The complete repair, rebuild, repaint, and v8 swap of my early model sedan

[The Dark Side of Will]

More of a project than I want to tackle at the moment. The Garagistic diff ear actually just bolts on. Should be like a 1/2 hour install. Doing the e36 diff cover would require swapping the speed sensor trigger wheel inside the diff, and fabricating a full new crossmember and mounting brackets, ensuring correct geometry.

The stock "crossmember" is basically tin foil and the Garagistic piece bolts to the trunk floor--across the edge of the crossmember to boot... Neither of those are great options.

[AndrewBird]

That Garagistic piece looks flimsy. I'd worry about the two diff cover bolts breaking. Plus did you watch the install video? One of the bolt hols is right on the curved edge of the spare tire well.

[JGood]

Well if anyone wants to volunteer to come back half my car for me, they are more than welcome.

It’s the same design as the factory mount, which is just sheet metal ears. If I replace the stock bushing, it should be fine, but I figured adding a second mount would help, given some people have broken the diff cover and/or torn the factory ears (me). I will not have the time in the foreseeable future to completely chop the rear end of the car for an e36 style mount, that’s not just a weekend project, so to me this is a good solution to be able to use the car.

[JGood]

So I got some 825lb, 4" length, 2.25" Eibach springs, and an Ireland Engineering rear perch kit. I really really like this kit, especially in comparison to my previous setup. The sleeve is machined to slip perfectly over the lower factory perch with no play, and the upper urethane hat fits the top perch perfectly. I did end up cutting the threaded sleeve down to avoid contact, since my car is fairly low.

The car no longer squats nearly as much, and the ride does not feel any harsher. If anything, it feels more closely matched to the front. And if you calculate the actual wheel rate for a 450f/825r setup, it comes out to about 395f/370r. Maybe not ideal for the track, but for a street car with a lot of torque, I think this is a really good setup.

I may ditch my UUC 19mm rear swaybar and replace it with a stock one, not sure yet.




The spring rate makes a big difference to static height, this is how I adjusted the 825lb IE setup to get me the same ride height as the 600lb GE setup.




Worked with Igor at CA Tuned, and ended up buying a new version of their upgraded axles to replace the stock axle I put back in after I broke the first CA Tuned axle a few weeks ago.






I found a cheap new 80a poly diff bushing in the classifieds, that should be here tomorrow. Going to put that in my spare 2.93 LSD and put that in the car in place of my current 3.25LSD, which I wanted to do anyway. Then I'm going to see how much diff movement there is with that setup. If it looks good, I'm just going to reinforce the diff mounting tabs and call it good, and hope the cover doesn't break.

[plain325]

I tossed a spare axle in, put a go pro under the trunk, and went for a drive. Got some interesting results!

https://www.youtube.com/watch?v=FAqoQipR4lM

Checkout how much the diff moves. I have the stock old diff bushing, and I did find a big crack where the ears come off of the body for the mount a few months back. I never realized it was moving that much.

I also didn't realize how much compression the suspension had under acceleration with those 650lb springs.


So, I just bought a set of 825lb 4" long 2.25" springs. I had to also order an IE rear 2.25" coilover sleeve kit, as my rear coilover setup was the GE group buy stuff, utilizing a custom spring. So the adjusters were 2.5", and there are no 4" long ~800lb 2.5" springs. Doh.

Also ordering the Garagistic 2nd diff mount. Haven't placed the order yet because I can't make up my mind on what diff mounts to get. I don't want a lot of noise, but I also don't want the bushing to deform and wear.

I read somewhere that the subframe moving around like that helps with antisquat. Unless your subframe mounts are solid or stiff urethane, the whole subframe is twisting along its axis, not just the diff.

[JGood]

I read somewhere that the subframe moving around like that helps with antisquat. Unless your subframe mounts are solid or stiff urethane, the whole subframe is twisting along its axis, not just the diff.

I have 85a poly subframe bushings. My diff bushing is actually torn, the inner rubber has separated from the outer race.

[moatilliatta]

Thanks guys. I went back and forth on fixing it, or getting a new car. Common sense tells me it's not a financially smart investment. Then I realized nothing about this car was "financially smart"... I bought it and modded it because I love the car, love driving it, and have become attached to it. This car brought me into the car scene, I've met so many great people over the past 10 years because of it. Some of my best friends, I met simply because of this car. I'm from a small town and pretty much anyone knows that this car = me. Sounds dumb, but it's true, and it means a lot to me. So I'm not ready to scrap it.

I haven't received a lot of positive reactions when I show people the damage and tell them I'm going to fix it, so it definitely helps to have some cheering on here!

Just read through the whole thread. Glad you're keeping it alive!

I remember seeing pictures of when the paint was completed, but never seen this thread.
Cool to see the mods slowly supporting the power. Adjustable subframe I think is the best upgrade to an E30.

[JGood]

I killed my TRE fuel pump tonight. It was brand new when I put it in 3 weeks ago. The in tank pump is still working, so I'm baffled. The in tank pump screen is clean, the external filter is new, the fuel looks crystal clear.

Symptoms are the same as each time the external pump fails. It starts making a lot of noise (cavitation), it starts cutting out, and within a few minutes it just stops pumping all together. Let it cool down for an hour or two, and it's good to go for another 1/2 hour or so.

I'm done dealing with it. I ordered a Walboro 255, and am doing the 318is pump conversion.

[JGood]

Well, turns out my in-tank pump was dead. I thought I heard it turn off when I unplugged it with the car running... turns out, the load of the seized motor was just bogging down the other pump since they share the circuit. So when I unplugged it, the sound changed, and that's what I assumed was the in tank pump turning on and off. Doh.

I gave it a few taps on the work bench with it plugged in to a battery, and it fired right up. Put it in the car and went for a drive, everything seems fine.


That said, I know I'm on borrowed time with both pumps, so the 318is pump conversion will still happen as soon as the Walboro arrives. The in-tank pump is an Airtex Vega pump, and I got a good year and ~5k miles out of it, not bad for $30 haha. The TRE external pump sacrificed a good portion of it's life span, as it cavitated to the point where it fully cut out. It's quiet now, but who knows when it will die.

[JGood]

Figured I'd cross post this here, as it's relevant to my ongoing fuel clusterfuck.

A really good seminar on fuel systems.

https://www.r3vlimited.com/board/showthread.php?t=425275

[slum dog]

I really enjoy coming to your thread every time its updated. Especially when things break, parts fail it really helps us " Me" understand the M6x motor swap better. All the stress the e30 chassis and stock components can take it's amazing. Looking forward to future updates...

[JGood]

There's rain in the forecast for the next two weeks, so I decided to dig into the diff and fuel pump conversion. I pulled the exhaust, heat shields, driveshaft, diff, and fuel tank last night.

I have a spare 2.93 LSD that was VERY rusty. Last week I cleaned it up as best as I could, and painted it. Also put in an 80A poly bushing. I decided to cut some M12x1.5 bolts I had laying around and install them as studs into the diff. Hopefully that works out.





The whole point in dropping the tank was to remove the 12mm low pressure fuel line and replace it with a new 8mm high pressure hose, for my single pump conversion. I was under the impression that there was a 12mm hard line attached to the tank. Turns out, it's just the soft line the whole way across, just laying there, and you can literally just pull it right out. Knowing that, I could have simply connected my new 8mm line to the end of it with a barb at the fuel pump access hole, and pulled it out from the side underneath the car. I wouldn't have had to pull the exhaust, heat shields, driveshaft, and drop the tank, etc... Doh.







No Rust!







Some shots of under the car where the tank sits. Gazelle Beige! Ah, the memories. This is actually the first time I've had the tank out. I think the only other part that hasn't been removed from the chassis yet is the e-brake cables. Look how nice and clean the metal fuel tank breather line is. That thing is 33 years old and has seen 340k miles in Northeast snowy, salty winters.












Tonight I'll get the Walbro installed in the 318is hanger and weld up/reinforce the chassis where it cracked at the diff mounting tabs. Then I can reassemble everything later this week/weekend.

[alistairolsen]

For those not in the know, what is different about the 318is fuel system?

Thanks

[JGood]

For those not in the know, what is different about the 318is fuel system?

Thanks

There's 3 different types of fuel pump/tank setups in e30's:

-Early model, (up to 87 IIRC), and M3: Dual pump. One in-tank, low pressure/high volume pump feeding an external high pressure pump. In-tank pump has a 12mm output and an 8mm return from the fuel rail. External pump has a 12mm inlet, 8mm outlet.

-Late model (but not m42 cars): Single in-tank high pressure pump. 8mm output only on the pump, return from the rail is built into the tank itself.

-m42 cars: Single in-tank high pressure pump. 8mm output and 8mm return from the rail.

My goal was to have a single in tank high pressure pump on my early model dual-pump car.

You can't (safely) put a high pressure pump on the stock early model in-tank hanger because the 12mm output line is not high pressure, the chassis line is 8mm so you'd need to adapt it there, and also most high pressure pumps are 5/16" (8mm) outlet so you'd need to adapt it there as well.

You can't put a later model pump in because it doesn't have the necessary return line.

You can use the m42 pump because it has the proper return and an 8mm output. You just run a new 8mm hose the hole way to the chassis line. And an aftermarket in tank pump goes right onto the hanger.

That said, I think a stock m42 fuel pump flows enough to support an N/A m60. I know a few people did m6x swaps in 318is without swapping pumps, and I read somewhere that someone was supporting a S/C s52 with a stock 318is pump as well. They are about $250 though. I bought a used pump for like $30 and am putting an $80 Walbro on it.

[JGood]

Early (12mm output, 8mm return):



m42 (8mm output, 8mm return):



Late model (8mm output, no return)