How to Clearance your Front End for Bulky Aftermarket FUCA's

I picked up my long awaited UAS V2 arms last week. In order to run any thicker after market FUCA I had to make sure I had the travel available in the front end.

Here's the issue: The FUCA needs to clear the bracket it uses to mount to the chassis. Many aftermarket FUCA's I've seen including mine do not account for this in their design and on lowered Z32's, this happens:



Photo taken from here: http://www.aus300zx.com/forum/showthread.php?t=315668&highlight=stillen+fuca

The mark on the bracket where the FUCA has been striking it is visible. This is why some after market FUCA's snap. This is a guide on how to gain more clearance for the FUCA so bulky aftermarket adjustables can be run on lowered Z32s. I know there are options out there that are designed with bracket clearance in mind, but if you've already got aftermarket adjustables and would prefer not to change them this is what is necessary. In the case of Powertrix FUCA's designed for additional bracket clearance, contact is still possible at very lowered ride height. In my case UAS V2 arms are the only FUCA's on the market that allow the arm to pivot, so in my eyes it's them or nothing. For reference the UAS V2 arms are 40mm thick, other arms with locking collars are even wider.

First step was to trim the bracket the FUCA uses to bolt to the chassis. The aim for me with my heavily lowered Z32 was for the hub side of the FUCA to be able to swing all the way to the underside of the engine bay without fouling. Remove the bracket from the car, fit the arm to it, size up where it hits and go at it. I used an angle grinder with a grinding disc but I suppose a bench grinder would be able to do the job too.

First test fit:



Trimming the bracket is probably enough for most but far from enough for the arm to travel to the bay. The next binding component which had to be dealt with was is the 17mm nut/bolt that bolts the bracket to the chassis.



Remove the bracket from the car and give one of the bolts a hard knock with a hammer. They're attached together to a flat bracket and to the engine bay with a plastic screw.





Insert the bolts back in from the fender well for more instant clearance. The flat side of the bracket is much lower in profile than the bolt/nut. This means the two top bolts holding the bracket to the body now do up from the engine bay. Tightening up these bolts did pull the paint under them from the bay, so if that's a concern a plate going between the two nuts may be something to think about. I did the nuts up very hard and the tower didn't dent/collapse at all without the plate to spread the load.





On the driver's side removing this bracket means unbolting the brake master cylinder - simply undoing the two 12mm nuts holding it to the booster and moving it away (flexing the lines) to give the bracket space to lift out. No fluid comes loose in this operation. One of the bolts will need a 2-3mm trim off of the end of it to clear the brake master cylinder (shown here with a 1mm trim, still touching but master cylinder bolted up correctly).



Unfortunately if you're still chasing more travel, even the bolt bracket fouls. I took a grinder to it as well.



Going together for the next test fit. Get the car on stands, take the shock out and disconnect the sway bar then jack up the rotor. Once the rotor's up as far as it'll go slip a strip of paper around the arm to find the bind. Be careful not to raise the rotor too high as the whole car will start to lift through the arm.





Next thing to bind was the chassis behind the bracket. I was very hesitant about trimming this however I found that I didn't cut through to hollow; it was completely solid where necessary. Weight off my shoulders with that one.

Picture taken after a few days with some surface rust, haha.





It is important to test fit by jacking up the rotor, not just swinging the arm up. Interestingly the last thing that needed trimming before the arm could travel all the way to the bay was the upright. Some metal protruding past the edge of the upright past the weld (completely non-structural of course) as well as a small (1mm or so) dip into the middle of the inner side. I'd hate to see how much would have to be taken out of the upright for locking collars to clear it :|



With that, the arm now jacks all the way to the underside of the engine bay without fouling. Looks a little hack and slash I know, but once everything was trimmed up it all received a coat of paint to prevent rust (very important!) and ended up looking better than when I started.



Remember, most cars won't need to be trimmed to this extent. I took it all the way because I want the peace of mind that even at my ride height, the arms won't be getting damaged. The components still feel as strong as ever. Out of interest a small bit of trivia is that 50 grams was removed from each bracket - from 710 to 660 grams per side.

At the moment my buddy is borrowing my BMC brace, so I'll update this thread in a few days when I've had the opportunity to chuck it back on and check for any potential fouling on the new nut/bolt location.

Very happy with how it turned out! Questions or comments, shoot.

-A

 

Very well written and documented, I like I like I like.

 

I hope I'm wrong for your sake, but are you sure you have the arms the right way around? With other aftermarket arms the adjustable section is suppose to be closer to the springs.

 

Thanks dude!

Nope Jono, arm body is offset to further clear the spring.

 

yeah the arms supposed to go the other way so its in the centre of the bolts.
gives main body arm clearance to bolts

plenty of spring clearance

this is when I had version 1's

 

Hmm, interesting. That's not they way I was told to install aftermarket FUCA's. For the arm to go all the way to the bay both would require flipping the bracket/trimming it, so no harm done either way. Good for those that don't need as much clearance as I do, and should give a bit more clearance on the upright side. If this goes to the tech section I'll add that in.

 

The offset is for clearance of the bolts otherwise they would be designed with main body in the centre..so you don't need to reverse the bolts like you did.

But good work

I slightly notched my brackets even though they have been modified and moved up 15mm ..just as safety precaution.

 

I doubt once the bracket was trimmed the arm would make it to the bay without hitting the bolts, even if it was the other way 'round.

 

Actually come to think of it there is no backwards. You reckon it's offset to clear the bolts but if unless you've cut out the bracket it doesn't even come close to the bolts. What's the logic there - instead of making the arm kinked/thinner to clear the chassis the middle section was offset so once the first section of the chassis side was cut out, the arm wouldn't foul as easily on the second? I don't think so

Check Dean's install as well, it's the same. Arm stays where it is for further spring clearance. Easier to get in there and adjust them both like that.

Like I said Ryan, needs a 2-3mm trim and in the pic mine only has a 1mm trim.

 

The center section is offset so the arms can also suit R32 GTR, on a Zed it makes no difference which way around they are as long as the inner/outer are in line. The adjusting end needs to be closer to the bracket to be accessed on the car though.

By trimming the chassis where you have the factory spot welds haven't been cut out, stronger than if it was trimmed in the middle although it's not much of a difference bolted together.

 

If you are notching out the bracket for further clearance it does matter as it can hit the bolt/nut.

Anti has reversed his bolts which isn't necessary to do IF installed the correct way.

why have it offset close to the bolt when putting it the other way puts it in the centre of the 2 bolts .

 

Could be right. We would have to try it and see, it still may hit the nuts before full travel.

 

cleverly done Anti.

One of those things ill never do (cause i wont go that low) but certainly shows another way of thinking, and getting around a issue.

 

Anti's picture here (shows that if he follows BB suggestion of using the offset of the T to swing up between the bolts he would not have to notch toward one of the bolts, he would be notching between the bolts)

 

I still think it would foul on the nuts. I'd like to give it a shot though, if anything to complete the guide.

 

Stop thinking .

Mine is this way and doesn't

 

Anti, your photos are excellent.
Your guide is excellent, clearly showing that grinding that section was necessary.
It would be an even better guide if the bit that you grind out is between the bolt heads or if you fit them the other way, between the nuts.
You may have provided enough info for the manufacturer to redesign their bracket to exclude that section of metal and achieve more clearance.

 

Thank you. I have some spare brackets/bolts, so I'll give it a go if I get bored.

I got my CZP brake master cylinder brace back from my mooch friend, it doesn't foul on the nuts - fits fine.

Yes but your bracket is raised

 

you still wont hit anything with a notch in the centre at full suspension travel .


Also saves someone else reversing the bolts to the engine bay for no reason.

UAS arms should be a slight notch in the centre of the bracket.


At least do it and prove me wrong