Back to the track! (Video with slow motion launch) Help me with my 60'

[mkb116]

Solved!!!! Tire pressure. Tire pressure. Tire pressure.

So I'm still trying to sort this launch out. I thought for sure slicks would help my 60', but they didn't help over drag radials, at all. Now that we have a slow motion launch video, I can definitely see why we are having 60' issues.

Solid axle in the rear
team Z double adjustable lowers
single adjustable Kenny brown uppers
mini spool
3.73's
Lakewood 50/50's out back
stock springs with 1 coil cut
MT bias ply 28x10.5 ET drags
6 point roll bar
About 750 rwhp.

Lakewood 90/10's up front
Team Z k member and tubular suspension
Coil overs, can't remember spring details but it was for drag.

Best trap to date has been 137. That was not at this event. Did 133 with a 1.8 60'

Car has NO subframe connectors OR anti roll bar (no rear sway bar either)

The two step launches were at 3000 rpms, and you can see how well that works for us.

After watching the video of the launch, it seems clear that I NEED subframe connectors and an anti roll bar. Any recommendations?? I will admit I have no idea what the pinion angle is, we need to get that sorted out.

Thanks for the help everyone.

[video]https://youtu.be/gH9h-hV44H4[/video]

 

[98 N/A 4V]

Tire pressure?

You need at least some rear sway bar (stock or anti roll).

Also the car looks low. Which means if you have the stock mounting points I'd bet your lower bars are pointing downwards and your IC is probably at ground level.

I used to have lakewoods too. Low powered cars they work great. At your level you need at least a single adjustable. Double is preferred.

-Mark

 

[BlckBox04]

I agree with tossing those 50/50's. Don't cheap out on that rear suspension. It also looks like you're not getting any weight to travel from off the front end and it's unloading your rear suspension as soon as the power hits. I'm having the same issues. And that's strange because you have k member and front suspension. Sub frames would also be a definite piece of mind just for the support of your whole body flexing.

 

[broke7]

Bushing type, and Pinion angle? Pinion angle will vary on bushing type.

Tire pressure? Was the track prepped?

Control arm angle? Should be close to level with frame side favoring up 2-5 degrees


As mentioned before when you go low like 1 coil off you really alter IC and the LCA angles which effects alot of stuff not in your favor.




To me the car is squatting, and unloading the tire. It should be forcing the tire down into the ground. Needs a stiffer shock or adjustable in the rear for starters with adjustability.

Also, search on yellowbullet, the amount of knowledge there is unparallel. However, if you post up be prepared for the same questions....and have all your datapoints to share.

 

[ctgreddy]

DEFF get subframes and set pinion angle. We seem to have a very similar setup. I have strange singles on front/back but similar suspension, wheel/tire and power. Last time out with my change to bias plys I got a few mid 1.4 60's. Best was a 1.42. So the potential is there man. I had 2 step set at 4k. Here's a vid of my launch even tho the vid sucks...

https://www.youtube.com/watch?v=5YGLso4pqSI

 

[mkb116]

So the tire pressure made a HUGE difference. Tried the 2 step at 2k, bogged. Tried at 4K. Money! Tire pressure set at 12 lbs.

New best everything in this pass We don't have a video because our phones were dead but man that pass felt awesome.

On the left

 

[98 N/A 4V]

what did you have them set at? I run my 28's at 9psi cold.

-Mark

 

[mkb116]

12 psi cold

 

[bunits19714]

I am more impressed with that mini spool - when is that going to let loose- hopefully at the line and not the 1-2 shift to keep the tire from taking out a wheel well. - crazy-

 

[mkb116]

It seemed pretty beefy when we got it. I bought another axle to send to Mark Williams for some 9" ends and full spool.