2010 Evo GSR. Will get seat time in at track over the spring summer and fall, but is also my dd.

I'm absolutely torn between the comforts and the dreadnoughts. while the comforts (at $1099) are cheaper, the dreadnoughts (at $1899) offer a bit more in terms of what I can get out of them.

thoughts? opinions?

any/all info is appreciated

 

If you're not really serious about tracking the car, then just go with the 510s. PM me if you need more help or would like a quote.

 

lol ive been pming you today. the 510s though, with a swift upgrade, are only 100 bucks cheaper than the dreadnoughts; in which case- id just get the dreadnoughts.

BUT ... the comforts offer the valving that the dreadnoughts have...

cant decide!

 

If you are going to spend 1900, why not wait for a used set of DFV's to pop up? I got my set for less than what you are prepared to spend, you just have to be patient.

 

from where?

 

I got them used off the forums. They pop up here from time to time. I think I have seen them for an evo X twice in the past in the low 2000 range.

 

kw v3 or eibach r2s

 

lol... v3s are waaaay out of my budget. very nice coilovers, I simply can't afford them tho. the dreadnoughts are pushing the envelope even.

 

Plot of the 510s:


Plot of the Dreadnaughts:


Not bad at all. Clearly not Taiwanese crap.

But I wish they would also provide the "football" plots, because Fortune Auto is known to have had serious hysteresis issues in the past. They claim to have fixed this, but evidence would be nice.

 

iowa, why do the 510s appear to be more digressive than the dreadnoughts? dont the dreadnoughts come with digressive valving?

 

I don't know how much you know, so please forgive me if this ends up being remedial to the point of insulting. (I've had problems guessing what level to post at in several recent threads; I can't fix the problem [as my mind-reading gizmo is in the shop], so I thought I'd just say something in advance.)

First off, regardless of what it says on Fortune Auto's website, digressive valving is really only important for compression, which is the top half of the graphs. No clue why they jump up and down about super digressive rebound. Digressive valving in bump (compression) is key to ride quality. You want to be under-damped in bump so that less of the bump is transmitted to the chassis.

Second, these shocks both have one-way (rebound-only) bleed adjusters, which is the best kind of single-adjustable, IMO, and they show virtually no cross-talk, which is also a good sign. In other words, the adjusters alter the low-speed rebound up until the elbow; from there the lines are parallel as the shim are now open (and they are not affected by the low-speed bleed adjuster). What's most important here is that the shocks can be set to have much more damping in rebound than bump. If you go under-damped in compression for ride quality, you need to go over-damped in rebound to make up for it. The rule of thumb to use as a starting place is the "2/3-3/2" rule. Choose a fraction of critical damping as a whole, then drop the compression damping to 2/3 of the target and raise the rebound damping to 3/2 of the target. This averages out to the desired amount of damping, but does most of the "work" during rebound, again, for ride quality and mechanical grip during a bump, which is much more likely to cause the car to skitter sideways than a divot.

With regard to details, you want to look at the upper half of the plots (bump), focusing on when the shims blow open (which is the elbow) and the damping before and after the elbow. The 510s are rightfully called "ultra digressive" since the slope drops to one-fifth of what it was before the elbow. That's a larger drop-off than you'll see on MR Bilsteins. If FA has solved their previous hysteresis issues, then 510s might ride incredible nicely. If anything, that's too digressive starting at too early an elbow, so turn-in may suffer a little. But for a DD, that could be very nice.

Next, staying with the 510s, look at the options for rebound relative to bump, maybe doing the comparison only at the elbow. A range of options from 1:1 to 6:1 is great. A lot of Koni SAs (Sports, Yellows) don't give you that kind of range. The one worry I have, which is related to relatively early and low elbow for compression is that, when these are set to full stiff, they are very likely to pack down the spring. (Packing down is when, as the suspension is cycled by road imperfections, the rebound damping doesn't allow the shock to re-extend between bumps, so the springs become progressively shorter and the bumps, effectively, all pile on top of each other. When this happens, the pre-load in the spring resists the subsequent bumps and suddenly the ride is awful and the car is skittering sideways. Many people mistake this for too much compression damping. I've even seen people accuse the shock of having cross-talk issues, even when the dyno plots show they don't. In other words, this can be hard to diagnose if you didn't know to watch for it. That 6:1 ratio option has me worried that people will crank this to full stiff for some kind of racing and they will be awful.)

Switching to the Dreadnaughts, note two things in comparison to the 510s. First, there's twice as much bump damping at the elbow, even though the elbow is still down at 1"/s. Second, note that the options for rebound now go from less than 1:1 to only 2:1, instead of 1:1 to 6:1. I'm not a big fan of this. I, personally, can never see wanting less rebound than compression (even on a wonderfully smooth track) and not being able to have more than twice the rebound is not so great, either. It's almost like these are so hung up on turn-in to the exclusion of all else that they are intended for drifters or some other kind of racing that I know nothing about. Are there really any US tracks so smooth that you'd run as much compression as rebound? I don't think so.

All in all, while the 510s seem a bit soft, everything else about them seems better than the supposedly fancier Dreadnaughts. Based purely on the math and theory, therefore (and please note [and you know who you are]: he didn't ask if I've ever tried these; he asked what I took to be a question best answered with math and theory), I'd go with the 510s over the Dreadnaughts, especially if this is also a DD. Final caveat: I'm just talking about these two shocks against each other, not in comparison to anything else.

edit: I just re-read your question. They are both digressive, in that there's an elbow after-which the slopes are flatter. The before-to-after ratio for the 510s is about 20%; the ratio for the Dreadnaughts is about 25%. They are both very digressive. Yes, you can make a shock even more digressive than that, but usually only with an external canister. Not that I think that you'd want them to be any more flat.

- Jt

 

thanks man, i always like reading your posts lol... purely objective and full of info.

now what about their "comfort series", do you know much about them?

also... if I were to get custom rates (obviously youre not me, and everyone is different) but... what would *you* get for an evo on the track but still a dd for damper rates (custom valving) as well as spring rates? I do know that it is preferable to match the damping with the spring rates as to get the best efficiency and performance out of the coilover set up, but dont know what would be suitable for this night and day difference of track/dd.

edit- fyi I do know the basics (and I mean basics) of shock tech, how to read a shock dyno graph, etc...

 

Springs-rates would be another long post and I'm burnt, thanks for asking.

Short answer: DD with occasional seriousness: 8/8 with good shocks; maybe only 6/6 with bad ones. Note that most places will suggest a higher rear rate, mostly due to the lower rear motion ration, but keep in mind that it's the rears that mostly determine ride quality when the car is nose-heavy. An adjustable rear sway bar is how you can have a nice DD that can still turn at the track.

 

alright thanks, and I do have a 3-way adjustable hotchkis rear sway bar, I totally forgot about that lol

and just to clarify; all-in-all, you would go with the 510s over the dreadnoughts for this particular application? if so- should I *really* upgrade to swift springs?

 

Yes, if the car is mostly a DD, then I, personally, would go with the 510s. And with that rear bar, I'd suggest 8/8 or 9/9 and, yes, I would pay for the Swifts. And don't forget my caveat that I'd really like to see the "football" plots (to make sure that they have solved their hysteresis issues of the past) before I spent any money. But it's time for someone else to chime in.