was looking into getting some helper springs for the Evo's droop travel, and Swift has something called assist springs also (first tab)

http://www.swiftsprings.com/products...elper-springs/

Definitions are as below:

Assist spring:
Helper spring:
I'm not super technical here as most of you know - I'm specficially interested in the bold part of the assist spring, but can anyone provide insight on this, especially if you use it? Looks like the assist springs have higher spring rates, that may be about it? I was looking into getting helpers so I could raise the car a little, specfically in the front. The way the damper is designed, the higher i raise it from the bottom, the more difficult it is to get my fingers in there to adjust the shock settings. Regardless, it may not be a horrible idea for me to get helpers or assist springs, since I'm getting close to lifting in a few spots. Likewise for the rears but I don't think it will change anything there

 

The position i'm taking now on assist springs is that they are good for the rear on a street car with high spring rates. And by high, I mean something that gets you under 1" of static compression. The extra droop dramatically improves ride over bumps where the standard shocks would fully extend and you'll feel that heavy shock.

I've been running them on track for years thinking its better to not have that shock but I've been convinced that's not important. A huge advantage the Evo has is the multi link rear means we can get pretty high rear grip. Don't fight the lift, let it come up and the car will turn better. Is the back too unstable? That's easy to fix with pressure/camber/toe.

 

on the rears, mine will be around 1" of compression (11k springs, cb'd & rears are about 600lbs both sides). I'm the one that's been saying let the rear lift, and others have been saying to keep it down! for god knows whatever reason.

I was thinking specifically on the fronts too though, when it's loaded up on one side, from the pics you can see the edges get some air in the front. may help there too, but how do you decide on

1) assist vs helper (per swift's website)
2) what rate to get?

 

I wouldnt run them up front. If you are properly loading the outside rear, the inside front will keep loaded also. No reason to carry that extra weight up front.

11k rear, i wouldnt run any tender/helper/assist spring. If you were around 16k and cared about street manors then yeah it would be ok. Im more than double your rear rates and I feel the assist is only working against me in getting the inside rear up.

I'll tell you, even big bad wolf (S2000 that destroyed SSM this year) purposely lifts the inside rear.

 

very interesting - the OSG spun in the rear, which I assume will be fixed with TRE, but even so, with a rear up, it may be able to put power down more effectively if it had a gentler initial landing?

 

May be wrong but I believe helper springs don't really help during street driving that much. I only notice my helper making it better when I would go up a driveway which my rear would normally run out of droop, and then im three wheeling it up the driveway until its more straightened out. Also another scenario if I was turning right onto the street(where there was a little slope) and my inner rear didnt go down the tiny slope like my front inner did, thus my inner rear wheel would kinda go off a curb down onto the street. That scenario, I didnt get a loud thud like usual, it would be very unnoticeable. As for on the road from bumbs, tiny pot holes and what not, made no difference.

I have an *** load of droop but my inner rear still lifts on some corners when I go in pretty hot. Those scenarios though, I never really am needing to gas it and by the time I do need to gas, my inner rear is already down. I got my helper springs pretty damn cheap so I went that route. If I had the funds, I would've went a dual spring setup route for performance and better daily drive ability.

 

Helpers are different than Assist springs. But the assist springs over something like railroad tracks had a dramatic difference in what I felt in the car. But since the car is trailered to parking lots now, there's no benefit having it.

I would just run a helper if my springs come loose when jacking the car up. And that is only cause dealing with springs seating can be a PITA.

 

what exactly is the difference? helpers are literally jsut to keep springs seated, and assist is for more of a dual spring rate kind of thing? i'm just looking to increase a little height on my fronts here also, without doing it from the bottom perch - i'm not able to raise any further at this point while still being able to adjust the shock

 

Assist springs are usually supposed to be more for dual spring rates, but swift assist springs spring rates are IMO too low to do that. Their rates go up to 600lbs at full collapse. Our rear are around high 500s-700 depending on corner balancing. This will make the assist spring pretty much at full collapse, thus its pretty much a helper spring/1 spring setup. Eibach had better options. But if all you want is more droop, the swift options are pretty alright.

Also note, the rear upper control arm front bushing will limit your droop. It wont allow your rear to drop a lot unless you swap the bushing out.

 

i do have the rear control arm bushings.

question on the general setup - let's say you don't add the preload to fully compress it, so it's in play when the wheel is up until the weight fully compresses it down - i.e., if i use a soft one in the rear, will it basically cause understeer until it fully compresses and then create oversteer when it's fully compressed and goes back to the main spring?

 

What kind of spring and lbs are you talking about? With that we would have a better idea.

 

i was thinking 3k helpers up front, maybe compressed 90% of the way full droop just to let me raise the car so i can lower it back at the shock body to adjust the shock better down at the bottom (inverted ohlins with the adjuster inside the shock body to the control arm, and 4k helpers in the rear, maybe compressed 50% to help a little with the lift when it touches back down

 

I see what you're assuming, and no thats not really what would/will happen. You're guessing cause the effective lower spring rate on that tire, it would be more prone to push when in effect. But when the tender spring is active, the load on that tire is pretty minimal so its not really doing a whole lot anyways. Just like when the inside rear picks up, the handling doesnt just snap to understeer as the effective rate at that corner is Zero.

What more likely happens is when the front is diving down from steering/turning forces the counter corner continues to push where it would normally have let go allowing the outside rear and inside front to take over. The tender is trying to push through the swaybar prolonging the time the wheel is on the ground which is probably fine with very little preload on the rear diff. The downside is that in the tightest corners the only way you arent going to lift is if your setup sucks. So you'll then struggle to get on the power early with that inside rear spinning up since which causes that torque bounce between front/rear when each end slips.

 

You gotta get your measurements and number right if you're trying to aim for those numbers lol. I didn't really look much into it but I doubt you will have enough shock body to be able to use light weight springs. My rears on Fortune Auto 510's couldn't use the full helper spring which is only 2.4 inches tall. I didn't really add any preload, just enough so the springs wouldn't ever be in a free fall state at full droop. There is a excel spreadsheet from hyperco which will tell you what your springrate will actually be when you run a dual setup. So your 3k spring up front isnt actually 3k(well, it is). Lets say you have a 10k spring up front. If you stack it with a 3k spring, then your real rate will be around 2.5k. After your assist/helper spring fully compresses, then the rate will just be your 10k.

Formula link at button of this webpage.
https://www.hypercoils.com/tech-tips...al-rate-setup/

Edit to add this in for clarification - running 2 spring lets say 10k main and 3k helper/assist. You will have a dual rate, which is 2.5k ish by using (RATE 1 x RATE 2) / (RATE 1 + RATE 2). When one of the spring fully collapses, your spring rate will not become the springrate of the spring that isn't fully compressed, which will most likely be your main 10k spring.

So (gotta use lbs in this instead of kg) 168x560/168+560 = 129lbs. 129lbs converting it to kg/mm is 2.3k.

So when I was planning this out, I aimed for a way higher spring rate on the assist/tender spring(no helper spring would be that high of a springrate). So if you wanted your dual rate to be 300lbs(5kg), then your assist/tender spring would need to be a 700lbs(12k) spring, a very small one that is so it compresses fully when at cornering load.

 

i'm not particularly looking for a dual rate - i expect that in racing, in the front, it will be fully compressed all the time - the fronts are really just to help me raise the car without adjusting the bottom perch so much. in the rears, i was basically aiming for a slightly softer landing essentially. the rear will lift, period, and i'm happy with that - but I just want to make sure it touches down a little better, especially considering the less aggressive rear diff i'm running. based on dallas's comments, it seems like for tight stuff, the weaker diff will still be a problem - i can't do too much about that at my current level.