mar3

iTrader: (8)

Carl! C'mon! There's an explosion and then there's a controlled burn....the two are an apples and oranges comparison! How many times have you heard of a C4 explosion suffering lossed efficiencies from detonation? That is, the explosion being started from somewhere else besides the primary ignition source? It doesn't happen because that C4 event is a real explosion...an almost all-at-once uncontrolled consumption of the fuel source. What happens in a combustion chamber is a controlled burn that is heating the air ingested to provide the mechanical push to turn the rotor. IT IS NOT AN EXPLOSION OF ANY KIND. The comparison is only vaguely useful...

lovintha7

Actually it is an explosion. And they are both controlled explosions. You only use what you need. He's not gonna use 5lbs of C4 to take out an ant hill, nor you're not going to use a 1/4 gallon of gas, and 400 cu. ft. of air to run your engine. Your carb, or FI is made to mix the gas at or close to a 14.7:1 ratio, or stoich. Controlled. If you've seen the high speed heat cameras inside piston engines (yes, the same **** happens inside those and rotaries) the result of the air/fuel mixture and spark is a quite violent explosion in itself. It has to be, there's no other way to turn that rotor, or push that piston around, or down without quite a bit of force behind it.

Rx7carl

Glad to see you back Mario! Where have you been?

I was more referring to his first paragraph in that post. Most of the ign products on the market dont do ****, you know that. Like plug wires with capacitors in them

purple82

Isn't this the same guy selling the useless little inserts for secondary port sleeves at $50 each?

purple82

Not entirely true, engines experience misfires all of the time where the mixture isn't ignited either because of reasons of flow or local mixture. A higher energy spark is more likely to start a flame kernel because of an increased introduction of energy. To start the flame kernel, the mixture must first have an introduction of energy at least as high as the activation energy.

Jeff20B

iTrader: (13)

kettleman, I remember when you mentioned to me that you had gone and done an ignition mod on your '80 (at the BBQ last month), but I don't remembr you saying if it made any difference in engine power. Your dyno test shows that it didn't make a difference on your engine.

Does your engine start up faster than before? How is the idle quality? Mileage? Emissions (can you walk behind your car when it's running and not have smelly clothes for hours)?

Siraniko

iTrader: (13)

its suppose to run rich...my co-workers love my new cologne "smell of unburnt gas"

Elysian

useless? useless that nets 4-5hp? i think thats worth 49 bux for 2 inserts.

Jeff20B

iTrader: (13)

I used to always were that cologne untill I upgraded the ignition. Three years of the same cologne was getting really old. Besides, cologne is supposed to help attract people to you, most of the time.

I'd try the inserts if I was into 6 port engines.

kettlman

iTrader: (2)

i've gotta answer no to those queations. my engine is just a year old and starts up every time unless i flood it or the started screws up. the idle has not changed at all, i switched it while hooked up to the dyno. there were no changes in idle at all on the car or on the machine. when you'r running a holley 600 with 65 primary jets and a #10 plate in the secondaries. not much can change the mileage...... and emissions? well, i wouldn't stand behind my car for very long. ha ha ha.

Blake

Talking out of your ***, apparently. The reality is that explosives are *extremely* controlled burns, and are spec'd in feet per minute burn rates. Sure, it's about 20,000 feet per minute for det cord, but we still had to tie the knots to suit the direction of the burn. Anyway, this was just an example of a similar primary/secondary ignition system. It wasn't meant to prove anything but, rather, illustrate a rather well-known relationship between ignition and burn. Both require a primary ignition source and, once that has caused ignition, the secondary "charge" is entirely responsible for the "work".

Think of it like this: If you build a very tall tower of bricks that is very finely balanced, then you push it over with your finger, your finger is NOT responsible for anything but initiating the release of potential energy stored by the construction. Arguing that a stronger finger will cause it to fall faster or land harder is ludicrous. Same thing with initiating combustion with a spark! The results of the burn are *entirely* the result of the potential energy of the secondary charge being converted to kinetic energy.

Again, as long as the combustable mixture lights reliably, there are no ignition improvements other that the precision of timing. Certainly, combustion can sometimes be incomplete and a second ignition can be benefitial, but we're talking *way* after the initial burn has been completed; a totally new combustion event. It won't add any usefull power, though. More spark energy may be required in certain situations to reliably ignite a combustible mixture, but unless you have the problem there is no need to "solve" it. Mazda's OEM ignition systems are very, very good, so there is no need to fix what isn't broken in 99% of the cases. I ran a peripheral port 13B with Weber 51IDA up to 11,000 rpm on the dyno using the stock distributor and experienced no ignition problems, so I find it hard to believe that any NA owner would have problems unrelated to simple maintenance.

bouis

As someone else said, I think that's missing the point of a direct fire ignition, with the wasted spark and the MSD "multiple spark" that I think only applies to the first 1500 or 2000 rpm on a rotary.

*Peak* power might not be improved, but idling, cold starting, and resistance to misfires is. I wouldn't be surprised if *average* power was up a few percent, especially if you could measure it from idle on up.

purple82

Proof? I don't want to go off topic of this thread too much, but we've covered these little things before and there is no flow benefit to them.

Blake

Nice attempt to hit below the belt. It really shows your true colors that you would try to assasinate the character of a respected vendor to discredit my well-founded statements. I suppose you mean "useless" in some other context than performance, where they are proven to have benefits.

Put down the book and show me all these misfires. Most people doing ignition upgrades are not having the problem you describe! I, personally, have run some very extreme setups (PP13B to 11,000rpm, etc.) using stock ingition systems without any problems whatsoever. And, again, everything I said clearly stated that once you get reliable ignition, there are no further gains to be had...I never said that there were no instances where a stock ignition was inadequate, just that the situations are rare and that a "hotter" spark than necessary wouldn't make more power. The best you can hope for is to find power you were losing; not gains something that was never there.

purple82

I got my masters degree studying engines at the University of Wisconsin Small Engine Laboratory. I've run a few experiments myself.

Blake

Oh, really? I would be interested to hear how you came to that conclusion. Also, how do you account for the very real improvements in quarter mile trap speed (indicative of HP) and power indicated on dyno sheets. No, I don't have them in front of me, but I've seen them personally.

Even just on a logical standpoint of evaluation, how can you even imagine there are no flow benefits to radiusing the port ends? What basis in theory do you have that contradicts everything known to me about fluid dynamics; that turning a column of air efficiently requires a consistent cross-section. And, what about fuel droplets, heavier than the air molecules, which have a hard time changing direction? Certainly, you can see the benefit of placing a wall against which they must turn with the airflow?

I don't know what you have against Pineapple Racing, but why try to invent issues. If you have a legitimate beef, at least stick to the facts and not get "creative" in your character assasination attempts.

Blake

Well, that's just great. Show me all these misfires on rotary engines and where ignition upgrades resulted in more power. Certainly, there are a few cases in very extreme setups, but the vast majority of rotary owners have no need to upgrade. Once the fuse is "lit", there is nothing more for the igntion to do. Do you dissagree?

Jeff20B

iTrader: (13)

I've never encountered a DLIDFIS install that didn't improve at least one aspect of the engine's runability. This is a first for me.

As for improving only one or possibly two aspects, neither of which include engine power, I recently hooked up DLIDFIS with two GM HEI ignitors on my friend's 7" supercharged '77 REPU. The engine is on its way out (bad seals in an S4 6 port, which will be replaced by an S5 T2 in a month). Anyway, the idle was choppy before and didn't improve after the upgrade. We don't think the power was improved since the Holley carb always seems to be mistuned and runs pretty rough most of the time. The '86 clutch fan is starting to suck more and more power and wearing the black anodized coating from the Atkins serpentine waterpump pulley (it screaches pretty badly under acceleration, and the belt is properly tensioned). The engine's side and oil seals are not sealing as they should which is evidenced by all the exhaust and oil spray that can be seen flowing from the breather line hooked to the oil filler tube. It sounds a little bit like it's got late leading sparks, but it runs so poorly/choppy that it's hard to notice it unless directly compared to his 5" supercharged '81 which still has a stock FB ignition system and a healthy engine. The exhaust smell (cologne) has diminished some, which is good.

In other words, it's a tired engine and we didn't feel a difference after DLIDFIS was installed. However, there is one point of interest that I hadn't even noticed untill my friend pointed it out to me. He's got a Camden air fuel mixture guage which consists of LEDs ranging from lean to rich and runs off of an O2 sensor. It used to always fluctuate around the rich ride of stoich. After DLIDFIS, only one LED is lit and I think it was either the 14.7 one, or the one just one tick to the rich side (I'll have to ask him which LED it is). Heh, he even questioned if I had accidentally unhooked it or something because it had never been that rock-solid before. Anyway, if nothing else, DLIDFIS has vastly improved the burning of the fuel, and I thought superchargers were supposed to cover for mistuned carbs lol! I can't wait to see how the freshly rebuilt S5 and a good clutch fan will work in that truck. He might even bring it the next BBQ.

purple82

https://www.rx7club.com/showthread.p...ight=pineapple

https://www.rx7club.com/showthread.p...&highlight=yaw

I don't have anything against Pineapple Racing. I've never dealt with them at all. It's just that the sleeve inserts don't do anything.

purple82

It's lighting the fuse that the more powerful ignition does more reliably.

Blake

And, as I said a dozen times, once you have reliable ignition, that's all you need. The stock systems are very, very reliable so "upgrades" are pointless in those instances where you are not having misfires. All I'm saying (again) is that you shouldn't waste time and money fixing what's usually not broken. If you experience a problem, worry about it then; not sooner. Anyway, the upgrades like direct fire and wasted spark do little or nothing to increase spark energy. Ignition boxes may do so, but capacitive discarge has proven no better than inductive discharge...perhaps because the ignition is already past the threshhold of being reliable. About the one thing that I can see benefit to (again, presuming you are actually experiencing misfires) are better coils. More energy and faster rise times are the way I'd go if facing an ignition misfire traced to inadequate spark energy.

I've played around with all sorts of ignition setups and never found any objective improvements. Money wasted, but at least it's educational, so I don't begrudge anyone wanting to experiment. However, very little is new under the sun and it might just be better to stop reinventing square wheels and move on to more promising frontiers of the performance envelope. Just my opinion.

Blake

All those threads show is that you are the lone voice making this claim and trying to convince people by flashing your degree in front of them. I've seen dyno sheets. I've seen 1/4 mile time slips with higher MPH. You're just bashing the product on a *theory* that they *shouldn't* work; not evidence that they don't. When theory and practice conflict, it's the theory that must be thrown out. You're like the engineer who tried to convince me Evans NPG coolant couldn't possibly work. Sure it has higher specific heat and falls short of plain water in many other ways, but it happens to work better because, unlike water or EG/W, it doesn't boil into a vapor insulation on hot spots. The real world triumphs over theory...again.

If you're an engineer, I bet you are a very young engineer...just knowlegable enough to be dangerous. How old are you? When did you graduate? What are your rotary engine porting credentials?

Elysian

i'm gonna be getting them when i can afford them(no job still)

rjerrells

Actually, I think you are all right.

If you expose more of the mixture molecules to instantaneous spark, complete combustion should, in theory, happen faster, and hence more potential energy is converted in a shoter time window. But I would expect that if the timing was left alone after upgrading the ignition system to do this, that no gain would be seen at all, hence the dyno results. Was the timing adjusted between the swap? Upgrading the ignition system shouldn't add anything unless, like everything else on engines, tuning is done to optimize it. And at higher RPM's where the time windows are smaller, I think it could be of SOME benefit if you know what you are doing with tuning.

As far as the brick wall analogy, if F=MA, I think a bigger finger (or other larger appenage of choice) would get it moving on it's own a little quicker.

I think that any potential gains would not be worth the $$$ for the average 7 owner, however.

R

Rx7carl

As a man of science I would have thought you would be more curious. BTW sorry for the hijack. I read your response in the thread and Yaws quote. Tell me, at what depression was he flowing them at? That makes all the difference trust me. I have many hours on my flowbench and truth is he may be right, or maybe not. I'll agree with you on one point and disagree with Blake (sorry dude). While Blakes theory holds water in a technical sense, air doesnt always flow like we think it should, and some really bad looking stuff aero wise outflows what "should" work. Unfortunately, subsonic aerodynamics research seems to have gone the way of the dinosaour. Pitty, we could learn much more with our current technology.

Also a dry flow test doesnt take into account all the other factors in effect in such a dynamic environment, so just because Yaw says they dont work, doesnt make it so. Dyno sheets and time slips will tell you more about a combo that works then anything else.

Now you can both hate and flame me.