Nitron R3 - Spring Rate 700f / 750r ?

[b7ff]

Hi,

I got a chance to purchase brand new unused Nitron R3 coilovers (divorced rear setup); interestingly it got a spring rate of 700f and 750r. Ive been reading a lot of post in the forum regarding spring rate -- and most of the conclusion seems to have a much bigger % difference in f/r spring rates (front being much lower)

Hence Im just wondering whether any of you have tried this spring rate setup and how does the call feel and handle in both street and track (most importantly street)?

In addition, this have been discussed a lot of time but I still cant figure it out. Nitron R3 comes with 5 bolts top-mount; while my car uses 3-bolts. I know the diff in bolt sizes (M8 and M10) -- question is can I use the 5 bolts top mount to my 3-bolts chassis while only using M8 bolts too? Have anybody done this before and any feedback on how it holds up?

Thankyou guys!!

[M3SQRD]

Not good rates for the R3 with a divorced rear spring. I’m not sure why F/R 700/750 lbf/in were selected? Those spring rates are close to what you’d run with a coilover rear setup. A divorced rear would be more like 700/1100 lbf/in divorced rear or 700/600 lbf/in for a coilover rear. If you were going for a flat-ride setup you’d run ~700/1400 lbf/in but you won’t find a spring long enough or have sufficient travel for a 1400 lbf/in rear spring so you’d have to switch to a coilover rear.

So, no, those are not good street or track rates. If you want a pure, or biased, street setup, I’d recommend 500/800 lbf/in which is what I installed on my wife’s DD f22 240ix with MCS 2WR dampers.

No. You cannot install a 5-bolt camber plate to a 3-bolt strut tower. You could drill the two additional holes but I’d recommend getting 3-bolt camber plates.

[M 4 FUN]

That sounds like a setup for a lot of built in understeer. I run 450/900 on my M4 with Öhlins coilovers.

[Inertia Lab]

Where did you get these speced this way? It sounds like you may have purchased them 2nd hand. We deal with Nitron everyday as a rebuilder and sales center and there are some setups that are softer in the rear, but generally the front is very low in that case. Either way reach out and Ill get you the top mounts you need (sounds like you need 3-bolt mounts) and the springs that make sense. Just let me know. Sounds like Im going to need to become a forum sponsor.

[b7ff]

Originally Posted by M3SQRD

Not good rates for the R3 with a divorced rear spring. I’m not sure why F/R 700/750 lbf/in were selected? Those spring rates are close to what you’d run with a coilover rear setup. A divorced rear would be more like 700/1100 lbf/in divorced rear or 700/600 lbf/in for a coilover rear. If you were going for a flat-ride setup you’d run ~700/1400 lbf/in but you won’t find a spring long enough or have sufficient travel for a 1400 lbf/in rear spring so you’d have to switch to a coilover rear.

So, no, those are not good street or track rates. If you want a pure, or biased, street setup, I’d recommend 500/800 lbf/in which is what I installed on my wife’s DD f22 240ix with MCS 2WR dampers.

No. You cannot install a 5-bolt camber plate to a 3-bolt strut tower. You could drill the two additional holes but I’d recommend getting 3-bolt camber plates.

Thanks for the input, appreciate it. Those numbers you quote does makes sense a lot more; I guess I need to order new sets of springs then. How about helper springs though - does the rate on helper springs matter and given its a divorced-rear so this will only stand for the front i guess?

[b7ff]

Originally Posted by Inertia Lab

Where did you get these speced this way? It sounds like you may have purchased them 2nd hand. We deal with Nitron everyday as a rebuilder and sales center and there are some setups that are softer in the rear, but generally the front is very low in that case. Either way reach out and Ill get you the top mounts you need (sounds like you need 3-bolt mounts) and the springs that make sense. Just let me know. Sounds like Im going to need to become a forum sponsor.

Interesting on the softer rear combo.. Pm'd!

[shaddy]

Chris at Intertia Labs is the North American Nitron specialist/dealer. My R1s are spec’d through him and know many people with Nitrons spec’d through him on various platforms. Strongly recommend giving him a call and working through this to get set up appropriately 👍🏽

[M3SQRD]

Originally Posted by b7ff

Thanks for the input, appreciate it. Those numbers you quote does makes sense a lot more; I guess I need to order new sets of springs then. How about helper springs though - does the rate on helper springs matter and given its a divorced-rear so this will only stand for the front i guess?

A helper spring has a very low spring rate and its job is to keep the main spring seated at full droop (max rebound travel). The spring rate is around 10 lbf/in.

You may not need a helper spring in the front for spring rates < 400 lbf/in. A helper spring could still be used but it would be fully compressed at full droop which defeats the purpose of a helper spring.

For the typical range of spring rates used on the rear, a helper spring is not needed because the main spring remains seated at full droop.

Definitely reach out to Inertia Lab because they are the preferred Nitron dealer in the US. He can get you everything you need, including the ideal spring rates for your needs.

[M3SQRD]

Originally Posted by Inertia Lab

Where did you get these speced this way? It sounds like you may have purchased them 2nd hand. We deal with Nitron everyday as a rebuilder and sales center and there are some setups that are softer in the rear, but generally the front is very low in that case. Either way reach out and Ill get you the top mounts you need (sounds like you need 3-bolt mounts) and the springs that make sense. Just let me know. Sounds like Im going to need to become a forum sponsor.

Not too long ago, a used set of R3 with F 685 lbf/in and R 400 lbf/in (coilover rear) were sold on this forum. With approximate spring and damper motion ratios that makes the rear spring rate ~750 lbf/in divorced. It seems there’s a Nitron distributor spec’ing R3 F ~700 lbf/in and rear ~750 lbf/in (divorced) setups. The OG Shark/Inertia Lab Nitron rates I’ve seen for R1 and R3 are around F ~600-800 lbf/in and rear ~800-1000 lbf/in (divorced) which is similar to what I’ve seen from other Nitron distributors (e.g., F 685 lbf/in and R 913 lbf/in divorced).

Any idea why someone would be spec’ing R3 with F/R 700/750 lbf/in (R divorced) spring rates? Handling balance is biased way too far towards understeer. Separate questions…what %change in spring rate can a R1 and/or R3 handle before needing to be revalved? Will the eT R1 and eT R3 handle similar rates to the conventional R1 and R3 dampers? Will the Nitron DCU give you more control over the eT dampers compared to the EDC plug-n-play eT dampers? What are the spring rates for the eT Roadsport setup? Thanks.