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YOUR RESEARCH991 Control Arms?
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I don't drive it on the street and have also replaced every other rubber component in the rear with metal.
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I used an air sander to level the step-up off and cleaned up the area inside the subframe.
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For a better performance in the rear suspension I used the stock arms with solid pucks and sport hardness end bushings from Elephant.
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I have been going through all of the components on my car this Winter. I just upgraded the car to custom Feal 441+ coilovers with Swift springs. I am upgrading the forward control arms front and rear with poly bushings. I also need to replace all 4 corners of the coffin arms. Through my research, I have heard of some guys upgrading to the 991 coffin arms. Upon investigation, they look to be using better bushings and have a slightly different aluminum design. Does anyone have any input on these arms and are these an upgrade?? Anybody currently running them? They seem to be cheaper than 996 arms and they also look like they are an upgrade to me.
Here is the evidence of this being done. If you don’t want to watch the full video, just fast forward to 6:30. Looks like certain shops have been doing this for customer’s cars. They look like an improved unit over the 996 variation to me. Maybe I’ll be a Guinea Pig and order them up. Would love to know if they offer any additional camber.
You Tube
It shouldn�t take much more than some basic measurements to decide whether they�ll work or not. If the measurements aren�t exact, it means that other parts and adjustments will need to be made for proper alignment�
Is Tom from TGE TV a member here? Would be great if he could give some input of why they put these on his car, and how he liked them over the stock units.
those are awesome, but they are $1300 per set. The 991 arms are $186.99 per arm. You can score all 4 arms for $710.56 with the Honey Coupon.
https://www.fcpeuro.com/products/por...rw-99134105301
If you go with Genuine Porsche parts you will get some items with 991 part numbers on them. Here's a link to my "forever targa" thread showing what parts I got. It includes a discussion on the lower control arms. Suspension stuff starts on post #62.
https://rennlist.com/forums/996-foru...r-targa-4.html
Below is a picture of the lower control arms, old next to new. The new part is a forged item, likely stronger than the original cast piece. Also note the part number stamped into the arm, also the part number on the UPC sticker. If you google the stamped number it will return hits for the 991.
Has anyone verified that the 991 parts will work? Looks like a few others have done it YouTube but wanted to see anyone on here has done it.
Thanks
Joey
The control arms pictured above are on my car, a 2002 targa, front and rear. They've been working for thousands of miles. I'm not sure how to make it any clearer.
Lol!! Long day for me today. Was great we could finally meet up today. Can’t wait to hear how your 4.0L project turns out. I may be right behind you on that one.
Looks like the major difference I am seeing in bushings design is more related to cars with the M030 option and PASM. Does anybody know if these arms would cause any issues with the regular 996 suspension? The bushings look a lot more robust with this design. Again, would love to know if anyone has tried these arms and has any feedback on how they perform?
Regular 996 control arm.
997 PASM control arm.
991 PASM control arm.
I pulled the trigger on 4 new TRW 991 control arms. I'll post up the specifics when they arrive, but from my research these are the same part numbers are the 997 arms. These definitely have a revised bushing design, and look like they will be less prone to tearing and offer more feedback. The arms also are forged which is an improvement over the standard 996 design.
Where did you find them being forged as opposed to cast?
The alloy designation supports this as does the 'wide' splitline of the tool halves but seeing raised part number and porsche parts logo is normally a give-away for a casting (at least for wheels)
I'm beginning to cross over from incredulous to astounded. Pretty soon I'm just going to unsub and let y'all swim in your own juice.
I have 991 control arms on my car
They've been on the car for thousands of miles
I got them by ordering my suspension parts directly from Porsche
The factory 996 part numbers were superceded all the way out to 991 parts
I posted pictures showing the part number
Yes you did and there probably isn't much difference in the ones you used. The poster here is ordering the ones for PASM cars (I don't really understand why) that seem to have a different thrust arm bushing. For a better performance in the rear suspension I used the stock arms with solid pucks and sport hardness end bushings from Elephant. In the front the only real performance gain I believe is with an adjustable arm.
I saw your post brother. That is why I ordered these. Mine have a different bushing design that yours though. That was the biggest reason why I wanted to ask if anyone had tried these specific units.
Probably difficult to tell, but was there a noticeable difference with the Elephant sport hardness bushings ? Did they tighten the rear end up ? and do they increase the NVH from large or small imperfections in the road surface ?
I guess ultimately I’m asking if you think they were a worthwhile upgrade ?
I don't drive it on the street and have also replaced every other rubber component in the rear with metal. I felt it was a good thing to change on my 20 year old arms. Since I was getting rid of the rubber thrust bushing and they were less than $200 for the set. I don't see just one component of the suspension making a huge difference in terms of performance or unwanted NVH. Unless of course it is worn out . With stock arms available for less than $100 hard to argue with just going with that for a street car.
Got all 4 arms installed today. They do require a slight modification on the front subframe only. They fit perfectly into the rears. The front subframe has a step-up in the recess that houses the control arm. Take note at the width and the diameter of the 991 rear bushing design compared to the stock 996. This is what causes the issue with from control arm fitment.
The wider rear bushing runs into this step-up of each side.
My solution was pretty easy. I used an air sander to level the step-up off and cleaned up the area inside the subframe. Once this is completed, the control arms can mount right up perfectly.
Very interesting, and thanks for posting this! Would it not have been possible to grind down the outer metal portion of the bushing, rather than subframe?
That is part of the bushing, so you would be damaging the control arm. The 1-2mm of material that was removed from the subframe was very easy to remove. This created a level surface to accommodate that larger area on the new bushing. The rear subframe is smooth which doesn’t create any issues. I frankly have no idea why the front isn’t also. I am sure the 997 subframes were revised and casted differently.
WDB you have the non pasm 991 arms and they fit with no modification correct?
Goo you have the pasm 991 arms and they need modification in the front correct?
You are both very correct. This is only an issue if you choose the 991 PASM arms. The non PASM arms do not have that wider bushing with the larger metal washers. Their bushing is similar to our stock 996 arms in shape. I chose to go with the PASM arms because of the difference in bushing design. My thought was they looked more robust and will provide more feedback while also providing stockish comfort. This is yet to be determined, but so far I like where this is going. I think these are going to be a positive upgrade to the car without breaking the bank. I am trying to find the sweet spot between an aggressive weekend driver, without going into an uncomfortable track toy. I have been guilty of this in the past with cars, and you can ruin a car by going too far. Also trying to not change too much at once. Give myself some time to experience the changes and determine if I want to go further.
991 non PASM arms fit without any modification. 991 PASM arms work but require you sand off that extra ridge in the front subframe recesses. If you look at my pictures closely, I didn�t take make material off at all. This was done with a sander and not a grinder. Just smoothed those areas out so they didn�t pitch at the tops any longer.
The 991 arms are a different allow and a different finish. I heard from several forum members that these were forged before I ever gained any interest in them. After seeming them in person you can see they are much different than the 996 arms. I feel like I have looked at enough and handled enough cast aluminum arms to determine these are not. I haven�t dug deep enough to prove it other than my own personal eye and touch.
First and foremost just look at them. If that is not enough:
https://www.makeitfrom.com/material-...96182-Aluminum
6182 (AlSi1MgZr, A96182) Aluminum
"6182 aluminum is a 6000-series aluminum alloy: there is significant alloying with both magnesium and silicon, and the alloy is formulated for primary forming into wrought products. 6182 is the Aluminum Association (AA) designation for this material. In European standards, it will be given as EN AW-6182. AlSi1MgZr is the EN chemical designation. And A96182 is the UNS number.
It received its standard designation in 2005, making it a fairly young material."
I am still running my original 996 porsche cast control arms with a decade and a half of tracking on them. They are pretty damn durable. Sure, it's about time I refresh my control arms. Forged or cast I like the idea of the 991 control arms. Especially for the price.
No doubt the cast ones are fine and are plenty capable for track use. I don’t see a control arm breaking under normal circumstances. Not unless you are doing some serious accidental off track exploring. 🤣🤣🤣 For the upgrade in materials and design, I was all in on these as long as they fit. I was able to be the person to explore this possibility, and the good news is they work. It’s yet to be determined how they feel compared to the stock units, but that will happen as soon as my Fikse’s come back from Powdercoating. At $187 per corner, I couldn’t be anymore happy with my decision. I can tell these are going to be a huge improvement to what was in my car.
After seeing a few wrecked cars, I can tell you that the control arm snaps long before doing harm to the chassis or subframes. I wonder if they intentionally used cast material to create a failure point.
I would think you are 100 percent accurate in that statement. Accidents happen all the time. The wheel and tire are part of the crumple zone. Basic accidents would snap a $150 control arm and save a much more expensive aluminum subframe. Plus when is snaps, a lot of energy is dispersed into that wheel, tire and arm, and not into the rest of the chassis.
Big development tonight. Lessons learned but it will be an easy resolution.
I received my new front arms the other day from European Parts Solutions. I stumbled upon their video on YouTube, and I ended up going with their arms with the ploy bushings already installed. I tried to press out the old bushings and bent the stock arms and damaged the bushing hub. I said screw this and bought a solution that was already assembled and warranted for 5 years.
This was unfortunately where the good times ended tonight. When I went to install the new arms onto the car, I quickly realized the 991 PASM bushings are 17mm wider than the fork in the stock 996 arms.
I was seriously panicked at this point. Being this far into the project and feeling like I screwed it all up. Well, a quick search of 997 and 991 front control arms revealed that the forks are indeed wider on the newer models. EPS offers the 997 arms with the poly bushings upgraded, so I will be in contact with them tomorrow to discuss solutions. Looks like the 991 PASM inner bushings are 60mm wide, and the 996 bushings and fork openings are about 43mm wide. The 996 stock arms are 14.5” from bolt center bore to bolt center bore. Now that I have cleaned up the crap in my pants and gathered myself, I’ll just have to swap the 996 arms for 997 or 991 arms. Whichever is dimensionally a solution to this upgrade. This is yet again another example of the how much more robust that 991 arm is over the 996 arm. I have included a couple examples of the 991 and 997 arms from FCP website below. You can clearly tell the fork is larger than the 996’s now that I know and am looking specifically at it.
Its so clear to me now, but yes I totally failed to measure the width of these the first go around.
What if the 997 version is a different length? You also realize that the 991 control arm was only used in the front? Be sure to order the longer bolts PET shows 95 vs 73.
Also google "eps control arm failure"
It doesn�t matter where the 991 arm was used. It was used front and rear on the 996. That�s what I need to look at. I am aware the length is a factor. That�s why I intend to figure out the solution to this issue sometime today. In terms of your EPS control arm failure, I was unaware of this. Just saw the posts you wanted me to see and I�ll be sending these back and going with TRW arms. I�ll just order the 997 arms for front and see what I get. The arm just needs to be 14.5� from bolt center to bolt center. Either way I�ll figure out the exact solution to this issue very quickly.
I am working with FCP Euro right now to get some measurements and pictures. They are able to walk back into the warehouse with a tape measure and check specs I will have a solution today and report back.
Ok according to the PET all Non-GT3 997 and 991 use the taller central bushing in the front LCA. If the 997 front diagonal is the same length as the 996 you should be able to use those in the front and back of a 996.
The 997 rear LCA has the same height bushing as the 996, they are essentially the same arm. The 997 rear diagonal arm would not fit these 991 arms.
I think what
@wdb
purchased was an updated 996 arm using the newer arm design with the shorter central bushing. You can even see the Porsche label designates it with a 996 number.
I have some 997 and 996 diagonal/caster arms and they are the same length, just wider where they mount to the center bushing...
So yes, the 997 diagonal arms should make this 991 LCA part work....
I have all the info and part numbers to make this work now. Let me get it all in and bolt it all up before anyone burns me at the stake for being wrong. Lol!! The 991 fork arms look to be 1/2" shorter, but we measured the 997 arms and they are 14.5" bolt-to-bolt just like the 996 arms. I have pictures FCP sent me to confirm this. You will also need to purchase the longer 997/991 control arm bolts since the 996 bolts are too short.
This is my exact list of parts for this upgrade:
4x 991 Lower Control Arm (TRW - JTC1619) - 991.341.341.02
4x 997 Tuning Fork Arms (Meyle - 4160500006) - 997.341.043.00
4x Longer Control Arm Bolt (OEM Porsche) - PAF008970
4x Control Arm Nut (OEM Porsche) - 99908444909
TRW 991 arms
Meyle 997 arms
Yes they are called the stock arms. Meyle ones sell for about $112,.
99634105317
If you want ones that have a larger degree of adjustability look at Rennline GT3, Elephant, RSS, SPC. These will allow more camber and some also have a caster adjustment.
But it looks like the 991 LCA and 997 diagonals might work. Maybe just the subframe modification is the only extra work.
I agree with this. I tried looking up the part number molded into the forging -- 991.341.341.02 -- and came up empty. It may just be a forging identifier. Also, here is a picture of a 991 arm with what I believe is the same number on the body but different bushings in both locations. The white part number label says 991.341.053.02.
The project is finally complete and everything bolted up perfectly. The Meyle 997 arms along with the longer 997/991 bolts were the answer. I am very happy with how everything looks and how much beefier everything seems. I can guarantee there will be a difference in feel and handling. Especially since I am replacing 20 year old original gear that was in need of replacement anyway. I didn�t want to go full blown race car with this because I have done that in the past, and I regretted how hard and uncomfortable the car rode on the street. I was looking to gain some feel and performance without sacrificing a bunch of comfort.
Congrats on getting it done. If you have the chance, anyway you can post the parts list that you ended with. Be good to compare with Wdb to line everything up. Thanks man!
This is all you need to do this swap. All of it is available from FCP Euro with a full lifetime warranty.
4x 991 Lower Control Arm (TRW - JTC1619) - 991.341.341.02
4x 997 Tuning Fork Arms (Meyle - 4160500006) - 997.341.043.00
4x Longer Control Arm Bolt (OEM Porsche) - PAF008970
This is awesome. Thanks for seeing it through to the end. Always a fan of folks trying new stuff that is not the "go to route". I might add this to my tentative list of things to do. The list seems to grow
Given what I spent over putting everything back to OEM Porsche parts, I saved hundreds of dollars. These were a significant upgrade over the regular 996 parts. Since I bought everything from FCP, I will never have to worry about paying for replacing the same parts again. Full lifetime warranty on everything. I can’t wait to get the car back on the ground and see how it feels on the road. Still waiting for my wheels to be refinished and for my tires to be mounted up.
You're awesome.
@googone20
My only question, and I was sure I asked in this thread but apparently not, don't shoot me😊 if I did, is about the subframe mod. Is the grinding or sanding of the subframe required to fit the one end of the control arms listed in your quote? Once done, would you always have to use 991 arms? Or does grinding leave the flexibility of going back to 996 meyle? Just for example meyle, but it could be any make. Thank you in advance!
The grinding is very minimal. It only clearances the top area of the subframe recess. At the top the casting has a bump that pinches the wider 991 bushings and doesn’t allow them to fit all the way up in. Just sand that bump down smooth to match the rest of the subframe recess, and you’re good to go. Yes, you can absolutely swap back to the stock 996 arms without any issue. In fact, the rear subframes don’t have any issue with this because the don’t have that bump in them.
Thank you
@googone20
that is very helpful. It sometimes takes a while, but I get there. It does look beefier in your photos. And mine are getting done this year. I'm thinking of street hardness poly bushings, and if I'm going to do that, might as well have the best arms.
You ordered 4 front LC arms, so you will need to modify the rear subframe to get the front arms on. The part number for the front is 981 331 053，for the rear is 981 341 053, do a search and you will see the difference. There are no two iron pieces for the bushing that connects the rear LC arm to the subframe. I had the question of whether the new LC arms（thinner and lighter version） were strong enough and wondered if it would make bad affect on ride feeling. Then I found this post of yours.
Is this the correct forum for your post? I don�t think a 981 part number has anything to do with 996, 997, 991 numbered control arms, etc. 996 control arms (coffins) are interchangeable front or rear.
Sorry to bump this old thread, starting to prep for suspension refresh, wondering if OP can weigh in on the experience after getting the wheels back on?
Questions for the group on 991 arm upgrade for 996: do you have to upgrade the fork arms as well to accommodate the 991 arm? Curious how the 997 fork arms recommended differ from 996 forks and how those will work with the 991 �coffin arm�
Reviving this thread as I refresh the suspension on my 996TT so there can be updated information. According to the Tarett website, the front 991 LCAs should be cross-compatible with both axles of the 996 if you still are using the 996 variants for the other control arms:
As it stands right now, my plan will be to go with TRW 991 LCAs but I am still undecided on the route I want to go with the remaining suspension members.
EDIT: My apologies, after double-checking everything it does seem that the center bushing on both front and rear 991 LCAs are thicker than the stock 996.
This is a source reference. Confirm exact model applicability in the original material.
