Front and rear coil over setups

05stroker

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I'm looking at doing coilovers on the front and rear of my car. I know the fronts are pretty common and the rears will require some custom work. The one thing I don't understand is spring rate. How do I determine what spring rate I want and does the spring rate control ride height on these setups or are the adjustments made on the coil overs?
 

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What we did on the cuda in the rear was to put a strong enough coil in to hold the rear of the car up. then we use the adjusters to either raise or lower the rear with the drive in the seat. So the car sits a little high on the right. I believe we have 120lb springs in the back. As for the front we have torsion bar setup which is another night mare all together. We also put the car on scales when we do the initial setup to keep the car balanced. We have used Strange, Santuffs which are in the car and Penske which you need a engineering degree just to understand and adjust.

Which coil overs are you thinking of?
 

05stroker

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What we did on the cuda in the rear was to put a strong enough coil in to hold the rear of the car up. then we use the adjusters to either raise or lower the rear with the drive in the seat. So the car sits a little high on the right. I believe we have 120lb springs in the back. As for the front we have torsion bar setup which is another night mare all together. We also put the car on scales when we do the initial setup to keep the car balanced. We have used Strange, Santuffs which are in the car and Penske which you need a engineering degree just to understand and adjust.

Which coil overs are you thinking of?

I was looking at QA1 double adjustable front coilovers and double adjustable rear shocks and started thinking about a rear coil over setup as well. Just have not seen a lot of rear setups on these cars and I don't understand the whole spring rate thing. For example, the QA1 fronts I've been looking at are a 200lb spring rate and I'm not sure how the car will set.

This is something I've been very hesitant about doing since the car will 1.35 60ft on the foot brake now. But we can all agree that my current setup with D Specs and Eibach Pro kit springs is not ideal for the track.
 

NoviBlownGT

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I have a qa1 double adjustable coilover set for the front on they way. Should be here Monday. Should be a nice improvement over my current strange singles with CJ springs.

I already have qa1 double adjustable rears. I haven't seen much for a coil over rear setup. Seems like it would have to be a custom fab setup.

As far as ride height adjustments those are made with a wrench.
 

Department Of Boost

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Billy

The questions I think you're asking are hard to type out because one answer will spark another question. And it's all "big theory" stuff. If you want I can explain it in detail and answer all of your questions on the phone. PM me if you want to do that.
 

swflastang05

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I have a qa1 double adjustable coilover set for the front on they way. Should be here Monday. Should be a nice improvement over my current strange singles with CJ springs.

I already have qa1 double adjustable rears. I haven't seen much for a coil over rear setup. Seems like it would have to be a custom fab setup.

As far as ride height adjustments those are made with a wrench.

I also have Strange singles and CJ springs, interested to learn how much weight you save with the coil overs, in addition to the performance. I have this on my "someday" list too..
 

NoviBlownGT

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I also have Strange singles and CJ springs, interested to learn how much weight you save with the coil overs, in addition to the performance. I have this on my "someday" list too..

I'll post up the weights when I do the swap. Coil overs should be here monday. I know the strange struts are deceivingly heavy.
 

Department Of Boost

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I also have Strange singles and CJ springs, interested to learn how much weight you save with the coil overs, in addition to the performance. I have this on my "someday" list too..

The "problem" with the performance offered by adjustable suspensions is that it gives the user a whole pile of ways to make it worse.

More often than not I've seen people bolt up the latest and greatest.........................and go a lot slower.
 

NoviBlownGT

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I can see how thats easily done! Thankfully there is quite a bit of info out there as far as baseline setups. Just need to have a solid understanding of how everything works and make adjustments. Takes some track time and some homework for sure.
 

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I can see how thats easily done! Thankfully there is quite a bit of info out there as far as baseline setups. Just need to have a solid understanding of how everything works and make adjustments. Takes some track time and some homework for sure.

This^^^^^^^

The process realy starts once everything is bolted up. That's when the hard work starts.

I just recently got back into mountain bikes after 20+yrs off. The suspensions have gotten sooooooooooooooooooooooooooooooooooooooo good it's crazy. I was lucky enough to hook up with a group of really fast riders and I have a fantastic shop up the street. I'm not shocked, but I'm shocked that despite knowing everything "mountain bike" these guys wouldn't know suspension setup if it was dropped on their heads. Their bikes are all messed up, LOL. I have been getting them dialed in though. But we're still on the basics of basic. They collectively have a lot more in the bag in regards to getting all dialed in.

Setting up drag cars has got to be tough because unlike a motorcycle, mountain bike, MX bike, etc you can't work off feel. If I were setting a drag car up the first thing I would do is set up a couple of GoPro's. One on a front strut and one in the rear so I could replay launches to see exactly what the suspension is doing. GoPro's are the "poor mans" linear potentiometers. Those are fantastic for setup, but are not cost effective for anything short of a full on race program.
 

travelers

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This^^^^^^^

The process realy starts once everything is bolted up. That's when the hard work starts.

Setting up drag cars has got to be tough because unlike a motorcycle, mountain bike, MX bike, etc you can't work off feel. If I were setting a drag car up the first thing I would do is set up a couple of GoPro's. One on a front strut and one in the rear so I could replay launches to see exactly what the suspension is doing. GoPro's are the "poor mans" linear potentiometers. Those are fantastic for setup, but are not cost effective for anything short of a full on race program.

That is very true. The track conditions, tires, weather conditions all make a difference in setups. We film every run and we have potentiometers with a racepack to look at what each side is doing and we make adjustments as we think is needed. A big help is write the setting you start with and every time you change one and the results.
 

05stroker

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I think I will need to mock up the mounts and decide on a shock length from there.

As for spring rates, how does one determine what rate is needed?

Here are the specs for what's on the car now.
Springs Specifications
Spring Rate: Front: 171-228 lb / in. Rear: 180 lb / in. Usage: Street
Year: 2005-2010 GT2010 V6 Model: Coupe Convertible
Progressive or Standard: Progressive Estimated Drop: 1.3"F / 1.4" R 1.3"F
 
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Department Of Boost

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I think I will need to mock up the mounts and decide on a shock length from there.

As for spring rates, how does one determine what rate is needed?

Here are the specs for what's on the car now.
Springs Specifications
Spring Rate: Front: 171-228 lb / in. Rear: 180 lb / in. Usage: Street
Year: 2005-2010 GT2010 V6 Model: Coupe Convertible
Progressive or Standard: Progressive Estimated Drop: 1.3"F / 1.4" R 1.3"F

When it comes to spring rates the ol standby is to go with what the fast guys are doing. In your case see what the Cobra Jet guys are running and start there.

The only other way is experimentation and that involves having a pile of springs and a repeatable/log-able environment to test them in.
 

05stroker

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When it comes to spring rates the ol standby is to go with what the fast guys are doing. In your case see what the Cobra Jet guys are running and start there.

The only other way is experimentation and that involves having a pile of springs and a repeatable/log-able environment to test them in.
I'm leaning towards a 200lb front and a 150lb rear to start with.
 

05stroker

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When it comes to spring rates the ol standby is to go with what the fast guys are doing. In your case see what the Cobra Jet guys are running and start there.

The only other way is experimentation and that involves having a pile of springs and a repeatable/log-able environment to test them in.
I'm leaning towards a 200lb front and a 150lb rear to start with.

Trying to decide between QA1 and Strange.
 

Department Of Boost

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I'm leaning towards a 200lb front and a 150lb rear to start with.

Trying to decide between QA1 and Strange.

I think the CJ guys run a 175# rear. And if you're running DR's vs slicks you will want to be on the stiffer end of the range so you deform the tire more.

Link me to the QA1's and Strange. If they have enough info posted, hopefully with some cut-aways I can give you my $.02.
 

NoviBlownGT

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Pulled the strange singles with springs/strut mounts and together they weighed in at 44.8lb., so 22.4lb each side. I'll weight the coil overs tomorrow with c/c plates attached to have an accurate comparison.
 

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