More info on Penske shocks

[tahdizzle]

This thread makes me wish I had 15k to use on suspension :p

[RBbugBITme]

Originally Posted by 7thgear

but this is not optimal, correct?


and if yes, is purely the progressiveness of the rate or the material choice/force distribution.

Its just one of many choices a designer has to make when designing a suspension. Only lap times will tell you if its optimal or not.



Andy, I would agree your assessment certainly makes sense. Have you experimented with removing the OEM bump stops while running high end shocks? Are they mounted on the control arm or the shock shaft? I'll also add that a lot of "performance" shock upgrades from the factory are the same shocks with stiffer bump rubbers.

[Racecomp Engineering]

Originally Posted by RBbugBITme

Andy, I would agree your assessment certainly makes sense. Have you experimented with removing the OEM bump stops while running high end shocks? Are they mounted on the control arm or the shock shaft? I'll also add that a lot of "performance" shock upgrades from the factory are the same shocks with stiffer bump rubbers.

For Subarus they're on the shock shaft. With some of the high end shocks we've run (JRZ, Moton, etc.) we do not use bumpstops. For OEM with the stock springs I suspect the shocks wouldn't last long, at last for BRZ since there isn't much travel and the main spring is so soft. New 2015 WRX and STI are bumpstop active but actually have much firmer main springs than they have in the past.

No bumpstops on your Penske set I presume or is there an internal one up front?

With our own lowering springs on stock shocks (different ball game then those shopping for Penskes) we use much shorter replacement bumpstops, a mild drop, and a decent bump in spring rate. We like it for the money, but a quality shock makes a big difference at that point.

Interesting on the last point...I wouldn't put something like that past BMW...

- Andy

[7thgear]

another question


you mentioned earlier that part of the cost for strutted cars is the strut, which is expensive to design/manufacture on a small scale.


I don't suppose that making an insert, such as what koni does, would ever be a possible solution? Not enough room for a monotube?

[RBbugBITme]

Originally Posted by Racecomp Engineering

No bumpstops on your Penske set I presume or is there an internal one up front?

The customer didn't ask for any. We also haven't had any feedback yet on the spring rates he's running since he didn't buy them from us.

[RBbugBITme]

Originally Posted by 7thgear

another question


you mentioned earlier that part of the cost for strutted cars is the strut, which is expensive to design/manufacture on a small scale.


I don't suppose that making an insert, such as what koni does, would ever be a possible solution? Not enough room for a monotube?

Not really practical for an inverted strut design.

[cdrazic93]

I feel like we're all talking to the cool kid on the block lol

Im curious to know @RBbugBITme's impression of the prototype damptronic setup @DougW is putting together.

[Jive Turkey]

dear lord, this makes me feel like a peasant with my AST's

[fooddude]

Originally Posted by RBbugBITme

Thanks errbody, glad I can help.

We have more than half the field. They're all non-adjustable for weight and packaging.

Sent from my SAMSUNG-SM-G900A using Tapatalk

Ah, I see. So I am assuming in F1 or other high end races, these non-adj shocks are internally built/valved to spec per session and per track, and maybe have several spares in the paddock/garage with different internal specs to swap? (ie: instead of having a set of adj shocks...they just have a grip load of non-adj shocks to swap..and that's their "adjusting") ..Wow.

[RBbugBITme]

Correct

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[fooddude]

Cray!

[mav1178]

Originally Posted by fooddude

Cray!

Not cray...

The track, speed, engine performance, tires, and even ambient temps are all known parameters.

Why add complexity to adjustable shocks when you just dial in the car for the track conditions? Makes the systems more reliable.

-alex

[fooddude]

I meant cray in a good way lol.

ie: very neat, cool, awesome, amazing, nice, fantastic, interesting, that's epic bro, etc.

[Shankenstein]

Hey Ryan. Thanks for bringing your expertise to our little community.

As a suspension guy who has probably had the BRZ up on a 7-post rig, did you identify anything heinous about the design or any "low hanging fruit" for the tuners to focus on?

From what I've seen, the camber and toe are relatively well-behaved (as long as you're not slammed). A few of the guys on here have had positive results from adding caster up front. Otherwise, the weight transfers are fairly smooth, and the chassis is pretty solid.

The supporting hardware seems to be the main weakness. With the "modern" approach to suspension design (bump stops, hefty sway bars, soft springs), it kind of puts damper quality and spring rate in the background. Packaging the suspension was a bit awkward in the upper rear and around the sway bars... but those are minor gripes.

What are some improvement you would have made?