FWD Suspension Setup

[RichardB]

Guys,
I would be interested in hearing from anyone with experience of setting up fast FWD suspension for drag cars, I'm struggling with my 60' times. I can still pull a 10.554@136mph but I only have a 1.795 60'

I run

D2 coilovers with 22kg/mm rear and 6kg/mm front
I've just uprated the fronts to 13kg/mm

I set all 4 corners on the hardest dampening setting (which may not be the best option anyone played with different dampening settings)

I also run
Anti lift straps
Front torshen bars

both to prevent too much front end lift.

From my logs I seem to spin a lot through 1st and 2nd before it really hooks up in 3rd and flys.

I run on MT 26x10's on 15" rims.

We currently pull 560bhp atw but we are looking to take that up to the 8-900 mark for next season with a new engine.

any help would be appreciated

www.mitsubishi-fto.net

 

[whe3ls]

have you tried wheelie bars yet?

 

[bullettdsm]

Your set-up is set to spin. Unless you use wheelie bars to keep the front end from lifting. And even then, you may have a problem with weight transfer (depending on your set-up).

You want a soft up front approach to allow the body to absorb the weight transference on "impact". If it is too solid (and there is nothing holding it down to the ground) the contact patch is lifted on launch and you have less force over the front end (which in AWD and RWD is what you want. With FWD you want the weight over the front end). Try setting your fronts to their softest setting so you get more body lift on impact and less contact patch lift.

The 26 X 10's should be enough, but you should be down in the 8psi range on tire pressure. Also, because of our axle sizes etc (one axle is shorter than the other so there is less "flex" absorbtion in the shorter axle), you will probably want a couple less pounds in the driver side vs the passenger side (try starting out with 10psi and 12 psi and work down from there. Air pressure is a very fluid choice. It depends on your set-up, time of day, barometer, weather, track conditions etc.).

Also, FWIW, I have experimented with solid struts in back. I actually ran worse times (as have two others that I know of who have tried it). So you apparently do need some absorbtion in back.

Oh yeah, I run pretty consistant low 1.8's with 15X8's, on 10-12 psi, right around 220whp to the wheels, with a simple Tien/AGX set-up. Softest in front hardest in back.

MB

 

[RichardB]

Thanks, we are not allowed wheelie bars in the class I run. I run consistent 1.7's Ive hit a 1.69 once, but the faster guys are running consistent 1.6's which is what I need to get down to. I will try softening up the dampers on the front to see if that makes a difference.

 

[shortydtp]

yeah you dont neeed wheelie bars .. In our fwd class here in the us, hondas are making 900 to 1200hp. and the suspension set up is pretty much harders setting on the back, fronts need to be soft. so you actually may need to go to a softer spring in the front.

also what kind a tire pressure do you run??

 

[RichardB]

7psi fronts,

Ive had a look at some of the honda drag suspension and people like Omni seem to suggest 12kg front 21kg rear. Thats why I thought I would try the 13 fronts, Ive already got 22 rears

 

[danl]

Slow rebound in the front with high compression. Slow compression in the rear with fast rebound.

 

[bullettdsm]

I will try softening up the dampers on the front to see if that makes a difference.

^^^You will gain time right off the bat here.

MB

 

[tkelly27]

What is your alignment like? You want slightly negative camber so when the weight transfer has taken the force off the front tires they present the pavement with the most surface area.

http://www.driftclub.gr/v3/images/stories/faq/camber_angle.jpg

I know this is about suspension, but do you already have a limited slip diff?

 

[RichardB]

What is your alignment like? You want slightly negative camber so when the weight transfer has taken the force off the front tires they present the pavement with the most surface area.

http://www.driftclub.gr/v3/images/stories/faq/camber_angle.jpg

I know this is about suspension, but do you already have a limited slip diff?

Yes Quaiffe LSD.

 

[TenSecondSTi]

Yes Quaiffe LSD.

Any why you can drop the front end more? Or raise the rear? an inch should be enough.

 

[shortydtp]

raising the rear wont help on the weight transfer.