Help me figure out how to launch, 400 hp and garbage tires

okay, im running around 400 rwhp ( mustang dyno )
and my best run so far has been a 12.85 @114 mph, now my tires are a rock crushing 360 treadwear. so pull the 12.85 i heated them up for a good 6 or 7 seconds, and dumped the clutch at 1700 rpm, as it just started to bog i punched it. and it barely spun.

but it feels like a super slowway to get off the line, im losing a solid second of WOT time doing my launch like this.

how do you guys launch your cars like this without snapping your rearend? im going to the track this weekend and dont want to have a flatbed come pick me up.

What are your 60' times?

Rich

2.2 -2.3 ish

not very good :(

A reasonable goal for street tire 4th gen's is 1.9x-2.0x sec. You should be able to accomplish this with decent street tires but it isn't easy, especially with an M6. First, don't heat them up much, just a quick spin to clean them. Then, the general technique is to use moderate rpm (maybe in the 2K range) and modulate the clutch and throttle to allow a bit of spin to avoid bogging but avoid the tries breaking loose completely. It takes a LOT of practice. Your rear will probably be ok on street tires with this technique.

Rich

You have a couple options here:

1. Get better tires
You need traction to really support 400hp. Get a set of DRs.

2. Fry your tires/clutch
You want more time at WOT? Then get those launch revs up. You just have to compensate with the clutch. Experiment with spinning tires and feathering the clutch.

My tires aren't great either, but I like to launch at about 2500rpm. Just enough clutch to get the tires to chirp as I launch, and WOT as soon as I feel them hook. One thing that will help you keep traction when you go to WOT: don't slam the pedal to the floor! Be smooth. Quick, but smooth. Smooth is the key!

You will get the most out of your tires if they're spinning just a little. Generally, they should be spinning 3-5% faster than you're actually moving. It's really hard to judge that, though, so go by the sound. If they're singing, too much power is getting to the wheels. If they're silent, you didn't give them enough.

Good traps, though. Sounds like your car is making good power. You're certainly making more power than I am (mostly stock over here), so you'll probably have better luck with lower launch RPMs than mine.

Just curious -- what tires are you using?

-Jake

i cant get dr's cuz im scared of my rearend.

i will try just slipping it again. how fast am i going to burn out my clutch doing this?

my tires are a Marshal Matrac tx or something like that ive never heard of them. but yea, ive spun the **** outa the tires and youd never guess it. so maybe theres 1 positive about them :rolleyes:

Lots of m6 buddies running nittos and not breaking their rearends and some with 500engine hp or more.Not run some et street radials or et streets or bfg drags then you can start worrying a lot.

As for street tires read a few guys that ran new fuzion firestones and said they got nearly same times as their nittos and more tire life,better in wet etc.Might be worth trying a set of them. I have them on front right now and may move them to the back for some testing sometime.

Traction is what breaks the rear end or wheel hop..And auto cars have gone low sixty foots without breakage. M6 cars well you can likely get to 1.9 or mabye 1.8,2.0s should be pretty safe. Under 1.8 then it seems you will have problems ,at least thats from observiing our local track fourth gen cars.

You don't build a 400+ hp engine without upgrading everything else. Clutch, tranny, diff all need to handle the amount of power the engine puts out. Although the stock parts will work for a while, they won't last forever.

trust me i would love to, unfortuantly i dont have $5000 to dump on that stuff right now. therefore, i am trying to do this as best as i can and also as safest.

Good luck using your clutch like that. I exploded my stock clutch doing that stuff on the street. It came out the bell housing like bullets :eek: . Anyway, im pulling the same 60' times as you with the pilots. i think it the tires more than anything. I think the rearend can handle the dr's, just have to compensate with clutch again though :death: . 400hp isnt THAT much more power for the rear end to not hold out rather well i would think, but hey, im justa guy.

I had 400 at the wheels and ran radials, which did not help, and never broke my rear. Your clutch should give first. Just don't put sticky tires on it and a good clutch. I finally broke it with ET Streets and a 5000rpm launch.

I always just cleaned off my tires and left the line at an idle otherwise I just spun too bad. :D

i just got a new gtech pro ss
http://www.gtechpro.com/ss.html

anyway, you guys are gunna laugh,

60 ft time. 2.339 :cry: hahaha
but
0-60 4.79 seconds

1\4 mile 12.89 @113.3 mph

so i got the power, i just need to launch !!!

k well i went to the track, so i have some official times. i figured out how to launch :cool: i surprised myself for street tires

60 ft 2.061
1\4 mile 12.86 @ 112.4 mph.

so traction is still an issue, i coulda came so much harder outa the hole if i had good tires. that was only a 2600 rpm dump. for the 2.061.

with dr's id be 1.8's or 1.9's forsure, if my rearend held.