Obioban's 2005 IR/IR Coupe

[Obioban]

Springs are progressive though aren’t they?

If you have a moment, what’s the diameter of the front springs at the adjustment collar? Do they taper down to 2.5”?

I don't believe they're progressive.

They taper down to 60mm up front IIRC. I'm going to use a spacers or custom spring perch so I can run 2.5" springs.

[r4dr]

Springs are progressive though aren’t they?

If you have a moment, what’s the diameter of the front springs at the adjustment collar? Do they taper down to 2.5”?

[Obioban]

Yeah, I just need height adjustable bilstein damper bodies. Not using the springs or stock valving, so paying more wouldn’t get me anything more.

... and if I were keeping the springs, the street setup isn’t far from the rates I’ll be running.

[r4dr]

Any specific reasons why the Street Performance vs the RSS? Or did you just get the cheaper ones since the spring rates don't matter as you will be tuning those to your liking anyway?

[S14]

The car was purchased with these on, so I never got to experience the OEM set-up (although I still have these stored). However, they give 1.27 vs the H&R 1.06 flatride. The ride height was set like this (Front: 640mm as measured from ground to centre of arch and Rear 635mm - same measurement) and the front camber was set to a smidge over 2° on standard mounts. It is/was very neutral and balanced with no ill traits. I'm now running different springs and dampers with much more camber thanks to Turner Hybrid top mounts.

Your CSL and garage look great Mike!

[Mike RT4]

Was there a lot less understeer / more oversteer with that setup?

Or...

If I'm reading this right, max front ride height is ~1.2" lower than stock. Is that correct? If so maybe the reduced camber gain in front balanced it out?

The car was purchased with these on, so I never got to experience the OEM set-up (although I still have these stored). However, they give 1.27 vs the H&R 1.06 flatride. The ride height was set like this (Front: 640mm as measured from ground to centre of arch and Rear 635mm - same measurement) and the front camber was set to a smidge over 2° on standard mounts. It is/was very neutral and balanced with no ill traits. I'm now running different springs and dampers with much more camber thanks to Turner Hybrid top mounts.

[IamFODI]

Front: 63N/mm (360lb)
Rear: 120N/mm (685lb)

Was there a lot less understeer / more oversteer with that setup?

Or...

If I'm reading this right, max front ride height is ~1.2" lower than stock. Is that correct? If so maybe the reduced camber gain in front balanced it out?

[Mike RT4]

Call H&R to verify (I disregarded it because can’t use the springs with my camber plates), but IIRC it was something like 400/700.

Front: 63N/mm (360lb)
Rear: 120N/mm (685lb)

[Obioban]

Do you know what the H&R street performance spring rates are? Mine are getting delivered to FCM this week. Hoping to have them installed by the first week of October. Thought about trying them with the springs it came with prior to my custom flat ride setup.

Call H&R to verify (I disregarded it because can’t use the springs with my camber plates), but IIRC it was something like 400/700.

[duracellttu]

I also noticed that they're flat ride, stock!

Perhaps I should throw them on and try them out stock for a while, just to have more experience with more setups.

I seem to be getting progressively less adjustable with time. On the track car we had quad adjustable remote reservoir JRZs and Motons. Originally on this car I had TCK doubles... then Ohlin singles... and now moving to non adjustable.

Do you know what the H&R street performance spring rates are? Mine are getting delivered to FCM this week. Hoping to have them installed by the first week of October. Thought about trying them with the springs it came with prior to my custom flat ride setup.

[Obioban]

The H & Rs are surprisingly good from the factory and with the stock spring rates give a flat ride of 1.06, where all the common aftermarket arrangements (KW Competition, Clubsport, V3, Ohlins, Nitron et al) all give pitch.

The H & Rs are what I had on the CSL for 7 years (and it surprised me to see in previous posts on the old M3 forum that they got a slating) as they made the car feel like a big go kart. My new arrangement has aimed to achieve a similar goal, but with more adjustability.

I also noticed that they're flat ride, stock!

Perhaps I should throw them on and try them out stock for a while, just to have more experience with more setups.

I seem to be getting progressively less adjustable with time. On the track car we had quad adjustable remote reservoir JRZs and Motons. Originally on this car I had TCK doubles... then Ohlin singles... and now moving to non adjustable.

[Mike RT4]

And the H&R coilovers arrived, that I'll be sending off to Fat Cats Motorsports for reworking. I go back and forth between being super excited and feeling like I've gone off the deep end, spending $5000-6000 for a non adjustable Bilstein setup

The H & Rs are surprisingly good from the factory and with the stock spring rates give a flat ride of 1.06, where all the common aftermarket arrangements (KW Competition, Clubsport, V3, Ohlins, Nitron et al) all give pitch.

The H & Rs are what I had on the CSL for 7 years (and it surprised me to see in previous posts on the old M3 forum that they got a slating) as they made the car feel like a big go kart. My new arrangement has aimed to achieve a similar goal, but with more adjustability.

[selm3]

Will do thank you!

[duracellttu]

If you guys don’t mind me asking what’s the average cost for a setup from Shaikh and the team at Fatcat?

You need to reach out him directly. I know he is in the process of updating his pricing. If you mention I sent you, he will give you a discount.

[selm3]

If you guys don’t mind me asking what’s the average cost for a setup from Shaikh and the team at Fatcat?