RACESENG X PENSKE | The Ultimate Racing Shocks

[RBbugBITme]

Originally Posted by solidONE

So kind of like the TTX in performance?

Not really

[EAGLE5]

Originally Posted by RBbugBITme

Not really

LOL.

[RehabJeff86]

Originally Posted by RBbugBITme

Not really

LoL nice


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[solidONE]

Originally Posted by RBbugBITme

Not really

Say no more. lmao!

http://www.penskeshocks.com/assets/E...S-6020-DB1.pdf

Edit: for reference http://www.bgmotorsports.co.uk/suspe...amper-anatomy/

[Captain Snooze]

@RBbugBITme
I was under the impression that Penske dampers were built to order using off the shelf parts. The only thing that had to be made was the lower casing for MacPherson Struts. That is, very little to be developed. You want a damper to fit a car. You know the weights at the wheels and the sort of damping curves you want so you grab piston A, put shims 1,2, and 4 on the piston, test it on the dyno, adjust as needed and voilà! There's your damper. I suspect I am missing about 50 steps. Could you please tell me/us what's involved in developing a damper for a car.

Ta.

[RBbugBITme]

Originally Posted by Captain Snooze

@RBbugBITme
I was under the impression that Penske dampers were built to order using off the shelf parts. The only thing that had to be made was the lower casing for MacPherson Struts. That is, very little to be developed. You want a damper to fit a car. You know the weights at the wheels and the sort of damping curves you want so you grab piston A, put shims 1,2, and 4 on the piston, test it on the dyno, adjust as needed and voilà! There's your damper. I suspect I am missing about 50 steps. Could you please tell me/us what's involved in developing a damper for a car.

Ta.

Not quite. For the BRZ the lower clevis as you mentioned is new, the inner and outer strut bodies are sized for the BRZ's stroke and length requirements, and we have a wide range of shafts in 1/4" increments that we do pull off the shelf. The bodies are custom for the car since we try not to cut off the shelf parts to size, you'll leave exposed metal where there would otherwise be one of our expensive coatings which leads to rust and that's not pretty.

Then of course each order is reviewed for its intended use and the guys in the shop will decide (unless you specifiy) which piston you're getting (VDP, digressive, double digressive, high flow, or linear).

Also, the BRZ was the application that allowed me to follow through with my dual-bleed shaft mount idea. Until now, we had no way to put our dual-bleed adjusters on a shock with what we call a shaft mount which is when the shock shaft terminates in a threaded shank instead of a spherical bearing, bushing, or clevis. The BRZs are the first with this and puts the rear shock (single or dual-bleed) adjusters in your trunk.

[churchx]

One shouldn't forget sample bill of:
"$5 - hit with hammer
$200 - knowledge exactly where it needed to be hit"
Even if process of designing/assembling may seem not THAT difficult, it required having highly paid people with enormous experience in field, to skip lot of common mistakes, to try out only best paths, to choose best parts even if those were off the shelf ones, to quicken development/fine-tuning/testing/to not do some compromises/shortcuts to compensate for less skills/experience/time/budget of 2nd tier manufacturers. Having all those bits for supposedly "simple" process costs. A LOT. And it needs to be compensated for. +High pricing limits customer count/less ways to save on high volumes of product. At the end you get adequately high price for supposedly "simple" work. Proven highest quality/no compromises work.

[RBbugBITme]

I forgot to mention, I reached out to Raceseng because I don't have the time to design, prototype, test fit, and possibly redesign an extended rear upper mount or camber plate when we don't have a chassis in house to do any of the work on. Raceseng created a modified version of their standard 1" extended rear mounts just for Penske Shocks that has clearance for our off the shelf spring retainer so that part is also new/custom for this car.

Also, I believe Raceseng's kit shipped today. Time to install and hit the track.

[RBbugBITme]

Almost every dyno graph you see is a PVP type graph that takes peak velocity force measurements at each speed increment (usually 1 thru 10 in/sec in 1 in/sec intervals) and just connects the dots to make your line. This gives you a good idea of general forces the damper is creating and is the predominate way Penske matches dampers unless we're doing something special. PVP's are useless for regressive curves for example.

What you don't normally get to see for various reasons are the individual CVP graphs which show far more detail about what is going on with the damper. Typically when we back to back test a competitors stuff, we'll match the PVPs but the CVP tells the story of why the Penske has more grip.

Case in point, here are the Raceseng initial front builds we finished yesterday.

10 in/sec PVP to match both fronts.... nothing special going on here


10 in/sec CVP of both fronts...


Big difference. Some might confuse the low speed region with a shock that has hysteresis even though the high speed region doesn't have any and the zero points are very close to zero. What you're actually seeing is the effect from cut piston bands on this build which can improve grip by limiting damper force at the initial onset of movement. By allowing the piston band to float tens of thousands of an inch in the piston, you delay a tune-able amount of fluid flow through the piston and shims thereby providing a very supple region for your tire to do what it needs to do.

If you aren't aware, the piston band is the graphite piece surrounding the main piston and contacting the inner bore of the damper body.
Its the big black piece here.


This is one of the many reasons we say, don't be scared, call us to talk about your build. There are too many things to account for and you shouldn't be able to purchase $3000+ dampers from a drop down list on a website.

Looking forward to on-track testing with Raceseng very soon and if I can find the time we'll put it up against my Vette!

[solidONE]

Want to see pics of the whole shabang mounted!

Question on the reduced damping force at initial movement. Wouldn't the limited damping force at the initial part of the stroke cause it to oscillate (bounce) under low load operation such as sustained low speed cruising (30-35 MPHish speeds)? @RBbugBITme

[RBbugBITme]

It could cause issues in extremely rare high frequency and very low amplitude inputs but that would probably require a formula car with no slop in all suspension connection points and probably high vehicle speeds that only an Indycar on an oval would see.

A street car won't be affected like that. Understand that regardless of shock shaft speed, once the cut band moves to the other side of the piston groove it sits in it acts like a regular piston band. So for this build in particular we're talking about .040" of shaft displacement regardless of speed.

[Racecomp Engineering]

Originally Posted by RBbugBITme

Almost every dyno graph you see is a PVP type graph that takes peak velocity force measurements at each speed increment (usually 1 thru 10 in/sec in 1 in/sec intervals) and just connects the dots to make your line. This gives you a good idea of general forces the damper is creating and is the predominate way Penske matches dampers unless we're doing something special. PVP's are useless for regressive curves for example.

What you don't normally get to see for various reasons are the individual CVP graphs which show far more detail about what is going on with the damper. Typically when we back to back test a competitors stuff, we'll match the PVPs but the CVP tells the story of why the Penske has more grip.

Case in point, here are the Raceseng initial front builds we finished yesterday.

10 in/sec PVP to match both fronts.... nothing special going on here


10 in/sec CVP of both fronts...


Big difference. Some might confuse the low speed region with a shock that has hysteresis even though the high speed region doesn't have any and the zero points are very close to zero. What you're actually seeing is the effect from cut piston bands on this build which can improve grip by limiting damper force at the initial onset of movement. By allowing the piston band to float tens of thousands of an inch in the piston, you delay a tune-able amount of fluid flow through the piston and shims thereby providing a very supple region for your tire to do what it needs to do.

If you aren't aware, the piston band is the graphite piece surrounding the main piston and contacting the inner bore of the damper body.
Its the big black piece here.


This is one of the many reasons we say, don't be scared, call us to talk about your build. There are too many things to account for and you shouldn't be able to purchase $3000+ dampers from a drop down list on a website.

Looking forward to on-track testing with Raceseng very soon and if I can find the time we'll put it up against my Vette!

Cool stuff. Thanks for the explanation!

- Andrew

[CSG Mike]

Porn should not be allowed here.