AWD Shock Stiffness - Front vs. Rear - 1/4 mile

[laser92awd]

I know every car is different, but searching the archives it seems that people have two completely different theories about the best way to launch an AWD car:

1) Soft front, Stiff rear
or
2) Stiff front, Soft rear

I am currently setup with option 2, and when we watched the video of me launching at the drag strip the weight transfer / rear squat is very, very noticeable. Also the track was slipperly that day and my fronts were having trouble staying planted on the launch. I wasn't getting any wheel hop, but lots of wheelspin (I think my front right is always the first to let go).

So it seems to me that running a stiffer rear (option 1) would help keep the fronts planted and minimize that rearward weight transfer.

But then other people were saying (some with very fast cars) to keep the rear as soft as possible and go full stiff in the front. To me that doesn't make as much sense but you can't argue with those fast times.

And what about stiffening up BOTH the front AND the rear?

Jonathan

 

[diambo4life]

Personally, I stiffen both front and rear but live the back much stiffer. I have good results with that although all the avid draggers have told me that it's best to stiffen the rear pretty good and live the front soft. ArcticTsi seems to launch pretty good with an overall stiff auto-X suspension. I think he has cut a low 1.6x 60 ft. with no stutter box. Just try different setups and see what works best.

 

[jtmcinder]

You are being too simplistic. When you talk about "stiff" vs "soft," you need to separate matters into compression vs rebound damping. You want lots of rear compression damping and lots of front rebound damping, but not the opposites. Since most shocks (especially those from Japan) adjust compression and rebound at the same time, you are forced to compromise. And sometimes the compromise works better getting the type of damping you want and living the other type, and sometimes it's better to avoid the wrong type and give up on what you do want.

Assuming that you are not about to change your shocks, the answer is for you to experiment. Do four runs (or four sets of runs) with the fronts soft and hard and the rears soft and hard. Compare the times for the four combinations and select the best.

- Jtoby

 

[laser92awd]

Assuming that you are not about to change your shocks
- Jtoby

Thanks for the good information. I'm actually about to do some shock replacement.

Let me ask a question this way: If you were going to have a set of shocks that adjusted compression & rebound dampening together, and you were also going to have a set that allowed you to adjust compression & rebound separately, where would you put each set on the car?

together-front & separately-back
OR
separately-front & together-back

(Which end of the car would benefit the most from having separately adjustable dampening?)

 

[jtmcinder]

That's a really good question (which is a fancy way of saying that I don't know the answer). But I doubt that it's really an issue. OTS doubles are hard to find for 1Gs. So my suggestion is to get in touch with Mike at DSS and talk to him about his hybrid system.

- Jtoby