Front Springs for Autox

[Silk]

Just ran my first autocross of the season with the Cobra this past weekend after upping my front springs to 550lbs, and the results were excellent. A big improvement over my 450s. The car was much flatter in the turns and much less inclined to nosedive under threshold braking. And the ride on the street is really not that much different then it was with springs in the 375lb range.

I've also got a C6 Vette that I autocross, and it's hard to tell which car is quicker against my benchmark competition. The course this weekend was extremely fast (close to 80 in one segment), which probably favored the Cobra. But if they ever come out with a good R compound tire to fit the 19" rears on the Vette, it would likely be the better of the two. In any event, they're both great cars to drive at the limit - albeit very, very different from one another.

For any of you in the Mid-Atlantic area that are interested in an autocross venue that caters to high performance cars (Cobras, Vetts, Porsches, etc), make the trip up to Cumberland MD. Great bunch of people and fast courses. Here's a link: http://www.nationalroadrally.com/index.html There are usually 5-10 Cobras/Daytona Coupes that show up.

[Naumoff]

Thanks for the info Gary.
I want to Autocross my Cobra just to see what it will do. Was trying to find a group closer to me in Southern Maryland but have not had much luck.
Looks like I will have to take a trip to Cumberland after all.

Have you ever tried spring wedges in your springs?
Every time you stop the movement of an active coil you increase your spring rate. I am going to do this as a way to have an option of playing with spring rates at the track without having to change the springs.

[Silk]

Tony,

Hope you make it up to Cumberland this year. And if you try the wedges, let me know how they work.

[Master]

Tony,

That sounds like a great idea, I am heading to Mid Ohio the 20th of this month and I think I will try the wedges. Is it best if the wedges are placed in the middle of the spring or does it matter?

[Naumoff]

Gary,
Time permitting I hope to make it to at least one autocross this year.

Scott,

I don't know if it makes a difference where the wedges are placed but I saw a guy at Carlisle with a S7 and all his wedges started at the bottom of the spring.
I have to find wedges first. I know they use them in NASCAR.
Haven't had time to look for them. I am swamped at work. I should of asked the guy where he got his.

[eliminator]

Try looking at spring spacers and not wedges.

[Joe LaFives]

Anyone tried progressive rate springs and if so which?

[Naumoff]

Thanks Rick,

My local speed shop has them. I called them earlier today.
And you are correct, they are called spring spacers.

[Slither]

Do spring spacers actually change the spring rate (and if so how)... or do they merely limit suspension travel? Do they cause the individual coils to flex as well as compress? This is interesting.

[Brent]

My friend at AFCO sent me this link. Should answer all of your questions.

http://www.stockcarproducts.com/spgtech.htm


Have fun!!

[Master]

I just purchased these for my track day. "trying to save the oil pan"

http://www.speedwaymotors.com/xq/aspx/paging.yes/dept_id.712/display_id.689/qx/Product.htm

[eliminator]

Gary,

What length spring did you go with on the front, 8"???

[Silk]

Rick,

I used 10" Eibachs. Wish someone made a 9", 'cause that would be just about perfect. I was worried about coil bind with the 8s, but at some point I may try 'em. The 10s are adjusted all the way down, and the ride height is ok. But for autox I'd like to be able to crank it down another 1/2 to 3/4".

[eliminator]

The 9" is the correct spring in my opinion for the Unique 427 cars. Maurice has recently told me he can get a 9" spring from Pro Shock that is powder coated. I tried the 8 inch springs and they are a little short for the front and the 10" springs leave the car too high. Rule of thumb I am told that you double the shock travel for the ideal spring length. 4 inches of travel, 8 inch spring, 5 inches of travel 10 inch spring, so on. That is pretty close as we are around 4 to 4 1/2 inches of travel, there is no way a Unique Car can acheive 5 inches of travel without looking like a 4X4.

[Silk]

Maurice has recently told me he can get a 9" spring from Pro Shock that is powder coated.

I'd definitely be interested in this - perhaps we can get Pro Shock to make up a batch of them if there's enough interest. One problem is that I suspect people may want different spring rates, which may make a group purchase impractical. :confused:

[eliminator]

It is my understanding that they can be purchase by pair and spring weight.
I am going to find out real soon.

[Silk]

Sounds good, Rick. Let me know.

[Naumoff]

I will be interested also.
I have installed the wedges( Spring spacers cut to fit) and took out a spring and a half. It is a noticable improvement.
Car does not nose dive or dip out.
It doesn't roll as bad in turns.
I am running the 10" 300# springs.

[eliminator]

I just ordered a set of 375# front springs, 9 inch. I am going from 325# in the rear to 350#, they will stay the same length 8". My front spings , 2 sets, are 10" 325# and 8" 350#, so I may have several sets to unload once I find the right combination.

[Master]

Rick, keep us posted on how your new set-up works. I am interested in changing mine as well. My oil pan scar's are growing.:rolleyes:

[Silk]

Rick,

What's the story with the Pro Shock 9" springs. Is this a special order that needs to be routed through Unique, or will Pro Shock do this for anyone directly? I take it these are black powder coated and not chrome?

Thanks,

Gary

[Naumoff]

Gary,

You are running a 550 LB spring, Right?
I would be interested in the same if not heavier. I am running a big block.
I am signed up for an Solo class with the SCCA on 8/5 in Frederick.
I have the spacers in right now and it is an improvement.
I might put in a couple more spacers but that starts to make the spring pretty short.
I am in England right now and will be back the 30 July, so it will be a quick turn around for me to go to the class when I get back.

Are you happy with the springs as far as the lbs.?

[eliminator]

You could get them through Maurice, don't know if they can be bought direct.
They are black powder coated. Maurice has the info on them.

[Silk]

Thanks, Rick

Tony - Yup, 550s on the front, and I'm very happy with them. I was getting way too much nose dive with the 450s, and now the car stays much flatter, particularly under threshold braking. The ride on the highway really seems about the same as it was back when I had 350s up front, so no problem there.

[Naumoff]

Gary thanks.
I am still interested in the 9" 550# springs.
I was pretty happy with the way my Cobra handled with the spacers I have in the springs. Not much nose dive and took the turn pretty flat.
It was a lot of fun.
The street tires definately show there weekness under classroom Conditions.
Six runs back to back. 15 runs total. 6-6-3. A great day.
I am signing up for the level 2 class next.

[eliminator]

Just finished installing 350# - 8" Hypercoil Springs in the rear. In the front I installed 400# - 9" provided by Pro Shock through Unique (chrome plated).
Since I have Billstein Racing shocks I can change the Nitrogen Pre Load with a schrader valve. I am running 150 PSI in the rear shocks and 175 PSI in the front shocks. I have a high pressure inert gas regulator and tank for the nitrogen and a Billstein fill tool. While I was at it I deflated all tires and filled back with pure nitrogen. After getting the ride height set I did a test run up I-65 Saturday evening and back (40 miles total) running 65 - 85 MPH, then a few side roads and I like the combination. Good solid ride but not to harsh, really smooth at 75-85 MPH. I think you could up to 450 - 500# with a 9" spring. With the Pro Shock and it's design a 10" front spring will probably work well (they are black, powdercoated). With the 10" spring 400 - 450# should work real good.

[Naumoff]

Sounds good Rick. Are you planning on any open track time?:shift:

And Thanks for the info.

[eliminator]

Just the breakfast runs in the Smokey Mountains, one hell of a road course.
Shades of the Past is coming soon, September the 7th through the 9th.

[Silk]

What a difference stiffer springs make! The first photo is with 450 lb front springs in a trun at about 60 mph. The second is a similar turn with 550 lbs. up front. Much flatter and much more stable (particularly the inside rear wheel, which was bearly making contact with the lighter springs).

http://www.clubcobra.com/photopost/data/500/12500Cumberland_Turn2.jpg

http://www.clubcobra.com/photopost/data/500/Cumberland_2_cropped_-_Oct_06.jpg

[Naumoff]

Looks good Gary.

I am thinking of ordering some 9" 650# springd from QA1.
Having a Big Block I figured I would go up to the next spring.
I Auto X this weekend at FedEx Field and had a blast. I ran my Good year slicks and they sucked. It was to cool and damp and sandy. I ran first heat and it was like driving on Ice. I should have switch to my street tires. I have the spacers in my springs right now and calculated at 525# with 7.5" of spring left. Alittle to short by Ricks specs for the spring hieght for our cars.
It was still fun.

[Silk]

Tony,

Glad to hear you enjoyed the FedEx autocross! It can be very addictive, can't it? Hope to see you up in Cumberland one of these days.

Nice to see that someone (QA1) has 9" springs. I may have to open the wallet one of these days.

Gary

[Naumoff]

It is way more fun than drag racing and it is not as hard on the engine.

I will make it up to Cumberland. Right now I am taking baby steps close to home.:D

[Naumoff]

Found a website of pics posted from the Sept. 3 AutoX. I thought it was pretty cool to see the car and what it is doing on the course.

[Silk]

Nice pics!

[clayfoushee]

Gary,

I've been taking baby steps too, but decided to get in a different car. I still suck, but it is addicting.............

http://i21.photobucket.com/albums/b268/clayfoushee/wdcr_06_6_ss_030.jpg

[Silk]

Clay,

Nice wheels!!! I'm envious. Way too much good stuff in your garage these days.

As I'm sure you know, at the national level the Elises have waxed a lot of Vetts in SS. What a great car to use for getting into autox. The only concern I've heard from the ace Elise drivers is that there's only so much negative camber (I think it's camber) that can be achieved with the stock suspension. Not sure if that was just with the initial cars or if it continues on current production models. That said, it's a potent package for sure.

How did you like the whole FedEx experience? I haven't done that yet, but I understand it's somewhat frenetic as they try to get all the cars through. But one of these days - - -

[clayfoushee]

Gary, you're right about the negative camber. The real pros, and there are plenty of them in this SCCA region here have removed shims and dialed it out somehow. Mine is still stock, but it has amazing grip, nonetheless. It's driver stinks, but that is a different story.

9/3 at Fed Ex was my first time after going to an SCCA school. It is a bit frenetic, but it is extremely well-organized, almost like a symphony. Cars in each class park in pre-assigned grids within run groups and stewards direct you out at your assigned time.

[Naumoff]

Gary, Clay is right. I beat his best time by 3 seconds in the Cobra with crappy tires.:eek:
Sorry Clay. I couldn't resist.:D

[clayfoushee]

Uh, but not when I've learned the course, I might remind you.............:cool: We old guys need more reps to overcome the Alzheimer's.

[Naumoff]

Not if I can help it.

http://www.uniquecobra.com/gallery/files/1/4/6/9/New9inch650lbsprings002Small.jpg

Next is tires.:D

[Silk]

Next is tires.

Ah, let the madness begin! There'll be no end to it. :D :D

[Naumoff]

I just came back from a test drive with the new front springs.
It is like night and day. Car even feels more stable at speed and the little shimmy at 65mph is gone.
And Gary it is funny. when I first put the car on the ground and re-adjusted the car height. I thought I made a mistake with the 650 because it felt so stiff when I pushed down on the car.
The drive is the proof in the pudding. It felt great and the comfort is not different. The car feels great.( do you think I am HAPPY!)

Everybody should drive a car with heavier springs just to compare. The springs I took off were 10" 300 lb springs. The ones I put on are 9" 650 lb.

[eliminator]

Your right on Tony.

The higher spring rates work real well with a big block car.

My car ran through the mountians better than it ever has, turned real good right and left. We even hit a little stretch of Interstate Saturday AM and it was very stable at 115 MPH, (we were in the rear catching up). I was afraid my passenger (Alan's wife Paulette) would be a little white, not so, she was all smiles.

My opinion is that all FE's and other big block cars need a minimum of 350# springs front and rear. Dont know what is the effect of 200 PSI charge in the Billstein Shock has on the sping rate but it has to be a factor.

Glad your satisfied with the changes.

[Unique 289_FIA]

Ok, I'm looking to get heavier springs for my FIA. I'm looking at the 550lb QA1 9" springs for the front. What are you guys running in the rear? The same? 9" or 10"? Currently have 10" 300lb springs with Pro shocks all around.

[Silk]

Robert,

I'm running 8" 300lb springs in the rear.

[Unique 289_FIA]

Robert,

I'm running 8" 300lb springs in the rear.


Ah, so the rears are 8"? I haven't really checked, I just assumed they were the same as the front. I just recently replaced the front suspension to the more current setup and installed adjustable (height) coilovers in the rear at the same time.

It's surprising to me that 550lb springs in the front with the stock 300lb in the rear doesn't cause the car to understeer horribly? I'm assuming, since you've autocrossed the setup, this isn't the case? I know my car pushed quite a bit the couple times I've run it (it's been awhile though).

Let's say I want to stiffen the rear also. Should I go for similar rates in the front? Maybe a little less or more?

[Naumoff]

A solo II instructor drove my car and said he would lighten up the rear swaybar or heavy up the front just a tad. That is with 650# 9" springs up front and the 4 300# 8" in the rear. I have not weighed the for corners either. Then I will have to redo my four wheel alignment.
It does get pretty involved with a suspension set up for what you want to achieve. But you also have to have the tires you are going to race with on before you start tweaking the set up to much.
I would ask Rick how the quad shocks in the rear effect the individual spring rate you would choose.

[Silk]

Robert,

As Tony noted, with quads in the rear, it's much different than having just a single 300lb spring at each rear corner. I've adjusted my spring rates based on actual performance, and I've found that moving up the rates in front helped significantly with dive and roll. The 300lb rears seem to be working well for me. I'm sure someone with real expertise in suspension geometry could determine whether this is the optimum setup, but I haven't gotten that serious about things (yet).

The good news is that springs are relatively cheap and easy to swap out, so you can always try a different setup and see if you like the results. At worst, you'll be like a lot of us and have a nice array of different spring lengths and weights sitting around on the garage shelf.

[Unique 289_FIA]

I agree that it's different with the paired spring setup in the rear, there's also a much longer lever arm which I'm sure also affects it. I also don't have a rear swaybar and am using a 3/4" front bar. What we should probably be comparing is wheel rates, but I was looking for some empirical evidence for a good setup and whether I should keep the rates similar f/r. The rear on my car feels realllllly soft, in fact, I suspect the rear tires are bottoming out and occasionally hitting the fenders (275/60's, so they are kinda tall (measure about 27 3/4")). I think I will just try some 400's in the rear and 550's in the front and see how that works. I don't mind a firm ride at all (my old MR2 with modified suspension was muuccchhh stiffer). The QA1 springs are only $36 each at Jegs and Summit.

[Naumoff]

I am running a shorter tire. A 295/50 15 which is 26.5 inches tall.
3/4" front and rear sway bars.
This winter I am doing tire research and will be purchasing some 17" wheels just for AutoX The tires are shorter than the 15" go figure. They are about an inch shorter than my 50s.

[Unique 289_FIA]

Interesting bit of info. I went to double check the length of the springs on the f/r. Turns out I have 10" in front like everybody else, but the rears are 9" instead of 8". Wasn't expecting that. I checked all four, with the springs in unloaded state, and they are all clearly 9".

This works for me, as the QA1 9" powdercoated springs are the cheapest. Just ordered 2 550lb for the front, 4 400lb for the rear. I'll let you all know how it works.

[peter]

Looking to buy some used rear coil-overs - PM me - thanks peter

[Unique 289_FIA]

Looking to buy some used rear coil-overs - PM me - thanks peter

PM sent.



{Gotta make the message at least 10 characters, so this ought to work.}

[Naumoff]

Cool Robert,
Keep us posted on how they work for you.
Remember to set the ride height the same unless you plan on doing another alignment.