Sat, 19 May 2012 04:53:15 +0000 1800 Hyundai Aftermarket.orgTutorials RSS Read more]]]> Being that this is an enthusiast and modifying community, we are more geared towards more power and are willing to accept the increase in NVH and decrease in longevity. But we should still be aware of what those things are and how the aftermarket parts affect our car as some of us still DD (daily drive) our cars and others have strictly track cars.

[B]Flywheels:[/B]

First, the purpose of the FW (flywheel) is to take the jerky up and down combustion events with limited power in them and give the crank shaft some momentum to help pull the crank around and have less up and down motion on it.

DMF’s are two FWs, conjoined with a spring, or rubber or numerous kinds of shock/energy absorbing properties. The one FW is attached to the crankshaft and the other FW is connected to the PP pressure plate, they aren’t rigidly attached. So when push the clutch pedal in and disengage it, both sections of the FWs are moving with the engine and the clutch plates are moving with the transmission, which if you are in a gear are moving with the wheels and if not in gear the clutches are slowing down or stopped. When you want to engage the clutch you usually release the clutch pedal out until you feel the clutch plate start to grip the FW and you slowly let feather it out. If you were to just release the pedal with no feathering the grip is somewhat instant and you have a fast moving engine FW and a different speed clutch trying to match the FW. This would put a ton of stress on your engine and transmission but your FW can absorb a lot of that as the crank FW has some give to it and the PP FW has some give to it and a bunch of stress that would go to your transmission and engine now get absorbed into the spring or whatever the DMF used. Though dumping the clutch is not does put a ton of stress on the DMF and can eventually break them. They still help to reduce NVH felt even when feathering the clutch as there is no rigid connection between the crank FW and the PP FW. They also are not made for very high rpm as the DMF is heavy and when you spin something heavy centrifugal force can tear it apart. They have been known to explode and go through the bell housing and into the cabin causing harm to the driver or passenger.
Here is a video showing how they work

[url=http://www.youtube.com/watch?v=YnaXB8q3uzQ]YouTube - 3D animation of dual mass flywheel[/url]

That is one reason the SMF’s are made. They are much lighter and can handle higher rpm and are less likely to separate at higher rpm due to them being a rigid piece of metal. They are also much cheaper to manufacture though some companies for other cars make after market DMF’s for those who want to run more power, but don’t want to sacrifice the NVH and longevity. Though you now have a rigid connection from the crank to the PP, just one solid piece of metal. So if you get too rough with the clutch pedal release you risk damaging or reducing the life of your transmission parts and possible the engine, though mainly the transmission and driveline.
Other than the safety aspect and the cheapness of SMF’s there is the weight loss aspect. The lower the mass of the FW the faster the engine will rev and you will lose less hp to the wheels with up to 30hp not lost being in 1st gear and slowly dwindling up 1hp in 5th gear. Though if you go too light the whole purpose of the FW is lost and you will have a rough very jerky engine with trouble idling and self sustaining. One way to get around the really light FW’s are is to raise the idle rpm so the combustion has more power to it require less momentum from the FW. Which again makes this less of a DD and more of a track car.

[B]Clutches:[/B]

The basics of how a clutch works, is it is a disk with friction on it (much like a brake pad) that is splined to the transmission input shaft and spins with the transmission. The FW and PP are bolted together and spin with the crank shaft. The PP pushes against the clutch disk to mate it to the FW so the clutch (and transmission) can spin the same speed as the engine. When you push the clutch pedal in, you are relieving the PP’s force on the clutch so the clutch is no longer pressed against the FW and the transmission and the engine are separate again so you can change gears.

A video demonstrating this
[url=http://www.youtube.com/watch?v=6BaECAbapRg&feature=related]YouTube - How Clutches Work[/url]

The formula for how much a clutch can hold is pretty simple:

(PP strength*Clutch disk area*Friction Coefficient)/Constant

Some companies actually use this formula to come up with a tq (torque) number, while others seem to use a percentage over holding tq when they describe their clutches.
We can change the PP strength. You could keep the same organic clutch let’s say it has a 1000lbs PP (remember you are hydraulically assisted and there is leverage) and your clutch slips at 300lb ft of tq. If you wanted to hold 600lb ft, you could just increase the PP force (to an extent) and all is good….. kind of. One issue will be your Popeye left leg you will need and/or develop and this can really suck in traffic. One way to get around the strength issue is to move the lever out further giving you more leverage, but then your clutch pedal travel will have to increase. Or let’s say, even if you are strong and this isn’t an issue, you are pushing hard against the FW and crank and can lead to premature crankshaft thrust bearings. So generally speaking, you don’t want to get a PP that is too strong, what is too strong is really up to you. But beware some companies try to brag about holding power, but really they are just using a really strong PP and that is why it doesn’t cost as much as the others.

What about clutch disk area is limited in diameter due to the bell housing. But we can increase this area another way, by added a clutch disk. There are twin disk clutches available or other cars even have triple disk clutches and some drag cars have multiple (as many as 5) disk clutches. Drag cars also have fingers with weights on them and slots that utilize centrifugal force to pull the weights out and add pressure to the clutch but this isn’t found of the average car. Usually multiple clutches will cost more but are really the best answer for increase tq holding capability. You have a floater that looks like a cog that goes between the PP and FW bolts and acts kind of like a FW so you can add another clutch to add friction. Chances are modifying your car to the current power levels wasn’t cheap, so why cheap out on a high PP that could cause damage to the engine you have just spend 3 times the money beefing up. Save yourself the hassle and spending the extra money up front on a multi disk clutch could save you a lot more money in the long run, and most likely make you car easier to drive, even in traffic and you could still have the holding tq needed.

Lastly we have the Friction, which also have their own trade-offs on holding power vs. ease of engagement, or how ‘grabby’ it is. The different types available are:

[I]“Organic (OEM on most cars): Metal-fiber woven into "organic" (actually CF amid with other materials). Known for smooth engagement, long life, broad operating temperature, and minimal-to-no break in period. Will take hard use, somewhat intolerant of repeated abuse (will overheat though). Will return to almost full operational condition if overheated. Material is dark brown or black with visible metal fibers.
[IMG]http://www.importedperformance.com/catalog/Advanced%20Race%20Technology%20Organic%20Clutch%20Disc%20SS%20Part%20Number%203000409.jpg [/IMG]

Kevlar: High-durability material more resistant to hard use. Engagement is similar to organic, but may glaze slightly in stop and go traffic, resulting in slippage until worn clean when used hard again. Higher temp range in general, but can be ruined from overheating; will not return to original characteristics if "cooked". Material is uniform yellow/green and may look slightly fuzzy when new.
[IMG] http://www.specialtauto.com/delorean-parts/images/kevlar-clutch-disk-2.jpg[/IMG]

Ceramic: Very high temperature material. Engagement is more abrupt. Will wear flywheel surface faster, especially in traffic situations. Due to it’s intrinsic properties, ceramic has a very high temperature range. Material is any of several light hues - gray, pink, brown.
[IMG] http://www.sjbmw.com/_images/parts/874_part.jpg[/IMG]

Carbon: Very high temperature material. Engagement is more abrupt. Will wear flywheel surface faster, especially in traffic situations. Slightly more durable and flywheel-friendly compared to other aggressive clutch materials. Material is black.”
[IMG]http://static.racingjunk.com/63/ui/6/30/21223306-772-ZOOM-105-CARBON-KEVLAR-CLUTCH-DISC-SO.jpg[/IMG]

Sintered Iron: Extremely high temperature material. Engagement is extremely harsh and is generally considered an “on/off switch” both due to it’s characteristics and the clutch types this material is generally associated with. It requires a special flywheel surface. Material is metallic gray in color.”
[IMG] http://www.proformancepros.com/PDGImages/CLUTCH-DISC.gif[/IMG]

[url=http://www.uucmotorwerks.com/CLUTCH/]SOURCE for clutch info[/url][/I]

As you can see from the descriptions above the trade-offs. Ceramic usually comes in Pucks (I have never seen a ceramic disk) and everything else usually comes in disks (though I have seen carbon pucks before. Sometimes you will find a mixture like a ceramic/sintered mix. Those slits you see in the sintered disk is usually where the centrifugal finger go that drag cars use.


[B]Clutch Disk/Pucks[/B]:

A Puck is basically like a brake pad, they are little pucks/squares of this friction material that actually touches the FW. The reason for pucks is basically they allow less weight. Where as a Kevlar clutch disk, the whole disk is Kevlar, the puck types the disk split into 3-6 even/balanced section (kind of like a fan blade) and the disk is just a cheap light material that doesn’t actually touch the FW, but the pucks or friction material does. They come in 3-6 pucks I have seen, and all the force on the PP is now concentrated to those small pucks and they grab much harsher than disks and are harder to feather. Also if your clutch and FW is really hot and engage, you can add un-even marks on the FW and cause chatter really bad much like a brake disk.
Picture of a 3 Puck
[IMG]http://www.kmodperformance.com/170_144_csupload_20008392.jpg?u=1367845252[/IMG]
6 Puck
[IMG]http://www.kmodperformance.com/170_158_csupload_20008079.jpg?u=761226489[/IMG]

[B]Sprung/Un-sprung:[/B]

You will sometimes see little springs on the center around the center of the clutch and these also help reduce the NVH. But they add weight, and those trying to get the lightest clutch possible (namely racers) use un-sprung clutches. Those springs that add weight are not on the clutch disk, but the clutch will tend to chatter a bit more and it can’t absorb any energy kind of like a mini-DMF and the transmission has to absorb all of that force. Racer who re-build their transmission all the time don’t have to worry about this, but the average DD would probably be better off with a spring clutch.
Picture of an Un-sprung and Sprung

[IMG]http://www.wallpaperinstaller.com/scooby/clutch.jpg[/IMG]

The basic break-in for a clutch is to just keep the rpm below 4,000 and don’t dump the clutch for the first 500-1000 miles. There is really no need to get a clutch that holds 800+hp if you only plan on making 300hp. All you are doing is screwing yourself, by possibly making your car harder to drive, and possibly wearing the transmission and driveline out faster. The point being, look at the above info and weigh you option, and buy what you need. No need to flex your manly-hood and buy a 4 times tq holding clutch.[/QUOTE]]]> Mon, 09 Jan 2012 22:04:38 +0000
A spark is a spark, not brand or design has anything to do with it.... For the most part.

Read more]]]>
A spark is a spark, not brand or design has anything to do with it.... For the most part.

A cheap ol' copper plug will be just as good as platinum or possibly iridium. I will explain and expand on this later. But, to clarify, it has nothing (directly) to do with the material used, rather the size/shape of the electrodes. The reason iridium is used is due to its great strength and high heat tolerance. Because it has such strength, it can have such a small tip and not break off under the high stress of combustion. So the small tip is what makes it work so well, while the material is what allows the tip to be so small without breaking.

Copper electrodes start square and have a 'tip' on the four corners and work almost as well as the Iridium. The problem with copper is it is so weak so micro particles break off and the corners get rounded and the gap increases. Platinum is harder than copper, which makes them last longer that copper. The corners won't wear as fast, and the gap won't increase so that is why they could be seen as slightly better. The actual spark occurring from them is no different than the copper and the performance is the same. Iridium is about 8 times harder than platinum and melts well over 2000°C (2466 °C/4471 °F)

Electricity arcs better the smaller the point, and iridium allows for a very small point. But iridium is more expensive than copper or platinum. The wider the gap, the longer and hotter it will burn and the fatter the spark. The smaller the gap, the shorter, smaller and less hot the spark.

The ideal thing to do is gap the plug as far as you can without blowout. If your spark gap is too wide, the combustion 'blows' out the spark, which is much more prevalent in F/I engines. So gapping a plug out of the engine and setting it to a point just before it no longer arcs is a bad idea. You will have blowout as soon as the first combustion happens and your engine will run poorly. If you use factory specs, you will be fine, though if you want to find the optimal gap, it will take some tuning/adjusting.

Basically just keep increasing your gap .0025” until you get misfire (at your highest boost level), then close it back by .005". They have aftermarket type devices that boost your spark voltage and have shown to keep a spark between .1” gap at 30 psi! Though something like that really isn't necessary for 99% of our applications and can add wear and tear to electronic parts and would require some beefing up in that area. But the wider the gap, the longer and hotter the spark will burn propagating the flame kernel and burning more fuel, more completely. You can only burn so efficiently, so if you are already at that point, a spark voltage booster or a wide gap won't do anything for you.

Having a spark gap too close will kill your performance. It won't be blown out, so some cheaper tuners who don't use a spark booster just close the gap (old school 'trick' apparently), but chances are they are killing their performance potential. They are turning up the boost and it is blowing out and misfiring, so they close the gap, they lose the misfire, and think they are all good form the higher boost. Though they probably are making more power from the added boost, they are making less than their full potential of power from the smaller gap. The smaller gap the less time the spark is available to burn and it isn't as hot so your fire kernel is potentially smaller and not burning as thoroughly robbing you of power and fuel efficiency.

The HMA spec for spark plugs is .0394”-.0433”. I checked mine and it was ~.028! I couldn't believe how narrow that is. This is why I think our Genesis Coupe tips are so black. Not from a rich mixture (as rumored), but from small gaps not burning it fully. As I was getting knock on my stock car so I know it wasn't rich (running 13:1 AFR at times when wide open throttle), but I still had black tips.

I have heard of 16%hp being gained from a proper gap. This is probably where certain companies boast about their horsepower gains from their plugs. They probably test a less than proper gap vs. a proper gapped plug (though they still stay in specs to be ‘fair’ and to be able to say “we used factory spec gaps”), but we just saw how gap spec can vary from 394 ten thousandths of an inch to 433 ten thousandths. It isn’t some crazy material or ‘special research’ or some voodoo magic that gets their spark plug gains, it is a proper gap. If you gap was so small that you would gain more than 16hp, you would be having misfires from the spark so small it couldn’t ignite the fuel at all. So if you go to a proper gap, you could gain 16%hp I could see, but anymore than that can't really be gained as your car wouldn't be running to measure the low efficiency dyno. 16% brings a stock car from 210hp to 243hp. But it is also possible (and very likely) they tested with a proper gap and your car is running as low as 176hp. Though we are talking the largest change you will most likely see.

Even though the gap on my car was very low, I don’t expect to see more than a ~5-7% gain as .028 is close compared to stock, it could be worse. There have been dyno’s testing wheel horsepower that have ranged from 175whp to 195whp and some of that is drive-train loss, but some of that could also be the cars having a crank horsepower of 190hp from the small gap you might have. Again to clarify it isn't really 'gained' as much as it is not being as lost. Basically putting back in the efficiency that you lost from an improper gap, and I am not guaranteeing you any gains, but the potential is there.

You do need to be more careful when gapping iridium and need to do it correctly. You must take extreme caution to NOT TOUCH THE CENTER ELECTRODE, THE POINT COMING OFF THE GROUND STRAP or THE PORCELAIN when making adjustments. This is probably why Hyundai doesn’t touch them, and companies that make iridium pre-gapped plugs say it is best not to touch them. Though as I have explained all different cars have different gap requirements based on boost, compression and many other factors and car manufacturers must make a car that ranges from enthusiast, to soccer moms, to granny drivers. These sites do say they adjusting them is not needed, but if you must, then it is imperative that you do it properly.

Use needle nose pliers and grab the grounding strap from the back along the sides and squeeze to get a grip, then bend it up or down to adjust as necessary and use a spark plug gapping tool to check your gap.

This is just my observations/thoughts. I take no responsibility for anything that happens to your car if you decide to change your gap and ruin your plugs or your engine runs poorly. But mine is now at .040”. I had some blowout at 20psi running .043”. I think with stock boost, I would have run .045” to test it out, but at my higher psi (running close to 20psi), I feel the top end, but lower than max will be a good first test to see if I get misfires or not. I might get a better gauge and open the gap if I run with no blowout or misfires for a while, but it is hard to get a gap that close to specs using the needle nose pliers. Also, It might not make a difference, but the fuel trims could be learned... so since it is so easy, you might as well pull your battery and reset your trims. And before pulling your spark plugs it is a good idea to disconnect the negative terminal from the battery anyway.

Heat range also has nothing to do with spark, it has to do with how long your electrode or your engine will 'last'. If your plug is too cold, it will dry foul (unless you have an oil leak and it wet fouls which can't really be cleaned) and you will get misfires unless you clean it more often, but it is safer for your engine. If it is too hot, the carbon deposits on the electrode will burn off so you won't need to clean it..... but you may get pre-ignition and blow up your engine instead. Basically the electrode is so hot, it ignites the fuel pre-maturely before the spark fires while your piston is travelling up, and this is very bad for your engine. Erring to the side of cold is a wise decision when you start to modify your car. Some say rule of thumb is 1 degree per 100hp gain. Since the spark plugs on this car take a whole 2 minutes to get to, it is very easy to clean and I would err cold rather than hot. If you do decide to use copper, erring to the cold side is even better as copper's don't really last that long and require service to re-gap you can go ahead and clean them while they are out, or buy new ones since they are so cheap.

Coppers should be checked every 1k miles. Also, where does that copper go when it 'explodes' off? In your engine, which most likely your oil and filter take care of it, I would rather not have bits of copper floating around. On WRX's and such where the plugs take an hour or so to get to, though you wouldn’t want to clean/service as often iridium and a proper heat range sounds more ideal. I have heard of iridium lasting 100k miles if not for a bad tune. Hot plugs is just more ceramic (insulator) so the electrode stays hot, the less ceramic, the metal dissipates from the plug to the engine block and the electrode stays cooler.

Cleaning your dry fouled copper plugs is as simple a non-metallic bristle brush and some elbow grease (metallic brushes are not advisable as they can have particles that can inpregnate and become hot spots to cause pre-ignition/detonation and/or cause shorts and cause misfires). With irridium, you can take advantage of its high heat tolerance (over 2000°c). Take a blow torch to it ~1300°-1700°C to burn off the carbon deposits.... the same thing your engine would be doing if you had hot plugs.

The more I think about it, the more this makes sense. People in the Genesis Coupe community are getting terrible MPG (compared to what Hyundai says). A smaller gap, not allowing the fuel to fully burn would do this. People also say their oil smells like fuel, also would make complete sense as if the fuel is not being burned completely, it is getting into your oil. And as I said those complaining about blacked exhaust tips, would also makes sense if fuel is not getting burned the whole way and you are getting carbon deposits on your exhaust tips much like you would on your spark plugs if the heat wasn’t there to burn it off.

Or if you do have (and need) colder plugs, if you don't beat the crap out of your car, you will still need to clean them more often from fouling. If you need the colder plugs for harder driving, that means harder driving is necessary to heat your plugs up and clean them every now and then. So now you have an excuse to beat the crap out of your car and have some fun. If your plugs are too cold, you might not ever reach that range no matter how hard you drive and that is why you don't want to go too too cold, though I think erring on the cold side is better than the hot side.]]> Mon, 09 Jan 2012 22:03:21 +0000 Read more]]]> http://www.hyundaiaftermarket.org/tech/headporting.pdf Wed, 03 Nov 2010 15:18:48 +0000 Read more]]]> http://www.hyundaiaftermarket.org/tech/intakeexhaustflow.pdf Wed, 03 Nov 2010 15:18:28 +0000 Read more]]]> http://www.hyundaiaftermarket.org/tech/bmshifterinstall.pdf Wed, 03 Nov 2010 15:17:20 +0000