Discussion of Chassis Setup for 8 Sec. Assault

[Alky V6]

One thing that people who restrict front suspension movement may not realize, and something to consider when you do restrict front end movement, is making sure you know where the heights of each side are at, when the suspension is on the stops.
With my car, with the bent frame, I had to make the front left side bumper pad 1/4" shorter than the right side to get the rise value the same for both sides. When I modify the dive bumper stops, I will have to make that same type of check to make sure that the front suspension is level when hard braking through the shut down area.
This tip would be much more important to consider for hard braking, since you really want both sides the same height when the suspension is on the stops in a dive situation.

 

[Alky V6]

I just finished measuring the distance between the lower control arm bumpers and the frame.
Left side: 1 3/4"
Right side: 1 3/8"
Yipes!

 

[Alky V6]

I spaced the bottom bumpers to allow 1/2" clearance between each bumper and the frame. Not sure what the total dive travel will end up being after compression of the bumpers, but the front end will be level when it dives hard.
I'm going to guess 3 inches of dive travel.

 

[Alky V6]

Why can't someone replace the flimsy stock adjusters for the rear deck lid with some more HD adjusters and set the height at the rear of the deck lid a little higher than stock to get a little more downforce?

 

[Alky V6]

I've moved on to the front grill. The plan is to block it off for aero reasons, and attach the whole grill with hidden Dzus fasteners or simple screws so that the grill can be quickly removed from the front without having to disassemble anything else first. I have things stuffed behind the grill and it would be nice to be able to get to them easily.

 

[Dusty Bradford]

I've moved on to the front grill. The plan is to block it off for aero reasons, and attach the whole grill with hidden Dzus fasteners or simple screws so that the grill can be quickly removed from the front without having to disassemble anything else first. I have things stuffed behind the grill and it would be nice to be able to get to them easily.

I'm going to block the grill off this time around in a different manner than I did before. I originally just attached a lexan sheet behind the grill. 1/8 mile was fine. My 1st 1/4 mile pass, the grill imploded at around 800 feet.

This time I'll be building some bracing from the core support forward to support an aluminum plate.

 

[Alky V6]

I'm going to block the grill off this time around in a different manner than I did before. I originally just attached a lexan sheet behind the grill. 1/8 mile was fine. My 1st 1/4 mile pass, the grill imploded at around 800 feet.

This time I'll be building some bracing from the core support forward to support an aluminum plate.

Yeah, I was figuring the bracing would have to be pretty stout. I was imagining what it might be like to take a flat piece of metal the size of the grill and hold it out the window at speed. Heck, with what the air does to your hand alone, the piece would get halfway out the window and get ripped from your hands. Ouch! Just thinking of those sharp metal edges.

 

[scot w.]

Why can't someone replace the flimsy stock adjusters for the rear deck lid with some more HD adjusters and set the height at the rear of the deck lid a little higher than stock to get a little more downforce?

Don why not go with a Monte Carlo SS rear spoiler instead? Better down force for sure..




SW.

 

[Alky V6]

Don why not go with a Monte Carlo SS rear spoiler instead? Better down force for sure..




SW.

I'll look into that. Off the top of my head, I don't recall what that spoiler looks like. Thanks for the tip.

 

[scot w.]

I'll look into that. Off the top of my head, I don't recall what that spoiler looks like. Thanks for the tip.

Here is a picture of it mocked up on my car.. I will more than likely be going with this when I paint the car, untill then i'm leaving it off and going to compile some tests at VIR (Virginia International Raceway) without it and then once it's installed I will go back and finish testing.

I'm really interested in seeing this front spoiler mock up that your planing as a couple of us are thinking of the very same thing right now. Please shoot me some pic's when you have it mocked up..

My plans for this car is Autocross & Road Race..


SW.

 

[Alky V6]

Here is a picture of it mocked up on my car.. I will more than likely be going with this when I paint the car, untill then i'm leaving it off and going to compile some tests at VIR (Virginia International Raceway) without it and then once it's installed I will go back and finish testing.

I'm really interested in seeing this front spoiler mock up that your planing as a couple of us are thinking of the very same thing right now. Please shoot me some pic's when you have it mocked up..

My plans for this car is Autocross & Road Race..


SW.

Very interesting. Please share the results after your testing. Is the Monte SS spoiler a simple bolt on?

I plan on sharing pictures of all the mods to my chassis that relate to this thread. If I did/do not post a pic of the mod, it's most likely because I did/do not feel there was enough interest in it to bother posting a pic of it. If I cover a mod, but did/do not post a pic of it, and someone is interested in some pics of the mod, please let me know and I'll get them posted. It may not be the way some of you will handle the mod, but it's always interesting to see how other people come up with a solution to a problem and maybe build upon it.

Back to the front grill. I think I have a system for mounting the blocked off front grill that will require only one hidden Dzus fastener to hold it in place. The Dzus will be accessable from the front, and the grill will lift out through the front. As easy as can be.

I'm not following any particular format or order here. If someone wants to start a tangent on a discussion on another aspect of chassis adjustment or modification, feel free to participate.

 

[charlief1]

One of the B4Black guys has done this same spoiler Don. He's got one on the car and another for sale. He posted in the last two weeks if you want to see if you can find the post and PM him. Looks really good.

 

[cdsttype]

i found a taller front spoiler. Tr custom parts - air dam - full width

i'm probably going to end up making my own one-off spoiler. The spoiler from tr custom parts is 1" taller than the stock one, but i'm going for something taller.
I'm debating whether or not i want to design in a splitter for the new front air dam.

i have that one and as soon as i put it on felt the
problem with the down force on the rear

 

[cdsttype]

don why not go with a monte carlo ss rear spoiler instead? Better down force for sure..




Sw.

that sounds like one i would try also
thanks scot

 

[Dusty Bradford]

I've been 184 with no rear spoiler and felt no issues that made me feel like I needed one. The only issue I noticed was how light the nose felt once I reached 160+. I'm thinking it was due to the grill not being blocked off.

 

[scot w.]

I've been 184 with no rear spoiler and felt no issues that made me feel like I needed one. The only issue I noticed was how light the nose felt once I reached 160+. I'm thinking it was due to the grill not being blocked off.

Dusty I too was up into the 174 range with my old GN while running a 06 Z06 and at those speeds the front of the car started floating all over the place and it got pretty damn scary so I lifted. Not sure what the cause of that would be contributed to but I can see a spoiler helping some what..

I find this thread interesting because I plan to be throwing my car around VIR next year and for one I want it to be safe and two, I want it to be functional!! so I am all eye's here...lol


SW.

 

[Alky V6]

Here's the progress so far on blocking the grill.

 

[Alky V6]

Is this the kind of thing that happens when you don't block off the grill?
YouTube - Buick GN hood comes off

Imagine the pressure that it takes to blow a hood. For a hood that does stay attached, that has got to be lifting the front end like crazy.

 

[Dusty Bradford]

Dusty I too was up into the 174 range with my old GN while running a 06 Z06 and at those speeds the front of the car started floating all over the place and it got pretty damn scary so I lifted. Not sure what the cause of that would be contributed to but I can see a spoiler helping some what..

I find this thread interesting because I plan to be throwing my car around VIR next year and for one I want it to be safe and two, I want it to be functional!! so I am all eye's here...lol


SW.

I think it's not so much the need of a rear spoiler as it is the air pressure under the hood from the massive grill.

 

[Dusty Bradford]

The block off plate looks great Don. Hard to tell from the photos but do you have some sort of frame work around the edge to help reinforce the grill. The grill will want to cave in at the middle and the plastic can't handle the load. I'd want some sort of reinforcement like a rib across the middle of the grill to help the load.

I'm going to let the core support take the load rather than the grill itself. My turbo is now in the grill so it will also have a giant hole in the center to help with some of this pressure.