1988 325is swap attempt

[Stvstr]

I've always loved the e30's as well as various japanese sports cars, and have owned a 325iC, 2 miatas, and a celica. I now have a supercharged '94 miata and an '88 325is, but in November 2012 I bought some American torque:

I loved the 5.0 torque and sound, and was surprised how much I liked the T5 shifting with the aftermarket short shifter, considering my benchmark is a Miata shifter. But the chassis and interior was so disappointing I got tired of it by March 2013. So I looked at Monster Miata swaps and the RX7 swaps on Norotors.com, and while doing that stumbled onto E30V8.com, and started making plans and gathering parts last April. I bought a one owner 88 325is auto at the same time:


It's in great shape with 244000 km and even with the auto was a nice car. So hopefully I won't ruin it by doing this:


I drove the 325 until July 2013 while I pulled the drivetrain out of the Mustang and sold what was left to a dragracer. While still driving the 325 I got the e30v8 swap parts and started prepping the 5.0 for the swap. The first minor problem I had was the oilpan wouldn't seat all of the way on the gasket - it sat about 1/4" below on one side, even after bending the oil pickup to fit. It took me awhile to discover it was the dipstick tube, so cut it and the dipstick down to fit and then all was fine. My lack of experience with wrenching and swaps hit me pretty early in this process, but hopefully I will learn as it moves on.

Then I read the e30v8 manual and didn't like the wilwood clutch setup detailed in the manual, so after some research bought an e30 manual pedal box and master cylinder at an autowrecker and fabbed up a slave bracket:


The slave in the picture is the Nissan one reccomended in a few build threads. It's inlet and bleeder are hard to reach once installed, so I have since replaced it with an 80's Nissan truck slave (Dorman CS37498) with a 3/4" bore and a rear facing inlet and bleeder.

In July I parked the 325 in the garage and started pulling out the M20 and wondered if I would be ruining a nice car. Also, I carefully measured the ride height to see if it would sit lower with the new motor, as I don't have any easy way to measure the weight of the car before and after swapping.

[e30_302]

Rock on. Take your time and do it right the first time.

[Stvstr]

Continuing on in the sequence of my swap, I spent July through October dealing with the details , mostly following the e30V8 manual. The heater hoses were a pain but ended up with enough clearance to work. I also installed the Massive booster delete.

Because my car started as an auto, I got as new pedal box assembly with master cylinder at a wrecker and hooked it up. I didn't like the idea of using the wilwood pedal/master/slave combo, so stuck with the e30 stuff so it looks more original.

Also used the e30 throttle pedal to keep the interior looking more stock. I modified the throttle assembly to accept the 5.0 throttle cable:

It's not perfect as the cable is a bit too short and will probably have to refine this in the future. Works fine now, but don't totally trust it won't bind or wear quickly because of the tight bends.

In order to get the BMW temp sensor into the adapter recommended by e30V8, I re-threaded the brass adapter by forcing a 14mm bolt into it. Working it back and forth with a bit of grease made for a cheap tap and it allows the temp sensor to thread in normally.


Because I intended to have rear-facing exhaust, I needed more steering linkage clearance near the firewall. I combined the upper part of an e46 steering shaft with the e30 shaft to end up with a shaft that comes apart in the middle, so you can remove it without dropping the rack. I don't recommend this solution as it won't collapse in a collision like the stock designs do, but safety wasn't the main goal of this project.


I wanted to drop the motor and trans into the car as one unit, so I cut out the core support only above the radiator. Looking at the structure of the car, it seems as though that bit of sheetmetal is not a major structural component, so I'm hoping it won't compromise the car's rigidity. Before I cut it I bolted brackets across the cut lines so it would bolt back into place accurately. It gave me plenty of clearance to install the motor/trans combo with a load leveller on the engine hoist and saved me from the hassle of installing the trans from below.

[MattAvino]

Subbed for an awesome 5.0 swap.
Also, you gotta turn one of the steering Ujoints 90 degrees.

[Stvstr]

Subbed for an awesome 5.0 swap.
Also, you gotta turn one of the steering Ujoints 90 degrees.

I'm not clear on how the u-joints should be oriented. Will they bind or fail the way they are now?

[omarquez510]

Will the headers actually clear with that steering link? Anyone actually test fit?

Sent from my SPH-L710 using Tapatalk

[JGood]

I'm not clear on how the u-joints should be oriented. Will they bind or fail the way they are now?

You'll likely have some binding and premature wear. You may not feel it right off the bat, but it will likely happen over time.

[Stvstr]

Will the headers actually clear with that steering link? Anyone actually test fit?

Sent from my SPH-L710 using Tapatalk

If fits with my tri-y header that I made by modifying a shorty header.

[Stvstr]

You'll likely have some binding and premature wear. You may not feel it right off the bat, but it will likely happen over time.

Thanks! I had no idea that was a problem, I appreciate the heads-up.

[Stvstr]

I dropped the 5.0 into the 325 in October, and it fit reasonably well.


I had to slot the left side mount because the trans was pointed off center. That rotated the motor forward on the drivers side which gave me slightly more clearance at the heater hoses.


Because I live in a cool climate (and I'm cheap) I thought I'd try the e30 radiator as per the e30V8 manual. I removed the A/C condensor from the auxilliary fan bracket and re-installed it.


I'm trying it without power steering, so to get the belt tensioner to work I moved it to the power steering bracket by drilling a couple of holes and spacing it forward by one washer thickness. A 57" belt seems to fit and puts the tensioner within the correct range.

I spent six weeks learning how to weld by modifying a shorty header into a tri-y that tucks between the steering linkage and the block. My welding never got past the amateur stage and looks like crap, but it doesn't leak. Anyone who valus good welding, look away:


I was quite happy it needed to be covered with exhaust wrap to keep heat away from my fuel hoses and steering linkage.


I now realize I should have combined cylinders 5/7 and 6/8, so I may weld up another once I see how this works.

[Stvstr]

I spent last winter getting my modified rear facing header to fit and not leak through my bad welds. By February I started it for the first time and was surprised it settled into a decent idle. It was pretty loud with open headers, but what neighbourhood doesn't like the sound of a Ford small block?

I had read about driveshaft interference on the subframe and csb mounts, so I decided to try using the e30 driveshaft. I took the yoke from the mustang driveshaft and had it welded to the e30 output flange from my e30 auto trans:


That allowed me to use the guibo to install the driveshaft - I can slide the front driveshaft into the rear section, slide the yoke into the t5, and then bolt them together at the guibo. I don't know how long it will last or if it's strong enough, but it's really convenient. Also, it's a stock 5.0 right now and the e30 driveshaft seems to handle the turbo m20 builds alright, so I'm hopeful.

I had the stock e30 driveshaft shortened from this:


To this:


I ended up taking out 8". Then I carefully lined up my motor/trans so the output points directly at the CSB. Had to slot my motor mounts and trans mount to get the alignment right.

I put the cooling system back together and spent some time getting the bottom rad hose to fit. I didn't like the inline filler on the top hose that the e30V8 manual recommends, so I deleted it and used the e30 coolant overflow and pressure cap instead. I just added a 5/8" heater hose connecting the overflow tank to a Tee fitting I added to one of the heater hoses near the water pump. Seems to work fine, but the Pacific Northwest climate doesn't stress a cooling system.

Since this is a budget build I used my e30 muffler which is high quality and in great shape and connected it to my headers with 2" pipe. It's quiet, but doesn't sound great. I will work on a better sounding exhaust next winter.

My first few test drives were spent diagnosing what turned out to be a wiring error, which is detailed in another of my threads on this forum. Now it's running great and is an entertaining little car to boot around in. It still handles like stock, I can't tell any difference in the way the front end steers or grips. The weight difference must be very small.

I deleted the power steering and the rubber rag joint in the steering linkage and the steering feels GREAT once your moving. I really like the feel and feedback. BUT at low speeds it sucks and makes the car feel like a project car, not a daily driver. I am going back to power steering next winter.

The booster delete with stock master is way underpowered. One of the members here, I think E30_302, mentioned using a 5/8" Wilwood master, but I'm not convinced. I'm still waiting to here from someone who has actually tried that fix, because:

The stock e30 M/C diameter is 22/17 mm. I assume (but don't know) the 17 mm piston is for the front brakes where most of your stopping power is. A 5/8" M/C is 16 mm, which I calculate would only give 18% more stopping power. I don't think that's enough of an improvement to fix how weak my brakes feel, so I am looking into using a smaller booster from a Geo Metro. Any input on this would be appreciated, as I am flying blind here.

[e30_302]

The 5/8" feels good from what little I have driven it. Pedal is a little long but it still firms up enough to where you can "feel" what is going on. The 1" was miserable. 3/4 may be a good compromise but I'm satisfied with the 5/8". Once I get it on the track if I see the brakes are hard to modulate/have a numb feel I'll try the 3/4". FWIW I drilled my pedal for the 6.4:1 ratio.

[Stvstr]

The 5/8" feels good from what little I have driven it. Pedal is a little long but it still firms up enough to where you can "feel" what is going on. The 1" was miserable. 3/4 may be a good compromise but I'm satisfied with the 5/8". Once I get it on the track if I see the brakes are hard to modulate/have a numb feel I'll try the 3/4". FWIW I drilled my pedal for the 6.4:1 ratio.

Good to hear it's installed now and working. Do you have stock e30 calipers? And can you lock up the tires with the 5/8"? The only way I could lock up the tires now would be to push so hard I'd be afraid of breaking something in the linkages.

[e30_302]

UUC front calipers, but apparently they're sized very close to stock as far as total piston area goes. Can lock them up now, which was all but impossible with the 1", even in gravel.

[Stvstr]

UUC front calipers, but apparently they're sized very close to stock as far as total piston area goes. Can lock them up now, which was all but impossible with the 1", even in gravel.

Great, thanks. That's a much easier solution than fitting a little booster into that tiny area.