, and i would also side with him over most anyone. he's one hell of a smart guy, and not just about rotary engines, about everything... if there were such thing as a know it all, rob would be it lol

I never said they flowed better because they looked pretty. I concluded they flow better because of the timeslips and dyno charts I've seen. In this case elegance and function just went hand in hand. I have also done something similar, myself, with Teflon (no sleeves) and the performance was incredible...I just didn't have back-to-back testing to confirm the results objectively (this was a port/rebuild job and the Teflon was not removable).

http://rx-sevenandahalf.com/misc/por...flonshaped.jpg

I have the Pineapple sleeve inserts in my Rotary Truck, but that project has been delayed by further development of my "RX-7.5" trailer and work on my Porsche 914-RE with the RENESIS.

http://rx-sevenandahalf.com/misc/RETransaxle.jpg

Oh, BTW, if there is no benefit, why did Mazda start radiusing the ends of the auxiliary sleeves starting with the new RENESIS 13B?

Purple82 I was kidding about the hating part. :D



Damn Blake, your a busy guy! That 914 is gonna be a badass car I bet. You mistook what I was saying though. All I am saying is that what looks like a good flowing piece aerowise isint always the best flowing in reality. It was just a general statement of fact, not an opinion about the sleeves.

And my trial and error work on the flowbench is inching forward and giving me a much better understanding about internal airflow of the rotary. ;)

to add to the airflow debate - it's long been thought that a smooth wing resulted in better laminar flow. However one aerodynamicist noticed the bumps on the leading edges of humpback whale fins, and incorporated them into wing design. His experiments this year are giving us new understanding on how to direct a compressible, like air, along a desired path.

Wind tunnel tests of scale-model humpback whale flippers have revealed that the scalloped, bumpy flipper is a more efficient wing design than is currently used by the aeronautics industry on airplanes. The tests show that bump-ridged flippers do not stall as quickly and produce more lift and less drag than comparably sized sleek flippers...
...As whales move through the water, the tubercles disrupt the line of pressure against the leading edge of the flippers. The row of tubercles sheers the flow of water and redirects it into the scalloped valley between each tubercle, causing swirling vortices that roll up and over the flipper to actually enhance lift properties.

"The swirling vortices inject momentum into the flow," said Howle. "This injection of momentum keeps the flow attached to the upper surface of the wing and delays stall to higher wind angles."

looks like rob's shop in the background eh;)

I can take care of that for you, just send it to me :wave:

Manntis, first let me say that I appreciate your questions and the respectful manner in which you ask them.

I stated that the inside corner of the bend is high pressure, that's incorrect and mis-spoken on my part. I think I corrected that statement later in the thread. It's a low pressure, high velocity region.

You're right that this port isn't exactly analogous to flow around a bend since the port isn't a smooth inner bend. As the flow tries to turn, it will separate from the wall of the bend and shoot towards the back of the port, but the airstream will be inside the chamber by the time it reaches that distance.

My point, however, is that most of the dynamic energy of the flow is on the inside of the bend, decreasing as you go to the outside of the bend.

Here's why the car analogy isn't as flawed as you might think. Think of a stream of cars 10 wide and 10 deep all moving towards a corner. The cars behind can only go as fast as the cars in front as you mentioned, these are reffered to as streamlines in fluid dynamics. As the cars go around the corner, the insided cars are forced into their line by the outside cars. They can't cross over each other, so the inside cars are forced to accelerate faster than the outside cars, this is known as streaklines in fluid dymanics. The cars along the outside of the bend don't need to stay in the same row with the cars along the inside of the bend, and they don't.

I realize that is seems counter-intuitive, but if you think about it, it does make sense. I sent Rotarygod a link to a really good example of this but I can't find it anymore. Maybe he'll read this and post it. Hopefully you can see that this isn't flawed anymore. If not, I'll try to find some info on the web for you (guys)

The bernoulli principle states that as velocity goes up, static pressure goes down and stagnation pressure remains constant for an incompressible fluid flow. The inside corner is low pressure/high velocity, the outside is high pressure/low velocity. In the bulk flow, wall effects neglected.

Yup

Ahh, you are looking at flow separation from the sides of the stream. In some cases, the bulk flow has enough energy that it will "separate" or pull away from the inner wall of the bend. That's what's going on in this picture. The resolution of the arrows to too small to see what's going on in the bulk flow.

I'm sure separation is going on in the ports as well, but like I said in the other threads, the flow sets up a high pressure zone in the outside corner of the port and will flow around it anyway. I love talking about this stuff so ask more questions! I'm a geek.

That's convenient.

This is due to a boundary layer phenomina. A laminar flow boundary layer has more drag than turbulent. Laminar flows can be "tripped" into turbulence to reduce drag without really effecting lift. Also, laminar boundary layers can be unstable and go back and forth to turbulent unpredictably, leading to strange disruptions in the bulk flow.

High pressure/low velocity vs. low pressure/high velocity, is not the net energy at any point of the bend the same?

Exactly. We use boundary layer destroyers on commercial jet wing surfaces. Look out the window next time, youll see little fins on the top surface on many aircraft. Actually they are also used in other places on an aircraft where they want to keep the boundary layer thin or nonexistant as possible. I wish I was a geek. I have to learn all this stuff the hard way, and thats always slower.

Actually, no. What is going on in the picture is exactly what the author said was going on in the picture - the velocity on the outside of the bend is greater than the velocity on the inside. I suggest you research the report I cited.

Makes sense to me. It has less restriction to its flowpath (longer radius). The inner side would have a harder time negotiating the sharp turn and would be forced to slow down since it cant muscle in on the water thats occupying the outer portion of the bend. Go stand in a stream and you can feel this effect.

I've been fishing enough times to know that the speed of the water (at least at the surface) isn't always faster or slower on the inside or outside of a bend; it depends on a lot of factors.

man this topic has sure gone OFF TOPIC

Yeah, you said it. All this flow stuff is fascinating though. At least we now know that DLIDFIS isn't a myth. ;) It may not add power to an engine that already has an adequate intake/ignition system, but it does help in other ways.

I spoke with my friend this evening who owns the '77 REPU. His air fuel meter does indeed run one LED to the rich side of 14.7 where before it would fluctuate up to three LEDs all the time. It's now a steady 14.0 or whatever that LED represents. He's happy. :)

We can't wait to see how the S5 T2 engine will run.

Sorry about being so far off topic. It's my fault.

Manntis, I will go to read the study that you're citing. In the meantime, I ran a quick simulation to show you what I'm talking about.

These screen shots show the speed increase of the flow at the inner sides of the bends. The pressures are also highest at the outer sides of the bends.

interesting... could you do one where you had a radius'd top part? instead of the 90 degree bend?

*whistles* Man, this turned into a port flow discussion. I think I'm going to stay out of that... though I've done a lot of research on CFD models of flows in rotary engines and think I have a pretty good grasp on things... but really I think the argument's being well handled by people with far better resumes than I. ;)

About the ignition though. We moved up to an MSD box firing dual lead coils a year or so back on the race car. I sincerely doubt it made any more power. What it did though is vastly improve cold starting, especially with the cold race plugs (which we previously had to swap in after it was warmed up as it absolutely would not start on them). It starts right away every time, no matter the temperature or anything else whereas previously with the stock system and all new components, cold starting was... iffy. It starts it hot, it starts it cold, it starts it when one rotor is completely blown and the other only has 40psi of compression (albeit, lap times sucked... as you might imagine).

For this reason, I like the upgraded ignition and think it worth the money even if it doesn't have any performance benefits whatsoever.

Yet another good reason for the DLIDFIS set-up if you're running nitrous on the street...now you don't have to change plugs for a 100 shot...anytime you can save an engine, that upgrade is worth its weight in gold and well worth the effort and expense when you start going after serious performance modifications.:cool:

I never had a problem starting a Peripheral Port 13B with Weber 51IDA, stock distributor ignition and 11.5 race plugs, even stone cold. I can't imagine a harder setup to start. Most rotaries will fire right up with only the trailing ignition! How did I learn that? My MSD died and the car still ran great, lacking only a bit of "oomph" and throttle response. Bypassed the MSD and the problem was solved. Even when it was working, I never noticed all these great benefits being touted here. It started the same, idled the same, accelerated the same. The only difference was that it proved unreliable. If any of you really want to objectively tell if there is a qualitative difference, teach a friend how to bypass the box (or whatever system you are using) and have them randomly connect and disconnect it without telling you...a blind "taste test", if you will. Also, be sure your stock setup is operating at 100% (new cap and rotor, new plugs, good condition plug wires, etc). A healthy stock setup is pretty damn good, IMO. If you don't have friends, as I suspect some of you do not (just kidding! ;) ), run with the MSD or whatever, then disconnect it for a day. The butt dyno is easily fooled when "upgrading"; not so much when "downgrading".

Funny upgrade story: back when I invested serious money into my custom cold air intake setup for my 2nd gen GTU-S (bonez filter, custom fiberglass box, KSP fresh air headlight cover, gutted FTP lens, etc) I swore it was waaaay faster. Seriously, I was gung ho over cold air. Once, I was being tailgated by a real asshole while trapped behind a very slow car on a two-lane (one each direction) somewhat curvy road with few passing zones and lots of oncoming traffic. When I finally got my opportunity, I blasted around the slow car and ran full out, redlining every gear including fourth briefly. Several minutes later, the asshole finally caught up after I got caught in more traffic. Redline in 4th gear was 138 mph! Wow, that seemed amazing performance, particularly because the road was not completely straight and level. Proof that the cold air system worked. Not really...a week later, I noticed my clutch slipping in 5th, then 4th, then 3rd. Yes, I redlined 4th gear, but the car was not going anywhere near 138mph even though in the excitement it felt as if it were. Under the conditions, I was not watching the speedo; just the more important tachometer. D'oh! I changed the clutch and dynoed the car at exactly 1hp above my previous run without the cold air setup. Of course, a cold air setup won't give you all the benefits on a dyno run, but having reverted back for the sake of testing on the street, the performance drop was negligible. The lesson: butt dynos SUCK! As enthusiasts, we are so biased about our "upgrades" that we will notice a beneficial change for just about any mod. BTW, that clutch was the best upgrade I *ever* made! Just a RB street/strip unit and initially I was not very impressed (probably because I was still adjusting to the heavier pedal), but after driving it daily for a while, I drove another 2nd gen with a brand new stock clutch and was SHOCKED how sloppy the engagement was.

Mods are fun, even if not totally worthwhile in terms of cost/benefit. If nothing else, we learn more about our cars and sacrifice some knuckle-blood to the rotor gods -- their favorite kind. But the least we can do is pass on our experiences so that others can make an honest decision if they want to walk the same path. I'm not trying to discourage anybody; just offer information. Make your own decisions. What I have a problem with are people who take "faith" in mods and treat those with dissimilar experiences as heretics. Notice I said "experiences". I have no love for theoreticians, as you may have noticed. :)

Anyway, no matter what gets said here, I'm just going to ignore the thread further and hope others do the same. If I ever run into Purple82, I'll buy him a beer and Im sure we can manage to have a rational, friendly discussion even if we continue to disagree. Same offer to Mar3. The internet seems to turn things into pissing matches when there is even slight disagreement. Most people I have arguments with on the internet turn out to be really nice people in real life and our positions are not so far off as we imagined.

Sounds good to me.

Well you're Jesus to Rob's God-like rotary prowess, so shut-a you face! lol :)

A friend and I tore down a rotten pineapple recently which has B11EGVs in it and a stock dizzy etc. I bet its previous owner learned how to start it 'correctly' with those plugs.

Oh, and Blake, no amount of ignition mod bashing coming from you will ever make me think twice about how cool the FC-like sound of DLIDFIS is.

Joking aside, DLIDFIS can pay for itself quickly due to no longer having to buy a new set of caps and rotors every now and then. I don't know if it's the wet weather up in the Pacific NW or what, but typical aluminum contacts inside the cap tend to corrode quickly up here. If you tell me to go out and buy a more expensive cap with brass contacts, well, I was the original poor man in the Poor Man's Direct Fire Ignition System which eventually became DLIDFIS, so you're wasting keystrokes. :) I haven't purchased a new cap and rotor set since '97 when I first hooked up an FB dizzy in my REPU. Wow, has it been that long?

I'll buy you a beer too, Jeff. And, since you're local, that might actually happen sooner rather than later. I'd like to hear that DLFDIBSTCDHW...er, what's it called again? ;) I've got nothing against direct fire and I suppose if you save money, that may make it worthwhile regardelss of performance. I've just never had a problem with the stock system, including needing to change the cap and rotor very frequently...but maybe that's just me. Ideally, I'd like to replace the whole deal with a CAS and microprocessor controlled programmable ignition, because timing is everything as far as I'm concerned. Too many projects, though! First, I have to finish my microprossesor controlled, datalogging and graphing DIY rotary engine compression checker...SHHHHH, it's a secret. :)

Well, cool... that's not my personal experience, LIS. And again, I don't claim to be any sort of guru with years of experience... it's just what I've found on my car in (yes) back to back tests. It's more than possible there's some other problem that the MSD box is masking (I wouldn't be surprised if the jets controlling low-rpm mixtures are off) but on my setup it seems to make a difference in starting.

Heh heh, this is damned true. At least on here it hasn't degenerated into people yelling expletives at each other... that happens irritatingly often on some other forums I frequent. ;)

I believe Portland is pretty wet too, right? Anyway, if you can imagine an FC with an R5 mild ported 13B with a dizzy which has the mechanical advance of a GSL-SE, and the particular make of Hitachi carb that come on the old R5s, that's what DLIDFIS sounds like on my REPU. The exhaust is kinda loud and unique-sounding as well, which makes for easier listening, if you're into that sort of thing.

Anyway, that late firing leading spark per rotor face is obviously doing something to change the engine's exhaust note from a putt-putt 1st gen-like sound to more of a smoother 2nd gen type of sound. The only way that's physically possible is that it's actually igniting more fuel than a stock FB ignition system can by itself. What does that mean to you and me? Less caps and rotors to buy as trailing can fire through a less than perfectly clean set of contacts without a loss in performance.

Speaking of controlling timing with a CAS and a microprocessor, I'm going to look into using MegaSquirt to control three ignition channels on the X outputs. This is mainly to provide the late leading sparks to my 20B that my modded dizzy can already provide (much more accurately of course), but it can also be used on a 12A or 13B I suppose. Since leading normally does 99% of the work (on a stock FB cap 'n rotor system), I won't lose sleep over not trying to develope a trailing ignition system. I'd rather focus my efforts on sparking the leading plugs twice per rotor face regardless of the number of rotors in the engine (one, two and three for example) as the benefits outway the loss of trailing sparking through those tiny stock holes. In other words, if I have a choice between running an unshrouded late leading spark vs a trailing spark to ignitie the squish zone, I'd pick the former every time. Butt dyno testing as well as real dyno testing influenced my descision.

This next part is total speculation, but I think the Pac Performance RX-3 had a late leading ignition system on its turbocharged 20B with powerglide tranny back in '00 or so. The exhaust note sounds kinda like my 20B when I was test firing it. All other 20Bs sound different. Of course they both had raspy exhaust notes too, due to very little muffling. :) I'll know more as soon as my engine is running. The exhaust system in 90% complete and shouldn't be too quiet. :D

I think I can better explain the phenomena than I did with the car analogy.

Typically, people with an understanding of physics look at fluid flows as solid body motions where a “wall” of water pushes it’s way along a channel. The wall must stay perpendicular to the channel, thus forcing the outer side of the fluid to move faster around a turn than the inside.

This view of fluid flow is incorrect, basically because it neglects the ability for the fluid particles to move relative to each other, and because it neglects the forces that particles of fluid can exert on each other.

As a fluid goes around a corner, the particles on the outer side of the corner of fluid press on the inner particles as they try to make their way around. The most inside particles are compressed between the inner surface and the next particles out. This creates a “squirting” effect of the particle, like pressing a wet pumpkin seed between your fingers. This is the shear force effect of the fluid particles on each other. This force is neglected by the bernoulli equation, incidently.

In the example that you cited, the shear force effect is much less pronounced because the force on the fluid on the inside of the bend is relieved by the separated water at the inside of the bend. It is known, however, that the flow around a corner that I described above is what causes a meandering river to meander further. The pressure difference between the inside and outside of the bend sets up a weak secondary flow in the water from the outside of the bend to the inside, causing the deposit of sand at the inside of the bend.

I ran a couple more simulations, trying to model the secondary ports geometry approximately. Although there are geometries that can SLIGHTLY improve flow by restricting the slight expansion/compression that can be caused by the corner flow, for the most part, adding anything to the inside of the port actually hurts the mass flow of air through the port. I can share some screen shots with you if you’re interested.

all or you guy dont know any thing

Ban hammer?

I had not actually read this whole thread until now. Blake,Jeff,Purple, all you guys owe me a beer for making my brain actually have to work to digest all of the technical data,lol.

I can say this though about the 2nd gen coil usage.

I was averaging 25.6 -26.5 combo city/highway driving with the 2nd gen coil and a max of 29.1 highway on my Se stock port with base mods.
I removed the coil and reinstalled the stock one. The mileage dumped down to 22.9. This was with a 100 mile run with only 8 miles of it intown driving.
No noticeable power increase but better starting and improved idle.
The question is. If I purchased a new stock coil and removed the 2nd gen coil, Would the mileage stay the same?
I don't know. However, a buddy of mine has one of the Jacobs Ultra coils that come with the ignition kits. The coil weighs about 5 lbs,lol.
I am thinking about running that coil and see if my mileage stays the same as the 2nd gen results have been.

Let us know if you run that experiment doctor! I was considering the upgrade on your previous post on the fuel economy improvements alone. But Blake's points bring up a question in my mind. Is the improvements observed with the 2nd gen coil upgrade thingy due to a better "spark" and "combustion" it provides, which inherently means the stock system was poorly designed or lacking by Mazda, OR is the improvement noticed due to a wornout/defective stock system that is just being restored to an adequate level by the upgrade?

As Blake says, if theory and reality conflict, throw out theory. In this case, a stronger spark should not make a difference once you have reached the threshhold of an adequate spark. MAny credible people have enjoyed the benefit of the dizzy setups, so there is something to this. So I guess the real question comes down to did Mazda create an adequtely "hot" spark in the first gens in the first place? It would seem to be a terrible oversite on Mazda's part if this is the case. Particularly since this affects the reason the US model first gens were not as powerful as the JDM version: emmissons and fuel economy.

Here is one part that I cant understand though. How can this setup at the same time burn the same about of fuel better, thus creating more energy for the same amount of fuel, which would account for better gas mileage, but NOT create more HP, which is a measure of energy, at any given range? As has been expressed, the improvements seem to be confined to idling, starting, and low rpms, so maybe the stock system is flawed at the bottom end and more than adequate at the top end? BUT this would even be more of a glaring oversight of MAZDA!!!!!!!

I LOVE THESE THOUGHT EXPERIMENTS!!! Not on either side of the argument just yet for the record. But my cheap ass would love to find out it really does add a few MPGs!!!!!!!!!!!

I reread most of this thread. Skipping over the arguments helped get through it quickly. :)

The S5 T2 still runs. It turns out the reason why the idle didn't improve on the old S4 6 port engine after the DLIDFIS install is because I goofed on the W and G wires (my first time with HEI and I didn't move the distributor so no need to check it with a light and all that...). The S5 engine ran the same when it was first fired up so I checked the timing and sure enough. It was off. A simple change in pickup polarity and it idles nice and smooth. :)

It wouldn't have helped the S4 NA engine though. That thing has bad internals. It was a shoddy rebuild from a garage specialising in asian cars. We'll tear it down eventually to see just how bad it is. Looking through the exhaust ports, you can see missing chrome. Suspect bad side seals too.

Since this thread was written, I've succesfully modded the MegaSquirt to output a late leading trigger signal to three J-109 ignitors and Diamond coils (thanks James for the code tweak). I could eventually upgrade to GM HEI or FC stuff if the J-109s prove to be too weak for boost. For now though, it's staying NA because it is an early engine and I don't want to break it.

As for the engine sound, it sounded a lot smoother with a full exhaust system, but still had that nice 20B exhaust note. The late leading sparks did make it sound a little different from most 20Bs I've heard, but not enough to notice unless you really listen. But who can resist. :) 20Bs always sound good.

The exhaust system was too small and too quiet for me. The next system will consist of 2.5" pipe (just right for high velocity and three rotors) and two Borlas. We all know now that Borla mufflers suit rotary exhaust characteristics very well, and last longer than Magnaflow. Racing Beat components cost more, last forever etc, but since this is all kind of untested, I don't want to spend very much on it. Plus if I go with a turbo I'll have to redo the whole system anyway.

I'm going to try late leading in the form of DLIDFIS on a 12A next. It currently is in an FB with stock ignition. It's not that bad, but it certainly doesn't fire up as quickly as the large ported R5 13B in the GLC with two GM HEIs on leading. To compare apples to apples, the 13B is coming out and the 12A is going in. A rather absurd way to test, yes, but I'm only interested in starting and idle quality, which makes the chassis part of the equation irrelevant. The 12A already flies at mid to high RPM in the FB, so I'm not worried about that, and the GLC is lighter and will have a better ignition system and exhaust, so I'm sure it will improve up there too. Big whoop. If it fires up quicker and idles smoother, I'll be a happy camper.

Jeff, nice descriptions, but we need pictures!!! And even better some sounds of that 20B!!! YOUTUBE!

Did you just call me a tube?


lol I know what you're talking about. I'll leave the video stuff up to PercentSevenC. I'm the audio guy. I have some audio clips of the 20B with the complete exhaust system around here somewhere.

Ok here are two clips from before the MegaSquirt. I got it running on a dizzy modded for late leading on a 3 rotor with a carb and just an open header. It revs quicker and sounds meaner than the Pac Performance RX-3. Teehee.

The mic is several feet away from the engine in this first clip. If you listen carefully you can actually hear the echo off the neighborhood at the end.

The second clip finds the mic 25 feet away from the engine, inside a garage with the door closed. Listen to how quiet the starter is now, yet how loud the engine still is. That's loud!

Note these are zipped MP3 files.

Here it is with the MS and the full exhaust.

The third clip is an oscilating idle because the MS is not tuned yet.

Fourth clip is firing up when partially warm.

Fifth clip is just a little driving away from the mic.

that purple fella was kinda a dick.

Yeah, man, what a jacka$$.

Was he behind me that entire time?

^ don't you hate it when that happens,lol.

.

Why the fudge did you bump this? If anyone was wondering dlidfs showed no power gain since the links to the dyno sheets are dead.
http://www.blisshouse.com/images/Bri..._Your_Dead.jpg

Wow i actually sat down and took the time to read all of this. It's quite a good read actually.

Blake and I often didn't see eye to eye, but I enjoyed going back and forth with him. RIP man.

Wow I read a 4yr old thread.