Hey guys i have the MM coilover setup and they were on the car when i bought it. they are great for turns and handling but really kinda suck for straight line performance. what ca i change do help me out on the track as i don't really hit the twisties too much. I don't want a full out strip setup but something more like a strip/street setup. thanks
setting up coilovers for street/strip
- Thread starter jamescb77
- Start date
First off, IRS or SRA?
sorry i forgot to put that in there IRS
Well to maintain the stock wheel rating, a 400lb rear spring would do that for you. If you want to go lower than stock, you just have to convert spring rate to wheel rate. For a drag setup, i calculated that to match a 130lb SRA CO spring rate, you would need a 300lb IRS spring rating on the rear coilovers. I think that stock does fine though, so I'd suggest a set of 400lb springs for your coilovers if you want it to have a stock-ish weight transfer.
what about upfront. I know a lot of the track cars are running 14x175lb springs. is this a good daily driver style spring or more of a track only. also what length is the 400lb spring that you are talking about?
I'd do a shorter spring, no more than a 10" spring in the back. I have an 8" spring in the back and I wouldnt go any longer. For the front i'd personally not want to run less than a 225lb spring. 175-14 springs are a drag only setup in my opinion. I personally think that a 250/400 setup would work well for you. But I'd talk to the guys at MM about setting up a street/strip profile as they'll likely have better info than I. They'll be able to suggest you a nice street/strip setup as they are not as heavy on drag racing as everyone else. Everyone will tell you that a 175-14 spring is streetable...and it is to an extent...but I actually like to toss my car into a turn. If its a street car, dont set it up like a race car. My car can take launches and twisties very well and rides great.
thanks i appreciate the help. It sounds like you have a setup very similar to what im after. Ill call and talk to MM and see what they say as well
My setup is probably stiffer than you want. I'm at 325 front and 525 rear maxing out the valving of the hd's. I'd suggest maybe 250 front and 400-450 rear.
Before you start changing spring rates the first order of business is to replace the spongy rubber rear A-arm bushing with delrin and nail down the pumpkin before you beak something.
Go here: Full Tilt Boogie Racing
Best mod you can do for a IRS equipped Cobra and you will love what I will do for the handling of the car and will make your diff happy. Lean to far in the drag race direction and it won't be as much fun to drive.
Go here: Full Tilt Boogie Racing
Best mod you can do for a IRS equipped Cobra and you will love what I will do for the handling of the car and will make your diff happy. Lean to far in the drag race direction and it won't be as much fun to drive.
The FTBG bushing kit is fantastic, and should be done on any IRS car. To say that it will be less fun to drive at the drag strip is just plain wrong! My bushings help plant my car hard and would be great in a 1/4 application. But OP just wants to nail down his spring rates to make it ride and 60' better, which the bushing kit does. But the changing of springs is only about $240 and little install time, versus the bushing kit which is like $675 IIRC and requires a minimum of 12 hours to do. Lets get his spring situation sorted out first and worry about selling him on the bushing kit later! :beer:
Who said anything about the bushing kit making the car less fun to drag race? Even for that I would consider the bushing kit to be way more important then the springs. Softer springs are great for transferring more weight tro the rear at launch and a smooth ride but that will work against you in just about everywhere else.
Don't forget a Billetflow brace or an LPW diff cover :rockon:
By the context of that post, the bolded seemed like adding the bushings would take away from drag racing. That was my bad of not reading it correctly.
The spring rates I chose for OP's application maintained almost stock spring rates in the front and did maintain them in the rear. So that is keeping him from leaning too far towards drag racing as they are not drag specific spring rates. They are very streetable spring rates that will allow corners to be taken spiritively and do decent at the track as well.
Bushings should be done, but that is not the topic at hand. Try to answer the OP's question and once he is squared away at that, then we will talk bushings. They are important, very important even. My bushings in the IRS i bought and put in my GT had 40k miles on them and the bushings fell to pieces when they came out. It is a wise choice to invest in the bushings for any Cobra. I love mine dearly and thank Bruce for the devine kit.
BTW, whats the intervals in which the bushings need to be lubed up? I got the zirc fittings and installed them but I have no idea how often i should grease them and what to use for it.
Yes the OP was inquiring about spring rates but as you know other aspects of the suspension should also be considered. Pulling springs is not a walk in the park and can be very dangerous if not done safely. If he decides to install bushings later on he will be pulling those springs out a second time. Replacing the bushing is not a fun job to begin with but I find it best to do everything at once and not several times but that is just me.
Hard to say what the lube intervals need to be. Every 10,000 miles or so would probably be a safe bet. I bought a tube of Prothane super grease :rockon:
Prothane 19-1751 Prothane Super Grease
and put it in a grease gun. This stuff won't ooz out like petroleum grease. I put grease fitting on everything that pivots including the upper A-arm bushings.
Thing is...pulling a coilover spring off is easy as when the car is in the air, the spring is not under load. At least mine arent as short as they are. Plus they sit on the shock/strut so if youre taking the spring off, you must first disconnect the strut/shock from the car and then remove the spring. Not painful in the least. 
And thanks for the info on the bushing grease. I probably wont have to do it but once a year, as my car is a DD. But would doing it too soon cause any harm?
And thanks for the info on the bushing grease. I probably wont have to do it but once a year, as my car is a DD. But would doing it too soon cause any harm?
Thing is...pulling a coilover spring off is easy as when the car is in the air, the spring is not under load. At least mine arent as short as they are. Plus they sit on the shock/strut so if youre taking the spring off, you must first disconnect the strut/shock from the car and then remove the spring. Not painful in the least.
And thanks for the info on the bushing grease. I probably wont have to do it but once a year, as my car is a DD. But would doing it too soon cause any harm?
I forgot he had coilovers. Yea much easier and safer. I just kept thinking about how I felt like I was defusing a bomb while waltzing with a compressed 600/in coil spring.
Yea...I <3 coilovers! Great invention.
the car alreadt has bushing in the IRS and a rear diff brace on it. If it didn't have those things then i would be tackling them first. It will probably be closer till spring before i actually get some springs and swap them out since the car is about to go up for the winter and my storage area is not big enough or heated to work on a car. I appreciate your guys help and if you have any more advice keep it coming
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