Travel!

[ccracin]

No, I'm not talking about vacation! I'm talking about front suspension. I have some things rolling around in my noggin, but I want to get some thoughts. How much wheel travel are you all designing for in compression and rebound? In circle track racing we always went for 3 up / 3 down. However, when we measured the travel we never used that much. Well, except for some air travel but thats a bad memory! When you calculate roll angle, it's not even close. Then when you add travel for things like bumps, off camber approaches etc. you need more. So that's my question what do you design for and does anyone know from autocrossing, street and track what you are actually seeing? Let me hear it! Thanks!

[Track Junky]

I'm no pro. I believe 50% of what I hear and 100% of what I do. Just through my own personal experience on the road course I like 2 up and 2 down. Not saying I'm right......just saying......

[ccracin]

Thanks Gaetano. I know where you are coming from. I appreciate the input. Basically, I am working on the front end of the truck and am looking at clearances. I would like to get more rubber on the front than when I designed it because frankly since it has been so long there are new tires available. As with all things I am playing the trade off game. I want more rubber but I don't want to cut any more apart than absolutely necessary. Do you ever get on to the stops with 2" on the compression side? If so, is that on the street or track? Thanks again!

[Track Junky]

I dont do very much street driving but so far with what I have done it hasn't been an issue. My car is too low for stops. They have all been removed. The most recent stop I had to remove was the stop above the rear differential. When I went to the 315's in the rear I had so much more rear grip that I would hit that stop excellerating out of the corners, car would squat, and then pivot on the stop. Pretty crazy feeling.

One thing I want to add.....my feeling is that with auto cross and 200 tread wear tires you probably want 3" of compression due to the tighter turning angles. Reason being.....100 tread wear tires will hold grip better than 200. Once you hit your compression limit with a 200 tread wear tire it will want to slide.

Shocks are going to be your best friend in everything you are trying to achieve so get intimate with your shock supplier. Corner weight the car and have the shocks valved properly and at a minimum get double adjustables. In addition, find the ride height you are looking for and be sure the shock you buy is designed for that ride height. If your on a budget look into Afco's pro touring shock. They are $300 a pop. If you cant find them let me know and I will dig up the part number.

[Payton King]

are using a 5 inch stroke coilover shock front and rear. That is by far the norm and what I had on my car.

[ccracin]

Originally Posted by Track Junky

I dont do very much street driving but so far with what I have done it hasn't been an issue. My car is too low for stops. They have all been removed. The most recent stop I had to remove was the stop above the rear differential. When I went to the 315's in the rear I had so much more rear grip that I would hit that stop excellerating out of the corners, car would squat, and then pivot on the stop. Pretty crazy feeling.

One thing I want to add.....my feeling is that with auto cross and 200 tread wear tires you probably want 3" of compression due to the tighter turning angles. Reason being.....100 tread wear tires will hold grip better than 200. Once you hit your compression limit with a 200 tread wear tire it will want to slide.

Shocks are going to be your best friend in everything you are trying to achieve so get intimate with your shock supplier. Corner weight the car and have the shocks valved properly and at a minimum get double adjustables. In addition, find the ride height you are looking for and be sure the shock you buy is designed for that ride height. If your on a budget look into Afco's pro touring shock. They are $300 a pop. If you cant find them let me know and I will dig up the part number.

The front suspension is complete allowing slightly more than 3" of wheel travel in both directions. I am contemplating putting a bump stop on the compression side limiting wheel travel to 2.5". If I do this, I should not have to modify the inner fender structure and limit the modification I need to do to the inner wheel well. I just don't want to be on the stops ALL the time. I also don't want to have to make it too stiff to keep off of them.

When it is closer to fully assembled, I will put it on the scales and get the corner weights. I have used AFCO products for years in circle track racing. They make nice products, but thanks for the tip.

[ccracin]

Originally Posted by Payton King

are using a 5 inch stroke coilover shock front and rear. That is by far the norm and what I had on my car.

I'm with yah Payton. I have plenty of shock travel, as I mentioned to Geatano above I'm concerned about my wheel travel and rubbing. If I can get away with 2.5" of compression wheel travel I think it will work out well. I'm just trying to decide how much to modify on the inner fender structure. The other consideration is that if I limit it to 2.5" I can also reduce the back space on the front wheels and move them out board a bit. Too many decisions!

[marolf101x]

5" stroke shock is not the norm.
5" of WHEEL travel is.

We prefer 3" compression, 2" extension from ride height.

[Ron in SoCal]

Originally Posted by marolf101x

5" stroke shock is not the norm.
5" of WHEEL travel is.

We prefer 3" compression, 2" extension from ride height.

Yep. Takes an engineer to mention motion ratio...

(Not that anyone's wrong here. Payton used JRS which comes with 5" travel front shocks. A good choice for Camaros IMO.)

[Track Junky]

Originally Posted by marolf101x

5" stroke shock is not the norm.
5" of WHEEL travel is.

We prefer 3" compression, 2" extension from ride height.

Can you educate me on this......I thought 3" of compression and 2" of extension equalled a 5" stroke.