Rake (stink bug mode)

[romeen]

Awesome, thanks Brian.

 

[romeen]

I haven't decided on a final ride height yet. But if I were to keep the front close to stock (humor me here), then in order to get the desired rake I would have to set the rear to actually be higher than stock. Other than raising the CG, stressing the geometry and having a funky looking car with an ugly wheel gap, are there any other issues that I'm overlooking? Of course, this is assuming that an acceptable alignment would still be possible. The camber kit I have gives me only .75* of negative adjustment over stock. Not sure if that will be enough to dial out the resulting + camber.

 

[romeen]

If anyone's interested, this is a '99 GST on stock 16" wheels at the following height, as measured from the center of the wheel to the bottom edge of the fender. No, I'm not going to keep it like this. But it probably wont be a lot less either.

Front 15.5"
Rear 16.0" (actually a hair more than that)

 

[snowborder714]

Thanks for getting that! I've always been curious what stock ride height is at.

 

[romeen]

The rear in those pics is about 1.25" higher than stock.

 

[knochgoon24]

Measuring from the center of the wheel to the edge of the fender:

Front = 15.75"
Rear = 14.875"

I finally measured the heights on my car.

Front: 13.5"
Rear: 13.0"

If that's correct, that explains why I scrape and bump rub so much. It sits 2.25" dropped in the front and almost 2" in the rear. Yikes.

 

[arrowhead]

The first thing recommended for proper stock alignment is ride height this is the same from Bear, Hunter,Sun, Optic line or any manufacturer of the equipment, when the RH is modified either up or down all angles change at the same time.

In out of stock specs you have to throw the book out the door, in RWD cars there is a natural rake since rear tires are larger than front, but still the weight transfer during hard braking will bring the nose down, and if the car is scrapping more anti dive has to be built into the geometry, heavier springs will help but it is not the solution.

In RR and ovals the rules are very specific about RH and it is always measured at the pinch not at the wheel well and they take the closest to the ground whether
towards the front or the rear.

We try to get the body as low as possible for all the obvious benefits if the angles have to be modified then they are changed to whatever is needed.

All the heights I have seen so far in the thread are extremely high at least for RR, they may be good for AutoX, but not for road racing.

Rake will help with downforce quite a bit but it is difficult when the car gets to be very low.

 

[knochgoon24]

Sure, lowering the car close to the ground has benefits, but there are compromises that have to be made.

With the factory control arms and mount points on a 2g, the roll center begins to move to locations you don't want when the car is lowered. Even my 2" drop had the front control arms pointing up and out.

And suspension travel also suffers. For a dedicated race car, you can run +900# springs and deal with 1.5" of travel before hitting the bump stops. On a street car, you can only run so much spring. My tires rubbed the top of the wheel wells HARD when I hit bumps at the RH I was at, even with 600# springs, because I didn't measure the bump stops correctly.

 

[jtmcinder]

It's all well and good to talk about "anti-dive geometry," except when you have lowered the nose so much that the compression arm angles up from chassis to knuckle. Some people have come up with ways to move the inboard pick-up point for the lateral arm, which helps to fix the roll center on an over-lowered 2G, but no-one (that I know of) has ever moved the inboard pick-up for the compression arm. Thus, the only "solution" for dive under braking is more spring.

Try some 850# fronts. The Konis can take it.

 

[knochgoon24]

I'd run 850#s if I didn't DD my Talon. I don't think 13k miles a year on springs that heavy would be fun.

I do have plans to get a DD this summer/fall. In the mean time, I'm making the Talon "less racecar" so I can drive it with less wear on the tires.

 

[ACM]

It's the dampers that make the ride ugly, not the springs - I ran 700-850 on the street in New England for a while, it's not a problem if you have good (and adjustable) dampers.

Having said that, if you're stuck with Konis then I totally agree, that would suck; 550 seems the limit with Konis to avoid weekly dental visits. My experience at least.

 

[snowborder714]

For reference, my Koni's with 700# front springs felt a lot softer/smoother than my old Tein Flex setup on 560# front springs. I guarantee the shock had a lot to do with it, but it almost is weird not having my teeth rattle when I drive

 

[jtmcinder]

+1

I was running 850 fronts in State College and had no problems at all. It's the rear that makes the ride stink, not the front, because a lot of it comes from the ratio of sprung to unsprung weight.

 

[knochgoon24]

I'd be fine running 850# springs in State College. I guess I should change my profile. I'm back in Pittsburgh again. Country roads with all the patchwork and pot holes. They pour gravel in the pot holes as a temp fix because they form faster than they can patch them.

 

[Scott McIntyre]

I've run 900/400 & Koni Sports on my street car for years and never found the front harsh. If anything, the rear 400's are more harsh (than the front) as the rear tends to be a bit bouncy over bumps. The front does a better job at soaking them up.

As Charles said, it's the dampers (not the spring rates) that control ride comfort.

 

[knochgoon24]

Anyone know any tricks to break the little internal hex screw loose on Koni collars? All 4 of mine are stuck after just over a year of use. I didn't Hulk them tight either. Booo...

I've broken two 1/8" hex keys trying to get them loose, and Sears no longer sells 1/8" hex key sockets in the stores.

And is anyone else having a problem with the shock body on Koni's rusting? I even added 2 coats of clear to them before putting them on my car because I've seen them rust on every car I've seen them on.

 

[Scott McIntyre]

Anyone know any tricks to break the little internal hex screw loose on Koni collars? All 4 of mine are stuck after just over a year of use. I didn't Hulk them tight either. Booo...

Mine have seized up before, but ultimately broke loose. Since then I apply anti-seize to them liberally.

And is anyone else having a problem with the shock body on Koni's rusting? I even added 2 coats of clear to them before putting them on my car because I've seen them rust on every car I've seen them on.

Yes, mine are rusted quite badly under the collar. Been meaning to repaint them.

 

[jtmcinder]

Anyone know any tricks to break the little internal hex screw loose on Koni collars? All 4 of mine are stuck after just over a year of use. I didn't Hulk them tight either. Booo...

Maybe this reply belongs in the "useless facts" thread, instead, but moving to Iowa worked.

 

[knochgoon24]

Well WD-40 make the nylon part slip enough to make it so I could turn them. I broke 2 sockets and a key trying to get that bolt loose.

 

[ACM]

As Scott said, anti-seize the crap out of them once (if ?) you break them loose.

To break them loose, soak them in your favourite version of PB Blaster for a week or so, then rap the screw with a small hammer to break the corrosion. It will require a sharp rap or 40, but that will break the corrosion enough for the screw to move before the Allen wrench gives out. You can also heat the collar, that will work if you can keep the heat localised, away from the spring and the damper body.