sensitive steering on Gen III with FFR power steering

[forcefed1]

I have about 1300 miles on my car It handles very well. Too well maybe. the car is darty. I have to hold the steering wheel very carefully to keep it from wandering all over the road.
Do any of you notice the same thing? I use a slightly smaller steering wheel (gtm). It gives me more room. I have been thinking of going with a larger one just to help reduce the sensitivity.

OR is there something else i can adjust my camber and caster are set up just like the manual suggests. camber is -.5 deg. I don't recall the caster.

[Bob Cowan]

Get caster to at least 5*, and even a little more would be good. Toe out can make it feel darty, too.

If you have a stock pump, consider putting a restricter valve or cutting the spring to reduce power assist.

[Jeff Kleiner]

As Bob said you want lots of positive caster (I go for about 8 degrees) and be sure you are set for toe in, not out (I like 3/32" total toe in).

Jeff

[edwardb]

I see from your build thread you are Coyote powered with the FFR supplied power steering. Not sure if it's the latest KRC setup they're now providing. If it is, the stock setup comes with a too large flow valve. Change it to the smallest one they have. 1.18 GPM (ID Mark 4) part number 253040000. It's what I have in my Roadster and others also have reported it's a better setup. Using it in my Coupe build as well. If you're not KRC, there are other ways to adjust the pump output if necessary, once you get the front alignment sorted as needed. Properly setup, these cars with power steering aren't darty at all. Good luck.

[Mark Dougherty]

7:5- 8 deg. Pos castor
1/2 neg. camber
3/16 total toe in
The toe in makes a big diff.
Also if this does not get you to where you want it then you must reduce the line PSI in the power steering system.
Which ever way works for your application.

[johnnybgoode]

I have about 1300 miles on my car It handles very well. Too well maybe. the car is darty. I have to hold the steering wheel very carefully to keep it from wandering all over the road.
Do any of you notice the same thing? I use a slightly smaller steering wheel (gtm). It gives me more room. I have been thinking of going with a larger one just to help reduce the sensitivity.

OR is there something else i can adjust my camber and caster are set up just like the manual suggests. camber is -.5 deg. I don't recall the caster.

Mine was the same way until I added 7-8* of caster and fixed the toe. I've got a Heidts valve as well but it's full open now with this amount of caster. Feel is just about perfect and very stable. Not twitchy at all.

Here's a link to upgrades and alignment on other forum. https://www.ffcars.com/forums/17-factory-five-roadsters/567161-suspension-upgrades.html Scott

[forcefed1]

Thanks guys.
I am using the newest KRC offering.

Ill get the caster adjusted ASAP then look at the pump flow.

[Mark Reynolds]

Just had my roadster re-done from about 4 degrees caster to 7.77/7.95 and it makes a huge difference. Before on the highway you really had to pay attention. Normally on the highway stabilize my elbow on my armrest on the door. I had on-center feel but just barely. I would tend to over-correct after say a lane change and would oscillate a few times - she really wanted to turn.
Now with the high caster the steering is very stable at speed. I don't have a lot of miles yet after the change.
BTW the dartiness was not bump steer as I have that tuned out since the beginning. My initial impression is that ideally I would like 6.5 or 7 degrees but I plan on running this into next season. If I forget about the alignment then is is good. If I keep thinking about it then I will have it backed down. For now it is too soon to tell. I posted more on this in the Northeast secton of FFCars.com