Launching A Drag Car-Baselinesuspensions.com

[Scoobum]

Sniffing around and found this article:

http://www.baselinesuspensions.com/info/Launching_A_Drag_Car.htm

[Steve Wood]

yes, Kevin has some good stuff.  I think Jason has some of his stuff.  Strangely, I have not seen much improvement over stock suspension on the Buicks which is strange as G bodies have a lousy instant center.  Seems like dropping the front of the upper control arms should load the rear tires better.  Maybe we are just not fast enuf.

[good2win22]

I have his uppers. He has a really neat calculator for plotting instant center.  http://www.baselinesuspensions.com/instant-center_general.php


You'll need to lower the rear of the car to get the lowers parallel or get some relocation brackets.


The door slammer book is a must read for suspension education.


I don't have enough time at the track to really fine tune my car. Someday along with a million other things....

[TexasT]

A lot goes into getting a car to hook well and hook with consistency. Front end plays a lot on it too.

[Scoobum]

Because I have the IQ of a house plant it forces me to keep things simple and think as little as possible...so this is what I did...and it ain't very scientific.

I had Dan Keller come out and videotape my car from the back DS rear quarter when I launched the car. What I saw on the vid was this. The rear was coming down...bottomi ng out and then coming back up again...and unloading the back tires...basica lly shifting the weight to the front of the car to quickly. I had cheapass 90/10 Lakewoods on the front and Lakewood 50/50's out back.

I bracket race the car and leave the line at exactly 2800 each time to keep the car on it's 'dial'. My solution was this. I swapped in a pair of QA1 single adjustables on the rear. I went to a Mix and Match nite at my local track. It's poorly attended...so I have the track to myself...while the locals are busy swilling Timmies coffee and scarfing down donuts...and wondering why they can't do what I do. Get off yer' arses and get out and practice. Anyway, I went out on the track with the knob set on 3 from the lowest soft setting and left at 2800 RPM. I kept going out and kept upping the stiffness until I got my best 60 at 2800. I increased the RPM and kept going out unti I hit the 1.5's. I know exactly what RPM to leave at and what shock setting to achieve a desired short time with my car. Track temp and tire pressure play a role as well...and I have a temp gun I check the track with before I go out for each run. Not scientific...b ut it works for me. I have an old skool ATR rear bar and Metco rear billet lowers. Springs front and rear are stock with the stock front sway bar in place.

[Steve Wood]

I have a couple of copies of the Doorslammers book.  It is still the best out there.

Performance Trends makes some good software that makes it a snap to compute instant centers and easy to input a bunch of what ifs if you want to adjust it.  I bought it years ago.

Years ago, I bought some drops from Chuck Leeper.  I put them on the GN that has been lowered an inch with shorter springs.  The car would come straight up in the air like a superstock Mopar from the '60's.  Only problem was that right before it shifted into second, it unloaded the tires and started spinning them.  Awesome to watch leave tho.

I believe the problem with most short times is the driver.  Many are simply afraid to hit it hard enuf to get that good short time.  A good short time really hammers you in the stomach and the car begins to move a bit so the driver lets off, or backs off from how hard he is leaving to begin with.

It also takes power to get a good leave.  The power has to be there when your foot comes off the brake-not a second later.  That gets us back to the converter/turbo match.

[Scoobum]

What Steve's referring to is G's when you leave the line. A 1.70 launch is 1 G. a 1.50 launch is 1.5 G's. It feels to me like I've had the wind knocked out of me...best feeling in the world...addict ive like a drug. Norbs was tuning 3 of the locals cars with XFI. All 3 files showed the TPS come down at launch. The G force from launching scared them.

[Steve Wood]

yes, the tps always find the liar!  LOL

[Forzfed]

Good Link!

[good2win22]

What's funny about the G's on a good launch is how instant it is. I have pulled more than 3 G's flying acrobatics with no problems. Maybe I need to get a real harness instead of the stock belt when launching from the sofa.  I had better launches in the white t... There may be something to the bucket seats and launching...

[Steve Wood]

A good launch is like being hit by Mike Tyson. It's instantaneous.

I bet a good belt setup would help a looks

[Scoobum]

Vid of the 4 point harness I installed in my car.

https://www.youtube.com/watch?v=3DNV7jvNiPE