81 replies to this topic

[38bfast]

The penskes are not a happy hands and feet kind of shock that the Bilsteins were. As evidence of the difference of the force curves.

[Steve Scheifler]

With stiff rear compression when you smack power down the car does not have a chance to squat (front end up back end down) so the tire is spiked for load/grip. That’s why Danny has to squeeze into it waiting for the shock to compress to get the back end down. If it was a car with adjustable compression I would soften up the rear for that situation. But it will also take away from mid coner balance. In SM we have other tuning tools in our box to help on power oversteer. Adapted, overcome, press on.

I’ll buy that as a possibility, even a probability if truly not hitting the stops, and it’s part of why getting into the stops produces similar symptoms. The weight is transferring too FAST, and as I think your subsequent post implies it can be mitigated in part by driving style.

[Danny Steyn]

The way I see it is

 

• the Bilsteins were so soft in both compression and rebound that the car would roll over to take a set, and you would essentially "wait" for the car to take a set
• the Penskes are MUCH stiffer in both compression and rebound, so the instant you turn in the car is set, there is no delay, and as Ralph stated there is no "squat" like there was with the Bilsteins on throttle application

Of course we are just on day 3 learning to drive with them but the car responds so much faster. I am still coming to terms with them but getting to like them more and more with each session. Sebring will be the real test as it is possibly the bumpiest track we go to. Those that ran them there in the recent Champ car event have been very quiet on their findings!!! 

[Jim Drago]

I'm having issues with my car with power so times likely wont show my satisfaction with the shocks. I had no learning curve, the shocks suited me VERY well from session one and my car is on rails! Bravo! IMO, many( most) are reading way too much into this... It is not rocket science. There will be NO WHERE, NO SITUATION where the billsteins will be better other than familiarity and in your mind.  The outright speed in the hands of a front runner likely not much different, but easier with the Penskes and more repeatable. Many crazy thoughts,ideas and opinions abound in the paddock.. In my experience, the shocks were spot on and set up was spot on out of the trailer, Corners where left side weight killed me in the past are a non issues now. No longer need to set the car at turn in. I am  looking very forward to this season, If I can figure out what is wrong with power we should be very good, if not we will have a long two weeks with a very good handling car   

[Jamz14]

Hey Danny, are you saying that at the same ride height the Penske has more potential travel? Or that the damper is traveling more? Or both?

If compression is stiffer, and there is more potential travel at the same ride height, why shouldn't we be able to run the car lower?

[38bfast]

There is more exposed shock at the same ride height but the bump stops are much shorter and much stiffer. 

[Jamz14]

Thanks Ralph. So the issue people are concerned about is that the bump stop doesn't respond as forgiving as the current one?

And am I correct that Danny is saying that the damper is using all that extra travel at the same ride height?

[Bench Racer]

James, referencing your bump stop comment, Search the site for a video of Ralph assembling the Penske shock and you'll see the bump stop is very thin and from Ralphs comment, HARD. IMHJ, there is zero usable travel into the bump stop. 

[Jim Drago]

James
In short... with Billsteins and fat cats... at any reasonable height we were hitting the bump stop. With the Penske, the shock in much more control.. many I believe look at the extra travel and set the car up too low. If you get these Penske on the stop, you WILL NOT like it, nor will it be fast or very controllable or consistent.

[Steve Scheifler]

Did anyone else experience the kind of mid-corner power oversteer Danny described?

[tburas56]

Did anyone else experience the kind of mid-corner power oversteer Danny described?

 

Big time Apex off oversteer, then we dialed it out. Steep leaning curve.

[Ron Alan]

James, referencing your bump stop comment, Search the site for a video of Ralph assembling the Penske shock and you'll see the bump stop is very thin and from Ralphs comment, HARD. IMHJ, there is zero usable travel into the bump stop. 

 

James
In short... with Billsteins and fat cats... at any reasonable height we were hitting the bump stop. With the Penske, the shock in much more control.. many I believe look at the extra travel and set the car up too low. If you get these Penske on the stop, you WILL NOT like it, nor will it be fast or very controllable or consistent.

 

Big time Apex off oversteer, then we dialed it out. Steep leaning curve.

Any questions?

[Jamz14]

Nope. Same setup. We never ran the car really low before.

A couple driver adjustments and good to go. Thanks all.

[Bi11]

Big time Apex off oversteer, then we dialed it out. Steep leaning curve.

same here

[Bench Racer]

Because within threads folks are asking questions, here's some answers.

 

Ralph's Penske shock assembly, thanks.

https://www.facebook...58275331590636/

 

Alan Cross posted Ralph's Penske bump stop compression data, thanks. Scroll down to post #190. The FatCat bump stop was IMHJ usable to approx. 19mm of travel. After 19mm of FatCat bump stop compression the rate increased on a hurry. 

https://mazdaracers....sa-scca/page-10

[Richard Astacio]

The car was a little loose at the rear for me as well however it felt like it was more predictable, I did not have to react with very quick hands if that makes sense. 

Once we dialed it in it was much better, for me though I will have to get used to the front not diving down under hard braking...

 

I guess I am allowed to give my 2 cents since I finished 8th on Saturday and only a few 10ths behind Jim on Saturday....Damn, I almost had the champ! 

[Jim Drago]

 on Saturday and only a few 10ths behind Jim on Saturday....Damn, I almost had the champ! 

Its coming unfortunately! You are driving really well and a far cry from a few years ago! I think Danica is not racing bc he is afraid you will beat him

[Richard Astacio]

Its coming unfortunately! You are driving really well and a far cry from a few years ago! I think Danica is not racing bc he is afraid you will beat him

 

Thanks Jim, this hobby is humbling for sure. I have been busting my ass, unfortunately, I started late in life racing. 

 

As far as Danica the only place I can beat her is in a marathon maybe....she has been training like a whore for sure and even dropped a few pounds. 

[Danica Davison]

As far as Danica the only place I can beat her is in a marathon maybe....she has been training like a whore for sure and even dropped a few pounds.

 

You would beat me in both races. I'm not that good in a racecar and I'm too ADHD for a marathon.

 

Now ... if we take it to the Pickleball courts ... you are all fooked

[lillyweld]

You would beat me in both races. I'm not that good in a racecar and I'm too ADHD for a marathon.

 

Now ... if we take it to the Pickleball courts ... you are all fooked

 

I hear you are a bit of a whore, though!