evo 8 hesitating? or clutch *video*
Mar 11, 2013, 11:14 PM
#16
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I looked again at the video on my computer instead of my phone.
It's definitely the clutch. Look no further.
I've had an ACT 2900HD and their Prolite flywheel in for 45,000 miles of track days, stop and go, and about 180+ autocross launches. It's still holding, but will be replaced soon when I fix my 5th gear synchro.
Good luck with yours.
It's definitely the clutch. Look no further.
I've had an ACT 2900HD and their Prolite flywheel in for 45,000 miles of track days, stop and go, and about 180+ autocross launches. It's still holding, but will be replaced soon when I fix my 5th gear synchro.
Good luck with yours.
thanks for the clutch reference, i was having a hard time finding a clutch for decent price
Mar 11, 2013, 11:18 PM
#17
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I despise these clutch threads because there's always so much generally misinterpreted info.
1. That COULD be the clutch, BUT... you shouldn't be doing a hard pull in a high gear (4th or 5th).
2. People always say that the best way to test your clutch going bad is to put the car into a high gear, and see if the clutch slips. No. Do not do this.
If you don't drive your car that way (and you shouldn't) then why would it matter if your clutch is slipping in those gears? If your clutch isn't slipping in day to day use, then your clutch isn't bad.
Clutches are wear items. The second they first heat up against a flywheel when they're brand new after break in, TECHNICALLY they have reduced gripping power. A perfectly good clutch with a strange set of gearing could be completely useless.
ANYWAY... my point is... if you know how to drive a vehicle, a clutch that is "going bad" probably shouldn't ever be an issue. There will of course come a point in which the clutch isn't drivable, or become undrivable for your tastes. You certainly shouldn't be doing hard pulls or launches on a clutch thats going out... Some of the advice is well meant, but it doesn't give the OP the logical information they should have in order to make an educated decision on what they're doing. /soapbox
1. That COULD be the clutch, BUT... you shouldn't be doing a hard pull in a high gear (4th or 5th).
2. People always say that the best way to test your clutch going bad is to put the car into a high gear, and see if the clutch slips. No. Do not do this.
If you don't drive your car that way (and you shouldn't) then why would it matter if your clutch is slipping in those gears? If your clutch isn't slipping in day to day use, then your clutch isn't bad.
Clutches are wear items. The second they first heat up against a flywheel when they're brand new after break in, TECHNICALLY they have reduced gripping power. A perfectly good clutch with a strange set of gearing could be completely useless.
ANYWAY... my point is... if you know how to drive a vehicle, a clutch that is "going bad" probably shouldn't ever be an issue. There will of course come a point in which the clutch isn't drivable, or become undrivable for your tastes. You certainly shouldn't be doing hard pulls or launches on a clutch thats going out... Some of the advice is well meant, but it doesn't give the OP the logical information they should have in order to make an educated decision on what they're doing. /soapbox
Mar 12, 2013, 04:16 PM
#19
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I don't want to fall into the "generally misinterpreted info" trap, so I'll ask about what you've written above. I'm afraid either I don't understand what you've written or you don't understand clutches. One can't accelerate through 4th and 5th gears? Is that what I'm understanding you to say?
I can assure you that all cars are designed to pull hard in 4th and 5th gears, and should do so without problem- unless their clutch is excessively worn, improperly installed, or incorrectly chosen for the vehicle. If you want to know if your clutch falls into this group, you SHOULD accelerate hard in a high gear, preferably on a grade. This is how you tell if a clutch is going bad.
I'm sure your advance is 'well meant', but I'm not at all sure it's accurate. You said..."a clutch that is "going bad" probably shouldn't ever be an issue"; what does that mean?
One would want to know if their clutch was going bad. When they start slipping in higher gears, they very quickly start slipping all the time. They become inoperable when that happens.
I think that you should make sure that your facts are right before you suggest other's may not be. Or maybe I just don't understand.
I can assure you that all cars are designed to pull hard in 4th and 5th gears, and should do so without problem- unless their clutch is excessively worn, improperly installed, or incorrectly chosen for the vehicle. If you want to know if your clutch falls into this group, you SHOULD accelerate hard in a high gear, preferably on a grade. This is how you tell if a clutch is going bad.
I'm sure your advance is 'well meant', but I'm not at all sure it's accurate. You said..."a clutch that is "going bad" probably shouldn't ever be an issue"; what does that mean?
One would want to know if their clutch was going bad. When they start slipping in higher gears, they very quickly start slipping all the time. They become inoperable when that happens.
I think that you should make sure that your facts are right before you suggest other's may not be. Or maybe I just don't understand.
A clutch is a friction wear item. We know this. The stock clutch in the Evo is designed to hold a certain figure (we'll refer to it in % of grip to perhaps illustrate my point). On one side, you have horsepower/Torque (lets say 300hp/TQ for ease), and on the other side you have the weight of the car (lets say 3,500lbs), and we'll leave the gearing completely out for simplicities sake.
The stock clutch can hold that just fine at say... 80%. If you increase any of those factors (HP or weight) the clutch needs to use the rest of the 20% holding power. Above that 20%, the clutch will begin to be less effective. You know this.
The REASON I say to people that "testing" to see if their clutch is bad by putting the car into high gear is a bad idea is... realistically speaking, this is the same as adding a significant amount of weight to the car, or HP to the car. Of COURSE if you stress something, it will be more likely to fail. BUT... people don't actually DRIVE their cars like that... so why is it relevant for someone to test their clutch like that? That would be like saying to test if your door seals are bad, you should drive your vehicle down into Mariana's Trench? It's overkill.
A clutch is bad when it isn't holding the power in the scenarios that it would normally encounter, and yes of COURSE throwing it into 5th and flooring it from a low RPM/speed puts it under higher load, and will show that it's weaker, but if it's still holding under your normal driving style, then why would it matter?
The other point you made about cars being able to do hard pulls in high gears... you're likely misinterpreting what I've said there as well.
If you're cruising at 2000 RPM in 5th gear, you most certainly should not be flooring it, ESPECIALLY with a forced induction car. The amount of pressure that the engine has to sustain will be extreme, and there's no reason. That's why, if you've ever done that, your diverter blow off will be significantly louder than when just driving spiritedly. Not to mention, the LENGTH of the stress period that the motor, and drivetrain are experiencing, is significantly longer than "normal", and as such it's very stressful.
So no. Don't floor your car in 5th gear from low RPMs. The combination of boost, and gearing makes this less than favorable.
Not trying at all to come at you... just perhaps trying to clarify a bit about what point I was trying to make.
Mar 12, 2013, 04:59 PM
#20
I have to say that your (ProPilot04) first input was not that clear. But as you explain what you meant again, I get your point and I agree. I would like to say with a bit high certainty based on the OPS input, that this is the point where his clutch, hence car perfrmance will start to degrade. I say this because, this is the first item that I notice, miles before my clutch started showing obvious slipping. It started with small blip up in the RPM as I shift and it goes goes down. I can still drive my car normally without slip below 3k rpm. I can also increase my speed slowly. I tried not to shift at high speed as well as this will wear my clutch more. As soon as I get to the right gear at proper speed, I slowly increase it meaning I tried to change gear at the minimum now that my clutch is slipping.
Last edited by Royal Evo; Mar 12, 2013 at 05:02 PM.
Mar 12, 2013, 07:16 PM
#21
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No... it's cool, you're misunderstanding what I'm saying, and realistically, it's probably not the easiest thing to explain in text.
A clutch is a friction wear item. We know this. The stock clutch in the Evo is designed to hold a certain figure (we'll refer to it in % of grip to perhaps illustrate my point). On one side, you have horsepower/Torque (lets say 300hp/TQ for ease), and on the other side you have the weight of the car (lets say 3,500lbs), and we'll leave the gearing completely out for simplicities sake.
The stock clutch can hold that just fine at say... 80%. If you increase any of those factors (HP or weight) the clutch needs to use the rest of the 20% holding power. Above that 20%, the clutch will begin to be less effective. You know this.
The REASON I say to people that "testing" to see if their clutch is bad by putting the car into high gear is a bad idea is... realistically speaking, this is the same as adding a significant amount of weight to the car, or HP to the car. Of COURSE if you stress something, it will be more likely to fail. BUT... people don't actually DRIVE their cars like that... so why is it relevant for someone to test their clutch like that? That would be like saying to test if your door seals are bad, you should drive your vehicle down into Mariana's Trench? It's overkill.
A clutch is bad when it isn't holding the power in the scenarios that it would normally encounter, and yes of COURSE throwing it into 5th and flooring it from a low RPM/speed puts it under higher load, and will show that it's weaker, but if it's still holding under your normal driving style, then why would it matter?
The other point you made about cars being able to do hard pulls in high gears... you're likely misinterpreting what I've said there as well.
If you're cruising at 2000 RPM in 5th gear, you most certainly should not be flooring it, ESPECIALLY with a forced induction car. The amount of pressure that the engine has to sustain will be extreme, and there's no reason. That's why, if you've ever done that, your diverter blow off will be significantly louder than when just driving spiritedly. Not to mention, the LENGTH of the stress period that the motor, and drivetrain are experiencing, is significantly longer than "normal", and as such it's very stressful.
So no. Don't floor your car in 5th gear from low RPMs. The combination of boost, and gearing makes this less than favorable.
Not trying at all to come at you... just perhaps trying to clarify a bit about what point I was trying to make.
A clutch is a friction wear item. We know this. The stock clutch in the Evo is designed to hold a certain figure (we'll refer to it in % of grip to perhaps illustrate my point). On one side, you have horsepower/Torque (lets say 300hp/TQ for ease), and on the other side you have the weight of the car (lets say 3,500lbs), and we'll leave the gearing completely out for simplicities sake.
The stock clutch can hold that just fine at say... 80%. If you increase any of those factors (HP or weight) the clutch needs to use the rest of the 20% holding power. Above that 20%, the clutch will begin to be less effective. You know this.
The REASON I say to people that "testing" to see if their clutch is bad by putting the car into high gear is a bad idea is... realistically speaking, this is the same as adding a significant amount of weight to the car, or HP to the car. Of COURSE if you stress something, it will be more likely to fail. BUT... people don't actually DRIVE their cars like that... so why is it relevant for someone to test their clutch like that? That would be like saying to test if your door seals are bad, you should drive your vehicle down into Mariana's Trench? It's overkill.
A clutch is bad when it isn't holding the power in the scenarios that it would normally encounter, and yes of COURSE throwing it into 5th and flooring it from a low RPM/speed puts it under higher load, and will show that it's weaker, but if it's still holding under your normal driving style, then why would it matter?
The other point you made about cars being able to do hard pulls in high gears... you're likely misinterpreting what I've said there as well.
If you're cruising at 2000 RPM in 5th gear, you most certainly should not be flooring it, ESPECIALLY with a forced induction car. The amount of pressure that the engine has to sustain will be extreme, and there's no reason. That's why, if you've ever done that, your diverter blow off will be significantly louder than when just driving spiritedly. Not to mention, the LENGTH of the stress period that the motor, and drivetrain are experiencing, is significantly longer than "normal", and as such it's very stressful.
So no. Don't floor your car in 5th gear from low RPMs. The combination of boost, and gearing makes this less than favorable.
Not trying at all to come at you... just perhaps trying to clarify a bit about what point I was trying to make.
I do full throttle pulls all the way through 4th and 5th gear as long as the straight allows for days at a time on track, and the clutch is fine. It's the autocross launches that kill it.
The stock Evo 8 clutch lasted only 15,000 miles (twice) with 2 to 4 of us autocrossing it for the first four years. I've had the same ACT clutch in for the last six years (with more tracking and less auto crossing, although still at least 40-60 launches a year). It has yet to slip, but as soon as I feel the rpm go up and then back down, it's getting replaced. It will happen first in 5th, then 4th, then 3rd, then 2nd, then even 1st if I let it go. And that's why you test it in 5th on the highway if you're concerned. Unless you're running ridiculous power, are near detonation, or have woefully undersized your clutch, it won't hurt anything. It especially won't hurt the clutch, because, if it's not bad IT WON'T SLIP.
Mar 12, 2013, 10:38 PM
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No... it's cool, you're misunderstanding what I'm saying, and realistically, it's probably not the easiest thing to explain in text.
A clutch is a friction wear item. We know this. The stock clutch in the Evo is designed to hold a certain figure (we'll refer to it in % of grip to perhaps illustrate my point). On one side, you have horsepower/Torque (lets say 300hp/TQ for ease), and on the other side you have the weight of the car (lets say 3,500lbs), and we'll leave the gearing completely out for simplicities sake.
The stock clutch can hold that just fine at say... 80%. If you increase any of those factors (HP or weight) the clutch needs to use the rest of the 20% holding power. Above that 20%, the clutch will begin to be less effective. You know this.
The REASON I say to people that "testing" to see if their clutch is bad by putting the car into high gear is a bad idea is... realistically speaking, this is the same as adding a significant amount of weight to the car, or HP to the car. Of COURSE if you stress something, it will be more likely to fail. BUT... people don't actually DRIVE their cars like that... so why is it relevant for someone to test their clutch like that? That would be like saying to test if your door seals are bad, you should drive your vehicle down into Mariana's Trench? It's overkill.
A clutch is bad when it isn't holding the power in the scenarios that it would normally encounter, and yes of COURSE throwing it into 5th and flooring it from a low RPM/speed puts it under higher load, and will show that it's weaker, but if it's still holding under your normal driving style, then why would it matter?
The other point you made about cars being able to do hard pulls in high gears... you're likely misinterpreting what I've said there as well.
If you're cruising at 2000 RPM in 5th gear, you most certainly should not be flooring it, ESPECIALLY with a forced induction car. The amount of pressure that the engine has to sustain will be extreme, and there's no reason. That's why, if you've ever done that, your diverter blow off will be significantly louder than when just driving spiritedly. Not to mention, the LENGTH of the stress period that the motor, and drivetrain are experiencing, is significantly longer than "normal", and as such it's very stressful.
So no. Don't floor your car in 5th gear from low RPMs. The combination of boost, and gearing makes this less than favorable.
Not trying at all to come at you... just perhaps trying to clarify a bit about what point I was trying to make.
A clutch is a friction wear item. We know this. The stock clutch in the Evo is designed to hold a certain figure (we'll refer to it in % of grip to perhaps illustrate my point). On one side, you have horsepower/Torque (lets say 300hp/TQ for ease), and on the other side you have the weight of the car (lets say 3,500lbs), and we'll leave the gearing completely out for simplicities sake.
The stock clutch can hold that just fine at say... 80%. If you increase any of those factors (HP or weight) the clutch needs to use the rest of the 20% holding power. Above that 20%, the clutch will begin to be less effective. You know this.
The REASON I say to people that "testing" to see if their clutch is bad by putting the car into high gear is a bad idea is... realistically speaking, this is the same as adding a significant amount of weight to the car, or HP to the car. Of COURSE if you stress something, it will be more likely to fail. BUT... people don't actually DRIVE their cars like that... so why is it relevant for someone to test their clutch like that? That would be like saying to test if your door seals are bad, you should drive your vehicle down into Mariana's Trench? It's overkill.
A clutch is bad when it isn't holding the power in the scenarios that it would normally encounter, and yes of COURSE throwing it into 5th and flooring it from a low RPM/speed puts it under higher load, and will show that it's weaker, but if it's still holding under your normal driving style, then why would it matter?
The other point you made about cars being able to do hard pulls in high gears... you're likely misinterpreting what I've said there as well.
If you're cruising at 2000 RPM in 5th gear, you most certainly should not be flooring it, ESPECIALLY with a forced induction car. The amount of pressure that the engine has to sustain will be extreme, and there's no reason. That's why, if you've ever done that, your diverter blow off will be significantly louder than when just driving spiritedly. Not to mention, the LENGTH of the stress period that the motor, and drivetrain are experiencing, is significantly longer than "normal", and as such it's very stressful.
So no. Don't floor your car in 5th gear from low RPMs. The combination of boost, and gearing makes this less than favorable.
Not trying at all to come at you... just perhaps trying to clarify a bit about what point I was trying to make.
i just want to clearify that i was not flooring it in 5th gear! lol i was casually accelerating SLOWLY and it was slipping
Mar 13, 2013, 09:59 PM
#23
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I have to say that your (ProPilot04) first input was not that clear. But as you explain what you meant again, I get your point and I agree. I would like to say with a bit high certainty based on the OPS input, that this is the point where his clutch, hence car perfrmance will start to degrade. I say this because, this is the first item that I notice, miles before my clutch started showing obvious slipping. It started with small blip up in the RPM as I shift and it goes goes down. I can still drive my car normally without slip below 3k rpm. I can also increase my speed slowly. I tried not to shift at high speed as well as this will wear my clutch more. As soon as I get to the right gear at proper speed, I slowly increase it meaning I tried to change gear at the minimum now that my clutch is slipping.
I hear what you're saying, but you forget that horsepower and torque are rpm dependent. At 2000 rpm, no matter what you've done to your car, you aren't going to be making enough power to slip even a stock Evo clutch, unless it's going out. That is the point of the test. It does increase cylinder pressures and therefore load on the engine, but when have you ever heard of someone blowing their engine at 2000-4000 rpm (the engine speeds we are taking about testing the clutch at). Therefore, that is how you test the clutch. If it slips under high load and low rpm, it's bad. Also, the clutch ONLY wears when it is engaging and disengaging. When it's engaged, it should not slip until you greatly exceed it's rated torque.
I do full throttle pulls all the way through 4th and 5th gear as long as the straight allows for days at a time on track, and the clutch is fine. It's the autocross launches that kill it.
The stock Evo 8 clutch lasted only 15,000 miles (twice) with 2 to 4 of us autocrossing it for the first four years. I've had the same ACT clutch in for the last six years (with more tracking and less auto crossing, although still at least 40-60 launches a year). It has yet to slip, but as soon as I feel the rpm go up and then back down, it's getting replaced. It will happen first in 5th, then 4th, then 3rd, then 2nd, then even 1st if I let it go. And that's why you test it in 5th on the highway if you're concerned. Unless you're running ridiculous power, are near detonation, or have woefully undersized your clutch, it won't hurt anything. It especially won't hurt the clutch, because, if it's not bad IT WON'T SLIP.
I do full throttle pulls all the way through 4th and 5th gear as long as the straight allows for days at a time on track, and the clutch is fine. It's the autocross launches that kill it.
The stock Evo 8 clutch lasted only 15,000 miles (twice) with 2 to 4 of us autocrossing it for the first four years. I've had the same ACT clutch in for the last six years (with more tracking and less auto crossing, although still at least 40-60 launches a year). It has yet to slip, but as soon as I feel the rpm go up and then back down, it's getting replaced. It will happen first in 5th, then 4th, then 3rd, then 2nd, then even 1st if I let it go. And that's why you test it in 5th on the highway if you're concerned. Unless you're running ridiculous power, are near detonation, or have woefully undersized your clutch, it won't hurt anything. It especially won't hurt the clutch, because, if it's not bad IT WON'T SLIP.
To your point, yes I understand that you of course can floor your car all the way through every gear. But if you're doing 30mph in 5th gear, and you go WOT without downshifting... THAT'S what I'm advocating against.
C'est la vie. I think we're all arguing the same points.
Right m8. I got you.
Mar 13, 2013, 11:59 PM
#24
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I don't think its the clutch because when the clutch is slipping it allows the car to free rev and that's not happening in this case.
Also if it was slipping that much it would stink out the car with burnt clutch.
My bet is its something in the tune or its turbo related that is stopping the car from making boost and holding it there, like it has no power. Do you have boost and afr gauge?
Also if it was slipping that much it would stink out the car with burnt clutch.
My bet is its something in the tune or its turbo related that is stopping the car from making boost and holding it there, like it has no power. Do you have boost and afr gauge?
Mar 16, 2013, 08:45 AM
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I don't think its the clutch because when the clutch is slipping it allows the car to free rev and that's not happening in this case.
Also if it was slipping that much it would stink out the car with burnt clutch.
My bet is its something in the tune or its turbo related that is stopping the car from making boost and holding it there, like it has no power. Do you have boost and afr gauge?
Also if it was slipping that much it would stink out the car with burnt clutch.
My bet is its something in the tune or its turbo related that is stopping the car from making boost and holding it there, like it has no power. Do you have boost and afr gauge?
They don't allow the car to rev freely, they slip and then grab. That is until they can't anymore, your care won't move, and then, maybe, you'd smell burning clutch.
When a clutch starts to slip, it feels exactly like your engine hesitates, but actually its speed increases, however your car's forward motion does not.
Let's all think about this; what in the tune or turbo system could make the revs drop without the engine missing (which it's not in the video) or throwing a code? Nothing that I can think of.
Besides, the OP said in an earlier post it's getting worse. My bet is he gets a new clutch soon.
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