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K Member, A Arms, Coilovers for Autocross - Worth it?
I’m looking to get some input and advice before heading down this road. I pulled the motor last week in prep for a 355 I am finishing the build on and while the motor is out, I am debating doing K member, A arms, and coilovers…which is a pretty hefty investment.
My primary use/dream for this car going forward is a summer driver/cruiser to and from work and weekend warrior. I autocross the vehicle and plan to move it towards more track applications (if future time and money allow). So, with all that said, handling is key.
1. Does anyone have a similar story and can attest to better performance gains with swapping these components out and running in autocross applications? Ie, without arguing the science behind coilovers, do you think or know it made a difference on your third gen which is a solid handling car to start with?
2. I am looking at going the UMI route (nixed BMR after a lot of personal experiences expressed on this forum), since a lot of you on different threads have attested to a good product. Will a 350 bolt up to this as well? It seems they are set up primarily for LS1/LSX swaps and nothing that I have found explicitly states a 350 will bolt on.
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
Before you even think about purchasing these products, keep in mind that class rules concerning these products may bump you into a much higher class - one in which a 3rd gen will never be competitive. Keep this in mind if you want to run time trials or competitively.
I have never seen any sort of data showing that coilovers are going to give any sort of real performance gain - other than lowering unsprung weight. And in many cases, coilovers may limit the amount of front tire you can run - not a good thing for best handling.
K-members and a-arms offer weight reduction, more clearance, and would be much stiffer than the stock parts - but are expensive.
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
A-arms are the only thing in your title that are worth it, but even then they are not a big bang for the buck - new bushings for sure.
Stock k-member is strong and any weight is low which is good. Forget coil-overs on the front.
Save for Koni yellows and good strut mounts (DSE first, Spohn second).
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
Tubular K-members are for drag racers that want weight reduction. Those things are weak in comparison to stock k-member.
Front coil over is just for drag racers too. It is a terrible idea for a car that is supposed to handle because it limits tire width inboard and puts a lot of stress on the strut tower which is already a weak point of the chassis.
Rear coil overs might be advantageous, not because a coil over is anything special, but because there are much better performing shocks available on the market of that type.
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
a buddy of mine that I run autocross with did this swap an he said that he feels that just doing the arm is worth it but not the k member an yes u will move up in class..with just the motor change u will move up a class.atleast that's what they did to me from esp to cp.i changed my arm bushing to poly an notice a big difference on the track.
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
The tubular K member is going to be weaker than the stock K member as well as lighter. It's weight that is as low a position as it gets so it's good weight in a way. The major drawback to the stock K member is it's size and the enormous pain of changing engine mounts. I switched to the UMI K member and have been happy. It frees up so much room and makes changing engine mounts a breeze. Working on anything down there is simplified now. Some autocrosses may bump you up class-wise but many now have classic american muscle category which you would still fit in. I also haven't been to any autocross that isn't the honor system for classes. Big meets sponsored by big vendors may be a different story. You can bolt a SBC, LT or LS to the UMI K member based on the motor mounts you need.
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
Originally Posted by 91@Z28
I am debating doing K member, A arms, and coilovers…which is a pretty hefty investment.
My primary use/dream for this car going forward is a summer driver/cruiser to and from work and weekend warrior. I autocross the vehicle and plan to move it towards more track applications (if future time and money allow). So, with all that said, handling is key.
Assuming you autocross SCCA and run in CAM, all of these mods are allowed.
1. I would skip the K Member. Or put it last on the list. This is the mod that will do the least for you.
2. A arms are also low on my list. Replace the bushings in the factory ones with the Global West Del a Lum pieces and put in new ball joints and keep them. Ridetech is working on a replacement unit that will give more adjustment to the alignment UMI makes a good set that provides weight reduction but the money is better spent elsewhere.
3. Coilovers. Rear coilovers in a single or double adjustable will help control the car on the autocross if you are serious about learning how to adjust them. Front coilovers will restrict your potential tire size and should be avoided. Adjustable shocks are a waste of money if you aren't willing to learn how and when to adjust. If you're serious about it, UMI has some nice custom valved units made by AFCO that we've been very happy with on our car. Double adjustable fronts and single adjustable rears.
Things I would do before any of these if you haven't already done them.
1. Subframe connectors
2. Upper strut mounts
3. Adjustable rear components (LCAs, panhard, torque arem, and LCARBs)
These will stiffen the car, keep the rear centered, and keep the stock strut mounts from coming apart under the pounding hard driving will put them through.
As for which vendors to use, I'm partial to UMI since we have mostly their stuff on the car. But Detroit Speed makes high quality products (that came out after we had the UMI parts on the car) and Ridetech is close to introducing a line of thirdgen parts. Of the current brands on the market, UMI has torture tested theirs the hardest at road course and autocross events between their 4th gen cars and our car. Once Detroit Speed finishes their build, that car will be out in force. Their current mule is the Raymond's performance car and it holds its own quite well at events. Ridetech is still in development and testing but based on their offerings for other platforms, their parts will be high quality, well engineered, and very capable.
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
I would also say only the a arms are worth considering. Another benefit of the a arms is tire clearance on the back side of the arm, I you go with really.wide front wheels and tires the extra room is nice to maintain some of your max steering angle. Also, some of them have the balljoint angle adjusted to accommodate a lowered car.
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
Originally Posted by Beater79TA
Ridetech is still in development and testing but based on their offerings for other platforms, their parts will be high quality, well engineered, and very capable.
I've been waiting and watching for them. Their performance and dollar value are exceptional.
They tested a strut two years ago - had a bracket failure of some sort. Then got pre-occupied with other stuff and never revisited. I'm waiting for that. I want something better than Koni Yellow; yet, not so pricey as Jri.
No one company makes the perfect line of all parts. Consumer has to pick and choose. Great to have more offerings than ever before!
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
I run Viking DA rear coilovers and front struts they are all made of aluminum and the fronts are 2.4lbs each lighter than the Bilstien HD's. I agree and K-Member should be left alone to keep the CG lower along with the factories strength. A arms seem worth considering but much more can be done for the money, if you are willing to put some work in you can gun drill the factories and take a bunch of weight out and still be plenty strong
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
Originally Posted by TEDSgrad
I've been waiting and watching for them. Their performance and dollar value are exceptional.
They tested a strut two years ago - had a bracket failure of some sort. Then got pre-occupied with other stuff and never revisited. I'm waiting for that. I want something better than Koni Yellow; yet, not so pricey as Jri.
No one company makes the perfect line of all parts. Consumer has to pick and choose. Great to have more offerings than ever before!
I spend far too much time at events with Ridetech's owner. The parts were officially developed last fall and are being tested on some shop cars. One belongs to the owner, the other to an employee and testing happens on their private track at the shop. Being located in Indiana, testing sometimes has to pause during the winter. I'll know more this weekend after visiting the shop as part of the FM3 Cars and Cones event. I've also recommended they get someone to open an account here to start showing off what they've developed.
For shocks, UMI has some AFCO units that fall in between the Koni and JRIs in terms of price. I know the dampening curves give more adjustment than the Koni's but don't have the curves for the JRI's to compare the UMI/AFCO pieces to the JRI units. The rear coilovers have been available for a while. We're torture testing the first set of front double adjustable struts with valving specifically tuned for road course and autocross use. The struts should hit the catalog soon but information is available to anyone who inquires.
2017 and 2018 should be an interesting year for new product hitting the market for these cars. Ridetech is developing parts. Speedtech is reportedly developing a completely new front setup that replaces the struts with upper and lower arms and a different wheel hub. And companies like UMI and DSE are continuing to expand their product lines.
Re: K Member, A Arms, Coilovers for Autocross - Worth it?
Not sure on exact timing of the release. I suggested they get a representative on the forum to start updating official information. What I do know:
1. The first production spec parts are on their way to Ridetech for installation on an employee car for testing of the production spec parts.
2. The prototypes are on a car and being driven.
3. Both cars are stock drivetrain so no real torture testing on a car with more than stock power or non-stock brakes yet.
4. The rear end components are as expected but, realistically, how much can you do with a panhard bar and lower control arms without modifying the mounting points.
5. The front uses a tubular a arm setup for only coilovers for the first release. This limits the front tire to a 275 width.
6. There are Ridetech shocks and struts coming out for the front and rear.
There should be someone from Ridetech joining the forum soon to start making official announcements around specs, pricing, and release dates.
04-24-2017, 09:34 AM
