Articles, Blog

How to Launch your car perfectly using a Clutch Release Valve – Jay’s Tech Tips #32

September 7, 2019


Hi, I’m Jay from Real Street Performance. Today, we’re going to talk about getting your manual transmission car off the starting line more consistently. So you’ve got your build together, making good power. It’s time to drive to the drag strip and run it. As the car makes more power, traction becomes less available, parts breakage goes up, And you have to get off the starting line more consistent. Some people are born with the talent to drag the clutch through first gear correctly and balance that clutch slip and wheel spin and driveline parts. And some people aren’t. I’m not. So I have to either let the clutch out quickly or use a valve to slow the rate in which the clutch comes out. If you’re launching the car very hard and you have enough power to get off the starting line, but you’re letting the clutch out too aggressively, you can incur a wheel spin, wheel hop, or parts breakage if the car just hooks. The mechanical fix for this problem is to install a valve between the clutch slave and the clutch master to slow the release of the clutch, so the rate that you come off your pedal with your foot isn’t the rate that the clutch is released. You can adjust these valves to release the clutch faster or slower until you have it dialed in for your car. The first example is from Clutch Masters. Tilton also makes one of these. This is just going to use a different jet size to regulate the speed in which the clutch comes out in relation to the pedal. Because this valve is mechanical, it’s going to slow the rate the clutch comes out on every gear change. Magnus Motorsports makes one with an electronic solenoid on it. You can use it with a first gear indicator switch or hooked in through your standalone ECU. And that way it’s only active in first gear. And it has a dial to adjust the rate the clutch comes out. This is a bit more tunable of a valve. We have installed one of these on one of the cars to the shop, and it helped us get the launch down more consistently. As you can see if we turn the dial, you can slow the clutch way down as it comes out. Or you can adjust the balance where it opens very freely, and the clutch will come out like normal. There’s a wide range to tune the valve in to make sure that you’re getting the best balance between when your foot comes off the clutch and when the clutch is fully released. This is also cool if you’re working on different surfaces because you can loosen the clutch up a little bit so it doesn’t hit quite as hard at the track if it isn’t great that night. So for the money spent and the safety purchased, it’s a pretty good investment. I hope you enjoyed this week’s tech tip. This is a pretty cool little device to help you get your drag race car working more consistently if you don’t have the magic foot. I don’t. Have a go week. See you next time.

32 Comments

  • Reply Darren G. August 10, 2015 at 1:43 pm

    That's pretty neat, and seems like this is cheaper than constantly blowing parts out.

  • Reply Rady Ten August 11, 2015 at 12:01 am

    Do you guys sell these?

  • Reply steisje August 11, 2015 at 8:17 am

    Thanks RSP. Did not know about this item. 😉

  • Reply 3SLights.com August 12, 2015 at 7:16 am

    Anyone seeing the bug moving on the wall at 1:37 on the right side of the screen?

  • Reply Rameesha Muzaffar August 14, 2015 at 4:12 pm

    can you guys make a video of which clutch is right for your application and for the power goal

  • Reply Paul D September 7, 2015 at 1:39 pm

    Where can I buy the electronic one?Thank You.

  • Reply Lake$ide Entertainment September 25, 2015 at 3:23 am

    isint the intro that schoolboy q type beat pretty dope

  • Reply geoff October 3, 2015 at 12:40 pm

    wouldn't this slow shifting once launched?

  • Reply shorty13942 October 6, 2015 at 1:10 pm

    can i use this in a cable clutch

  • Reply shorty13942 October 6, 2015 at 2:02 pm

    alright thought so…well time for some 2 step action for me

  • Reply Tristan Saunders November 13, 2015 at 2:30 am

    Hi! First of all I love these videos so please keep them coming. Jay seems like a very knowledgeable person when it comes to tuning vehicles for performance applications! It's a real privilege to be able to learn from one of the best shops out there IMHO. I'm an apprentice bmw technician and I want to learn as much as possible about the performance world.

    I just thought I'd share that in most bmws built after 1995 with a manual transmission have mechanical clutch delay valves in them installed from the factory! However these valves are not intended for performance application (launching). They are intended for drivability and longevity of drivetrain parts for the average person. However I removed mine because I didn't like the lack of pedal feel and the fact that I couldn't have complete control over my clutch for drifting, burnouts, or even daily driving

    It wasn't as fancy a part as some of the examples you have here, nor was it adjustable, it was basically a one way check valve.

  • Reply Pericles Wanless December 27, 2015 at 2:03 pm

    Why haven't i seen more videos of that dodge?lol

  • Reply Ryan Sammut January 15, 2016 at 4:38 pm

    Hi Jay,
    Great vids!
    Question – Adding this device to a car like mine (6 speed Supra 740whp) with a full face South Bend single disc clutch. Does the clutch take more abuse with this? Should i consult with South Bend first before i get one of these?
    Thanks
    Ryan

  • Reply Michiel Mitchell July 3, 2016 at 12:11 pm

    I can vouch for Marco's setup… it works better than advertised…

  • Reply Steven Holmes July 15, 2016 at 2:37 am

    4l80e

  • Reply Milad Fakhoury August 15, 2016 at 7:03 am

    Would this work on a 2015 Ford Focus ST? Australian model
    completely factory standard.

  • Reply Leshaun Brookes September 21, 2016 at 3:24 pm

    Hey jay I didn't get the name of the electronic valve

  • Reply Doug Swartz December 22, 2016 at 8:49 pm

    Would the magnus one be streetable? thats the one im looking at

  • Reply SpeedPerformance February 26, 2017 at 12:24 pm

    hi Jay, did u notice that u have to adjust the Magnus almost to the end of the turning radius of the know to see the effect? this is what i notice

  • Reply Hector Quinonez April 30, 2017 at 4:22 pm

    i enjoy this guy's videos so much. but every one has a talent. if u can't launch just drive automatic. hahahahahha

  • Reply FRiCKAAA July 3, 2017 at 5:41 am

    Would this be useable with a sequential manual, only need it for lunching

  • Reply Scott Rees July 6, 2017 at 4:54 am

    Magic foot! Love the angelic light and music!

  • Reply 2000 teggy July 31, 2017 at 10:56 pm

    Thanks so much for all the awesome tech tips, may seem for some, but others would have no clue without them! Keep it up please!

  • Reply AL J August 3, 2017 at 12:38 am

    https://youtu.be/n5518nf6OSA

  • Reply hugoortiz05 February 4, 2018 at 6:45 am

    Will this interfere with a wot box?

  • Reply Mr Ahhsum March 7, 2018 at 8:30 pm

    Never heard of this. But I love the idea

  • Reply Sikk Raz3r March 11, 2018 at 3:11 am

    Would this work with hondata v3?

  • Reply careca April 26, 2018 at 11:51 pm

    I got a cable for the clutch so it's a no-go

  • Reply Vinnie Russo July 29, 2018 at 10:18 pm

    Im running a Magnus controller, Also the car has a Tilton Twin disc Carbon / Carbon w/Hydraulic release bearing. The flywheel is also a one-off billet flywheel made by Magnus specifically for the Tilton twin disc. I run a Haltech Elite 2500 and the gearbox contains a Shep / PPG gearset (4 speed). 1st gear is extremely long. How do you recommend I activate it? Through a momentary button like the one on my steering wheel or can this be completely controlled by the ECU to remove the chance of human error?

  • Reply Gamma Light January 26, 2019 at 4:59 am

    This is exactly what I was looking for! Thank you :]

  • Reply MrClassiccarenthusia March 1, 2019 at 1:49 pm

    OMG! Why would anyone want this? My BMW 3 series came with one of these stupid clutch delay valves from the factory.. Deleting it along with its dual mass flywheel and being able to control the clutch fully myself turned it into a completely different car! 😊

    Maybe this doesn't apply in the US where people can learn to drive and pass their test in an auto then buy a manual, but over in the UK, if you have an automatic license, people will generally look down on you as some sort of inferior driver.. Hehehe..

    If your first experience and your subsequent learning phase behind the wheel involved a slush box, then don't be surprised if you never gain the ability to autonomously work a clutch pedal.. 👻 For the rest of us, it's a bit like walking, or breathing, you don't think about doing it, your leg just does it for you.. 🤷🏻‍♂️

  • Reply Brad Urban April 18, 2019 at 3:00 am

    Clutch delay vlave. Just about every new manual car out has one from factory. Trust me, having the right clutch setup is key.

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