FC Subframe Swap - Observations/Thoughts
02-06-15, 07:58 PM
#77
Hardcore Rx7 *****
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Ey8s,
First off, my hat's off to you for a very good job so far on this project. I also am a long time lurker of this forum and have been ever-so-slowly working towards getting to this point with my latest FB. The time is getting near for me now and for the longest time I figured I had nothing to worry about once I got to this point in my FB because RE-Speed was around and I knew they made the rack and pinion conversion kit. Now that the time is getting near for me, turns out they are practically not around anymore or I just don't feel comfortable enough to go drop some money and wait indefinitely for a fantasy part that may not come(that figures!). So, I'm back to square one with my car. My first FB I got to build into an awesome car but one thing that always bothered me was how loose the steering was. I replaced the stock rack, tightened it, replaced bushings, etc. but for me it was still scary to work with at over 100 mph! Anyways, as I get ready to start over with this other car, I want to face this monster now instead of later. After reading this great thread you have going I have a couple of questions/observations:
1)Why were you interested in swapping to the FC crossmember in the first place? You're putting a V8 in there so easier mounting of an S4/S5 engine couldn't be the reason, there are also universal kits available out there so that one can add a rack to most cars out there, and with FB suspension components and available upgrades for the FB setup you could get close to the same results if not the same/better as with FC components.
2)Instead of doing all that work on the shock towers, couldn't you have just ground off the lower control arm mounts and moved them back an 1 1/2" to satisfy the FB caster angle and just used the FB springs and pillow mount to make it all work?
No disrespect with my questions. Again, it is just that I'm getting close to having to deal with this myself and I'm not as good a welder as you are and so the less I have to do...the better! Again Awesome work!
First off, my hat's off to you for a very good job so far on this project. I also am a long time lurker of this forum and have been ever-so-slowly working towards getting to this point with my latest FB. The time is getting near for me now and for the longest time I figured I had nothing to worry about once I got to this point in my FB because RE-Speed was around and I knew they made the rack and pinion conversion kit. Now that the time is getting near for me, turns out they are practically not around anymore or I just don't feel comfortable enough to go drop some money and wait indefinitely for a fantasy part that may not come(that figures!). So, I'm back to square one with my car. My first FB I got to build into an awesome car but one thing that always bothered me was how loose the steering was. I replaced the stock rack, tightened it, replaced bushings, etc. but for me it was still scary to work with at over 100 mph! Anyways, as I get ready to start over with this other car, I want to face this monster now instead of later. After reading this great thread you have going I have a couple of questions/observations:
1)Why were you interested in swapping to the FC crossmember in the first place? You're putting a V8 in there so easier mounting of an S4/S5 engine couldn't be the reason, there are also universal kits available out there so that one can add a rack to most cars out there, and with FB suspension components and available upgrades for the FB setup you could get close to the same results if not the same/better as with FC components.
2)Instead of doing all that work on the shock towers, couldn't you have just ground off the lower control arm mounts and moved them back an 1 1/2" to satisfy the FB caster angle and just used the FB springs and pillow mount to make it all work?
No disrespect with my questions. Again, it is just that I'm getting close to having to deal with this myself and I'm not as good a welder as you are and so the less I have to do...the better! Again Awesome work!
02-07-15, 06:04 PM
#78
Hardcore Rx7 *****
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Ok so,
After "sleeping" on it, I realize the predicament with my suggestion. The lower control arm has TWO mounting points to the crossmember which makes moving the arm back on the subframe a bit more difficult. Not only that but I also realize that moving only the arm back on the subframe ALONE, would make things much worse by taking away even more caster!!! ARGH! back to the drawing board....lol!
After "sleeping" on it, I realize the predicament with my suggestion. The lower control arm has TWO mounting points to the crossmember which makes moving the arm back on the subframe a bit more difficult. Not only that but I also realize that moving only the arm back on the subframe ALONE, would make things much worse by taking away even more caster!!! ARGH! back to the drawing board....lol!
08-01-17, 03:20 PM
#79
Whoa...Escort strut tops? After reading that I did some searching and found that you guys are referring to ZX2/Escort strut tops.
Does anyone have a comparison picture between those and FC strut tops? I did some Google image searching but didn't come up with any thing definitive but it appears that they locate the strut/spring much higher than FC strut tops, which move it down about 2" (compared to SA/FB mounts tops).
Because if the Escort top moves the strut/spring assembly up, then it may save me the trouble of raising the top of the shock towers on my Cosmo.
Does anyone have a comparison picture between those and FC strut tops? I did some Google image searching but didn't come up with any thing definitive but it appears that they locate the strut/spring much higher than FC strut tops, which move it down about 2" (compared to SA/FB mounts tops).
Because if the Escort top moves the strut/spring assembly up, then it may save me the trouble of raising the top of the shock towers on my Cosmo.
Do we have confirmation the escort strut tops work? I am doing this swap now and wanted to check in before I order a pair.
I have been using slotted strut tower bolt holes to help with camber. I was considering camber plates, but then I would need camber plates that have FB strut tower pattern and FC strut top diameter...
Need to make some decisions
08-02-17, 01:28 AM
#80
Banned. I got OWNED!!!
Bringing up old thread:
Do we have confirmation the escort strut tops work? I am doing this swap now and wanted to check in before I order a pair.
I have been using slotted strut tower bolt holes to help with camber. I was considering camber plates, but then I would need camber plates that have FB strut tower pattern and FC strut top diameter...
Need to make some decisions
Do we have confirmation the escort strut tops work? I am doing this swap now and wanted to check in before I order a pair.
I have been using slotted strut tower bolt holes to help with camber. I was considering camber plates, but then I would need camber plates that have FB strut tower pattern and FC strut top diameter...
Need to make some decisions
FC KSport Coilovers + FB Camber/Caster Plates from my buddy Robert @ MillProMachining in San Jose, CA.
Works flawlessly with a low profile 12pt aerospace grade top nut due to short thread penetration on top. The bigger issue with the FC Front Subframe is knowing how to tie it into the car properly and making it STRONGER than the FB unit or the FC unit in the FC. There's no point in doing this stuff if you aren't upgrading chassis torsional rigidity in the process so you can actually enjoy this without dying.
Last edited by RGHTBrainDesign; 08-02-17 at 01:31 AM.
08-02-17, 01:56 AM
#81
www.AusRotary.com
I made a set of spacers for mine. Used FB Top Hats and spaced my FC Coilovers to fit onto those.
FC KSport Coilovers + FB Camber/Caster Plates from my buddy Robert @ MillProMachining in San Jose, CA.
Works flawlessly with a low profile 12pt aerospace grade top nut due to short thread penetration on top. The bigger issue with the FC Front Subframe is knowing how to tie it into the car properly and making it STRONGER than the FB unit or the FC unit in the FC. There's no point in doing this stuff if you aren't upgrading chassis torsional rigidity in the process so you can actually enjoy this without dying.
FC KSport Coilovers + FB Camber/Caster Plates from my buddy Robert @ MillProMachining in San Jose, CA.
Works flawlessly with a low profile 12pt aerospace grade top nut due to short thread penetration on top. The bigger issue with the FC Front Subframe is knowing how to tie it into the car properly and making it STRONGER than the FB unit or the FC unit in the FC. There's no point in doing this stuff if you aren't upgrading chassis torsional rigidity in the process so you can actually enjoy this without dying.
08-02-17, 08:53 AM
#82
I made a set of spacers for mine. Used FB Top Hats and spaced my FC Coilovers to fit onto those.
FC KSport Coilovers + FB Camber/Caster Plates from my buddy Robert @ MillProMachining in San Jose, CA.
Works flawlessly with a low profile 12pt aerospace grade top nut due to short thread penetration on top. The bigger issue with the FC Front Subframe is knowing how to tie it into the car properly and making it STRONGER than the FB unit or the FC unit in the FC. There's no point in doing this stuff if you aren't upgrading chassis torsional rigidity in the process so you can actually enjoy this without dying.
FC KSport Coilovers + FB Camber/Caster Plates from my buddy Robert @ MillProMachining in San Jose, CA.
Works flawlessly with a low profile 12pt aerospace grade top nut due to short thread penetration on top. The bigger issue with the FC Front Subframe is knowing how to tie it into the car properly and making it STRONGER than the FB unit or the FC unit in the FC. There's no point in doing this stuff if you aren't upgrading chassis torsional rigidity in the process so you can actually enjoy this without dying.
I have the subframe partially mounted, just need to get my buddy to weld rear brackets to mount it to the old steering bolt holes.
I guess I am going to have to mock this thing up because I am just not sure what is need to get an FC strut mounted.
As an aside, I can't see how torsional rigidity would be negatively impacted with this swap? I mean a strut tower brace has been on my agenda for awhile but not sure what it has to do specifically with FC subframe swap.
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Jeff20B
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