How does ride height effect launch?

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Aug 14, 2007 | 01:29 PM

1SlowFormula

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From: West Linn, Oregon

How does ride height effect launch?

I am in the middle of setting up my new QA1 fronts and don't want kill my weight transfer by dropping the front, but wanted to lower it some for the sake of looks. Would dropping the front negatively effect the launch any and if so how much? I am going from stock fronts to the QA1 shock and springs and it was recommended to start the QA1's at stock ride hieght and tweek from there, but I'm not sure of how to best do this. Wouldn't you have to play with settings to get it dialed in, then when changing ride hieght you'd need to retest all your settings? Then how much do you drop it before retesting, about 1/2" at a time? This sounds like a whole lot of testing just to find a base line, and honestly I don't have that long since I need to have the car ready for a race in 2 weeks, and I still have to repair a few things before I can get it to the track. So I was thinking of just setting it about 1" lower and start to dial it in from there if people thought there was no real negative effect from that...

Oh, the rears are stock springs minus the rubber insulator (heater hose mod) and adjustable Comp. Eng. shocks riding on 275 60 MT DR's (28" tall) so the rear has been a little higher then the front for a while...

Thanks...

Aug 14, 2007 | 02:04 PM

1SlowFormula

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From: West Linn, Oregon

If it helps here are pics of the ride height before the front QA1's

http://www.gallery.smithspeed.com/di...bum=22&pos=181
http://www.gallery.smithspeed.com/di...bum=22&pos=182
http://www.gallery.smithspeed.com/di...lbum=22&pos=74
http://www.gallery.smithspeed.com/di...bum=22&pos=235
http://www.gallery.smithspeed.com/di...lbum=17&pos=82
http://www.gallery.smithspeed.com/di...bum=17&pos=306

And these are after the QA1 install. Yes, I know that it's too low, but I thought it was cool looking and took some pics like that.

http://www.1slowformula.com/images/a_little_low.jpg
http://www.1slowformula.com/images/a_little_low1.jpg
http://www.1slowformula.com/images/a_little_low2.jpg
http://www.1slowformula.com/images/a_little_low3.jpg
http://www.1slowformula.com/images/a_little_low4.jpg

It is currently 2.75" lower then stock, I was thinking of either splitting the difference and raising it up another 1.5" so it has a 1.25" drop from stock in the front, or just making it closer to a 1" drop if the launch will be effected at a lower point. But then again this car is mainly going to be a drag car (whenever I get the money) so whatever gets the better launch will probably be ideal, but I have no idea where to start, or if dropping the nose will help or hurt it...

Aug 14, 2007 | 04:35 PM

Bitemark46

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From: Tampa, FL

In theory yes. Lowering the front will take longer for the load (aka weight transfer) to shift to the rear. Your tires may start to spin until your fenders are greater or equal to the ride height of your rear fenders. Typically you don't want the front fenders to be lower than the rear. If you lower the front, you lower the rear to the equal height.

-Mark

Aug 14, 2007 | 04:52 PM

Anonymous

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Don't forget, everytime you adjust the ride height of the front end, you have to get an alignment done.
Have QA1's been there done that.
With 28" tires you won't want to go too low?
I have 26" and the car sits level. No problem with hook.

Don't believe the hype, the car won't settle much if at all.

Put it where you want it.
Drive it around a little and check it on a level surface.
Been there done that too!

Aug 14, 2007 | 05:45 PM

1SlowFormula

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From: West Linn, Oregon

Quote:

Originally Posted by Bitemark46

Thanks Mark,

I was thinking the same thing, but wanted to see if that was true or not, or if it was noticable. So I guess I will be setting the front and rear ride height to be about the same, and checking how that looks. I think that is still doable, but here is the question...

Where are we worried about measuring? Fender lip height? Body height off the ground behind the front's and in front of the rear's? or measure both and split the difference?

Aug 15, 2007 | 09:50 AM

Bitemark46

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I always go by the fender lip height to the ground. Measure it using the center cap on the rims as a guide to ensure you are in the center of the fender. -Mark

Aug 17, 2007 | 09:47 PM

1SlowFormula

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From: West Linn, Oregon

OK I just finished setting everything up before heaading out to a test and tune session tomorrow.

Currently with no weight in the car it the front sits .25 lower then stock, but it's even front and rear. Should I have set it even empty or with the driver/weight in the car? Maybe I can have my wife and a few sandbags in the drivers side to set it that way, if I should have it even with weight in the car...

So the questions are:
1) Should it be set level from side to side with weight in drivers seat?
2) If set at 2 different heights to compensate for weight on the driver side does this effect suspension travel, weight transfer, or launch?