Gus

Front Suspension change issues and questions:
In moving the front suspension mount points to the outer holes, (wide body)and flipping the top strut mount locations how has this helped the car handling characteristics??
I know that you need to change the tie rod ends for the extra width - but, how did/do you handle using the stock sway bar since the wider sway bars are not longer available. Is there way to modify/make the down link to work with the narrow body sway bar??
What body width front fenders works best with a 8.5 inch rim and 235/245 tire set up spaced out 20 mm on ET 45. GT Racing offers a 9 inch wide and an 11 inch wide front fender modification. Figure that the 9 inch wide fender is more than enough to cover the mount locations and wheel offset.
If you have moved your front suspension mounts out - Would appreciate feed back on what issues you ran into, changes you made and whether or not this is a good "handling" change -

Vandit

Go look at that maritime RS thread. That car has the lower longitudinal members in the widebody position, hence the hella negative camber. JZM was selling it and they had undercarriage photos that made the suspension position very clear.

https://rennlist.com/forums/964-foru...4-cup-car.html

Clear undercarriage photos here.
http://forums.pelicanparts.com/9034053-post89.html

Gus

Bandit - looking at the pictures it is very clear that the bottom has been moved out. But, it appears that the top strut mounts have not been reversed bringing the camber back to normal with a wider front stance. The problem is that with the narrow body front fenders you can not reverse front strut location unless you go very negative . Need to look at front shock upper mounts to determine if the reverse has been done. This would move the upper strut/tire position out about 33mm. Which would remove that radical camber look.
Thanks for the feedback. / nice looking car but needs some front suspension work.

Spyerx

what are you trying to accomplish?
You can do the math, I have a 8.5" ET 48 front with a 235 40 18 front tire and there is NO more room there. So, if you push out each side 10mm, you're going to need at least that much more fender.
Regarding the drop links, an adjustable one may work if there is enough threading/length - ERP or Tarett I'm sure could make something custom. ERP has tie rods that will work and leave plenty of engagement.

But, I'm not sure what you gain. You do get wider track, you can get that with wheel offset too. So maybe there is a better motion ratio of the shock to the control arm? In general you want your suspension pickup points closer to the center of the chassis, not further out, so unless you're getting some mechanical advantage on the shock or the geometry I'm not sure you are gaining much.

Gus

I am a holder in the belief that a wider front track promotes better handling. Jim Hall in the late 60's and early 70's believed this in the cars he built. Porsche did this with the 917 to improve handling- read follow -


A wider front track effects handling in a number of ways. Assuming that all other things remain the same...

1) A wider track will make the springs feel weaker since you will be using a longer lever on them. So a wider front track will make the front suspension feel softer, promoting a reduction in understeer.

2) A wider track on one end of the car rather then the other will affect the way that load is transfered when cornering. When Porsche developed the 917/10 out of the 917K, they had a number of handling issues, one of which was power oversteer (going from 600 to 1000 HP -- duh!!! ). When they developed the 917/30, they actually reduced the rear track some. So the changes looked like this...

Track Front/Rear (rear as a % of Front)
917K 1564 mm / 1584 mm ( 101.3%)
917/10 1620 /1638 ( 101.1%)
917/30 1670 / 1564 ( 93.7%)

The result was that when cornering, the load would be transfered to the outside front wheel sooner then the outside rear wheel since the front wheels had a wider track and thus were traversing a longer distance for a given amount of body roll. This will tend to reduce oversteer.

3) A wider track will lower the roll center at that end of the car, thus making it softer in roll. This is because the car's CG will not change, and thus the vertical distance between the CG and the roll center at that end of the car will increase, kind of like using a torque-wrench with a longer handle that pivots at the roll center. So a wider track at the front will make the front softer in roll which will once again tend to reduce understeer.

4) A wider track will tend to reduce the load transfer to the outside when cornering, which in general will increase cornering power since you'll be able to get more traction from the inside tires. So once again, increasing the track at the front will tend to reduce understeer.

So in general, making the track wider will increase cornering power -- but -- it is important to maintain an optimum ratio between the front and rear tracks as a means to managing the load transfer from the front to the back, and thus the resulting balance between the two ends of the car.

Now, widening the track using spacers also does a number of other things to the geometry...
1) It increases the front scrub radius, which can increase the steering effort and affect the feel and kickback.

2) It can increase the load on the bearings since the load will be cantelivered further out then the suspension designer may have intended.

3) Without working out the geometry, I'd also be concerned about causing the suspension to pick up a tendency to change track under bump/rebound which can cause all sorts of sudden strangeness in the handling as the suspension loading is changed.

Spyerx

is this for your convertible? how much track time?

Gus

Yes, -
Track time ? Car per session? or How much do I have ??
I do about 6 to 9 events per year plus 8 - 10 AX's

Earlydays

Gus....looking good!