Where to begin? (Starter mods/work)

[JamesKoz]

Hi! Made my account a while ago, lurking ever since. Apologies if there's a FAQ or topic better discussing this, if there is I'll remove this one and check that out instead. (I'm new to forum posting in general)

I have a 1988 E28 535i that I scored for VERY cheap a few years ago. Next to no rust, runs great, only issues I have with it are small stuff (Odometer, headlights acting wonky, interior trim pieces etc.) I've done zero work to it aside from a full detail and removing the instrument cluster to replace the odometer gears. It's a full blank slate untouched car.

My goal is to have this car be a fun driver, not built for speed but to have power in the pedal when it's needed.
Of course it's a 35 year old car that's been sitting for a while, it drives fine but feels pretty gutless. I understand it's not like I'm hopping into a race car expecting it to be track ready, but what are some beginner/starter jobs that can be done to get this thing towards my final goal?

[kojo96]

It's a common opinion that the car will need to be baselined. Do a search and you'll get a very good idea of what's involved.

[Mike W.]

Headlights acting odd is unusual, describe it more. Odo gears you seem to have a handle on.

Power. Now to me my 535 always felt overgeared until I changed the diff from a 3.25 to a 3.46 and then it felt right. But it was more like I was in the wrong gear, a gear too high than a lack of power, I'd have to get on it or downshift and build up revs. As you seem to be aware, at 35 the car could have a variety of issues. Start with a compression check. Do a basic tune up, plugs, spark plug cables, cap and rotor and O2 sensor. Make sure all the vacuum lines are tight and the intake boot isn't cracked. A plugged or restricted cat is always a possibility.

[Blue Shadow]

Hi!

My goal is to have this car be a fun driver, not built for speed but to have power in the pedal when it's needed.
it drives fine but feels pretty gutless.

First, well after baselining, the car will not have power under foot when needed and will continue to feel gutless because even though the 85 535i was the fastest 4-door sedan available in America that year, times have changed

The car can feel a bit quicker with a lightened flywheel, shorter diff and a proper tune. Mike mentioned the 3.46 which is about right. The 3.64 and first gear isn't used as much. A 3.73 and the car is Always poised like a cat ready to jump and is too much. Some love it.

Port and polish along with headers and increased compression 10.0:1 vs 8.0:1 stock only gets you to about 245HP and the jump to 218 from 182 is from compression, the Euro motor.

So since you aren't going to get power from the motor, look at improving handling to keep the speed in the twisties.

Make it fun to drive, connected to the road with proper driver involvement.

Springs
Shocks
Anti-roll bars if desired
Steering components (these last about 120,000 miles from new and other than Lemfoeder don't last as long)
Stereo
Short shift kit
Big brakes
16" wheels and tires or smaller.

Bigger wheels are heavy and make steering harder so the car isn't as fun to drive but dang some of those larger sets do look good.


That list and other crap can be considered after resetting the maintenance clock to Zero with a full Inspection II service which includes Oil Change Service, Inspection I, coolant replacement and Brake fluid change.

All listed in the owner's manual and part of the baselining. Then talk to us about what you want to do.

[stuartinmn]

I don't think it's been updated in quite some time, but the M535i.org website has some useful information that is still applicable for various upgrades to braking, suspension, engine and driveline, etc. Go to the tech FAQ section and search around. http://www.m535i.org/main.html

[Blue Shadow]

Not much reason to update M535i as there aren't a lot of new things to do to the car. Good info on what to do though.

Lots of dead links and some good ones on projects and access to the electrical diagrams at www.e38.org/e28.

[1st 5er]

Is it manual or automatic?

[JamesKoz]

Thank you for the responses! The car is unfortunately an Automatic (I meant to mention in the original post) so I understand some of my options are more limited. I appreciate the term "Baselining", it's something I've never come across being new to the auto scene and it's pretty much exactly what I was looking for.

Blue Shadow I appreciate the list of "fun to drive" to-do's. The car is a little squeaky over bumps as well as feeling generally "floaty" so suspension is towards the top of my focus. I'll have to do some more research on what's right for my goal. My dad owns a set of factory 2002tii rims, I think they're a 14-15" so I should do some digging to see if the bolts match up because those would be awesome as well as small enough!

Mike, I'd need to pop the battery back in the car and re-diagnose the headlights as I can't recall the exact problem. I think it's something along the lines of one light not working for high-beams, but then turning on when the high beam switch is turned off? I've replaced the bulb itself but it has the exact same issue which leads me to believe it's a wiring concern... something I'm sure I'm not savvy enough to tackle yet. It's the time of year to drive this car now in Canada so I'll get it running again asap!

Apologies for probably asking questions that have been asked 100s of times over... I appreciate the help!

[Foonfer]

My dad owns a set of factory 2002tii rims, I think they're a 14-15" so I should do some digging to see if the bolts match up because those would be awesome as well as small enough!

Wheels on a 2002 are 4-bolt. Wheels on E28s are 5-bolt. All 5-bolt BMW wheels are 5x120mm bolt circle diameter.

I believe the "big brake upgrade" is one of the best investments you can make, paired with stainless steel braided brake hoses. In most cases it'll force you to go to larger wheels, 15" or 16" from the stock 14". E28s came with 14" wheels, the M5 came with 16" wheels, and some models came with size 390 metric wheels (a bit less than 16" - there's painfully few manufacturers that still make those tires, they are very expensive, and no one really cares about them unless you are an über-purist).

There is an indispensable thread and downloadable Excel file on wheels, tires and sizes. I believe it might be a bit out of date. When I did my Big Brake Upgrade, I went for 16" wheels and 215-55/16 tires. The E28 is very particular with this, as it doesn't provide a lot of latitude: Go too wide/too tall, and you'll rub the inside of the tires against the strut tower at the front, and/or the outside of the tires against the inside of the rear fender. That's why M5s came with factory-cut rear fenders, to accommodate the stock tires it came with, which I believe were 225-50/16.

Also there is an endless (and endlessly funny) tug-of-war between those who believe 16" is the largest wheel that looks appropriate on an E28, and those who incorrectly believe that larger wheels (17", some even go 18") look cool.

This is the tire tutorial: viewtopic.php?f=9&t=35751 aaaaaand it appears to be inop for the moment. Keep it handy for when Shawn D. updates it - it's worth it.

[Galahad]

internet archive has it here

[Justin_FL]

The car is unfortunately an Automatic (I meant to mention in the original post) so I understand some of my options are more limited.

Assuming the car is staying an automatic for the foreseeable future, if you can find a 3.73 or 3.91 differential, that is an great swap for the auto and makes a world of difference. The equivalent ratios in the auto are all taller than the manual, so the auto trans cars especially feel underwhelming with the same 3.25 diff ratio.

I ran a 3.91 in my one auto 535is on a 3000 mile road trip and at a brisk touring pace through mountains, didn't miss the manual that much to be honest. The 3.91 was "borrowed" from my M5 for the road trip, but I found an E30 3.73 limited slip diff later and that is what lives in the car now. A little lower RPM on the highway and that felt about right to me.

Keep in mind that BMW used the 3.91 in the late production 635csi autos with the 208hp M30, so I think they knew what they were doing. With that said, a 3.91 diff with an E28 compatible case is pretty rare, so I ended up with the 3.73 as those were cheap and fairly plentiful from parts E30s back then.