HPDE experiments, results and observations

[M3SQRD]

Originally Posted by rhyary

My JRZ after rebuilt with recomandation of clicks to start the season.

I’m drawing a blank…what is the CB adjustment? 4-way adjustments are independent low-speed and high-speed compression + independent low-speed and high-speed rebound. The damper force-vel dyno plots have LSC, HSC, CB and REB. I know TTX offers a 5th blow-off adjustment option but that’s not abbreviated CB.

[rhyary]

CB = shaft or roughly medium speed.
The HS and LS are on the remote canister

[M3SQRD]

Originally Posted by rhyary

CB = shaft or roughly medium speed.
The HS and LS are on the remote canister

Since it’s at the top of the piston rod, it’s medium-speed rebound? No low-speed rebound? Interesting if there’s no low-speed rebound adjustability.

[rhyary]

Originally Posted by M3SQRD

Since it’s at the top of the piston rod, it’s medium-speed rebound? No low-speed rebound? Interesting if there’s no low-speed rebound adjustability.

.
The top has two knobs. The bigger is rebound, the smaller is medium speed compression. The canister has HS and LS as mentioned before.
In the picture the red points to the shaft compression and the blue points to the rebound.

[M3SQRD]

Originally Posted by rhyary

.
The top has two knobs. The bigger is rebound, the smaller is medium speed compression. The canister has HS and LS as mentioned before.
In the picture the red points to the shaft compression and the blue points to the rebound.

Interesting 4-way setup - LSC, HSC, MSC (CB) and REB. Why don’t you want independent control of LSR and HSR? LSR helps control body motion and weight transfer; e.g., increasing LSR to keep weight on the rear wheels under braking, help keep load and grip on an inside wheel thru a low-mid speed corner, etc. I’m trying to think of an example where direct control of MSR is needed and not adequately covered by a combination of LSC & HSC?

[rhyary]

It is how JRZ designed their competition level damping system. I am very happy with the system so it is not about what I want.

[M3SQRD]

Originally Posted by rhyary

It is how JRZ designed their competition level damping system. I am very happy with the system so it is not about what I want.

If the cb adjustment is doing what you’ve described then it’s effectively a redundant adjustment. LSR adjustment will capture low velocity as well as medium velocity responses as it blends in with the high velocity response. If your description is accurate then JRZ is the only race damper manufacturer with an independent mid-speed compression adjustment. If cb means compression bleed and applies to the blow-off valve then that would make more sense.

[rhyary]

Originally Posted by M3SQRD

If the cb adjustment is doing what you’ve described then it’s effectively a redundant adjustment. LSR adjustment will capture low velocity as well as medium velocity responses as it blends in with the high velocity response. If your description is accurate then JRZ is the only race damper manufacturer with an independent mid-speed compression adjustment. If cb means compression bleed and applies to the blow-off valve then that would make more sense.

First, I am not 100% sure how to describe the function of the compression on the shaft.

Second, I met a racing team at WGI that knew all about that shaft adjustment and they say they were involved in that develoment. They called it “the magic dial”

Basic usage is that once you set the LS and HS on the remote canister to where you want it. You fine tune with the shaft compression.

I am not a suspension engineer. So I can tell you what I feel. When I used the shaft dial I felt is if I am controlling the spring directly. The HS made a difference on the bus stop at WGI. The LS made difference coming into T-3 at LRP. The shaft made a difference in the long big bend at LRP and on the long back straight at WGI.

I never felt that I need better Rebound adjustment. What ever JRZ is doing with the one dial was fine for me.

[rhyary]

This can help.
The canister has the HSC and LSC compression
I have the 3030 piston and the 50-da shaft which has its own Compression and Rebound.
The compression on the shaft works together with the Canister compression to tune the damping more preicisly to what you want.

https://www.jrzsuspension.com/fa-3030.html

https://www.jrzsuspension.com/50-da.html

[M3SQRD]

Originally Posted by rhyary

First, I am not 100% sure how to describe the function of the compression on the shaft.

Second, I met a racing team at WGI that knew all about that shaft adjustment and they say they were involved in that develoment. They called it “the magic dial”

Basic usage is that once you set the LS and HS on the remote canister to where you want it. You fine tune with the shaft compression.

I am not a suspension engineer. So I can tell you what I feel. When I used the shaft dial I felt is if I am controlling the spring directly. The HS made a difference on the bus stop at WGI. The LS made difference coming into T-3 at LRP. The shaft made a difference in the long big bend at LRP and on the long back straight at WGI.

I never felt that I need better Rebound adjustment. What ever JRZ is doing with the one dial was fine for me.

Ok. I think I understand what this adjustment is and it’s not an independent mid-speed compression adjustment. It basically does what you said above - it fine tunes the entire compression curve. Intrax does the same thing on their 4-way race dampers.

Thanks!

[MaX PL]

rhyary, you have any interest in 3 x this tire new for $120?
https://www.tirerack.com/tires/tires...RatingsReviews

purchased last year but could never use as the tire never never returned to stock and I could not purchase a fourth.

[rhyary]

Originally Posted by MaX PL

rhyary, you have any interest in 3 x this tire new for $120?
https://www.tirerack.com/tires/tires...RatingsReviews

purchased last year but could never use as the tire never never returned to stock and I could not purchase a fourth.

I have three sets of 19” wheels.
if your link is correct then it is pointing to 18”

[MaX PL]

yes, theyre 18s. sorry about that. didnt realize you only run 19s.

[Bartledoo]

Originally Posted by MaX PL

rhyary, you have any interest in 3 x this tire new for $120?
https://www.tirerack.com/tires/tires...RatingsReviews

purchased last year but could never use as the tire never never returned to stock and I could not purchase a fourth.

Omg i was sitting on four rear 325/30r19 SC3R tires for my C8 and needed that size or the 275/35r18 to make a set and put down some silly lap times…I just sold all of the rears because I could never get fronts. Where have you been all this time 😭

[rhyary]

On my todo is to try the SC3R 265/35/19 front and 305/30/19 rear. But I keep finding deals on other tires.

[rhyary]

It is with great sorrow that I am announcing I will be giving up my A/C for 2025. The project will be starting in winter 2025.

This is coming to the realization that I can’t have it all. With a full set of do88 and my pace getting faster, we did everything we could to delay the car getting hot after a few laps. In addition, to compensate for the extra weight on the nose the supercharger is contributing, I am hoping the effort and discomfort driving to the track will be worth it.

Removing the A/C radiator (not sure what it's called, Condenser?) will allow more room to position the remaining radiators better, and airflow should be better.

I bought from Bimmerworld the 2008 power steering (Genuine BMW Power Steering Pump - 2008 M3 (Early)) since they had it new and I was not sure for how long these will be available. There are many PS on eBay for $100, but I don’t know the direction they spin, and for all the effort that will go into the project, I wanted to start with new.

And as always, there is a question at the end of my broadcasted intention. I am not the only one to do this project. But I have an ESS supercharger.

Question 1: What should I be aware of when removing the A/C when I also have the ESS SS?

Question 2: What should I do at the front to improve cooling with the now extra space?

Many thanks for all the suggestions in advance.

P.S. For the old-timers on this board, no, my next project is not 18” wheels.

[amg6975]

Originally Posted by rhyary

On my todo is to try the SC3R 265/35/19 front and 305/30/19 rear. But I keep finding deals on other tires.

I dropped 3s at WGI going from a 200TW to the SC3R. It's an amazing tire.

[roastbeef]

rhyary the best thing you can do to optimize your cooling system is proper ducting. find a fab guy to bend/cut some sheet metal and seal it to the face of your radiator.
the next thing is hood vents. did we talk about this? they'll help significantly. if you reduce the pressure behind the radiator, its going to flow better. might not be the final solution, but its going to help significantly.

[Ximian]

Originally Posted by rhyary

P.S. For the old-timers on this board, no, my next project is not 18” wheels.

17" wheels?

[rhyary]

Originally Posted by roastbeef

rhyary the best thing you can do to optimize your cooling system is proper ducting. find a fab guy to bend/cut some sheet metal and seal it to the face of your radiator.
the next thing is hood vents. did we talk about this? they'll help significantly. if you reduce the pressure behind the radiator, its going to flow better. might not be the final solution, but its going to help significantly.

I have the two opening of the OEM hood open, but nothing custom. DRLane sent me a link to hood louvers, but I am not sure I want to cut the hood. Falls under the “can’t have it all” category

[DRLane]

Originally Posted by rhyary

I have the two opening of the OEM hood open, but nothing custom. DRLane sent me a link to hood louvers, but I am not sure I want to cut the hood. Falls under the “can’t have it all” category

You need to cut your hood. You have a giant wing and reasonable splitter on the car already. Just commit.

[rhyary]

Originally Posted by DRLane

You need to cut your hood. You have a giant wing and reasonable splitter on the car already. Just commit.

You have 10 months to convince me.
Don’t give up.
I am already warming up to your idea of electric fan.