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Autocross Springs

4672 Views 87 Replies 14 Participants Last post by  toonwarrior
My current setup:

Hotchkiss springs, bilstein shocks, spohn adjustable swaybar endlinks, BMR front and rear swaybars, BMR fixed extended length control arms upper and lower, spring perch relocated on axle adding like half an inch of ride height to the rear.

The car feels fairly planted street driving and what not, but when I took it to the course I was being thrown left and right with the roll. So it seems like the suggested advice is to go with a non-progressive spring which would be the global west 750#s.

But I've seen many mentions that if people could re-do it they would go with 800#+. I guess my question is where would I buy springs like that.

Then there's the question of ride height, what is the ideal ride height for these cars front and rear. Right now my current ride height is 27" inch rear and around 26" front. If I get the new springs for the front should I be aiming for 27"?

As for the rears, is keeping the progressive Hotchkiss rear springs ok?

Orrr do I just wait and save up for an adjustable setup.
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But that's the great thing about coilovers is that YOU set the car up. The springs just give it the height for the most part, the double shock adjustment that most coilovers give you allow you to set the car up to your liking.
That’s the + on coilovers, you can dial in the compression and rebound which you need to control body roll.
You guys have a break down of the costs for the setup?

The level 2 kit starts at 4k USD ouchie.

The reason I'm not even looking into it is because:

  • The best guys that I know autocross all follow a fairly similar template, stiff springs up front, soft in the rear with a smaller bar in the rear
  • I'm not even at the level where I'm hitting the limit of my current setup so I don't think the advantage of coil overs is going to that beneficial at least initially without driver mod.

Don't get me wrong I'm not against it, but the cost/benefit is just not there yet for me.
If you daily the car you will enjoy coilovers all the more. The more wild you go with the springs, the suckier the car drives during normal operation. Coilovers you just dial back the settings and you got a cushy ride again.
What are you looking at? I am looking at QA1. Now personally I would mix and match brands this one time and get a Viking shock and coil with QA1 arms but that is just me.

I can understand the cost/benefit isn't there but this is a scenario where you buy once cry once rather than spend 3 years trying out different springs before realizing those assholes on the board were right :D :D
Maybe but 5gs isn't really chump change 😁. It maybe something for later down the road

And the setup I'm talking about is tried and tested. 120 CAD for the 750# springs up front, 200 bucks for the AK1503 shocks, find a smaller bar for the rear since the BMR bar just fishtails the car and does not allow you to put power early out of the corners. Then wider tires pretty much. My basis of this setup is off brian coleman, ed runnion, impalo, terry kehne, michael kazmar. They all have different variations of it but for the most part it follows that combo.

If the combo sucks then just go back to the hotchkis setup then contemplate coilovers.
Also another fun thing to think about, you said wider tires on stock wheels.
You ever think about wider stockers?
The springs just give it the height for the most part.
Care to expand on that a little?
That reads as if you dont feel rate is important
Sorry don’t mean for it to come off that way. I think that the spring rate on coil overs just matters differently than the spring rate on normal springs.

With the adjustable shocks you have a little bit of a crutch to fall on if the spring rates aren’t perfect.
I don't know how wide I can go before it does more bad than good since I'm pretty much stock power and don't plan on changing that.

Wouldn't mind a set of widened though looks great
275/40-17 in a high performance summer tire works well. No all-season radials.
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200 TW tires, get the Falken RT660 in 275/40/17 for a stock sized rim.
NOTE: do not use this tire in cold weather and do not let the tire get below freezing unless you remove them from your car.

I have some Hankook RS4 tires on my GTO that cracked due to freezing temperatures.
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Ooh they are pricey,

Well my nitto's are fairly brand new so going to use them well before I do any switch.

In terms of PSI's I'm just running the recommended amount which is like 36 psi all around I think? I've seen people here and there adjust it to some pretty high amounts so would love some insight on that if you have any. (all this in relation to autocross)
Some use dial-in ,or white shoe polish where tread meets sidewall to see how far wear extends. If running out of tread portion? Add air.... 36psi to start is about right. Tires will add their own pressure as the heat up.
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Yea, and the fact that only very few that install coilovers autocross their car so there isn't as much info to go off with in terms of setting the car up.

I'm just going for an OEM+ build which means:

As stock interior as possible, so this means those big couches stay
As stock exterior as possible, essentially can't change out the wheels

So that limits me to like 270/40/17s but that won't be happening till these 255 nittos are used up.

Within my limitations just trying to find the combo that can rotate my car nicely.

From what it seems like most do is:
750 + springs in the front + a shock with valving that matches the spring
Keep the rear similar to the stock SS rear spring rate as possible and go small with the rear bar.

Which is not too far off from what your setup currently is madamorr. It maybe the way I think I'll be at least experimenting with.

Best mod is a driver in control. Here is my seat mounted on Impala power seat rails. EZ to switch back to stock seat for the Highway.
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Damn that's great.

Is the harness just strapped onto the seat i.e no roll bar?

What's the process for seat removal/ installation. I'd love to get like a grey version of that so it at initial glance you wouldn't notice.

Don't know much about fitting aftermarket seats, is there like a bolt pattern that I would be looking for similar to how wheels are?
Have the same harnesses from years ago.
Don't need roll bar to install eye bolts in the seat belt location(s) front ,and rear.
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I am a fan of that setup, but doing a bit of reading seems like the 5 point harness was a kit sold by gene bennett which seems like unobtanium now so unfortunately I'd have to be hand-held through the setup process and specific parts required without an impala specific instruction guide.

Since my car is primarily just going to be autocross and car shows I think this is the route I'd be going down, just need to do more research on it.
+1 on adding a harness. I have a 6pt harness that attaches to the stock mounts. Two attach to the front seat to floor bolts. One on each side of the seat attaches to the seat belt attachments. And then the rear I have running to rear seat belt mounting points. I also have a H-Style rear straps to prevent them from splitting apart.

Now for an alignment:
1/16" toe in
1.5 degrees negative camber
+4 degrees or more caster. The more the better. I am hoping to have at least 6~7 degrees with the new front upper a-arms.

Please share the model number for that Corbeau Seat. I am very interested in doing that mod as the stock seats really do not keep my large ass planted.
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So it looks like you can just buy their vehicle specific seat rail.

And then that allows you to bolt on your corbeau seat of choice I think, pretty cool especially if you get it upholstered in grey with SS badging.

Doesn't look cheap by any means but I guess if that makes the difference in driving then it's something to invest in. For me I'd have to figure out the harness part first with the stock seats before I look into those.
corbeau FX1 They make the seat as an FX1, Fx1 PRO and the FX1.Wide. When I bought mine Corbeau sold a mounting bracket to mate their seats to the Impala rails.
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