Tuning
#1
Fri, 11/30/2012 - 09:22
Tuning
Okay for all you tuning types I have a question. I've been working on my first real tune and I have one area that is giving me problems. I am using a 69 Trans Am and currently experiencing understeer when off the throttle going into a turn. Now from the guides I am using there is a number of things I could adjust to correct this. Camber, Toe, anti-roll bars, and a few others.
My overall question is what do you all usually go to first to correct over or understeer on a car? How do you determine which of these above settings needs to be the one you change first?
Thanks in advance. I'm finding that it is addictive to try and tune my own cars. Really has added a new part to the game for me.
LOL, apply more throttle after entering turn? (<---not a real tuner)
Soften front, stiffen rear? ARB's and springs. Then go to differential for throttle steer. Then ask a real tuner...
Try playing around with the Differential Decel settings. Lower=looser, higher=tighter.
Firstly, can you be more specific about what and where?
A number of things happen when you go into a turn, off throttle. You'll have to decide which one suits!
As soon as you lift the throttle, the decel on the diff is starting to kick in. A diff with 0% decel can turn tight than a car with 100% decel. However, the 0% decel car will be more twitchy than the 100%. (this is loosly the case) A decel in the range of 30 - 75 is normal. Set this for stability and turning circle.
Once the decel is kicked in and you are about to turn, then the Rebound / springs are going to come into play. The rear rebound is complicated to explain its technical details. However, the higher the number on the rear, the more responsive and unstable the car is on change of direction. Whislt this is happening, the springs are coming into play and loading up. If your springs are too soft on the rear then front will be trying to drag the rear and about (think about a dead weight.)
After the initial turn in the ARB's start to take action, if the rear is getting loose mid corner then decrease the rear ARB.
In summary, get the spring balance right, then turn in of the car sorted and finally move on to the ARB to fine tune the mid corner
IF you like, post your settings.
Have two, large head with background on hood, I'll send it over, everyone can set 'em up.
Ideal, thanks! :D
I've noticed at the intial turn in point just after the hard braking zone. It has halped a bit to do some trail braking but still the car pushes wide. I have to say though your explination is probably the best I have seen as far as the sequence of what happens regarding the suspension when entering a turn. A lot of great information.
I'm at work right now but I'll try and post my settings tonight. I have been using the Forza 4 tuner on the iphone to get a starting point then tweaking from there.
Cotter, I went back and started on the Mustang last night and was able to get a much higher PI. Going to look at the Trans Am again tonight cause I think I can get it higher also.
I'm going to relocate this thread to the tuning painting & racecraft sub-forum.
Yea after I posted I realized there was a forum for this above..gif "93")
I've only just seen this and it sounds very much like your rear rebound is too soft.
Try these settings
Rebound F7.4 R8.4
Bump F3.8 R3.6
Rear Diff decel 27%
And let me know what it does, we can move on from there.
Sorry hadn't checked the thread in a few days. I'll try those settings and post results.
No worries :)