SPC vs SPL for Track and Weekend Driver
 

I am looking to replace the Stock Upper Control arms for Camber adjustments to achieve an optimal square track set up...while keeping the car street-able. I have researched many thread and forums...where all point to issue and concerns with SPC; however, most are older threads (2013).

Is it possible that SPC had design/manufacturing issues that may be have been corrected in recent years...or is SPC still unacceptable for track use?

I am not concerned about the extra $300...rather I am concerned about the "ride" on the street with SPL. Are the spherical SPL bushings going to be noticed (by my wife) during weekend driving?

I don't use SPL because they're illegal aliens in STR lol however the new SPC arms look better than the old design:

https://www.z1motorsports.com/suspen...37-p-9584.html

I'm using the z1 street arms:

https://www.z1motorsports.com/suspen...ms-p-8534.html

I know people were reporting issues with the ball joint coming loose, but I have not experienced that issue. If you go z1 make sure to use the proper thread locker and let it cure 24 hours before driving.

They aren't bad either for street driving, they don't make noise and camber adjustment I'm told (by the technician) was easy, but I did take it to a professional race shop for the alignment. Hope this helps.

I would use the (new design) SPC arms over anything else out there, only because they seem to be the only ones using rubber bushings. In my view, spherical bushings don't belong on a street car. You won't get the same service life before they start clunking, compared to rubber or even urethane bushings. And yes, your wife will notice them.

My Nismo is all SPL. I track mine alot. Had the front upper control arms and lower bushings on for 3 years now. No increase in noise when installed. The SPL upper arms are the easiest to adjust.

Get the SPL, you will thank everyone later.

I'm trying to get SPL all around but am confused on which ones to get for the toe. I have the divorced setup in the rear.

Rear camber arms
Rear toe arms (made for true setup)
Rear toe bolts (not recommended for track use according to SPL)
Rear mid links (I don't see much people going with these)

Any suggestions would be appreciated. Thanks

you'll need to get the arms with the buckets to hold your springs. The other option is for true coil over type setups.

To expand on dP3NGU1N's reply

New list for the rear:

• Rear camber arms
• Rear mid links
• Eccentric Lockout Kit

Toe arms (for true type setup) is not applicable for your divorced setup. Toe bolts aren't needed because you will change Toe setting via the SPL Mid Link. You should get the Eccentric Lockout kit to eliminate any potential Toe slippage the OEM toe bolt may allow.

Thanks guys. Just that I didn't expect this much $$ for rears...

For those of you with other brands like SPC, Kinetix, Z1 etc., they don't offer the mid links like SPL so are they good enough for track abuse?

The stock buckets are beasts already. What you'll get from SPL are adjustability (the buckets can adjust up and down to lower/raise ride height) and potential weight savings. Though by how much, I'm not sure.

They're only really necessary if you're not going for new toe bolts. If you get the mid links then you want a lockout kit. It's really just there for toe adjustment. If you get toe bolts you don't need the mid links unless the toe bolts don't get you enough adjustment (which shouldn't be an issue if you're looking for reasonable geometry).

My Z1 upper arms still make plenty of noise... No matter how much grease I use... I have tried everything Z1 has told me about getting rid of the noise.. I have just learned to accept it...

Thats what I thought too, but according to SPL toe bolts are prone to slip if you track the car. Any one experience this slippage issue?

Yep. :shakes head:

Yes, technically. One strategy that some people use is to mark where their bolts are and to check it before each race day. If you go with the mid arms they lock in and are less prone to slip. The slip is very minor though and, if you're streeting your car, should be taken care of during your normal alignment interval anyway.