I have a D-Class Ford F100 that I am having some trouble tuning. On some tracks, such as the turn right before the Corkscrew on Laguna Seca, the truck tends to bounce or jerk around a lot under moderate to heavy braking and it feels sort of like it’s bottoming out, but I’m not 100% sure it is. I think this is happening because of my tune, but I’m not sure where to look to make changes. I think that looking at the Rebound and Bump Damping settings and making some changes would resolve the issue, but I honestly have no idea if that is correct.
I’m hoping some of you more experienced tuners can give me some pointers and steer me in the right direction. I don’t mind posting the upgrades list and tune here if it help.
It’s probably a mixture of things… your suspension could be to soft, your damping could be to stiff or even both… If u post your tune on here we can look at it and give out some pointers. If u don’t want to do that try raise your spring setting. Also look into raising the truck if u are running really soft springs
1956 Ford F100 (D400) Upgrades:
5.7L V8 Engine Swap
Forza Front Aero
Forza Race Wing
Rear Bumper Removed
Rear Tire Upgrade to 195/70R16
Kosei K1 Racing TS Rims
All Platform and Handling Race Upgrades
Sport Driveline
Race DIfferential
Can you post the weight of the car please? And from a first look your Diff settings look off (try 25-40 in Accel and 15-20 in Decel) and the brake pressure might be too high(try 100-110)! And that alone will unsettle the car under heavy braking. And you don’t have enough Camber (You said you left it stock…) Laguna Seca loves camber! More aero weight will also help but try one thing at a time …Also General Swift has a great open source D class F100 truck! You might wanna take a look at that…
Diff is backwards so just flip those numbers and see how that feels. Next make front and rear camber much higher. Ride height is really low so I would take it up and inch or 2.
Next ditch the race cams and go with centrifugal supercharger. I know the camber and supercharger werent involved with you question but they will help out your lap times.
Never use a race cam on the 5.7 unless you have all the power in the car and need It for pi.
Laguna Seca was just an example. The car does this on several tracks under moderate to heavy braking or where you must reduce lots of speed in a short amount of distance. The car weighs 2797 pounds with 54% over the front end.
I know there was another discussion about cams versus centrifugal supercharger in the FM5 subforum and I understand that. I just though the car didn’t have a lot of rpm range to begin with but I will give it a try. With the centrifugal charger you get a much higher bumpin power in the higher rage whereas with the PD you get a linear increase in power throughout the RPM band. Why does that make the CSC better?
I ditched the Race Cams, added the Centrifugal Supercharger Conversion, and then I added a Sports Exhaust, Street Transmission, and changed to the Race Driveline which puts me at D399 and slightly increased the weight (12 pounds) to 2797.
when you say make the Camber higher, you mean make it more positive, right??
EDIT: I went with a default “let’s try this and see how it handles before making any changes” alignment configuration of
Camber: -2.0 / -1.6
Toe: 0.2 / -0.2
Caster: 5.4
Also, I made the changes you guys mentioned above and the braking issue has gone away. Overall, the car also drives smoother and feels much more stable, there is less side to side bounce and I must say I like it with the supercharger better - especially when I remembered the transmission added one more gear.
That’s a good start. But leave the toe alone for now! That way you can find the exact problem. If the ride does not improve then add some toe then one click at a time! And the camber should be in the -3 range front and back ( for Laguna for sure! Other tracks with that car I don’t know) Also your springs might be a little too stiff for that kind of weight (27XX Lbs) …
Cam shafts are nice but they cost to much pi for what little you get. Yes the speed is better but I would take the Accel over speed any day. The 0 to 60 and 0 to 100 times are usually better with cams but u only do 0 to 100 once in a race. I would rather my 40 to 100 and 40 to 140 faster because that’s where u spend most of your time racing.
Another thing to look into is race exhaust. Out of everything besides the supercharger I will add this mostly commonly.
Camber could still go even more negative front and rear bit you are getting close :). Toe is more of a last gasp type of thing usually. Try those at 0.0 and see how it feels after u have increased your camber some more.
Glad to see the truck is performing better for you!
I would have put the Race Exhaust on but it takes me out of the D-Class and into the low C which I can’t do for the Vintage American Muscle League. This has been a tricky car to set up and figure out but it has been well worth the learning experience. I have decided that I would max out my (Ferrari and) Ford affinity as they were the highest and the only Ford cars for this league were the Truck and the 40s Coupe so I figured I’d give it a go. I know my Vintage Ferrari Tunes aren’t the best but I can’t wait to tweak them a bit with all the new tuning stuff I’ve been reading on and attempting with this darn truck.
No superchargers there but I bet I can make them even quicker for the bonus events.
As for my question, I was asking more why the centrifugal supercharger is better than the other one, but the answer would be very similar, wouldn’t it?
Yeah similar answer. Supercharger is less pi but almost same power if not more and alot more torque. Next game it might be different but for this one that’s the best combo usually
Just wanted to let you know that after making these changes and fixing the brake issue, it drastically improved my lap time in the truck and I surprisingly set a D-Class personal best in Prague of 2.24.022. In a truck, on a very drift happy lap, oh yeah! Here comes 2.20!!!
I think the drift happy was part tune and part me not driving as sensibly as I should but I will play around with it. I’ve never really understood the Rebound an Bump settings that much, so I tend to leave the rebound at what it is stock and then I tune the bump to be 35-45% of the rebound as I read in someone’s tuning guide on here somewhere.
I got a dirty 2.20.116 because the bed tapped a wall in the tight section after Charles’ Bridge. I can get that clean but I don’t think the truck will go much faster so I’m going to make some tweaks. I got rid of the tire upgrade in favor of the Sports Transmission and an Air Filter so that I can change the acceleration and I should be able to go a little bit faster.
EDIT: Yeah that didn’t work, back to the old tune. But, I did post a 2:20:947 but I completely missed the clutch at one point which cost me precious time. I think I can get low 20 or even under but that will have to wait for a later time.
try -3.5 camber front and rear. also try putting the bump to minimum,i know you have read otherwise but just try it when i built this car i noticed stiff springs did help it not turn into a tripod in the turns as the car/truck has little weight in the back.
when i built this car i noticed stiff springs did help it not turn into a tripod in the turns as the car/truck has little weight in the back.