Launch control and slicks - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 09-02-2010, 05:32 PM   #1
Junior Member
Thread Starter
iTrader: (9)
 
Join Date: Apr 2007
Location: Hanover, MA
Posts: 237
Total Cats: 0
Default Launch control and slicks

Iíve been to the drag strip a few times with my Miata but didnít have good luck messing with launch control on street tires (RS2ís). It would either bog or I ended up getting lots of wheel spin or wheel hop so after a few tries I went back to slipping the clutch. I still would fight wheel spin and most 60í times were around 2.3. My best was 2 seconds flat but that was a fair amount of clutch slip and after that the stock clutch did not want to grab too well the rest of the day.

This year Iím going to be running drag slicks. Iíve never launched anything on slicks before and donít really know how hard they will bite or if I will still get wheel hop. Slicks are 24.5x8.5x15 and are not radials and Iím also running a pucked clutch. Iíd like to see how other people are launching and come up with a strategy since Iíll only get a few chances to try at the track.

So who uses launch control? Slip or dump clutch? What RMP are you launching at? Whatís your best 60 foot? Will the softer slicks cause less wheel hop?
Pseudosport is offline   Reply With Quote
Old 09-02-2010, 06:09 PM   #2
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,165
Total Cats: 2,573
Default

What do you have your lc set at?
18psi is offline   Reply With Quote
Old 09-02-2010, 06:25 PM   #3
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,894
Total Cats: 109
Default

Forget launch control. On slicks, you do not need it.

I have found that wheel hop is eliminated when using slicks. Slicks bite hard, so you will need to come out at a high rpm. I come out at 7000. My best 60' was a 1.71
miata2fast is offline   Reply With Quote
Old 09-02-2010, 06:36 PM   #4
Elite Member
iTrader: (8)
 
Join Date: Aug 2007
Location: Bellingham, Wa
Posts: 2,732
Total Cats: 3
Default

One day we had our autox timing equipment set up at a launch station during a school we were putting on. I used that to set up my launch control. I dont know the distance so its irrelevant. The best I could do without the launch was 2.5 seconds, with it I did 1.8 consistently and so did my girlfriend. I could have turned the launch RPM up a little more as I was still slightly bogging but I was happy with it. The nicest thing about launch is the consistency of your launches. Of course I do not drag race, only autox so its a pretty different scenario.

This was on RS2s as well.
wayne_curr is offline   Reply With Quote
Old 09-02-2010, 06:39 PM   #5
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,894
Total Cats: 109
Default

/\The game changes when you have slicks
miata2fast is offline   Reply With Quote
Old 09-02-2010, 06:41 PM   #6
Senior Member
iTrader: (1)
 
Join Date: Mar 2008
Location: Cromwell CT
Posts: 1,106
Total Cats: 48
Default

wheel hop is all dependent on tire pressure and suspention settings. there is no perfect formula, its all practice and trial and error. the purpose of launch control/2step is so you dont need to focus on holding your revs. you can concentrate on the tree better.

your tire pressure is gonna be key, and getting the slicks hot in the burnout box. your prob gonna wanna start out with 10psi or so in the tires. and just play with it. but i recomend launch control so you can focus more on what is happening. being consistant is the name of the game.

i dont drag my car, but i work for an engine shop that builds alot of pure drag engines and my boss and his wife are both hardcore racers. so i have learned alot from them
ctdrftna is offline   Reply With Quote
Old 09-02-2010, 06:50 PM   #7
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,894
Total Cats: 109
Default

I have had tire preasures from 8lbs to 20lbs, and never had a problem with wheel hop on slicks. Radials on the other hand, I am about to have to spit my broken teeth out after a launch.

If you have launch control, great. But if you don't have it, you can still cut a good light and have a good 60'. Practice.
miata2fast is offline   Reply With Quote
Old 09-02-2010, 08:35 PM   #8
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Well if you have slicks and a pucked clutch then rev it all the way to redline and sidestep your clutch. FWIW I do say go with launch control but not megaboost- like 5psi. I say save that for the last drag of the day because **** will break from the mad torque transition.

I assume you are asking for GRM competition strategy? I think it's super awesome that you have entered and placed so high already. You are a celebrity!
Faeflora is offline   Reply With Quote
Old 09-02-2010, 09:21 PM   #9
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,165
Total Cats: 2,573
Default

Quote:
Originally Posted by miata2fast View Post
I have had tire preasures from 8lbs to 20lbs, and never had a problem with wheel hop on slicks. Radials on the other hand, I am about to have to spit my broken teeth out after a launch.

If you have launch control, great. But if you don't have it, you can still cut a good light and have a good 60'. Practice.
You have experience with n/a miata's, but how many turbo miata's have you launched at the track?

Having launched n/a cars and f/i cars I'd say the difference is SIGNIFICANT in the amount of effort to get an f/i car in that "perfect spot" of not bogging and not spinning. The torque onset is nowhere near as predictable as n/a. sure the slicks will definitely help not spin or hop, but its still a bitch to not bog.

Launch control simplifies that greatly, and takes out one more variable: lag.

Just sayin
18psi is offline   Reply With Quote
Old 09-03-2010, 12:05 AM   #10
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,894
Total Cats: 109
Default

Wirelessly posted

Nitrous=forced induction
miata2fast is offline   Reply With Quote
Old 09-03-2010, 01:25 AM   #11
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,165
Total Cats: 2,573
Default

that may be, but its still not the same as a turbo
18psi is offline   Reply With Quote
Old 09-03-2010, 08:49 AM   #12
Elite Member
iTrader: (13)
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 5,702
Total Cats: 237
Default

Go tune your carbs.

I personally find launch control a lot more predictable and get better launches with it. Have not tried slicks yet, even the 1.8 torsen can/will blow up.
Fireindc is offline   Reply With Quote
Old 09-03-2010, 10:36 AM   #13
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

What rear end are you running? Miataturbo.net shoudl sponsor you
Faeflora is offline   Reply With Quote
Old 09-03-2010, 10:40 AM   #14
Elite Member
 
Join Date: Feb 2008
Location: Victoria, BC
Posts: 2,322
Total Cats: 12
Default

I use a set of BG Goodrich drag radials and have my launch control set to 4500RPM, and i make 4 psi of boost while there. My last drag race session with launch control was my absolutely most predictable session I ever had.

I think one of your main problems is that your launch control probably isn't making any boost. Fix this and you will not bog at all.

Secondly, you need to get rid of the stock clutch.
dustinb is offline   Reply With Quote
Old 09-03-2010, 11:23 AM   #15
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,165
Total Cats: 2,573
Default

Quote:
Originally Posted by Fireindc View Post
Go tune your carbs.
18psi is offline   Reply With Quote
Old 09-03-2010, 05:41 PM   #16
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,894
Total Cats: 109
Default

Quote:
Originally Posted by Fireindc View Post
Go tune your carbs.

I personally find launch control a lot more predictable and get better launches with it. Have not tried slicks yet, even the 1.8 torsen can/will blow up.
Go learn more vlad.
miata2fast is offline   Reply With Quote
Old 09-03-2010, 05:58 PM   #17
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,165
Total Cats: 2,573
Default

his name is not vlad
18psi is offline   Reply With Quote
Old 09-07-2010, 01:04 PM   #18
Junior Member
Thread Starter
iTrader: (9)
 
Join Date: Apr 2007
Location: Hanover, MA
Posts: 237
Total Cats: 0
Default

I first set launch control at 4000 RPMs and moved down from there. It made about 5 psi and with street tires I just did not have the traction. I tried lowering it to about 3000 and it would either grip and bog or spin tires. Maybe with a little more time I could have found a sweet spot. Also with the EBC boost hits like a hammer. The car can grip then break loose as it spools. I might try a MBC or switch the EBC off in first and run wastegate pressure. Something I can mess with later since I don’t want to add too many variables. Also rear diff has been upgraded to 7” with an RX7 LSD shimmed with a beer can.


Ha, this would be GRM competition strategy. I start my runs at 8 psi and make sure I get a time slip then start adding more and more boost. Last year I got up to 19 psi out of the 14b but I did not go any faster then when I was running 15 psi. 19 just made the clutch slip more and blow hot air up top. This year I’m running a 60 trim T3 and maybe a 50 shot of nitrous. Yes, I know the rods might not like this.
Pseudosport is offline   Reply With Quote
Old 09-07-2010, 09:11 PM   #19
Elite Member
 
Join Date: Feb 2008
Location: Victoria, BC
Posts: 2,322
Total Cats: 12
Default

Quote:
Originally Posted by Pseudosport View Post
I first set launch control at 4000 RPMs and moved down from there. It made about 5 psi and with street tires I just did not have the traction. I tried lowering it to about 3000 and it would either grip and bog or spin tires. Maybe with a little more time I could have found a sweet spot. Also with the EBC boost hits like a hammer. The car can grip then break loose as it spools. I might try a MBC or switch the EBC off in first and run wastegate pressure. Something I can mess with later since I donít want to add too many variables. Also rear diff has been upgraded to 7Ē with an RX7 LSD shimmed with a beer can.


Ha, this would be GRM competition strategy. I start my runs at 8 psi and make sure I get a time slip then start adding more and more boost. Last year I got up to 19 psi out of the 14b but I did not go any faster then when I was running 15 psi. 19 just made the clutch slip more and blow hot air up top. This year Iím running a 60 trim T3 and maybe a 50 shot of nitrous. Yes, I know the rods might not like this.
Are you seriously running a stock clutch?
dustinb is offline   Reply With Quote
Old 09-08-2010, 02:27 AM   #20
Junior Member
Thread Starter
iTrader: (9)
 
Join Date: Apr 2007
Location: Hanover, MA
Posts: 237
Total Cats: 0
Default

I was running a stock 1.8 clutch the first 2 years. I didn't know what my set up was going to be capable of. This year I'm running a 6 puck XTD.
Pseudosport is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
My solution for Oiltemp and Oilpressure input into Megasuirt (MS3) Zaphod MEGAsquirt 41 01-24-2016 01:25 PM
1991 special edition with hard top full part out JC, NJ russian Miata parts for sale/trade 6 10-08-2015 04:01 PM
New personal best 1/8th mile tehzack Dynos and timesheets 10 09-21-2015 07:30 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:24 AM.