Spring Rates

RET_COP · #1 (**permalink**) 07-12-2011, 05:29 PM

I wanted to stiffen my rear as it tends to bottom out on the snubbers at times when I use a lower ride height. I have carrera hypershocks with QA1 8-375 front and 10-185 rear. This was what came from B&B. I called QA1 and they recommended 225lb rears which I ordered. I'm not actively racing the car but a stiffer ride is better than a soft ride to me. I looked at front springs and QA1 offered a 500lb for the next step up. This sounds too stiff as my front seems good at the moment. I don't plan on running a sway bar. Is it true that there is about a 2 to 1 ratio front to rear on spring rates for our cars, excluding racing setups? What are some or your setups so I can get a idea on this matter. I've seen spring rates all over the place but I'm really asking about B&B cars since different geometry's can alter rates.
Thanks LOU

Wbulk · #2 (**permalink**) 07-12-2011, 05:44 PM

Lou, it will be interesting to see how the new rear springs turn out. I had read on previous post where guys said that the 225 lbers were just about perfect for the rear of a B&B. I was thinking if going with the 225s you might have to go to 9" to keep from running out of adjustment. Let us know how it turns out.

Wayne

RET_COP · #3 (**permalink**) 07-12-2011, 06:25 PM

Wayne, good to hear from you again. Hope all is well. Thanks for the post. I bought spacers for the front springs which worked out really well as I was getting close to running out of adjustment. I'll have to do the same for the rear if it comes to that. I'll let you know.
I'll tell you what, I broke the mold on running the same or close to the same diameter tires on these cars. I went with Mickey Thompson Sportsman SR 28 dia. on the rears. Man does it look great. It fills the well nice and with the bigger sidewall looks mean. The fronts are 26dia. The tires have really good grip and don't catch stones with the flame tread.

Lou

lnfletcher · #4 (**permalink**) 07-13-2011, 03:45 AM

Ok, I think I speak for a number of us, where are the pictures of your car with the Mickey Thompson Tires? Sounds like it looks pretty sweet.

Wbulk · #5 (**permalink**) 07-13-2011, 08:31 AM

I second that. After I read about the tires I went looking. Couldn't find them.

RET_COP · #6 (**permalink**) 07-13-2011, 04:15 PM

Larry and Wayne, here is the link to the rear tires I ordered
Mickey Thompson 6640 - Mickey Thompson Sportsman S/R Tires - Overview - SummitRacing.com
If you go into my username and then Lou's pictures the latest picture is the one with the firetruck in the background. Yea I know you should have seen my car after he took 5 minutes to park that thing. I had diesel streaks all over the driver side.
He was a really nice guy and we laughed about it.
Also on the springs. I just changed them and haven't taken it out for a ride as it started to rain, but here is what I observed. The adjusting collars at the same ride height are about 1/4 lower so I believe I accomplished my goal. I lowered my ride height and now the springs hold more weight and won't give as much.
Lou

Wbulk · #7 (**permalink**) 07-13-2011, 07:54 PM

So Lou, yours are 2 1/2" X" 10 high springs ? Do they look like these?

Wayne

RET_COP · #8 (**permalink**) 07-14-2011, 01:46 AM

Wayne, Yes, they look like that except they are adjusted higher. I have the silver power coated springs. The part number is 10-225

mbeers6 · #9 (**permalink**) 07-14-2011, 07:42 AM

Great post, I will be replacing my rear springs soon as well.

The rear of my B&B sits too high so I have the preload adjustment all the way out. I think it would be best to get a better rate spring.

I think I would need to go with a softer spring if the car sits too high?

Are there markings on the spring to tell what rate it is?

Lou, where did you order them from and how much did a rear set cost?

RET_COP · #10 (**permalink**) 07-14-2011, 01:31 PM

mbeer6 remember there is the length of the spring and the rate. Going to a softer rate may cause the rear end to hit the snubbers on a bump. Going to a softer rate may not work well with the rate of the front springs. If you have a 12 inch spring that may be your problem, a 10 inch would correct it and allow you to lower the ride height and get the adjustors higher on the shock. There is alot of science to this shocks included, but I tried to make a simple move and just went up in rate.
My suggestion would be to pull out a spring and look at the length and rate and get back to us. Take a measurement of the rear end housing to the snubbers, how high the adjusting coller is on the shock and the ride height [space between the top of the rear tire to the lip of the fender and length of spring under weight. Wayne and Larry have good knowledge about the B&Bs. At least that is my thinking.

Lou

RET_COP · #11 (**permalink**) 07-14-2011, 01:43 PM

One more thought, I wanted a high ride height in the rear. I like the look of the forward rake. I had too much space between my rear tire and fender all the way around, the 26" tire looked lost. That is why I chose the 28" dia rear tire. I thought this out and took a thousand measurements, and when I ordered the tires I really stressed over it. $825.00 is not easy to come by for me, and all information said to stay with the same diameter tires [front to rear] or close as possible.

Lou

RET_COP · #12 (**permalink**) 07-15-2011, 05:30 PM

Ok I took the snake out for a cruise and I have to say the springs were perfect. I went over a particular dip in the road on the way to Watch Hill, which I usually bottomed out and with a 1/4 inch lower ride height I had no issues. The stiffer ride was a nice change.
That is what I like about these cars. they're made to take apart tinker with, from drag racing to road racing, from cruisn' to showing, to fit anyone's desires, and yet, popular and ageless, we are all connected as COBRA owners.
Lou

mbeers6 · #13 (**permalink**) 07-16-2011, 12:36 PM

Quote:

Originally Posted by RET_COP

Ok I took the snake out for a cruise and I have to say the springs were perfect. I went over a particular dip in the road on the way to Watch Hill, which I usually bottomed out and with a 1/4 inch lower ride height I had no issues. The stiffer ride was a nice change.
That is what I like about these cars. they're made to take apart tinker with, from drag racing to road racing, from cruisn' to showing, to fit anyone's desires, and yet, popular and ageless, we are all connected as COBRA owners.
Lou

Glad to hear it worked out Lou!! I'll get back to you guys once I have a chance to measure everything on mine. I'm in AZ now

RET_COP · #14 (**permalink**) 08-28-2011, 08:35 AM

To update the spring situation. I Put QA-1 300 lbs in the rear and QA-1 500lbs in the front. I have thought of AX the car when I get the chance. I really like the way the car handles now. It stays closer to level and doesn't feel like its flopping over. Its not bad for cruising, I don't mind a stiff suspension. My wife hasn't been in it yet. She'll never notice

Wbulk · #15 (**permalink**) 09-07-2011, 05:37 PM

OK Lou, you didn't tell us why the change. What happened to the 225 lb. springs and why did you change your mind. I am thinking there is no way the 185 lb. springs are going to work with mine. I think the rear looks good at 28"-28 1/4" to the rear fender lip, but that just gives you about one inch before you hit the bump stop. When I set in the car with my 240 lbs. the car drops another 3/4", so either I jack these light springs up or go to a higher rate spring. Where did the 225 lb. springs end up as far as threads for adjustment.

Wayne

MFE III · #16 (**permalink**) 09-07-2011, 06:08 PM

Interesting how different makes are sprung so different. My Hurricane came with 9" 400 lbs QA-1's all around. My fronts are fine, but I do bottom out occassionaly on the rears. I'm planning on upping the rears to 450's or 500's on the rear but I'm happy with the fronts.
I'm running a small block, IRS (less unsprung weight) and my 205 lbs butt!
Matt

Wbulk · #17 (**permalink**) 09-07-2011, 06:52 PM

It must be the the weight of the IRS vs. the unsprung weight of the solid axle. IRS does have advantages.

RET_COP · #18 (**permalink**) 09-08-2011, 01:58 AM

Ok Wayne here goes. The 225 were a good ride for the street but since I want to autocross the car whenever I get the urge I wanted something where I could go from the street to the course. The 225s did not pin the front end down good enough. When I fooled around in a parking lot the left front rose too much on a hard left turn and same but opposite on the right. I wanted a better compromise. I was also hitting the bump stops just a little too much as I had the rear about 27 at the lip of the fender. My ring adjusters at this time were a little below half way on the shocks. I had a delema and I did not want to go too stiff. I chose the 300s and put them in. When I lowered the car to my ride height the adjusters were about 3/4" from the end of the shock, so I was happy there [whew!]. I clipped about a 1/4" off the bumps. When I took the car out for a test what a difference!. It pinned the front of the car down and it got rid of the floppiness, and I don't hit the bumpstops anymore. Overall all I am happy about the move. I also was looking at the bottom of my front tires and saw that there was a slight gap of air on the inside. When I looked into it further I found out that I had POS. camber! and upon measuring my caster with plumb bobs [rather crude I know] I had no caster. Well after spending 6 hours on the front alignment I got things were they should be, at least alot closer and it just feels like a different car. I also put on Cooper cobra 295/50/15/on the rear and 235/60/15 on the front. I know, I know. The MT SRs had a little too much flex in the sidewalls for AX and were not wide enough for me, they a nice sticky tire but the coopers feel better. [they are for sale at a great price by the way] The car is now closer to my goal. Oh the ride is not bad, I expect my car to feel like a racer. The wife is rolling her eyes

Next a wilwood master cylinder and front calipers, the GM Metrics have to go.

lnfletcher · #19 (**permalink**) 09-08-2011, 04:09 AM

Let us know what you go with on the brakes up front. I have been wanting to upgrade the front brakes and master but want to keep the 15" wheels.

Wbulk · #20 (**permalink**) 09-08-2011, 12:08 PM

Thanks Lou. Love the the detail. By the way I have been told a couple of times the MT are made in the same plant as the Coopers. The tread is very close.

Wayne