My Vette came equipted with the F45 suspension and active handling. Currently I have a coilover suspension system on my car with Z06 swaybars. I have billsteins in my garage, however I hate the ride currently, and would feel safer in the wet, nasty weather conditions I daily drive in with the active handling feature working. It also is very annoying to constantly have the messages flash up. Can I keep everything the way it is and place F45 shocks back in with the current coilovers? (I do not understand suspensions at all so forgive me if my questions are dumb) I understand engines and drivetrain, but in the past I have no experience with suspensions.


Another question do the F45 shocks suck? From reading posts it seems on here nobody likes them. Why is that?

Safety and ride quality are important to me.

 

I doubt that your shocks will work well with the coil overs. Most coil overs have adjustable shocks and usually have different settings than regular shocks. If they are the same length you might try putting your stockers on and see what happens.

 

To the top for more replies

 

Bump!

 

Spend the money and get yourself a set of 2004 Z06 shocks. You won't regret it. I had the F55 option (updated F45) which had poor handling characteristics, then went with Bilstein sports - better handling but bumpy and a little harsh - got the 2004 z06 shocks and it's just right with the z06 sways bars. I'm now waiting to put my z06 springs in and it will be comeplete. Shocks/sway bars/springs work as a system. The best handling ride I've had was from 04 vettes with either z51 suspension or z06.

 

Will the active handling system still work without the F45 shocks?

 

IMHO playing with the suspension (changing springs, shocks, sway bars, etc.) when you aren't sure what you're doing is a recipe for disaster.

I'd either return the car to stock (F45 Selective Real Time Damping) or go with a "package" solution that calls for the correct mix of shocks and springs. It sounds like you chose a "package" that won't work with the F45 system (the Bilstein's can't be controlled by RTD), which means that if you install the Bilsteins (or any other non-F45 shock) you're either gonna have to get someone with a Tech2 scanner to turn off the F45 option in your BCM or alternatively put up with the warning messages that this will cause.

Active Handling (AH) has no idea what type of springs/shocks/sway bars that you have.

AH uses input from the wheel speed sensors (in the wheel hubs), an accelerometer and a yaw sensor, and steering wheel position sensor to determine when it wants to intervene. Now a messed up suspension system that creates oversteer or understeer in corners will cause AH to have to get involved more often, but changing shocks and/or springs otherwise has no effect on AH

 

I am aware you need F45 shocks for the F45 to work. Thank you for answering my questiona bout active handling. However when I drive on the DIC it comes up with an error about the F45 and an active handling warming up message. I will need to check the DIC for exactly what they are but that is the gist of it.

I have not done anything to the suspension of this car. I bought the car with coilovers, Z06 sways installed and billstien (I belive HD's I will have to check) brand new in the box waiting install. The previous owner said he purchased the new shocks because the ride was so awful, he is right. I posted up before about giong back to stock and I was advised to definetly keep the coilovers because they are night and day better then the stock F45.

I continue posting up here regarding the suspension till I am educated on it before I actually install the billstiens or make a purchase because I understand the consequences of messing up.

 

Getting a F45 message indicates that the BCM interprets you have a shock issue and in all likelihood this is what is shutting down your active handling.

Take your car to a savvy dealer or a local tuner that has TechII expertise and shut off the F45 option. From there, if AH is still not working, look at the wheel sensors and grounds.

 

Let's back up a bit. You bought a car with coil overs and high performance shocks (for lack of a better name). We don't know if the shocks are adjustable or not. The car came with F45, so you're getting messages associated with that and "Active Handling Warming Up".

You want a car that drives well and is safe, but it doesn't sound like you're wanting to take the car to the track.

If that's the case, I'd recommend putting the car back to stock, completely. Get some F45 shocks and stock leaf springs (someone here will make you a good deal on those, I'd bet); leave whatever swaybars are installed in.

This should cure your AH problems, ride better, and you'll understand just what you've got.

BTW, there are lots of other things that can cause the AH Warming Up message, but this will give you a good baseline.

HTH, and have a good one,
Mike

 

It’s very possible you have two unrelated issues.

The F45 error is occurring because you are no longer using the F45 shocks. It’s my understanding this can be turned off with a Tech2.

The active handling error is most likely unrelated to the F45 issue. The active handling warming up code is often caused by a steering position sensor issue.

I see live near me. I should be able to get my hands on a Tech2. PM me if you want to look into your issue with a Tech2.

 

Mike thanks for your reply. I appreciate the fact that you took the time to understand what is going in, and your right as you can tell I do not currently understand what is going on with the suspension of the car, and I sure wish I did. I do not know if the shocks are adjustable or what brand coilover system I have on the car.

The car currently rides real rough on the street, it has 18/19inch wheels, lowered, and supposed worn out shocks.

It is possible to have a still semi decent ride with new shocks? Or is all hope lost with maintaining the coilovers.

As you stated I do not plan to autocross the car, I am more looking for a smooth riding safe daily driver.

I enjoy learning about this as much as I can.


Thanks to everyone else for their responses and MGorman thanks for the offer, I will be sending you a PM as soon as I figure out what I want to do.

 

Alright, let's do a bit more figuring. Using 18/19 wheels, I imagine you're running pretty low profile tires (probably 30 or 35 series?). Those tires transmit a lot of energy into the suspension, just because they don't have room to deflect much. Think of them as having high spring rates, but they don't have a shock to control the energy.

Next, you say the car is lowered. Hard to tell how this would affect the ride since you've got COs, but probably the springs are pretty stiff. Lowering the car also moves the suspension up higher in its travel range. If it's really slammed, you could actually be getting the car onto the bump stops when you hit a bump in the road. This stops the suspension from travelling any farther (think of the springs turning to solid steel). You might smooth out your ride significantly just by raising the car an inch or so. Coilovers make this an easy thing to do.

Finally, you ask it you can have a smooth ride (note I didn't say soft) with coilovers. Yes you can, but it might take a fairly considerable investment in some adjustable shocks. Going back to the stock F45 suspension could be the most affordable method, since you could most likely resell your COs on the forum and recoup part of your investment.

One other thing: if you could snap a picture of one of the rear shocks we could get an idea of what we're up against.

HTH, and have a good one,
Mike