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I've gone out to the track 3 times in my H/C/I Z06. The car makes 600whp and 544wtq. I'm having trouble with the launch and clutch slip technique.
So far, I've only managed a 10.8 @ 133 with my highest trap speed being a 136. This was pretty much spinning all first gear on a 4k rpm launch.
The closest track is 1.5hrs away, so I can't make it out there every weekend to really get some practice in. Which brings me to the point of this thread, has anyone used a hydraulic control valve to regulate clutch slip?
On paper, it looks to be exactly what I need. Being able to manipulate the amount of slip/length of slip, consistently should allow me to run better times and have more fun at the track. Instead, I'm get frustrated because I can't get the technique down in only 2-3 runs every other month I go to the track.
I've gone out to the track 3 times in my H/C/I Z06. The car makes 600whp and 544wtq. I'm having trouble with the launch and clutch slip technique.
So far, I've only managed a 10.8 @ 133 with my highest trap speed being a 136. This was pretty much spinning all first gear on a 4k rpm launch.
The closest track is 1.5hrs away, so I can't make it out there every weekend to really get some practice in. Which brings me to the point of this thread, has anyone used a hydraulic control valve to regulate clutch slip?
On paper, it looks to be exactly what I need. Being able to manipulate the amount of slip/length of slip, consistently should allow me to run better times and have more fun at the track. Instead, I'm get frustrated because I can't get the technique down in only 2-3 runs every other month I go to the track.
I have no experience with this-But it looks interesting and should work. I may try it. Even if it lessened the life of the clutch-Cheaper than replacing transmission.
I would use the MAP or Magnus versions, with the solenoid. Lingenfelter sells a MPH window switch that can be used to shut the valve off after a certain speed so the clutch won't slip during shifts, only on the launch. If you choose to build it yourself (which is what I am going to do), the materials should come out much cheaper. You'd likely be all in, with the window switch, for the same you'd pay for just the kit from MAP.
I would use the MAP or Magnus versions, with the solenoid. Lingenfelter sells a MPH window switch that can be used to shut the valve off after a certain speed so the clutch won't slip during shifts, only on the launch. If you choose to build it yourself (which is what I am going to do), the materials should come out much cheaper. You'd likely be all in, with the window switch, for the same you'd pay for just the kit from MAP.
Thanks, I'd love to build one of these too. I'm in the same boat as you as far as making time to get to the drag strip. My last trip was ruined by my clutch so I spent the money and ordered one finally
Not sure when I'd be able to get it done. Closing in on the end of the season, with lots of holiday festivities. I'll probably order the solenoid and flow controller this week to work on that. Need to confirm that Lingenfelter does have the MPH window switch in stock, as well.
In-line fluid restriction style clutch slippers slow clutch pedal travel thru the entire release cycle, including that deadband travel near the top. No problem if you are launching from a full tree, just launch earlier. With pro-tree or flashlite/armdrop they add reaction time. That entire release cycle delay also does more harm than good after the shifts, so adding the bypass solenoid will show an improvement in et. That et improvement might lead one to think all clutch slip after the shift slows you down, but that's not true. There is a sweet spot in between where some slip after the shifts can improve et even further.
Moving the delay element to the pedal itself allows choosing the effective point in pedal travel where engagement delay becomes active. This eliminates the early release cycle "deadband" delay that hurts reaction time. Also no need for eliminating all delay after the shifts, as pedal deadband delay is no longer a problem. This puts you in the sweet spot with a measured amount of clutch slip after the shifts. Not only does this make it much easier to effectively run radials, but it also keeps the engine from being pulled down as far after the shifts, which adds a little to your power production timeline.
In-line fluid restriction style clutch slippers slow clutch pedal travel thru the entire release cycle, including that deadband travel near the top. No problem if you are launching from a full tree, just launch earlier. With pro-tree or flashlite/armdrop they add reaction time. That entire release cycle delay also does more harm than good after the shifts, so adding the bypass solenoid will show an improvement in et. That et improvement might lead one to think all clutch slip after the shift slows you down, but that's not true. There is a sweet spot in between where some slip after the shifts can improve et even further.
Moving the delay element to the pedal itself allows choosing the effective point in pedal travel where engagement delay becomes active. This eliminates the early release cycle "deadband" delay that hurts reaction time. Also no need for eliminating all delay after the shifts, as pedal deadband delay is no longer a problem. This puts you in the sweet spot with a measured amount of clutch slip after the shifts. Not only does this make it much easier to effectively run radials, but it also keeps the engine from being pulled down as far after the shifts, which adds a little to your power production timeline.
Grant
Im aware of the delay, even on the initial take-up of the clutch before it starts to engage. I don’t bracket race the car or don’t care for any kind of heads up racing (at least for now). Just trying to run an ET/MPH. I have a 9.99 goal, N/A. After I get used to it I can start working on RT and experimenting with the clutch pedal to get a faster RT.
Ive research quite a bit and found multiple instances of that info you provided about clutch slip during the shifts. To accomplish that, I would think I’d have to run a dual stage device. Like you said, there is a sweet spot for the gear shifts . The amount of slip during a launch will be a longer duration that what would be needed for a shift change. Having the same amount for the entirety of the run would likely put a lot of strain and heat through the clutch assembly.
I was able to find someone that has successfully installed one of these in a C6 Z06. I got a few tips and tricks from him. I will be ordering the parts needed, today. I’ll be out of town next week for the Thanksgiving holiday. I hope to have it installed and dialed in before the end of the race season here in Texas.
Ive research quite a bit and found multiple instances of that info you provided about clutch slip during the shifts. To accomplish that, I would think I’d have to run a dual stage device. Like you said, there is a sweet spot for the gear shifts . The amount of slip during a launch will be a longer duration that what would be needed for a shift change. Having the same amount for the entirety of the run would likely put a lot of strain and heat through the clutch assembly.
No need for a dual stage device. There's initially a huge difference between road speed and launch rpm, which means the clutch slips longer during launch than after the shifts using the same rpm pulldown rate.
In a drag race setting, controlled clutch slipping basically makes it possible to raise an engine's average rpm, increasing the amount of power it can produce in a compressed time period. Sure you lose some of that power increase due to heat absorbed into the slipping clutch assy, but there's plenty of that power increase left over to make the car quicker/faster. The NMRA Coyote stock guys are great examples of exploiting this to net more power, as they are required to use a $6500 factory sealed naturally aspirated 302cid crate engine that puts out 412hp@6500 / 390ftlbs@4250 using class spec fuel/tune. At 3175lbs, current class record is 10.075 @ 131.86 using the class required diaphragm PP and a single Ram 900 series disc. Also use the same clutch hit/delay settings for both launch and shifts. Calculators say 10.075 @ 3175lbs requires around 620whp.
Depending on how it is connected, clutch operation would be with no delay in pedal.
From the Magnus website--"The built in line lock is used only when launching the car. It is bypassed when you are off the 2step button so there is no clutch slippage between gear changes."
Depending on how it is connected, clutch operation would be with no delay in pedal.
From the Magnus website--"The built in line lock is used only when launching the car. It is bypassed when you are off the 2step button so there is no clutch slippage between gear changes."
Steve
They make it sound like any slippage on the gear change is a bad thing, but they simply had too much slippage on the shifts without the solenoid. They are missing the sweet spot of controlled slip where it's a little quicker, parts don't break, and you can keep radials stuck. I don't know of any racers that prefer the solenoid style release after having used both types of delays.
The below graphs show "Psi" data recorded from a hydraulic throwout bearing, while using an adjustable hyd cylinder to control the release of the clutch pedal.
...This graph shows a range of incrementally increasing amounts of "initial hit" available, basically giving you the ability to instantly release the clutch pedal to a precise point in the pedal's travel. This is important because it gives you the ability to temporarily withhold or "dial out" excess clutch clamp pressure, which would otherwise pull the engine down and cause a bog. Notice how quick and sharp the transition is from unrestricted to delayed travel...
...This graph shows a range of secondary pedal release rates, all using the same "initial hit" setting. This gives you the ability to precisely and independently control the clutch pedal's travel rate beyond the "initial hit" point, which is important because it gives you the ability to separately control how long the clutch slips...
With the Magnus style inline restriction delay, the curve basically ends up looking like the 3.5 turn setting on the second graph. This more vertical pressure curve results from compromising to improve reaction time, at the cost of not enough slip time. It's also common for Magnus style users to partially engage or "pre-load" the clutch prior to launch, an effort to cut reaction time to allow more slip time, but consistency suffers as you are relying on your foot to find the same amount of preload each launch.
Biondo Racing Line Lock Solenoid - 1/8" NPT in/out
(2) 1/8" NPT to -4 AN straight adapters
(2) 1/8" NPT to -4 AN Tee fittings
(2) 6" -4 AN Female - Straight to 90 Degree Brake Line
(2) 12" -4 AN Female - Straight to 90 Degree Brake Line
Speedway Motors Adjustable Brake Proportioning Valve - 1/8" NPT
This is what you need to convert your clutch hardline to AN:
I ordered these off Hydraulic Discount Hose
(2) 9606-04-S06-14
(2) 5204S-06 DIN 2353
(2) 5202-06 DIN 2353
It was roughly $190 in material.
The person I spoke to said he had to modify his kit before he was able to get it to work properly. He did have a Tick master cylinder, though. He told me that he had to widen the orifice in the solenoid to get the pedal to feel like "stock". I will try to install it, as-is, since I am still on the stock master cylinder.
They make it sound like any slippage on the gear change is a bad thing, but they simply had too much slippage on the shifts without the solenoid. They are missing the sweet spot of controlled slip where it's a little quicker, parts don't break, and you can keep radials stuck. I don't know of any racers that prefer the solenoid style release after having used both types of delays.
The below graphs show "Psi" data recorded from a hydraulic throwout bearing, while using an adjustable hyd cylinder to control the release of the clutch pedal.
...This graph shows a range of incrementally increasing amounts of "initial hit" available, basically giving you the ability to instantly release the clutch pedal to a precise point in the pedal's travel. This is important because it gives you the ability to temporarily withhold or "dial out" excess clutch clamp pressure, which would otherwise pull the engine down and cause a bog. Notice how quick and sharp the transition is from unrestricted to delayed travel...
...This graph shows a range of secondary pedal release rates, all using the same "initial hit" setting. This gives you the ability to precisely and independently control the clutch pedal's travel rate beyond the "initial hit" point, which is important because it gives you the ability to separately control how long the clutch slips...
With the Magnus style inline restriction delay, the curve basically ends up looking like the 3.5 turn setting on the second graph. This more vertical pressure curve results from compromising to improve reaction time, at the cost of not enough slip time. It's also common for Magnus style users to partially engage or "pre-load" the clutch prior to launch, an effort to cut reaction time to allow more slip time, but consistency suffers as you are relying on your foot to find the same amount of preload each launch.
Grant
I hear what you're saying. I daily drive my car. I need something that I can disable to continue to drive the car, normally, every day. As I've stated before, clutch life is a higher priority for me. My whole reasoning for attempting this is to lessen the chance of any driveline breakage at the track. I will eventually experiment with gear shift clutch slippage but that's not what I am currently after. I don't know how well my Monster LT1-S will hold up and eventually plan to go to the Mcleod RXT.
hey jay. Before you go this route, I would get some more seat time. I just got back from the track with a very similar setup as you. Best run was a 10.001 @141 with a 1.49 60'.
It is definitely achieveable. What clutch are you running?
hey jay. Before you go this route, I would get some more seat time. I just got back from the track with a very similar setup as you. Best run was a 10.001 @141 with a 1.49 60'.
It is definitely achieveable. What clutch are you running?
The closest track to me is an hour away. The closest track that's not a pile of excrement is an hour and 45 minutes away. I drive to and from. It's not something I can do every weekend. If no cars break or oil down the track, I can get, maybe, 3 runs in a night.
I run the Monster LT1-S.
Good run tho! I saw you post in another thread and was waiting to hear what you ran. What was the DA?
I hear what you're saying. I daily drive my car. I need something that I can disable to continue to drive the car, normally, every day. As I've stated before, clutch life is a higher priority for me. My whole reasoning for attempting this is to lessen the chance of any driveline breakage at the track. I will eventually experiment with gear shift clutch slippage but that's not what I am currently after. I don't know how well my Monster LT1-S will hold up and eventually plan to go to the Mcleod RXT.
There's absolutely nothing that keeps you from daily driving a pedal based slip controller. Casual clutch pedal release is not affected. Unless you are doing full throttle quick pedal release, there is no added slipping.
Casual engagement with less than full throttle takes place at a lower point in the clutch pedal's stroke, where clamp pressure more closely matches the engine's part throttle output. Pedal based slip controllers are tuned for wot conditions which require more clamp pressure, so they don't become effective until a higher point in the pedal's travel. No need to disconnect for casual driving.
The closest track to me is an hour away. The closest track that's not a pile of excrement is an hour and 45 minutes away. I drive to and from. It's not something I can do every weekend. If no cars break or oil down the track, I can get, maybe, 3 runs in a night.
I run the Monster LT1-S.
Good run tho! I saw you post in another thread and was waiting to hear what you ran. What was the DA?
I already ordered the parts.
Thanks. I dont know what the da was but im sure it was very low. Im curious to see how the install goes. Ill be staying tuned. Try to get in on a track rental so you can get a lot more runs in.
Thanks. I dont know what the da was but im sure it was very low. Im curious to see how the install goes. Ill be staying tuned. Try to get in on a track rental so you can get a lot more runs in.
Not very many happen around here. Hoping to get it done before the end of the season for sure.
11-13-2017, 05:12 PM
Hydraulic Launch Control Device
