Help on choosing clutch. please!!
Help on choosing clutch. please!!
i basically have greddy headers, nology wires, injen intake, greddy power xtreme cat-back exhaust, and maybe some minor small things on my 98' 240sx...its possibly heavier than the stock weight because of all the bondo and welding..but im going to do the manual swap and im wondering whut clutch i should get from clutch masters: fx100 to the fx 500. i dont know whut would be a good stage. it would be alot of help if you'd shed some light on how to choose the right clutch. thankx!!!please help!!
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SunshineAcid
- Posts: 149
- Joined: Fri Nov 28, 2003 9:22 am
- Car: 89 240sx Ka24de swap
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Ubernoober
- Posts: 539
- Joined: Mon Mar 08, 2004 6:51 pm
Hell, the stock system will be enough for your car, but if you want an upgrade I wouldn't go higher than the FX100. People seem to go ape**** over clutches for no reason other than "my car must be making so much p0w3r I need a full on race clutch". Usually it isn't the holding power of the clutch that is the problem, its the driver and his poor style of shifting.
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Eastcoast Wildboy
- Posts: 42
- Joined: Wed Jun 30, 2004 5:04 pm
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Ubernoober
- Posts: 539
- Joined: Mon Mar 08, 2004 6:51 pm
I like the ACT street clutch. A good combination of pressure plate and disc. It would work well for you. Also, why a new flywheel? Do you have $400 burning a hole in your pocket? I think a lightened flywheel is getting entirely too much press with these tuners.
It seems there are so many rumors about clutches. This is only what I know and some may be a tad wrong, but I don't really know how to shorten this, so....
http://www.howstuffworks.com/clutch.htm
There are a few things they dont mention. "Marcel" is a description of a small gap between the front and back side of a disc. Between these two surfaces is usually a small wavy spring. The amount of marcel can affect the smoothness with which a clutch engages. More = smoother, but longer pedal engagement feel. Some people call this "sloppy", but most factory discs have an excess of marcel to make driving easier for grandma. Aftermarket el-cheapo "high performance" clutches will usually have stock everything, but reduce marcel to give the clutch a "sharper" feel. Not better, just a shorter engagement distance. "Racing" clutches typically have no marcel. These rely totally on the friction material to provide smooth engagement. Puck type clutches will have no marcel. I like my clutches with a slightly reduced marcel. They are sharper, but still engage smoothly.
Another thing people confuse themselves over are the coil springs used near the hub. These affect engagement very little, though they do help with chatter. They are there to reduce NVH (noise, vibration, harshness) so grandma doesn't complain that her transmission buzzes with engine vibration. On cheap clutches, these usually wear quickly and are held poorly. They quickly begin to rattle and there is a small chance they could literally fall out of their cage. Discs without these can cause loud buzzing in trannys (especially 4 cyl engines), but have one less component to fail. I prefer good discs that have these. They are heavy duty, don't fail, and reduce annoyances with the clutch.
Lastly, too many people go too aggressive with the friction material. Organic provides smoothness and long wear. Modified organics are still smooth, but have added bits that resist higher temps for lazy drivers that insist on slipping their clutches. Kevlar can behave like an organic, but provide superior heat handling and friction. The downside is that Kevlar disperses heat poorly and once you cook it, it is totally ruined. Metallic media has the ultimate in heat handling and friction, but are abusive to the surfaces they run against (flywheel and pressure plate). Metallics also chatter. A lot. I personally have never understood the point of a "dual-friction" disc. One side is metallic or ceramic, and the other organic. Supposedly they offer the smoothness of organic with the great friction of a metallic. To me its like this: "Add a drop of wine to a gallon of sewage, and you have a gallon of sewage. Add a drop of sewage to a gallon of wine and you still have a gallon of sewage".In other words, the discs only performs as good as its weakest (organic) component. The metallic side is simply marketing. I like modified organics. They do everyhting I need.
Lastly, most clutches fail due to driver fault. If your clutch system is working correctly (all the hydraulics, pressure plate, flywheel and disc), and with your foot OFF the pedal, you can accelerate at WOT to max RPM and the clutch never slips, then you have all the clamping force you need. Failure comes from dumping the clutch on a high-rev launch, or more commonly, sloppy shifting. I see this all the time. When "hardcore" drivers shift, they just hammer the throttle without giving the clutch time to match engine speeds. Slippage occurs which instantly heat the disc, reducing its friction causing more slippage, causing more heat until true catastrophic failure. When you shift, you let the clutch completely out (without dragging it) and let the RPM's match your current speed, then apply your power. This all happens very quickly so we aren't trying to granny-shift here. The only reason to power-shift is if you are looking for that last 1/10th in the 1/4. And if you are, you should already know your clutch requirements.
Sorry for the rant but misinformation seems rampant out there.
It seems there are so many rumors about clutches. This is only what I know and some may be a tad wrong, but I don't really know how to shorten this, so....
http://www.howstuffworks.com/clutch.htm
There are a few things they dont mention. "Marcel" is a description of a small gap between the front and back side of a disc. Between these two surfaces is usually a small wavy spring. The amount of marcel can affect the smoothness with which a clutch engages. More = smoother, but longer pedal engagement feel. Some people call this "sloppy", but most factory discs have an excess of marcel to make driving easier for grandma. Aftermarket el-cheapo "high performance" clutches will usually have stock everything, but reduce marcel to give the clutch a "sharper" feel. Not better, just a shorter engagement distance. "Racing" clutches typically have no marcel. These rely totally on the friction material to provide smooth engagement. Puck type clutches will have no marcel. I like my clutches with a slightly reduced marcel. They are sharper, but still engage smoothly.
Another thing people confuse themselves over are the coil springs used near the hub. These affect engagement very little, though they do help with chatter. They are there to reduce NVH (noise, vibration, harshness) so grandma doesn't complain that her transmission buzzes with engine vibration. On cheap clutches, these usually wear quickly and are held poorly. They quickly begin to rattle and there is a small chance they could literally fall out of their cage. Discs without these can cause loud buzzing in trannys (especially 4 cyl engines), but have one less component to fail. I prefer good discs that have these. They are heavy duty, don't fail, and reduce annoyances with the clutch.
Lastly, too many people go too aggressive with the friction material. Organic provides smoothness and long wear. Modified organics are still smooth, but have added bits that resist higher temps for lazy drivers that insist on slipping their clutches. Kevlar can behave like an organic, but provide superior heat handling and friction. The downside is that Kevlar disperses heat poorly and once you cook it, it is totally ruined. Metallic media has the ultimate in heat handling and friction, but are abusive to the surfaces they run against (flywheel and pressure plate). Metallics also chatter. A lot. I personally have never understood the point of a "dual-friction" disc. One side is metallic or ceramic, and the other organic. Supposedly they offer the smoothness of organic with the great friction of a metallic. To me its like this: "Add a drop of wine to a gallon of sewage, and you have a gallon of sewage. Add a drop of sewage to a gallon of wine and you still have a gallon of sewage".In other words, the discs only performs as good as its weakest (organic) component. The metallic side is simply marketing. I like modified organics. They do everyhting I need.
Lastly, most clutches fail due to driver fault. If your clutch system is working correctly (all the hydraulics, pressure plate, flywheel and disc), and with your foot OFF the pedal, you can accelerate at WOT to max RPM and the clutch never slips, then you have all the clamping force you need. Failure comes from dumping the clutch on a high-rev launch, or more commonly, sloppy shifting. I see this all the time. When "hardcore" drivers shift, they just hammer the throttle without giving the clutch time to match engine speeds. Slippage occurs which instantly heat the disc, reducing its friction causing more slippage, causing more heat until true catastrophic failure. When you shift, you let the clutch completely out (without dragging it) and let the RPM's match your current speed, then apply your power. This all happens very quickly so we aren't trying to granny-shift here. The only reason to power-shift is if you are looking for that last 1/10th in the 1/4. And if you are, you should already know your clutch requirements.
Sorry for the rant but misinformation seems rampant out there.