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With a release controller there is no need for a sky high launch, as you can launch without losing rpm. Less starting line rpm = fewer revolutions of clutch slip = less clutch heat.
In my case, 1 second of clutch slip carries me out 36' to 6000rpm @ 48mph.
I spent some time reading about these systems and I think the overall opinion is that they work.
A great driver of course will not see a big gain in 60' but a novice will certainly be able to get things under control and possibly save the drive line from abuse.
I have gathered that the two types work equally well. However any changes in the Tilton one will necessitate a clutch line re bleed for the orifice change.
I have sourced the main two components (flow control valve and line lock solenoid) for well under 100 bucks. Good parts also, materials and name wise. Lines and fittings will come after I decide where to mount the flow control valve inside the car. I like clean installations and insist it be planned out.
I have a CC dual disc going into this car soon and think it will be a great upgrade for consistency. I will interface this system to my AEM Infinity stand alone.
Does anyone have any experience with setting up such a system? What are some things to consider?
Why not use a real clutch? It's been a long time since I've raced FWD Honda stuff so I dont remember, is there not enough room in the bellhousing?
wolfe racecraft made some years ago (yes david wolfe) and they are still floating around but from talking with him year back he didn't think they woulld hold the power we are now making.
wolfe racecraft made some years ago (yes david wolfe) and they are still floating around but from talking with him year back he didn't think they woulld hold the power we are now making.
RAM made a few as well back in the day. I believe they only had single disk. I had a friend that was sent 2 for testing but never used them.. I talked to RAM a few times about a clutch and they told me they wouldn't hold up.
I built a triple disk about 2-3 years before they where on the market...
I was gonna say I have a magnus launch control device for my evo. I've never used it and now selling the car. But a buddy had one and was doing 2.0 60's and installed one next day at the track consistent 1.5 60's. I may be selling the magnus device if anyone wants to try it.
Here's some pictures of the universal underdash version of the ClutchTamer (under 2lbs installed). This is a 2 stage unit with separately adjustable active point and engagement rate...
Below shot shows a ez install clamp-on style pedal bracket, but there are also smaller/cleaner brackets that install with small bolts which require minor drilling...
This version installs thru the dash structure instead of under...
Here's a link to a page that explains how it works and it's advantages over a simple in-line restrictor... ClutchTamer.com
Do you think i should bother with a Honda specific version? You could still install a line-lock style valve if you wanted to leave off a button.
Here's some pictures of the universal underdash version of the ClutchTamer (under 2lbs installed). This is a 2 stage unit with separately adjustable active point and engagement rate...
Below shot shows a ez install clamp-on style pedal bracket, but there are also smaller/cleaner brackets that install with small bolts which require minor drilling...
This version installs thru the dash structure instead of under...
Here's a link to a page that explains how it works and it's advantages over a simple in-line restrictor... ClutchTamer.com
Do you think i should bother with a Honda specific version? You could still install a line-lock style valve if you wanted to leave off a button.
The only problem with this is that its active on upshifts which might be less than ideal. if you have a solenoid with a half decent EMS, you can shut it off by mph after your launch-before the 1-2 shift.
The only problem with this is that its active on upshifts which might be less than ideal. if you have a solenoid with a half decent EMS, you can shut it off by mph after your launch-before the 1-2 shift.
I think you may be missing the point of a clutch buffer…reducing that parts/traction breaking inertia induced "torque spike" that occurs as the rotating assembly loses rpm. Remember, your rotating assembly loses rpm on the shifts as well as during the launch. If you are limited by the ultimate strength of your transmission or axles, minimizing the intensity of this torque spike can allow you to increase power without exceeding their capacity. As you take advantage of having eliminated the spike during launch by adding power, you quickly come to realize that reducing the spike on shifts is the next thing that needs to be addressed.
I’m using general numbers here, hopefully to make this concept easier to understand….
…Lets say a generic 450ft/lb engine is tested for how fast it can accelerate WOT with the clutch pushed in, no load applied. Acceleration rate is found to be 8500rpm/second thru the heart of it’s torque band. At this rate, the engine gains roughly 2000rpm in .235 seconds.
…Now the car is launched and .235 seconds later, rpm has dropped 2000rpm as the clutch locks up. If it took 450ft/lbs to accelerate the engine’s inertia 2000rpm in .235 seconds, it also took 450ft/lbs to remove 2000rpm from that launch rpm in the same .235 second time period. Where did this 450ft/lbs of inertia energy discharged over .235 seconds go? Into the transmission’s input shaft along side the engine’s WOT 450ft/lbs, That’s a total of 900ft/lbs for a brief .235 second time period, then torque drops below 450ft/lbs as the engine starts gaining rpm and some of it’s output is siphoned off as energy being recharged as inertia back into the rotating assembly. To the driver, this change in overall torque output feels like a bog.
From there you can play with the rate of the rpm loss and how that effects the torque that the input shaft will see. To remove 2000rpm from the rotating assembly over twice the period of time requires ½ the torque, so doubling duration to .47 seconds will cut that torque spike in ½ to 225ft/lbs. In this instance, the input shaft will see 675ft/lbs for .47 seconds before dropping below 450ftllbs. Speed up that 2000 rpm loss to just .118 seconds (typical of what you might see with a grabby clutch), the torque spike increases to 900ft/lbs. In that case, the input shaft would see 1350ft/lbs for .118 seconds before dropping below 450ft/lbs. This would feel like a huge bog, and be more likely to break a transmission. Change the ultimate limiting factor from breaking a transmission to exceeding the ultimate traction of the tire, reducing this torque spike is beneficial either way.
As you know real life power application isn’t binary like my example, but I hope this helps illustrate where I’m coming from.
There’s a reason why the guys with clutchless transmissions want a clutch that slips after the shifts
I bought a Tilton flow control last week and now I'm reading this thread thinking: "maybe I don't want my clutch to slip in 3 and 4..... should I send this back and go with the magnus controller?"
And clutch slip on the shifts is not beneficial. Id rather control power with other things then a slipping clutch. Only for the initial 50-100ft would I want to slip the clutch.
Could your car accel any quicker if you could remove 60lbs or so from the rotating assy? That's basically the same benefit as you get with an automatic using a torque converter well matched to drag racing. Think of it as "pre-accelerating" the rotating assy. Even though the automatic's converter slips all the way down the track and builds tremendous heat from that slip (wasted energy), they still end up quicker overall. They could easily choose a more efficient converter that slips less, but that would slow the car down. Too much slip is bad, they spend a lot of money on converters to find one with just the right amount of slip.
On a man trans car if the clutch slips a bit just after a WOT gear change, result is engine rpm does not drop as far after the shift. This is bonus time where the car is free of the burden of accelerating the rotating assy, making more power available to accelerate the car. Just as with the automatic guys, the key is finding just the right amount of slip to maximize the benefit.
Here's some feedback sent to me from a NMRA Factory Stock racer. Sealed engine, stick cars are required to run a diaphragm clutch. This guy was having a terrible time as he was trying to gain a little efficiency by switching from slicks to radials. With a 4300 launch, the radials bogged the engine to 2300rpm and 1.71 60's. Stepped up to a 4800rpm launch in an attempt to eliminate the bog, this is what happened to his faceplated TKO...
He repaired the transmission, and I sent him a ClutchTamer to try. He installed it, made a few test hits in the driveway to get familiar with it, then went to the track. Results were dead hooked radials and back to back 1.45 60's. This graph is from a 1.42 run...
Couple months later, still 1.4 60's at class weight and no transmission failures from 5200rpm launches.
Here's the same graph w/ a couple lines added to help illustrate the benefits of delaying clutch lockup. This graph is fairly easy one to understand, as there is very little wheelspin to confuse things...
The added orange line is a rough representation of the engine's ability to gain rpm in 1st gear.
The 1st added vertical black line represents the beginning of clutch engagement.
The 2nd added vertical black line represents the point of clutch lockup.
The distance between the two vertical black lines represents the time it took for clutch lockup to occur.
Clutch lockup was delayed roughly .7 seconds, engine rpm at lockup was about 5100.
If clutch lockup had occurred at .4 seconds, engine rpm would have been pulled down to appx 4200.
If clutch lockup had occurred at .25 seconds, engine rpm would have been pulled down to appx 3500.
The basic point is- the earlier clutch lockup occurs, the lower the rpm point on the orange line that the engine will have to accelerate from.
This is a bit of a simplified explanation, as reduced engine output at the lower rpm would also reduce the engine's ability to gain rpm. That added loss is not reflected here.
I made mine from a few parts from parker store. Flow valve + electric line lock, wired to the nitrous settings in my Kpro. With my safety/activation switch activated, any time I'm under 20 mph the line lock is closed, forcing to route the fluid through the flow valve. 21 mph+, the line lock opens up.
I only have it set this way because I'm running running a synchro trans and use my clutch.
Controlled clutch slip after the shifts is quicker than minimal clutch slip. Don't waste time trying to eliminate clutch slip, thinking that it's only a waste of power that could otherwise could be applied to the track. Truth is that the engine is burning more fuel spinning at the higher rpm, producing additional energy beyond that which is being absorbed as heat in the clutch assembly.
Anyone wonder why that orange line on my graph aligns with 2700rpm at launch instead of zero rpm? It's because the line representing rate of acceleration is actually even steeper before the clutch locks up. This happens because no power was used to accelerate the rotating assembly prior to lockup, so more power was available to accelerate the car. Here's the same graph, with a red line added to represent acceleration rate before clutch lockup...
See how much steeper the car's acceleration rate was before clutch lockup?
This launch could have reached it's shift point even quicker if the clutch had slipped longer, as the car would have rode the trajectory of that steep red line to a higher point before switching to angle of the orange line. Same applies to the shifts as well, a car can simply accelerate quicker before the clutch locks up. The longer the clutch experiences controlled slip after a shift, the longer you can ride a steeper acceleration rate.
The lightest clutch assy may not necessarily be the quickest when it comes to exploiting clutch slip, as the clutch needs to have enough thermal capacity to absorb the slip without overheating/warping. Having plenty of clutch capacity for the task is the 1st requirement, then it's a matter of controlling the application of clutch pressure to match engine power.
I like what you have produced here. It seems that you may have a formula to equate HP and rpm with the optimal clutch engagement for a given vehicle.
I am aware that other factors exist though these observations and graphic illustrations help convey the proper use of clutch slip technology.
I think it is a great topic not well explained past theory until now IMO.
Thank you
02-15-2015, 04:57 PM
Re: Clutch Release Controller ?
