Nose dive after launch Help

[camaroaddiction]

So I just put in a Mcleod RXT twin disk clutch and a two step. Before I did this my best 60' (only 1 good pass before my stock clutch shit the bed) was a 1.69. I figured after putting in a new clutch that could handle a 5300 RPM launch i would definitely see a better 60' but a couple days ago at the track i was consistently cutting 1.775 60' times. I did notice that my car seemed to be taking a nose dive shortly after launching. i will post a video so you guys can see what im talking about. the launch in the video is at 4000 rpms but its the best angle to see the nose dive that i could get.

[frankwjr]

it's called BOG...your clutch is hookin faster so you gotta up the launch rpms...keep increasing the rpms by 200...

also what rear tire combo/psi....any other work done on the car?

[camaroaddiction]

They're Hoosier slicks 28x10 and I was running 19 psi. It's cammed FBO dss axles eaton truetrac and LPW diss cover

[frankwjr]

so yup, start thinkin about a 5k launch...seriously...you want the tires to spin like once or twice before hookin...what kinda of burnout are you doin? should be all nannies off, quick spin in the water and then dump the clutch at 5-6k in 2nd gear...should get a nice burn and as you start to roll forward clutch in...do not dry hop if you like your axles!

I got some great info and education at the 'fest this year and hopefully this Friday I can get back to my track with my new rear DR setup...and will be postin the results..

good luck!

btw - post a couple of your time slips, great info there!

[camaroaddiction]

i have other videos of me launching at 5300 rpms i will post those as well, it still dives down. and i wasnt doing huge burnouts because the car hooks pretty well but the next time i go i am going to try to have the tires spin a little and maybe slip the clutch a little bit? also is this something i should talk to my tuner about?

[camaroaddiction]

[frankwjr]

that looked pretty good...get the tires heated up a bit more I would think, slicks like heat. what are your times?

btw - nice car..where in NY?


my setup for tomorrow at Mason Dixon here in MD(NO RAIN!!!!!) Nitto NT05R 305/45r18 on 18x9.5..I can drive to my track, literally 10 mins from the garage..I'm in big trouble...

[flyby]

So you were at Island?

[frankwjr]

I still have the stock clutch and slip it just a bit...you need to hit up the folks runnin twin disk setups on how they hit....

btw - with the slicks you should be spinnin the tires a bit, could try lowering tire pressure some...15 psi I hear but watch out for the rim to spin on the tire bead(mark it)

[camaroaddiction]

I'm in Westchester but I go to Island, Lebanon and e town ... as long as I know it's engine bog and not something with the suspension I'll try slipping the clutch a bit on the launch and see if that works next time out

[QUICRNU]

silly question, its no where near the limiter when it dives right?

[acammer]

First one looks like a bog - slow the clutch release down or continue to raise the launch RPM. Second one looked better - doesn't have much trouble hooking. Still a 3.45 gear?

[camaroaddiction]

no its not near the limiter when it bogs lol and no it doesnt have trouble hooking at all and i have 3.91 gears installed in it

[BFASTNOTLAST]

Originally Posted by camaroaddiction

no its not near the limiter when it bogs lol and no it doesnt have trouble hooking at all and i have 3.91 gears installed in it

Go back and make sure you have all the torque management settings off or maxed out. More than likely it's in the tune. Or simply the clutch is more aggressive vs the car weight with the power you have and is causing the bog by inertia.