Nakoz

iTrader: (2)

I have a 2002 SS that dyno'd 330hp with 345/lbs at the rear wheels and for some reason the best I can hit are 13.50's on ET Streets. Talking to a few people I figure I should be in the low 13s but I never get there. The main problem I have is getting out of the hole. For some reason evertime I launch my car takes off great, then falls on its face and takes a sec to come back to life. This is slowing me down big time in my 60ft and times. I have an M6 and have launched at 5000 before but it still bogges from the line. Any ideas?

Thanks
Nakoz

x phantom x

iTrader: (14)

All driver, your launching it completely wrong. A bog by definition is when you launch, then it falls on its face because the RPMS come back down. Try this to get u used to it ... put it in first, drop the clutch and mash the gas. You'll spin the tires badly. Next, do it again, and mash the gas less. Spin the tires less. Keep doing that until you find the sweet spot of your car. On mine I bring it to right around 2500 rpms, and then give it about 1/2 throttle until it gets rolling, then gradually push it down. No tire spinning, no bogging, but still a good quick shot. On my g-tech I used to pull consistant 2.0's on a crappy street and on street tires. Just get out there and practice.

Vendetta

I gotta get one of those... but there's nowhere around here to practice without getting the cops called. Any suggestions on where to practice launches, Phantom?

DD966

iTrader: (3)

I agree w/phantom. I also have a M6, and 5000 RPM is way too high to launch, on street tires especially. My best 60' was at 2000 RPM (saving for wider rims and DR's). IMO the best place to 'practice' is at the track. Good Luck

redsscamaroboy

iTrader: (7)

Just a question,but do you have traction control and are you turning it off to race????
That would explain the falling on its face after a hard launch.

ATEURZO6

Practice!!Practice!!Practice

x phantom x

iTrader: (14)

Well, I live like 4 blocks away from a movie theater, and it has a HUGE parking lot. I used to go there late at night, and pull like 15 launches, run to the end of first where I would normally shift, then just put it in neutral, coast down, then stop and do it again. I found its the best if you have a friend with you to yell GO! Otherwise I always found myself starting to roll before I actually decided to go.


Traction control would definately make you fall on your face ... but I think its more of the wrong RPM he's launching at ... it sounds like hes going from too high.

WS6_KID

Since were on the subject, i've been getting some really good launches lately. I use tha same technique listed above. bring the revs up to 2k and give about half throttle till i start rolling and gradually get on the gas. This has resulted in some very very very good launches on the street, but my clutch will sometimes act like its goin back to the floor when I finally get to wot.....someone wanna gimme some insite to that?

Iv_z28

It's totally Ok to launch from 5k-rpm, if it hooks. I don't know why people tell you to drop rpm if you bog... you really should do exactly the opposite - go up. On ET streets and good track... I suppose redline launch is Ok. As long as you don't spin. What you need to do is keep rpm up, gas pedal to the floor and don't let them (rpm) drop as you release the clutch. Keep it say at 4krpm... when it starts to choke (rpm go below that) - ease the clutch a bit. This is not easy on the clutch, but that should take care of your problem. In no event let the rpm drop below your power band... I do hope you have something other than stock 10-bolt

x phantom x

iTrader: (14)

Are you serious? Do you understand what that burning smell coming from your car after you feather the clutch at 5 grand is? Thats telling you that your doing it WRONG. The bogging is caused because of a sudden drop in RPMs when your clutch engages ... going higher will make you bog MORE. You are not only going to run through clutches every other month, but your most likely going to spin like crazy, and if you do manage to get traction after a redline clutch drop, all your going to manage to do is snap that 10 bolt into lots of tiny pieces. Take it from what everyone else says, that is the proper way to launch a car on a stock 10 bolt on the street. If you get a 12 bolt, DR's and a set of gears that will allow you to do a 5k rpm drop and not bog or destroy your clutch, then your all set, but until then do it our way.

Vents

iTrader: (9)

put a gear in that car, and it'll help keep the nose up ;D

Iv_z28

Did you read the 1-st post? What DR's are you talking about? What spin? The guy is on ET streets at the track and is trying to use their potential, for christ sake...
..sure, it's not easy on the clutch and rear end. That's what I said. And you WILL break something, if you drop the clutch at 6k all the time. The point was whatever rpm you launch at, don't let them drop. And you propose to cure bog with lower rpm? Higher rpm's make you bog more? whatever, pal...

Nakoz

iTrader: (2)

Thanks guys for all the Posts I really appreciate your info , and to answer a few questions, I dont believe I can turn my low trac on or off, either way it doesnt really effect my launch. I can literally do a 5 minute burnout and it will never come on. But it does engage when I downshift at high rpms.

Currently I do not have anything other than a stock 10 bolt. I did however get the aburn gear posi when i bought the car but that really doesnt help much.

I have a set of 4:10s in my closest and may put them in,(still debating on it).

Either way I will try your suggestions.

Thanks

x phantom x

iTrader: (14)

Pal ... he said he HAD launched from 5k RPM ... and it bogged. What are you proposing that he does??? As you say he should go higher ... to where? 6k? With ET streets and a stock 10 bolt? Maybe if your on crack. If he takes your pathetic advice, he will snap that 10 bolt into millions of pieces, guaranteed.
As a few people here have stated, go from a lower rpm, do EXACTLY what I said rolling into the gas as you go ... and you will not bog. Very simple. I don't understand what your gripe with the laws of physics are, but I would love to see you launch a car with ET street at 6k and not bog/break anything. Send me a video of it happening and I'll take back all my statements. Btw, I have only once seen an fbod at a track launch from a really really high RPM ... and they towed him off the track a few seconds later.

Nakoz, if you want to break your car, without solving your problem, go ahead and take this guys advice ... if you want the simple solution that will work, take the advice from the rest of the people that have responded.

1320_PERFORMANCE

I once launched my car @ 4500 rpm with bfg's drag radials and my god damn clutch spun since then I now launch @ 3500 jus to be on the safe side, maybe when i get my spec stage 3 clutch ill launch @ a higher rpm, the next thing ill have to worry bout is my rear end goin!

FLYNLO

Phantom, I guess it all depends on what your ultimate objective is. If it is the best ET at no expense, then IV's advice is the best. It IS hard on the drivetrain. But with ET streets you are either going to bog, pull a wheelie, or your drivetrain(most likely clutch) is going to absorb some the energy. The goal should be just the right amount of wheelspin without really breaking the tires loose(kinda like the inverse of anti-lock brakes). I like to think of the clutch as an infinitely variable torque converter ....not really because I can't afford to keep replacing them but it can be used that way.
BTW, J-rod launches his near stock ZO6 on ET streets on the rev limiter. Look at the remark on this site where his avatar should be.

x phantom x

iTrader: (14)

I would assume most peoples objective would be to get the best launch you can, without breaking your car. Personally, I dont think that dropping your 60ft time a few tenths of a second is worth destroying your drivetrain ... obviously there are some people that do think that it is worth it.
The method I have suggested is tried and true, I have been using it for awhile, and I'm sure that is the method that most people use. I always seem to get a pretty good launch, with minimal tire spinning, and no bog ... so it definately works. Plus, even with a bunch of hp, and 4.10s, I have yet to break anything (knock on wood).

Vendetta

Sometimes I'm glad I have an automatic

x phantom x

iTrader: (14)

Yeah, honestly an auto is so much easier to drive / more consistant / less problems / alot nicer in traffic .... but a manual is just so much more fun to drive.

Iv_z28

xphantomws6x :

I'm really tired.. I'll try to explain for the last time. If a person cannot understand in 3 attempts, then I normally give up.
Nobody tells nobody to launch at a specific rpm of 5krpm or 6198rpm or whatever... ...I just explain that whatever rpm you launch at, if you allow rpms to drop to 1000 - that's what the bog is. So it doesn't matter if your original rpm is 2000 or 6000 - if you drop the clutch and your rpms drop to 1000 - you WILL bog. So, again, if you decide to launch at 2000rpm - keep it at that #, don't let rpm's drop. If you launch at 3krpm - keep it there, don't let it drop. Ultimately, provided you have traction, guts and good parts, you can launch that way at 6k+ rpm.
Now it doesn't make no sense to launch at 3-4krpm and then allow rpm's to drop - that's how you toast parts... ...if you want to go up the range - use it.
It seems to me that you are not arguing with the "don't let rpm drop" part, you just fixed yourself on the 6000 #...

My personal technique is to actually go almost off-idle (1.5-3krpm, depending on track prep), and INCREASE rpm as the clutch engages, so that by the time it's fully engaged, I try to be at 4-5krpm. FWIW, that gave me relatively consistent 2.0 60' on street potenzas 245/50ZR16 at one of the worst tracks in the country (SIR), no VHT on tire trick or anything like that...

In the end I'm not sure what you are proposing; like the guy above said, I only gave the recipe to get the best #'s. If you want to save parts, just use street tires.

anyway, try to read it twice if something doesn't make sense to you, I'm not going to explain anymore..

_________________________
as a side note, I did try to start moving at 4+k couple times, that's when [stock] clutch pedal goes to the floor... now this is subjective, but IMHO it's the difference in rpm and sharp clutch drops 6krpm-1krpm that snaps 10-bolts. I.e. if you start at 6krpm and ride the clutch, your rear end will be Ok (sort of like converter), though riding the clutch is riding the clutch and will burn it eventually, but it's better than let it go at 4k...