Report after upgrade to 993 uprights - long
12-16-2014, 06:42 AM
#1
Drifting
Thread Starter
Report after upgrade to 993 uprights - long
Last winter I decided to upgrade my front end to 993 spec, meaning 993RS uprights, tie rods and brake rotors. It isn’t an upgrade that’s so common on 964’s, so I thought I would share some issues I had doing this and also my findings after a season driving with these parts. I haven’t seen any other “after reports” so I thought this could be a good idea!
But you before you start you should get the idea of why you should do this upgrade. First I’d say it is for you who track your cars. For street use only, it’s not worth the money. The benefits are, reduce of/no bumpsteer, lower weight, no adapter needed for bigger calipers, thicker dimensions – meaning stronger, and you can use 993TT floating rotors. Finally in my case I also got more track width meaning more grip, but I’ll come back to that. If you lower your car for track use all these things are good things, but again on the street it doesn’t matter. There’s also some confusing info, sometimes calling these parts GT2 or GT2 Evo parts. The uprights are from 993RS, and were used on GT2 so there are no GT2 uprights. There used to be GT2 tie rods though, but they are out of production so you now buy the 993RS version. I also assume you already have big red calipers otherwise a pair of those also goes into the parts list. The final list gets long!
Step 1, the part list:
• Uprights: 993-341-157-81 and 993-341-158-81
• Tie rods: 993-347-031-81 x 2
• Nut for tie rod: 999-084-449-09 x 2
• Rubber bellows, tie rods: 171-419-831C x 2
• Ball joint: 993-341-049-06 x 2
• Nut for ball joint: 999-084-449-09 x 2
• Knurled screw pressed into wishbone: 993-341-465-00 x 2
• Nut for knurled screw: 993-084-621-09 x 2
• Brake rotors 993TT: 993-351-046-10 and 993-351-045-10
• M12 for damper: 999-067-039-09 x 2
• M14 for damper: 999-072-006-01 x 2
• Captive nuts for damper: 993-343-156-00 x 2
• Hub nuts: 999-090-010-01 x 2
• Hub bolt: 900-082-123-01 x 2 (not needed but I wanted fresh parts)
• ABS-sensor: 993-606-404-00 x 2
• Wheel bearing: 999-053-041-04 x 2
• Screws holding the bearing: 999-217-042-09 x 8 (need longer than on 964)
• Side beams, if needed: 993-341-111-01 and 993-341-112-01
Step 2, mounting the parts:
There are some guides out there on how to do this so I won’t go through all the steps. These guides also have a lot of good picture so I just have a couple of pics to clarify the issues I had. The guide I used was this one http://www.jackals-forge.com/lotus/9...suprights.html . This is a big job and you need a press tool but it is also a pretty straight forward job to do if you have some knowledge of using spanners. Corroded bolts can be an issue depending on where you live but otherwise it’s more a question of bolting on and off parts.
First thing to decide before you order the pile of parts is how you want to do with your control arms. The ball joint for the upright uses a M12 bolt instead of M10 on the 964. This bolt is pressed into the control arm. You can do either of two things. If you have the money and want to spend more, buy a set of used control arms from a 993. Or, press out the bolt with a vise, drill a larger hole and press in the correct bolt. This is what I did and you can buy these bolts separately from Porsche, Pelican etc.
Next issue, but a smaller one, is that the 993 upright uses a M14 bolt instead of M12 for the lower fixing point on the damper. The 964 uses M12 for both holes. This means that you have to drill out 2 mm from the lower mounting hole on the damper. I have Bilstein RSR dampers on my car so the lower hole was already M14. I think KW dampers also already are made with a M14 hole.
The BIG issue No 1 I had though was the length of the tie rods. If you have a wide bodied car this isn’t an issue. But since this isn’t such a common upgrade on 964 NB cars this came as a bit of surprise to me. The rods are longer because the 993 has a wider track than the 964 and the RS and TT are even wider. Mounted on my car this meant that the rods bottomed out, so no there were no threads left for toe-adjustment. I ended up with a toe out setting! The 993 rods are also different, see pic, with just two parts instead of the 964 set up. I found the solution (I thought) from a guy on RL who had shortened the rods and then made new threads. I did this to with assistance from a friend.
Now the steering looked good, but now the BIG issue No 2 occurred, camber bottomed out at -1,3 (I used to run -3,0). Ant this was the real surprise. I’ve never heard of this problem before. After a lot of searching I finally found this thread on Pelican http://forums.pelicanparts.com/porsc...pension-2.html. This guy had the exact same problem with the tie rods and then with the camber, and his findings explains it all. Now, if you have the correct top mount (read lucky enough) you can get away with this and get the camber you need. But even though I have the factory RSR mounts which are adjustable I couldn’t get more than -1,3. Please note that you can’t use stock rubber top mounts, you need one of the aftermarket top mounts out there.
The only solution to fix this is to get the 993 longitudes or “side beams” (name used in PET). So I had to top up my parts list with another €250 and bought a used set of beams. This gave me the necessary 12,5 mm on each side. This is achieved because the mounting points on the 993 version are extended and curved so they push the control arms outwards. A very sublime difference and if you didn’t know you wouldn’t spot the difference. Luckily there was enough length left on the tie rods, with the now wider track.
The beams themselves are easy to replace. With these parts I can now adjust toe as I want and get -3,6 camber if I want to. So this is something to think about before you start. An option could be to move the side beams to the outer/WB position but increases the track width even more so your sway bar will be too short. Even with my set up the rubber stop on the sway bars are 12,5 mm off so I used a hose clamp as a spacer between the rubber and welded stop on the sway bar. But the NB sway bar still fits.
Finally, brake rotors. You have to use 993 rotors because the offset is different so there’s no cheaper way around this. But the flipside is that you can use the 993TT rotors which are a bit lighter than the 964 3,6T disc, with a floating hub at the same price or even cheaper.
Step 3, driving:
So finally, everything is mounted but was it worth the money? I’d say yes but it’s not a dramatic difference, just a little better. I run my car 3-4 mm below Euro RS spec and this is I my conclusion:
1. No bumpsteer - I can now drive on a curb, or if one of the front wheels passes over a bump or pot hole, the front end stays calm and in a straight line with only the suspension working up/down.
2. The wider track, 25 mm, gives more front end grip. I didn’t have any real problems with understeer before but it is even better know.
3. Steering is a bit easier if you have a manual rack as I do. The feel and force needed is more linear when turning the steering wheel. Before there was a “bump of resistance” passing the initial movement with the steering wheel going into to a turn. So the car is a bit easier to drive and requires less effort.
4. More stable under heavy breaking. The front end is calmer and more stable in the braking zone. You can more comfortably hold the steering wheel with one hand when shifting down, even in bumpy breaking zones. I could do this before to, but it feels even more planted now.
5. Ease of mind knowing that the parts are fresh and designed for more strength is a good feeling on the track. The tie rods for example are much stronger than the 964 set up with the hollow pipe holding the inner&outer joint together.
Conclusion
So…..what’s the overall conclusion was it worth the money? For me it was, the five bullet points above are enough for me. The car feels better but it's more of evolution than revolution. I have also done so many other things on my car so doing this also felt logical in a way. Especially since it was time to replace parts like ball joints, wheel bearings, ABS-sensors since all this was from 1992. Brake rotors are consumables.
Finally a reminder: Decide about the control arms and decide or check on what top mounts you have before you start so you do a correct budget.
I hope I’ve helped to clarify some things about this upgrade. Just ask or send me a PM if you want any additional info.
Thomas
But you before you start you should get the idea of why you should do this upgrade. First I’d say it is for you who track your cars. For street use only, it’s not worth the money. The benefits are, reduce of/no bumpsteer, lower weight, no adapter needed for bigger calipers, thicker dimensions – meaning stronger, and you can use 993TT floating rotors. Finally in my case I also got more track width meaning more grip, but I’ll come back to that. If you lower your car for track use all these things are good things, but again on the street it doesn’t matter. There’s also some confusing info, sometimes calling these parts GT2 or GT2 Evo parts. The uprights are from 993RS, and were used on GT2 so there are no GT2 uprights. There used to be GT2 tie rods though, but they are out of production so you now buy the 993RS version. I also assume you already have big red calipers otherwise a pair of those also goes into the parts list. The final list gets long!
Step 1, the part list:
• Uprights: 993-341-157-81 and 993-341-158-81
• Tie rods: 993-347-031-81 x 2
• Nut for tie rod: 999-084-449-09 x 2
• Rubber bellows, tie rods: 171-419-831C x 2
• Ball joint: 993-341-049-06 x 2
• Nut for ball joint: 999-084-449-09 x 2
• Knurled screw pressed into wishbone: 993-341-465-00 x 2
• Nut for knurled screw: 993-084-621-09 x 2
• Brake rotors 993TT: 993-351-046-10 and 993-351-045-10
• M12 for damper: 999-067-039-09 x 2
• M14 for damper: 999-072-006-01 x 2
• Captive nuts for damper: 993-343-156-00 x 2
• Hub nuts: 999-090-010-01 x 2
• Hub bolt: 900-082-123-01 x 2 (not needed but I wanted fresh parts)
• ABS-sensor: 993-606-404-00 x 2
• Wheel bearing: 999-053-041-04 x 2
• Screws holding the bearing: 999-217-042-09 x 8 (need longer than on 964)
• Side beams, if needed: 993-341-111-01 and 993-341-112-01
Step 2, mounting the parts:
There are some guides out there on how to do this so I won’t go through all the steps. These guides also have a lot of good picture so I just have a couple of pics to clarify the issues I had. The guide I used was this one http://www.jackals-forge.com/lotus/9...suprights.html . This is a big job and you need a press tool but it is also a pretty straight forward job to do if you have some knowledge of using spanners. Corroded bolts can be an issue depending on where you live but otherwise it’s more a question of bolting on and off parts.
First thing to decide before you order the pile of parts is how you want to do with your control arms. The ball joint for the upright uses a M12 bolt instead of M10 on the 964. This bolt is pressed into the control arm. You can do either of two things. If you have the money and want to spend more, buy a set of used control arms from a 993. Or, press out the bolt with a vise, drill a larger hole and press in the correct bolt. This is what I did and you can buy these bolts separately from Porsche, Pelican etc.
Next issue, but a smaller one, is that the 993 upright uses a M14 bolt instead of M12 for the lower fixing point on the damper. The 964 uses M12 for both holes. This means that you have to drill out 2 mm from the lower mounting hole on the damper. I have Bilstein RSR dampers on my car so the lower hole was already M14. I think KW dampers also already are made with a M14 hole.
The BIG issue No 1 I had though was the length of the tie rods. If you have a wide bodied car this isn’t an issue. But since this isn’t such a common upgrade on 964 NB cars this came as a bit of surprise to me. The rods are longer because the 993 has a wider track than the 964 and the RS and TT are even wider. Mounted on my car this meant that the rods bottomed out, so no there were no threads left for toe-adjustment. I ended up with a toe out setting! The 993 rods are also different, see pic, with just two parts instead of the 964 set up. I found the solution (I thought) from a guy on RL who had shortened the rods and then made new threads. I did this to with assistance from a friend.
Now the steering looked good, but now the BIG issue No 2 occurred, camber bottomed out at -1,3 (I used to run -3,0). Ant this was the real surprise. I’ve never heard of this problem before. After a lot of searching I finally found this thread on Pelican http://forums.pelicanparts.com/porsc...pension-2.html. This guy had the exact same problem with the tie rods and then with the camber, and his findings explains it all. Now, if you have the correct top mount (read lucky enough) you can get away with this and get the camber you need. But even though I have the factory RSR mounts which are adjustable I couldn’t get more than -1,3. Please note that you can’t use stock rubber top mounts, you need one of the aftermarket top mounts out there.
The only solution to fix this is to get the 993 longitudes or “side beams” (name used in PET). So I had to top up my parts list with another €250 and bought a used set of beams. This gave me the necessary 12,5 mm on each side. This is achieved because the mounting points on the 993 version are extended and curved so they push the control arms outwards. A very sublime difference and if you didn’t know you wouldn’t spot the difference. Luckily there was enough length left on the tie rods, with the now wider track.
The beams themselves are easy to replace. With these parts I can now adjust toe as I want and get -3,6 camber if I want to. So this is something to think about before you start. An option could be to move the side beams to the outer/WB position but increases the track width even more so your sway bar will be too short. Even with my set up the rubber stop on the sway bars are 12,5 mm off so I used a hose clamp as a spacer between the rubber and welded stop on the sway bar. But the NB sway bar still fits.
Finally, brake rotors. You have to use 993 rotors because the offset is different so there’s no cheaper way around this. But the flipside is that you can use the 993TT rotors which are a bit lighter than the 964 3,6T disc, with a floating hub at the same price or even cheaper.
Step 3, driving:
So finally, everything is mounted but was it worth the money? I’d say yes but it’s not a dramatic difference, just a little better. I run my car 3-4 mm below Euro RS spec and this is I my conclusion:
1. No bumpsteer - I can now drive on a curb, or if one of the front wheels passes over a bump or pot hole, the front end stays calm and in a straight line with only the suspension working up/down.
2. The wider track, 25 mm, gives more front end grip. I didn’t have any real problems with understeer before but it is even better know.
3. Steering is a bit easier if you have a manual rack as I do. The feel and force needed is more linear when turning the steering wheel. Before there was a “bump of resistance” passing the initial movement with the steering wheel going into to a turn. So the car is a bit easier to drive and requires less effort.
4. More stable under heavy breaking. The front end is calmer and more stable in the braking zone. You can more comfortably hold the steering wheel with one hand when shifting down, even in bumpy breaking zones. I could do this before to, but it feels even more planted now.
5. Ease of mind knowing that the parts are fresh and designed for more strength is a good feeling on the track. The tie rods for example are much stronger than the 964 set up with the hollow pipe holding the inner&outer joint together.
Conclusion
So…..what’s the overall conclusion was it worth the money? For me it was, the five bullet points above are enough for me. The car feels better but it's more of evolution than revolution. I have also done so many other things on my car so doing this also felt logical in a way. Especially since it was time to replace parts like ball joints, wheel bearings, ABS-sensors since all this was from 1992. Brake rotors are consumables.
Finally a reminder: Decide about the control arms and decide or check on what top mounts you have before you start so you do a correct budget.
I hope I’ve helped to clarify some things about this upgrade. Just ask or send me a PM if you want any additional info.
Thomas
The following users liked this post:
Schlyter (02-02-2021)
12-16-2014, 07:05 AM
#2
Thomas,
thank you very much for the review and detailed parts list!
I have this on my plans for the end of next year, and had been looking around what parts are needed.
I have KW topmounts, but they are not camber adjustable
, so I'll also require the side beams
thank you very much for the review and detailed parts list!
I have this on my plans for the end of next year, and had been looking around what parts are needed.
I have KW topmounts, but they are not camber adjustable
, so I'll also require the side beams
12-16-2014, 08:03 AM
#3
Drifting
Thread Starter
Yes, you probably do. But do this work when you have time. Then you could try first and buy the parts if you have to. But be prepared!
Thomas
Thomas
12-16-2014, 09:17 AM
#5
Nordschleife Master
Nice write up Thomas and glad you are pleased with the end result. I'll bet that list of parts ate up a few euro! Even though my 964 is mostly track these days I think I'll skip this one because I wouldn't see the benefit from the cost. By this I mean that I've realized that it's me as the driver which is the limiting factor in going any faster. So, such subtle changes to the handling wouldn't make any difference in my case. This was brought home to me when I realized I was still doing the same times round my favorite tracks as I was 2 years ago. Despite making significant weight reductions on the car in that period!
12-16-2014, 09:35 AM
#6
Drifting
Thread Starter
The cost is always depending one how you chose to do it. In this case I had the calipers and top mounts. Brake rotors are consumables. After 23 years it was time for wheel bearings, ball joint, ABS sensors, and outer tie rods. So left on the list are more or less the uprights and tie rods. This way the net-cost feels a little better :-)
Then I also had a contact in the US so I could get all the parts paying in USD without tax and shipping. And last year the SEK vs USD was better than today!
Thomas
Then I also had a contact in the US so I could get all the parts paying in USD without tax and shipping. And last year the SEK vs USD was better than today!
Thomas
12-16-2014, 11:07 AM
#7
Nice write up Thomas and glad you are pleased with the end result. I'll bet that list of parts ate up a few euro! Even though my 964 is mostly track these days I think I'll skip this one because I wouldn't see the benefit from the cost. By this I mean that I've realized that it's me as the driver which is the limiting factor in going any faster. So, such subtle changes to the handling wouldn't make any difference in my case. This was brought home to me when I realized I was still doing the same times round my favorite tracks as I was 2 years ago. Despite making significant weight reductions on the car in that period!
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12-16-2014, 11:21 AM
#8
Burning Brakes
Fantastic man maths justification!
I have been acquiring parts, little by little, for this mod, hopefully get it all sorted and installed early next year.
Great write up...
Cheers George
I have been acquiring parts, little by little, for this mod, hopefully get it all sorted and installed early next year.
Great write up...
Cheers George
12-16-2014, 02:28 PM
#10
Rennlist Member
Wonderful project Thomas! You've made your car even more awesome, if that was possible.
I also really admire the technical knowledge that led to this change.
I thought I was a 964 nut, but guys like you take it to a whole new level. Wow!
I also really admire the technical knowledge that led to this change.
I thought I was a 964 nut, but guys like you take it to a whole new level. Wow!
12-16-2014, 02:32 PM
#11
Nordschleife Master
The tie-rod length issue is not related to wide body vs narrow body track. The difference is the dimensions of the 993 longitudinal subframe members versus the 964 pieces.
Read through Perelets discussions and measurements in this thread.
http://forums.pelicanparts.com/porsc...pension-3.html
Read through Perelets discussions and measurements in this thread.
http://forums.pelicanparts.com/porsc...pension-3.html
12-17-2014, 02:50 AM
#13
Burning Brakes
Great write-up Thomas! Beside your descriptions of the install challenges, it was nice to have your objective analysis of the results. I'm right behind you with the side members - car goes in for alignment on Friday - and looking forward to comparing notes.
12-17-2014, 03:32 AM
#14
RL Technical Advisor
