S550 Rear Rear Shock Dyno Graphs - Base VS Performance Pack

[DickR]

Interesting.

In my opinion, the low speed C and R are pretty decent on the PP shocks we tested, and should be more than capable of damping a 728lb/in spring.

I have tested the PP rear shocks with well over 1000lb/in - and I thought they performed decently, considering.

I guess it is just a little subjective.

Kelly - I was looking at it from an autocross perspective. I didn't like any extra squat and associated rebound during hard shifts and in transitions. From a general on the road ride they were fine from my "not an expert" subjective perspective. Also, subjectively I think the Koni is less harsh at high shaft speeds over sharp bumps but that is typically a Koni goal and at their price point they can afford the manufacturing and parts cost involved.

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[BMR Tech]

Kelly - I was looking at it from an autocross perspective. I didn't like any extra squat and associated rebound during hard shifts and in transitions. From a general on the road ride they were fine from my "not an expert" subjective perspective. Also, subjectively I think the Koni is less harsh at high shaft speeds over sharp bumps but that is typically a Koni goal and at their price point they can afford the manufacturing and parts cost involved.

Do you happen to have the dyno graphs for your rear shocks?

 

[DickR]

Do you happen to have the dyno graphs for your rear shocks?

No unfortunately. I don't know if Koni makes those available for off the shelf products like these. I'm sure Sam Strano would sell you a set if you want to get them dyno'd

FYI I'm not mentioning the normal application for these shocks because even though it isn't a secret Sam came up with this solution for a bunch of "couldn't wait" F Street autocrossers so I'm just trying to do my part to return the favor by encouraging people to buy the shocks from him. Sam, like you, is extremely helpful to both customers and anyone else who asks for help.

 

[jbailer]

I try to keep the arguing about the spring designs minimal, but I would never use a progressive rear spring on this car without a very good damper. The low speed control would be "okay" - but higher shafts speeds, and compression travel on that progressive spring - watch out.

Kelly, I understand what you are saying but the progressive springs actually improved my ride significantly over the stock EB PP springs. It is clear that the dampers are not sufficient though. Do you have a recommendation?

 

[347CobraII]

I had 2011 GT Brembo car vs 2015 GT PP car the 2011 hopped more.

 

[BmacIL]

I like that combo.

I have driven on it, and IMO it makes an amazing difference.

So I put the PP rear dampers on my base car, which for suspension only has the addition of the PP rear bar. Around town and up to ~55 mph, EVERYTHING is better. Ride control, squat/dive, weight transfer control through corners are all noticeably improved, probably 30-40%. Launches are much better, also. That said, it is more bouncy at freeway speeds (70+ mph) than the base dampers. I need a few days to make sure I can live with it. The benefits everywhere else are so great that I'll probably stick with them, but we'll see.

 

[ABQautoxer]

Just changing the rear shocks makes a very big difference.

 

[BMR Tech]

So I put the PP rear dampers on my base car, which for suspension only has the addition of the PP rear bar. Around town and up to ~55 mph, EVERYTHING is better. Ride control, squat/dive, weight transfer control through corners are all noticeably improved, probably 30-40%. Launches are much better, also. That said, it is more bouncy at freeway speeds (70+ mph) than the base dampers. I need a few days to make sure I can live with it. The benefits everywhere else are so great that I'll probably stick with them, but we'll see.

Put rear PP springs in it?

You could always put our SP080 Performance Springs on it, too.

 

[BmacIL]

Put rear PP springs in it?

You could always put our SP080 Performance Springs on it, too.

No, just the dampers. It's could be a hair overdamped or perhaps right near critically damped, but since it was so easy to do I figured I'd give it a try.

Having driven on it to work this morning, it's only certain sections of road that are bouncy, the rest is very nice. I will probably put the GT PP rear springs on as I'm not looking to lower the car.

 

[Nazgul]

Bmr do you feel that the PP shocks will. Be able to handle your handling Springs? Or will we have to wait for after market shocks?

 

[SK GT]

Are the PP struts as much of an improvement over the base GT strut as the rear shocks are?

Bump for this.

I'd like to barely lower my non PP GT but don't want to spend an arm and a leg at this point.

 

[BmacIL]

Bump for this.

I'd like to barely lower my non PP GT but don't want to spend an arm and a leg at this point.

They're the same type of damper (twin tube), just different tuning for the heavier PP front springs.

 

[SK GT]

They're the same type of damper (twin tube), just different tuning for the heavier PP front springs.

Thanks, but can they "handle" a BMR front lowering spring without issue?

Regards,
SK

 

[SK GT]

Thanks, but can they "handle" a BMR front lowering spring without issue?

Regards,
SK

bump. Planning to put springs on my non PP car very soon and was just gonna do the rear PP shocks and the stock non-PP front struts.

 

[BmacIL]

To your question, I would imagine so, yes. The stock non-PP GT rates are 160 lb/in, the PP rates are 165 lb/in. That's a very small difference, so the tuning is probably very close.

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