Launching a turbo Miata with a 10 pound flywheel

I've been autocrossing my new to me Miata this season and so far its been a complete blast. The car is powerful ( Thanks FM ) well balanced, has a ton of grip ( thank you Hoosier A7) and other than my not fitting in it terribly well I'm delighted with the whole thing. What I am struggling with is getting launched hard enough. The light flywheel makes engaging the clutch smoothly a struggle at the best of times. Along with the Turbo, the car has the FM level one clutch, that seems to be easily overwhelmed. If I engage the clutch quickly, there is a bog and if I try and feather occasionally I get it perfectly smooth and launch well, but most times it induces clutch smoke or bog.

The car is a dedicated autocross car, and in my region the top 10 are usually within 1/2 second so I'm really trying not to leave anything on the table. I have the Hydra Nemesis ( Thanks again FM) so I do have the ability to use launch control if I can figure it out which seems like it will be a steep learning curve, and perhaps also kill the clutch.

What are fellow GRM ers using for a launch technique with their turbo cars?

It sounds like you need a little more engine rpm to prevent a bog at launch. Get those tires to slip a bit. The clutch shouldn’t have any trouble holding up to a normal FM II, but something’s going to have to give on launch, and those sticky A7s need a little more encouragement to break free. 

+2 for a higher RPM launch. 

You say you have Hydra... Why don't you set up launch control? It's quite easy on any ECU worth it's weight in salt. 

Generally there is a point where you have enough momentum in the engine that even with a quick clutch release it won't totally bog. I wouldn't be surprised if that number was 5-6k rpm in your case. Having a launch control program doesn't change the physics but it does allow you to do accurate adjustments and get repeatable results on the things it controls (which tire heat doesn't fall under). 

two-step/launch control would also pre-spool the turbo.  transition from the 2-step to instant boost.  if the tires and clutch can hold, it is impressive. 

In reply to Keith Tanner :

Thanks Keith, was hoping you would chime in. For some reason I'm overwhelming the level one clutch if I try and rev higher. It seems like its builds boost and then the clutch slips through first and second. I cant replicate slip under load  and under any other circumstances the clutch holds strong. I have yet to try and just rev it a few times and "dump" the clutch....mostly out of fear:) Ive been racing V8's all my life, so I think alot of it is a learning curve, but I have never struggled like this with launch technique. Whats your take on the Hydra launch control? 

In reply to goingnowherefast :

I need a little help figuring out how to set it up. I have no experience with laptop tuning on any system, let alone the Hydra which I think is quite robust. I have never been scared of a car, but for some reason I feel like im on the verge of blowing this thing up all the time... still amazed at the power it makes, and how well it all works together with no drama. Time to get my hands dirty I guess!

You'll want to pop the clutch fairly quickly so the shock breaks the tires free. If you slip the clutch, there's a good chance it'll just keep slipping. If it seems violent, well, a hard launch IS violent.

I've never personally used the Hydra launch control, so I don't have any comments there. My street car runs a Hydra but I don't launch it. My track car used to run a Hydra but it was a naturally aspirated engine so I just did it organically.

Not a turbo car but my old CSPish 97 had the FM1 clutch and flywheel.  Standard launch procedure is rev to 5 grand and sidestep the clutch as you mat the throttle.  On 275 A7s that’s good for about 10’ of wheel-spin and a very violent launch.  

The Magnus Launch Control combined with a 2step can basically automate clutch feathering. You would get a quicker/less violent launch than a wheelspin start, but shifts would end up more violent depending on how far overkill you go when upgrading the clutch.

Grant

In reply to weedburner :

Never knew that even existed! I found a local tuner to help with the lauch control software install and tuning, so I'm taking the car there tomorrow so he can download the base map and send to FM, they will add the launch control and send back and we can tweak from there. The car has upgraded axles and an OS Giken diff so if the clutch holds it should be a fun ride.