SPL SUSPENSION PARTS
 

talked to the owner of spl last week sean farrah about his new line of 6th gen suspension parts after he took his 1le out to cota last week for super lap battle ! parts look super nice , they are mostly known for nissan/import parts but trying to break into the domestic line starting here!


https://www.splparts.com/2016-6th-gen-camaro/

I love SPL stuff! I want their whole catalog of parts under my car !

Those look great!

yes sir i agree i asked him if we get a group buy or a coupon code and he said let hes not a forum sponsor but we can try to work something out! his car was 100% stock other than all the spl parts at super lap battle

Apart from the claimed benefit of rear toe arms/eccentric lock out, what benefits do all the other parts have?

thats a good question and they website is super vague so i couldnt answer that lol

They look really nice but that's a hell of a premium over BMR.

I'd assume they're lighter as SPL uses aluminum and Ti hardware vs steel, but uffda.

i talked to sean and he said to email them at sales@splparts.com or tech@splparts.com if you have any questions !

anybody bite the bullet on any of these parts yet?

I talked to Turner, who works there, for 40 minutes and I can verify that they definitely want to break into the Camaro market!

Most of the suspension stuff is over my head, but he seemed to focus a lot on geometry of the suspension, correcting role rate from a lowered car etc... and he says their stuff is motorsports grade, for what that’s worth

I was going to, and then when I totalled up the parts list it was about $4500

Plus I realized I really have no idea what I’m doing with suspension and so it would be unwise to go blow a whole bunch of money on it without knowing what I’m doing, let alone maximizing my driving skills to the catch-up with ability of the car as it is in its current form

Words of wisdom GMG!

They make somebody richer?

I know, i know...bad Trackclub! Real bad!

:smoking:

Their rear toe links are very nice. Look to be top-quality parts/materials and easy adjustment.

Some of their other parts I can understand the offering, but in limited cases, like the adjustable front radius arm (they call it "Tension Rod"; GM calls "Ride Link") for caster adjustment and rear adjustable trailing arms for camber. The thing with some of this is that if you mess with one, you end up effecting other alignment specs (like camber+toe), so in end you end up needing all/most of the components (mostly speaking to the parts that move in more than one dimension).

already ordered and installed the rear toelinks with lockout and they are awesome!

SPL said this to me...


Number 1 I would replace the tension rod, which is where you have that BMR lower control arm bushing, but if you are planning on getting the Vorshlag camber plates, you MAY be able to get the castor you need, but it only has a few settings for castor, it is not on a slider like camber.

Otherwise, in order of importance
1. Front lower control arm - Roll center correction and additional camber
2. Tension Rod - Castor adjustment, elimination of play in bearing up front
3. Rear Upper Camber Arm - More rear camber

how much more do you need? 1.7 should be plenty, no? Does he have recommendations as to camber/caster/toe that his parts help achieve?

I have the rear toe arms installed and have -2* camber in the rear with 0.15* total toe in. I also have the Vorshlag camber plates set to -3* camber. At first I was at the stock caster setting (7*) but I changed to the only other caster setting on the Vorshlag plates (9*).With the caster at 9* I can see the wheel sitting slightly closer to the rear of the wheel well. SO the tension rods would be good if you wanted more caster and you could center the wheel more. The upper rear camber arm, imo, is only needed if you want to go more extreme with the negative camber or want to use a lockout on the lower control arm.

Just to clarify, if your F wheel moved visibly to the rear, this would decrease caster, correct?

yea i have the toe rods with lockout already and looking at the camber plates but i have aftermarket struts so not sure if they will work

No, the other way. Positive caster is the rearward tilt of the steering axis. Because the wheel centerline is above the lower ball joint, the caster change can cause the wheel location to change. How much it changes varies based on amount of caster change and physical location of the lower ball joint and the wheel center.

Yes, maybe. If the bottom of the tire, where it touches the ground, moves to the rear, yes, caster will decrease.

But, If the top of the tire moves to the rear, then caster will increase.

Understood. Yet it seems counterintuitive to me, that a wheel would move rearward when caster is increased.
Perhaps a key here is where such movement would be measured. A bit surprised, that's all.

Hmmm....not sure how you move a top (or a bottom) of a round object without automatically affecting both, as a relationship between top and bottom is always 0 degrees (on a round object).

In any case, if the wheel did move rearward, presumably this would have an affect on F to R weight distribution (and not in a positive way imo).

All in all, interesting discussion. Apart from rear toe part, not quite sure how all these $ translate into faster pace, or better tire wear, etc. Cheers!

I could have detailed it a bit better, for sure. The tire goes where the knuckle places it. And it's the knuckle that tilts. Given enough change, the relationship of the tire, within the fender, will start to change. Small changes might not be visible. I think the caster will change faster by moving the radius rod vs moving the upper strut mount. Caster is not a measurement of any of the tire's geometry, but of suspension geometry. As seen in the picture above, the caster line does not necessarily intersect at the contact patch, depending more or less on the amount of caster. On my Gen5, I once had Moreno camber plates that would allow me to add positive caster by rotating the plate. With the Moreno design I would have to give up max negative camber to get more positive caster, but never the less, more positive caster was obtainable at the top of the strut. Atleast with the Vorshlag Gen6 camber plates, as in Scargoes case, there is no compromise, you can have max camber and more caster.

Here is my 1LE, +7.2* top pic, +9.0* bottom. notice the gap at the front of the tire to the fender edge. The tire is pulled forward with the +9.0*. All of my caster gain is done at the radius rod (Gen6 ZLE), but if I was able to add more at the top, again, as in Scargoes case, the top of the knuckle would tilt more, pulling the tire rearward.

Attachment 1049874

Attachment 1049875

In reality, the movement was less that 5mm. It is visually perceptible if you look hard enough. The average person would likely not notice. But the positives from 2* more caster outweigh the shift in weight distribution. As for the rear toe links, I did them so I could make sure I attained the toe setting I wanted at the camber setting I wanted. And with the lockout, no replacing rear toe adj bolts every alignment.

Thanks guys, yep that makes sense now.
And yep, what the bottom pic shows was my expectation hence my original reaction. NB Obviously, i get the benefit of the rear toe link.
Not sure i would conclude that an increase in caster automatically negates a weight ratio difference, but i suspect it all depends on what one is after.
Thanks for the added explanations - appreciate it!
Cheers!

Increased caster will help with return to center but the most important thing, especially on a strut car that loses camber as the suspension compresses, is the camber gain when turning. 2* doesn't net you camber gain vs stock but reduces the amount of camber lost in corner. I also noticed a decrease in the amount of understeer on tight corners at the autocross. I haven't noticed any drawback to applying power like this but I also have the alternate eLSD tune.

I agree, we are fighting an uphill battle on our strut cars, trying to find grip and good tire wear. I’ve done a lot of work on my Gen5 when it comes to additional caster. More is beneficial to help the loaded tire in a turn and the unloaded tire in a turn. One of the consequences of adding caster beyond the factory specs is bump steer.
On my Gen5 the additional caster increased the bump steer, and the car drove like a dump truck on uneven, rutted and bumpy roads. With the addition of a bump steer kit and some trial and error on its tuning, the steering is feels pretty awesome. Lots of confidence when I’m pushing it hard. Without the bump steer kit I was very busy with inputs in the steering.

I plan on purchasing a Longacre bump steer measuring kit to fine tune it, if needed. Since this thread is about the SPL parts, I see they have a bump steer kit for you Gen6 guys. Don’t be afraid to try it. If you sense a loss of your fantastic OE steering feel and feedback with adding caster, the bump steer kit can help bring it back.

I test drove a 2021 SS1LE A10 this past Monday. My god, the steering feel and front grip was amazing.

Fighting for front end grip and good tire wear? Maybe on a gen5, but sure as heck not on gen6 SS 1LE!

Randy Pobst was a first pro to test this car at large and one of the very first words that came out of his mouth was amazing front grip! And he knows what he feels, eh?
My tire wear at 2.6F and 1.6R is near damn perfect.
If i push my tires too long, they cord on the inside, on both sides. So for damn sure i will not dial any more camber, lest they will cord faster!

The car turns in as if it was telepathic and the steering feel is truly excellent. If somebody complains about lack of front grip, may i suggest they check their alignment. And if that is ok, then may i suggest they learn how to trail brake effectively, in order to manage weight transfer and overall balance on entry. If I wanted even more grip and faster laps i would simply put G3Rs on (as many have done here with zero changes to suspension geometry).

The SS 1LE comes with tons of caster out of the box.
You will be hard pressed finding any race cars with this amount of caster. Maybe rear end engine sports cars, as they benefit by more caster to offset the weight balance.
But rarily does a front engine car benefit by more caster as far as outright handling and pace. To the contrary.

Caster indeed helps maintain camber on the outside wheel (while reducing it on the inside wheel) which may provide for better wear, BUT at a cost:
1) slower steering response (by design)
2) likely more understeer
3) possibly MORE tire wear because of the above (caused by slower transitions).
4) possibly rears getting overloaded (because of a weight shift).

Higher caster makes the car less responsive and more stable. Some seasoned pros will have it reduced as much as practical, to make the car as responsive as possible to their inputs. Some pros may have it increased to dumb the car down if they are new to a given class/etc. No pro will increase caster to go faster.

Lastly, you must have a good feel for the balance given your comments about the 2021 SS 1LE test drive.
Now imagine this car with proper track alignment...
Go buy it! Cheers :)

Haha, yeah, the Gen5 SS 1LE is nowhere near the feel and grip of the Gen6 SS 1LE! I've driven other Gen6's but not near the limit. That has been my comment that I can only imagine what they are like with a track alignment. I have described them as intuitive, but your description of telepathic is spot on. The first time on the track when stock, my Gen5 felt like it knew when I wanted to turn, but I never felt that with just street driving. The Gen6 on the other hand, with just a little bit of loading, on the street, gives a ton of amazing feel and feedback. The only thing I didn't care for was the steering feel on the Track mode, it was way too heavy. But IIRC, the steering settings can be adjusted between the modes. I've driven a ZLE too, and wow, what a great time to be a car guy!

I like to play with my car, to better to understand it, and I'm not afraid to try something. My aim with the additional caster has been to lessen the static camber while keeping the same level of grip. All because I street drive my car more than I track it. So I drive all summer on the track alignment and as you mentioned, the inner shoulder gets abused from the high static camber. I've been reducing my static camber while bettering my PB. That's not to say that increasing my static camber won't help my lap times, it certainly will. Again, other variables effect lap times. Just trying to find a street/track balance. Caster can help both tires in a turn but as with everything else, there is a limit. The list of other side effects shows there is no free lunch. But I'm not sure about comparing caster #s between different types of suspension as there other variables that come into play.

As far as what I've observed on my car, unfortunately, 2* more caster doesn't equal 2* of better dynamic camber control. I'm actually down on caster from my above picture of 9*. I'm currently at 8*. Mac strut suspension is not optimal if we want to turn and keep the tires happy as far as wear goes. The camber curves suck. I've run through various caster measurements at different steering inputs and I have seen the results. This winter I may try to measure the camber, caster and bump steer with the suspension at different ride heights, trying to mimic the car being loaded in a turn. There's other dynamic variables involved but understood. Maybe next year I'll go back to the factory 5.6* and see how she goes! My current setup is quite different from OE, going to 5.6* would be an interesting change.:D

Agree, well said indeed. And obviously you know what you're doing and why. The unfortunate thing is, that all too often folks read about somebody doing something, they develop a perception this is a must have and then follow like proverbial sheep over the cliff :)
Cheers!

Yeah I’m not sure to be honest, I just checked my alignment sheet and I’m already at -2 for the rear without any aftermarket parts, so I’m not sure how much more will help if it will help at all.

I imagine the mount of camber desired has something to do with the track and the tires being used, I’m at a corner heavy track (19 of them with a lap time of 1:20) with lots of off camber corners and I’m using SC3R tires. Anyone want to chime in with advice and experience?

Yes he does have recommendations and told me that he would phone the shop that does my alignment in order to get them to set the car up right and best for the track considering my car is also slightly lowered, although only by about 1/2 to 3/4 of an inch or so.

No first hand advice here, but second hand a ZL1 buddy with G3Rs and 3.5F camber corded his new tires in a day. I find it very weird that he would not discuss his recommendations incl pros/cons with you and instead will call your shop. What are you? Chopped liver?!

On a related subject, if these mods will cost you $4.5k (if i recall correctly), you may as well consider DSSV kit, as it starts to look like you're about to build out a race car.
Whatever you do dont spend your money twice :)

I think I will probably only buy the lower control arms for $700 USD (for camber and roll Center correction for lowered car) and perhaps the Front tension rods $600 USD (the BMR bearing I’ve already replaced and castor adjustment) so
I can increase camber to some thing around 3 or 3.5 considering that I already have the rears at -2

The $5000 figure was if I bought every single part SPL offered for my car. He also has no problem sharing the alignment spec goals, I just didn’t want to know how to set up all the parts in order to get there


I have thought about the DSSV‘s considering I would think they would pay a bigger dividend considering just how many corners I have on my local track, however I really don’t want to ruin the ride quality of the vehicle when I drive on the street, even though it’s not a daily driver. Having said that I mostly only driving on the highway now.

There seemEd to be a few guys who switched their MRC to DSSV and gained very minimal time on the track. however it was an extremely low sample size, I imagine it’s also very driver dependent and very track dependent as well. I can’t help but wonder how much of a difference the DSSV would make when doing 19 corner in 1 minute 20 seconds

Have you noticed more roll, or understeer, since you switched the springs? Have you measured the angle of the control arm with new springs? Has he?
Usually corrections for roll centre are needed if a ride height is lowered quite a bit and results in negative handling effects. If your half inch is not producing these negative effects, than no correction is needed per se.

If you are starting to worry about absolute perfection, then an upgrade to eliminate any roll centre issues (if you have them at all) would be to put oem springs back on at ZERO cost. This would also solve for any issues regarding springs to damper valving ratios. Something i would not forget about, if you are looking at maximizing performance set up to a proverbial "T". It would also be a timely (and cheap) test, to see if the handling and/or pace changes any. What if ya went a few tenths faster?
If you wont test, you will never know. Even IMSA teams test multi spring/damper combos before picking the best handling set for a given race.

As far as DSSV, i would consider them seriously, if aero was in your plans. With more aero, you will need a harder sprung suspension. Note Nicky Bobby's build details. They are very well thought out.

As far as increase in pace, driver and tires will make the most difference. But, a well balanced car, which is easy to push is equally important. At this stage, given your big success this season, future gains might be in tenths vs seconds. Not having laptimes from another well driven ZL1 on the same tires, you wont know what the delta is.
A good lap timer could be of help based on optimal sector times, but these are about driver vs mechanical mods and not necessarily 100% accurate (but helpful nevertheless).

Judging by Fastest Laps at various venues, it seems that ZL1 1LE is damn fast as a package. This tells me that GM did a nice job marrying different components together to max pace: suspension, tires and aero.

PS it seems you were surprised you have 2R camber. Do they not set up your car based on your specs? Do you not check them? Note my comments about high camber and tire wear. Have fun! Cheers!

I wish I could tell you if I noticed more roll or not, but I’ve changed too many things at the same time and only went to the track four times this summer due to car problems and the crash, and because of the car problems I was focussing mostly on that. I only had one and a half track days of no problems and that was spent getting used to all the new modifications I had made to the car while shaving slightly more than 3 seconds off my best lap Time.

As for how the car was set up, I believe I simply told him to get as close to the ZL1E alignment specs as possible, but with the crash of my car at the track I really stopped paying attention to the alignment, so I forgot that the rears were set to slightly more than the -1.7 that the ZLE has.

I like the look of the slightly lowered car so I’d rather correct for this with aftermarket parts if possible, even though it’s more expensive. Yes I’m probably being very perfectionist but on a corner heavy track I want every single advantage I can get in order to stay ahead of all the Porsche gT3‘s I’m up against on this tight technical track.

Overall I hope to beCome a better observer of how my car is handling as I get more track time next season with my Current modifications and set up.
But like you said last year, it’s definitely hard to tell what’s going on when everything is happening so fast and I’ve only had about 10 full track days if you don’t count the three training days Where we weren’t pushing hard and all the Half track days I had car problems

I think the question remains: how do you know the car's geometry needs "corrections" just because you lower it slightly? And if so, what will you correct, and how will you know what to correct? Don't forget, if you increase the effective spindle height (which is what the "roll center correction" shims achieve), then that has other implications for geometry, such as where the RC moves and how quickly as the suspension compresses and rebounds. The existence of these parts implies that "RC correction" is needed, but has anybody really quantified that? Again, I don't think Chevy does anything to correct it for the different ride heights of the various Camaro models.

toe rods with lockout are awesome going to see if i can get more camber in front without camber plates first then see what else i want to add spl parts makes good products just gets $$$

Bingo!