It looked so simple at first!

[GySgtFrank]

In the shop. I'm not that fancy.

Yeah, housing prices in Kansas are a LOT cheaper than Va, or much of anywhere else I've seen, which is why I moved here. I got sick of competing in the rat race. That and most folks here are pretty nice people.

[GySgtFrank]

No picture update. Waiting on parts and figure I've already posted plenty of pictures of it torn apart, you can go look at those if you want.

This may get lengthy, go get a drink. I know I need one.

Sharing what didn't work out as planned is probably the most useful part of showing your builds. Most people kind of gloss over the problems, understandable, but it doesn't help others to avoid pitfalls.

Well the 275s still aren't working out as planned. If you use that wide of a tire with the stock axle width you will need about a +50 offset (Mine are +42), even with the shorter GSL axles vice the SE axles. (SE axles would be even worse) This is under the assumption that you want a working suspension and setting it up rock hard is not acceptable.

Alternatively fender flares and cutting of the fenders would be necessary. The problem is where the rear fender curves inward behind the wheel centerline. As the suspension cycles the tire hits in this spot if not tucked in quite a bit. I refuse to go with flares because I'm not very bright.

I haven't given up on the 275s though. The next plan of attack, (I do believe we're on plan U or plan V by now), is to modify the Moser axles. I talked with the guys at Moser about my little problem. Good bunch of guys and very helpful. I decided to send the axles back and have the seat for the bearing machined 1/2 inch further out and shorten the axle the 1/2 inch to compensate. With the discs, I have about an inch of room to play with between the flange and the bearing retaining plate. I'm modifying the brake brackets again to pull the caliper in the 1/2 inch also.

This should pull the wheel in an extra 1/2 inch and allow me to run wheels with a reasonable offset. Wide +50 and over wheels are scarce and pricey. Hopefully it works this time. It looks like it should, but I've said that before.

Another thing that I've had to rethink is spring seats and bump stops. The springs weren't very well secured and could possibly even fall out if the back of the car launched into the air from doing something stupid. Solution was to use the stock rubber portion of the SA bump stop on the top spring seat. Also weld the steel cone portion of the bump stop (it was removed from the floorpan when I did the upper spring seats) onto the axle spring seat. They both fit perfectly inside the Mustang springs. I'll be screwing a 1" bump stop from a Toyota on top of the cone portion when I get them.

This accomplishes two things. It keeps me from being severely embarrassed by having my springs fall out and provides a bump stop that will move as I adjust the suspension.

Also had to cut the over the axle portion of the driver's exhaust pipe off and redo it again #$%^&. I just HAD to have true duals . I was still having interference problems with the axle when it came up to the top of axle movement. I do believe I got it this time. The bracing for the G-Force panhard bar makes pipe routing a real pain in the a** and you can't get a normal muffler shop to do the work.

The pipe on both sides has to follow the floor pan pretty closely or the axle will hit. (Not much room left in there on a 1stgen when the axle is at the top of it's travel.) This requires removal of all the extraneous Watts link mounts and other BS in the way. Also had to move the brake line junction over about 6 inches and redo the brake lines as it was too close to the exhaust as well.

Currently putting in the exhaust supports, now that I have all the little problems ironed out. I'll eventually redo the over axle portion in mandrel bent SS, but this has to do for now.

Will post pictures when I get some parts back. If I haven't been committed before then.

[GySgtFrank]

Since I'm stuck until a few more parts get here, I figured that I may as well post up a few of the pictures I referred to above.

This is the stock bump stop adapted to fit my top spring perch. Fit almost perfectly.


bump stop_upper by GySgtFrank, on Flickr

Had to space my caliper brackets another 1/2 inch to accommodate moving the discs back that amount, made up a spacer using 1/2 X 1 inch bar and modified the rear anti-moan brackets.


caliper bracket 1 by GySgtFrank, on Flickr


caliper bracket 2 by GySgtFrank, on Flickr

Used the stock spring seat from the chassis to form a more secure lower seat on the axle. It will also allow me to put an adjustable 1 inch bump stop on top. This way my bump stop will always follow any spring height adjustments I make. The original seat probably would have worked, but I was a little concerned with the short springs I am using and I needed bump stops anyway.


lower spring seat by GySgtFrank, on Flickr

Also put in exhaust hangers and finished redoing the rear axle brake lines when I moved the T block.

Still waiting on axles, the other bump stops, and some limiting straps with clevis' and mounts. There is no bind left in the suspension so I need something to keep it from dropping too far and breaking the shocks.

[GySgtFrank]

Now that I finally have internet back, time for a few updates. Where was I? Oh yeah.

As I was saying, I had a few problems out back. I got the axles and everything reinstalled, took it out for testing. Found out I have clearance issues with the driveshaft, also with the tires running this close to the fenders even the little bit of side-to-side movement induced by the panhard rod was causing a rubbing problem on the fenders.


floor pan mod ver. 2 by GySgtFrank, on Flickr

Re-modified the floor pan for more clearance at the back. Come to find out the factory did not have the axle centered for a reason. They moved it slightly to the drivers side (approx. 1-2 inches) to accomodate more floorpan indentation on the passenger side. No doubt because some ga-genius in marketing thought that worrying about rear seat hip room for the JDM market was actually important.

Also modified my transmission mount to drop it downward again by about 2 inches. This caused more driveline angle than I want, but I plan to also drop the engine in the chassis enough to bring the driveline angle into spec. (Also lowering the car's center of gravity ) Basically what I have is a severely lowered suspension, except that the larger tires don't actually bring it any lower. Which is why so much was required to gain suspension travel and clearance above what the factory provides. We'll see if it's enough. I have a little over 3 maybe four inches of upward travel and 6 downward. I can make more room, but then I get back into tire clearance issues.

Fabricated a Watts link to replace the panhard bar. Which keeps the tires centered without that nasty side-to-side movement. I used the factory center pivot, modified it so the arms are in the same movement center and reinforced it. Also used the existing G-Force panhard mount (with a few modifications) to mount the lower of the link arms.


Watts center link by GySgtFrank, on Flickr

Center mount fabbed and welded in.


Watts link by GySgtFrank, on Flickr

Watts link installed.

I also got the suspension travel limiting straps in, which was a bigger pain than they look due to limited space.


limiting strap by GySgtFrank, on Flickr

The bump stops also came in and were installed. For some reason the passenger side has an inch more travel than the driver's side when the car was leveled. Not quite sure why as the spring mounts are identical copies of each other on each side. Only thing I can figure is that the passenger side frame rail was an inch higher throwing my measurements off. No picture of this as it's just a 2 inch urethane button on top of the cones. Well a spacer too on the passenger side.

Pictures are of the rear wheel fitment with the half inch taken out of the axles. ( Actually the axles could have easily been modified for another quarter of an inch, but I didn't want to get carried away. )


rear wheel fitment 2 ver. 2 by GySgtFrank, on Flickr


rear wheel fitment 1 ver.2 by GySgtFrank, on Flickr

Then moved to the front suspension. Pulled the engine and transmission as well as the front suspension to get to work.


looking forlorn by GySgtFrank, on Flickr

I modified the K member and did the initial fit to find out what I had to do to make this pig work. My poor protractor, tape measure, ruler/square, and calipers are getting one hell of a workout with all the measuring and re-measuring I've had to do.


K-member 1st fit by GySgtFrank, on Flickr

I went ahead and replaced both front frame rails with 2X2 inch 1/8 inch tubing located above the old rails. Then removed the old rails. This gives me more clearance for the long A arms and strengthens the front frame area, which the rally guys say is a weak spot on these cars. Also cut the steering shaft at the box and removed it as I will be adapting it to the Ford rack and pinion.


new frame rails 1 by GySgtFrank, on Flickr


new frame rails 2 by GySgtFrank, on Flickr

Currently I have a little more reinforcement to do in the frame boxed area and then refit the K member. It looks like I'll need to move the A arm mounting points in about two and a quarter inches to get the tires tucked in where I want them. Happy Days, having more fun than a barrel of monkeys.

[infernosg]

Living up to the thread title I see. Excellent work! I really want to get into serious chassis modification at some point but I need to focus on getting the car running for a bit first.

[Whizbang]

so what made you go with the wonky mustang front suspension over something simplier yet likely as effective, (FC subframe)

[GySgtFrank]

Originally Posted by Whizbang

so what made you go with the wonky mustang front suspension over something simplier yet likely as effective, (FC subframe)

Ummm... I had it at hand? Actually the way it's set up by Kenny Brown it should be more effective geometry wise than the FC subframe, as well as lighter, and allow me to use the larger spindles, bearings and brakes from the SN-95 Cobra R. I also plan to convert it to an SLA (Short Long Arm) unequal length arm suspension and this will make that easier. Severe overkill for an RX-7 I know, but I've never been accused of being particularly smart. An alternate suspension solution became necessary after having vendor problems and unable to get parts that I needed.

As to the question of Why? Are you insane? Short answer.. yes. One of the questions always asked by 1st genners is how much tire can I fit under the stock sheet metal?, and what would I have to do to fit really big rubber under there? Granted, the question is usually asked by someone that's new to 1st Gens (still a legit question). The standard pat answer is, You can't.

Challenge accepted.

I have had to cheat a bit in the back with the tubs, but the outer sheet metal is still stock. I may end up losing this personal challenge, but I'll give it a good shot anyhow.

[GySgtFrank]

As to the naysayers not liking 17s on a first gen. I understand, buuut....


new brakes by GySgtFrank, on Flickr

They're kind of necessary. Original SA discs on right, new 13" Cobra R discs on left.

[WE3RX7]

What a small caliper for 13" rotors...

[GySgtFrank]

Originally Posted by WE3RX7

What a small caliper for 13" rotors...

It should do the job in a 2300 pound car. Upgrades are easy if needed. Everybody makes go fast parts for Mustangs to satisfy us dumb rednecks.

[GySgtFrank]

Small update. It has been slow going lately, ran out of funds to buy needed parts , so trying to drag it out a little to keep me occupied. K member has been fitted, modified, refitted, measured, torn down, etc. so many times that I'm unsure what I started with at this point.

I ended up moving the A arm mounting points inward 1.5" on either side narrowing the track to approximately what it was stock. The pictures are the final? positioning where the tires are going to sit. Ride height should be close, but I'll have to see when I get further along.

I have to order the pieces to convert the MacPherson Strut Mustang spindle to accept upper ball joints. Also need to order the adjustable upper A arms and get it all fitted.

At that point I can start looking for coil over shocks for the front and see what kind of trimming on the inside of the wheel wells I'm going to need so the wheels will turn fully lock-to-lock without hitting.


front tire 1 by GySgtFrank, on Flickr


front tire 2 by GySgtFrank, on Flickr


front+rear sideview by GySgtFrank, on Flickr

I would like to go to a 245/40 17 on the front. Once I get the upper arms in and back on the ground I'll have to do some more measuring.

[GySgtFrank]

Got the spindle adapters ordered today. (stole the pics from Griggs Racing).

Might have to rob a bank to afford the rest of it though.

[chibikougan]

Bling!

[scarsofcarma]

Props to you cool build I'm guessing you've owned a mustang or two in your day?

[GySgtFrank]

Originally Posted by scarsofcarma

Props to you cool build I'm guessing you've owned a mustang or two in your day?

Just a few. Boxes of brand new spare parts needed a new home and the RX7 needed suspension and brakes. Match made in heaven, or , maybe someplace considerably lower.