The Cart Before the Horse: Spec 3 Build

[Senor_Taylor]

I would say that engine bay temps are something that aren't a bad idea to lower when the car isn't moving. It's not just about cooling the radiator, but keeping air radiating from the block moving out of the engine bay.

Got the car aligned and asked for custom alignment numbers, which they gave a shot at. around -1 degrees negative camber in the front I guess from lowering it, since it's not adjustable. Basically 0 toe in the front. Rear between -1 and -1.5 degrees negative camber and near zero toe. Not ideal, but much better than it was, I got my Kuhmo Ecsta ASVs mounted in the spec size on my style 32s and the winter tires are for sale. I also got a set of almost new RA1s on Style 29s from another Spec 3 guy.



The car is currently on jackstands right now waiting for me to take the front struts out again. I think I forgot a washer in between the top hat and the upper spring perch which is causing the rubber of the top hat to squeak on the spring perch and not let it turn easily. I also removed the sway bar until I can get new bushings to see if that alleviates the clunk I've been hearing. I also need to pull the belt off the alternator to see if that's what's causing my whine.

Last night I also installed the subframe X Brace. This piece came standard on convertibles and I think later M3s. It ties to two "Frame rails" together with the subframe and protects the oil pan, whereas the stock bar just tied the rails together. Since mine is a 95, the holes in the subframe are pre drilled, but 1) they aren't big enough and 2) they aren't threaded. What needed to be done was buy/rent/borrow a $200 tool to install nutserts. These are threaded rivets that crush on the backside of the hole when tightened. They're a pain in the butt to install because you have to keep the nutsert itself from spinning while tightening or else you have a loose rivet in your subframe and you're screwed.



I started by using a drill bit that was a bit bigger than the nutsert to add a bit of taper to the hole, then I widened it with a smaller bit. I then hammered the nutsert in and put some red loctite on the flange on the nutsert to hold it into the subframe. Then I made a little tool with a longer bolt, 2 washers with grease between then, and a nut. I threaded the bolt into nutsert, tightened the nut down to the nutsert with the two washers between them, then hold the bolt still with one wrench and tightened the nut. This pulls the nutsert down without allowing it to spin and crushes it. It's a lot easier said than done, but overall, it was an uneventful affair.



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[D_Eclipse9916]

Does anyone have an example of how they wired up their fan?

I could either
1. Wire it up to a switch (relay optional, but smart)
2. Wire it up to turn on with the aux fan
3. Buy the Bimmerworld wiring kit for it, but have to put a bung on my radiator for the temp switch.

Are they other options? I honestly don't suspect the car will ever get too hot with the aux fan and the robust cooling system, so I figure I can wire it to a switch and just flip it on if I ever see temps creep. It'd be nice to be able to leave the fan running after coming off track and having the car off.

Unless you got a real water temp gauge, #1 doesnt owkr.  The stock gauge "overheating" is far too hot and just indicates popped gasket, or danger if you get lucky.

#2 is how i have always done it on street cars.  However, I have known others who had the switch fail and said the fan didn't work so I shy away from this solution nowadays.

#3 is the best solution, and guess what, the most expensive.  Funny how that always works.

X-braces came on Verts and 95 LTWs as part of their "trunk pack".  AKA you picked up your 95 M3 LTW with an x-brace, wing, dual pickup oil pan, and a couple other things in the trunk.  Installing it was on you or the dealer after the fact.  It is a noticeable and immediate difference on any car I have ever driven and saves your oil pan during oopsies off track (apparent when you see tons of these x-braces with huge gouge marks from hitting things)

[Kaan]

#1 works if... you turn it on while you are loading/unloading, driving around the paddock, waiting on grid, and/or while in traffic.

I just leave mine on. There was no difference when on track, but off track in the heat it helped keep the temps down while waiting 45 minutes on grid for a session to start.

[Senor_Taylor]

Does anyone have an example of how they wired up their fan?

I could either
1. Wire it up to a switch (relay optional, but smart)
2. Wire it up to turn on with the aux fan
3. Buy the Bimmerworld wiring kit for it, but have to put a bung on my radiator for the temp switch.

Are they other options? I honestly don't suspect the car will ever get too hot with the aux fan and the robust cooling system, so I figure I can wire it to a switch and just flip it on if I ever see temps creep. It'd be nice to be able to leave the fan running after coming off track and having the car off.

Unless you got a real water temp gauge, #1 doesnt owkr.  The stock gauge "overheating" is far too hot and just indicates popped gasket, or danger if you get lucky.

#2 is how i have always done it on street cars.  However, I have known others who had the switch fail and said the fan didn't work so I shy away from this solution nowadays.

#3 is the best solution, and guess what, the most expensive.  Funny how that always works.

X-braces came on Verts and 95 LTWs as part of their "trunk pack".  AKA you picked up your 95 M3 LTW with an x-brace, wing, dual pickup oil pan, and a couple other things in the trunk.  Installing it was on you or the dealer after the fact.  It is a noticeable and immediate difference on any car I have ever driven and saves your oil pan during oopsies off track (apparent when you see tons of these x-braces with huge gouge marks from hitting things)

So do you install a bung in your thermostat housing or radiator to run the fan? Or do you have it run with the aux fan?

[Deceus]

I used an aftermarket Flex-A-Lite controller for the electric fan in the Demon. It worked pretty well and didn't require a new sensor or bung. Shoving a rod into radiator fins probably won't get you the most accurate reading but that's why it's adjustable.

https://www.summitracing.com/parts/flx-30332

You can even wire in a switch and manually turn it on if you want.

https://static.summitracing.com/global/i...-30332.pdf

[Jake]

Regardless of what other method(s) you use to control the fan, use a switch. I love knowing the fan is running "for sure" when I say it should. My switch has a red LED that lights up if the fan itself comes on. If the switch is flipped and no LED, something isn't right.

You don't need it above ~30 mph but around the paddock, waiting on grid, warm up/cool down laps, etc you absolutely want it running.

What is your radiator ducting situation like right now? You need to either have the stock pieces to funnel air (undertray, nose pieces, etc) or something like the Motion Motorsports undertray. If you don't have either, a lot of air will not make it to the radiator and the car will want to run warm/overheat on anything warmer than a mild spring day.

[Senor_Taylor]

I don't have an undertray but I have the pieces above the core support.

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[BLINGMW]

I don't know why you're talking about adding a fan. The stock aux fan moves a lot of air (if the shroud is in place as Jake states) and will keep the car cool when coming off track, especially if you are considering removing the AC. And once you're moving, no fan needed.

Anyway, good call on the crossbrace, sounds like that was fun!

[Senor_Taylor]

Added insurance, especially if the fan is free. (Thanks, Kaan!)

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[Apoc]

My 944 was #1. It was on when sitting on grid, loading/unloading, and sitting in the paddock after exiting the track. There was no aux fan.

[D_Eclipse9916]

I don't know why you're talking about adding a fan. The stock aux fan moves a lot of air (if the shroud is in place as Jake states) and will keep the car cool when coming off track, especially if you are considering removing the AC. And once you're moving, no fan needed.

Anyway, good call on the crossbrace, sounds like that was fun!

I would not trust the stock aux fan. #1 is the easy button, just please add a coolant temp gauge.

[BLINGMW]

well whatever, add my vote for a real temp gauge before/with any of this. My E36 radiator cracked a few minutes from home and system was almost dry by the time I got there, temp gauge said NO WORRIES BRO THAT COOLANT SMELL MUST BE SOMEONE ELSE

[Apoc]

#1 is the easy button, just please add a coolant temp gauge.

This. Both oil and water were VDO and, conveniently, placed right above the fan switch.

I take zero credit for any of it. The car was mostly sorted when we bought the pair.

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Oh, and the water temp could be PEGGED and the oil would have only risen like 5 deg.

[Senor_Taylor]

What kind of trans and diff oil should I be using? I see people saying ATF, some people MTL. The diff, people claim 75-90 unless it's an LSD or something specific for M LSDs. I'm not quite sure. What do you guys use?

I do have an LSD.

[BLINGMW]

I don't remember on the diff, but I always did MTL in the trans. A little sluggish when cold but that goes away pretty fast.

[Senor_Taylor]

I don't remember on the diff, but I always did MTL in the trans. A little sluggish when cold but that goes away pretty fast.

Ordered 75-140w for the Diff. Seems BMW retroactively changed the specified fluid years after the E36 came out. 

For the trans, I ordered some MTL. I'll see how it feels and possibly consider ,Mt90 if I have any issues. Matthew helped me discover that second gear is very unhappy on a downshift when it's cold outside. 

Also, I took my front struts out again, and to no one's surprise, I had assembled them without a washer between the top hat and upper spring perch. Threw those in and steering feel improved. The noises and squeaks that used to happen when turning the wheels is gone as well. Also diagnosed my suspension clunk to be the sway bay bushing, so I have some new ones ordered. I think I'm just going to #sendIt with the current alternator whine unless I see a screaming deal on a used one. The car is ready for the March VIR pending a brake line flush.

E36 dudes, have you done the bigger Diff bolt mod? Has anyone snapped a diff bolt before? I'm very anxious about the diff moving around with the worn bushings and breaking shit. I really want to make it one season before I touch those so I can have Deren or someone weld in my subframe reinforcements and do subframe/diff bushings all at once so I can avoid that nightmare.

[D_Eclipse9916]

Honestly the 90 or 110 or 140 is fine. Redline also has formulas for lsd friction modifier. Do not use that.

For the trans, there’s two specifications because the ZF in the 328i and M3 use ATF while your getrag uses MTL.

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Honestly the 90 or 110 or 140 is fine. Redline also has formulas for lsd friction modifier. Do not use that.

For the trans, there’s two specifications because the ZF in the 328i and M3 use ATF while your getrag uses MTL.

Also I broke a diff bolt. For road racing you would never but if you are autocrossing you might.

[Jake]

Yeah, the diff bolt thing seems to be an autocross issue given the launches off the line. I wouldn't worry for now given your uses.

[Senor_Taylor]

DJ, you're saying NOT to use the redline with the friction modifiers for LSDs? I ordered MTL and 75W140 with friction modifiers. Both refline.

Thanks for the information on the diff bolt. I get a lot of clunk when bumping the clutch. I don't know if that's the dual mass flywheel or the diff clanging around.

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[Senor_Taylor]

Quick update before March VIR.

Installed new sway bar bushings in the front. Picked up a spare trans for $100. Wired up the fan than Kaan gave me with the help of Tom. Wired up always hot so I can run it with the car off. The fan is a lot smaller in comparison to the radiator than I thought, but it's better than nothing. Also have fiddled with the car here and there in the last 2 months like removing everything from the trunk and pulling the headliner.

Decided to enter an autocross to test out the car before driving 4 hours to VIR and really "sending" it. The car has been extremely reliable and trouble free and it continued the trend this weekend. Seeing as I've been driving a turbo, fwd hatch on all seasons for the last year, I wasn't sure what to expect with something NA, RWD, and on race tires, but I was pleasantly surprised by how predictable and easy to drive it was. The main lesson learned was that I don't have the balls to push these tires anywhere near what they're capable of just yet and it'll take some getting used to throttle-on oversteer again since this is the highest horsepower RWD car I've owned.

My runs were nothing to write home about, but I wouldn't say there were slow. I was keeping up with a stock-ish 330i. My inputs are jerky and inconsistent and I was more "hurling" the car than driving it. Oh well, I'm not here to be competitive. I've been worried about 2nd gear being crunchy, but I didn't run into any issues as the day went on, so either the new gear oil finally made it up to those synchros, or I've stopped shifting so aggressively. This is my first car with a short throw and I think I just need to slow my 1-2 and 3-2 shifts down to give it more time to sync.



This gave me a good chance to give everything a "dry run" with packing all of the tools and tires in the car, getting it there and swapping things over. Getting comfortable in the car with a helmet and feeling what cold race comp tires are like. Overall, I'm pleased and VERY excited for VIR this weekend.