SCTS Racing M4 Race Car Build

[MPACT]

Originally Posted by scottn2retro

The weigh in at Sonoma was 3446 lbs. with a 160 lb. driver. We thought we were about 3300 lbs. at BW with nobody in the car, so we came out about 14 lbs. or so less after the cage install and removal of the weight we could shed before the O'fest races. So we think the car is about 3285 lbs.

Thanks for that Scott! I am surprised, I was expecting closer to 3100#, but it seems to carry the weight well. Excited to see the continued development.

[carno]

Originally Posted by MPACT

Thanks for that Scott! I am surprised, I was expecting closer to 3100#, but it seems to carry the weight well. Excited to see the continued development.

We still have A/C stuff under the hood and a fair amount of wiring to remove. Not sure what that will get us but we'll be a lot closer to 3200 for the next race.

[scottn2retro]

More on wire removal process. Driver's side footwell


Passenger side footwell


Some of the wiring removed so far (in addition to the entertainment harness that was removed for the cage build)

[scottn2retro]

Time to pull the ECU so we can run it over to GIAC. It's located under the intake manifold, so it's a couple of hours to get it out. Here's what the engine bay looks like after removal.


You need to remove the liquid cooled intercooler on top of the engine. We were a little surprised by the color of the liquid that came out of it.


The ECU (middle left side), since it is mounted near the engine has what I'll call a cold plate (upper side) that air from the intake/intake manifold cools.

[scottn2retro]

So I took the ECU out to GIAC in Irvine, Ca.


Seth opened it up and re-flashed it


And re-sealed it up (they used something that seemed like our 3M Weatherstip Adhesive on the seam)

[HP Autosport]

A good time to change that and use a higher percentage of distilled water with a Redline Water Wetter.

[FLOSS M]

shouldn't that coolant be blue?

[scottn2retro]

Originally Posted by FLOSS M

shouldn't that coolant be blue?

That's the big question - what would cause that in the charge cooler?

[DieGrüneHölle]

Originally Posted by scottn2retro

That's the big question - what would cause that in the charge cooler?

Rust?

[scottn2retro]

Originally Posted by Blipit_

Rust?

The car was wrecked and sat in a salvage yard. Wouldn't rust have to come from some kind of contamination?

[FLOSS M]

Originally Posted by scottn2retro

The car was wrecked and sat in a salvage yard. Wouldn't rust have to come from some kind of contamination?

It's a separate cooling circuit from the main radiator. Wonder what that looks like?

[scottn2retro]

Originally Posted by FLOSS M

It's a separate cooling circuit from the main radiator. Wonder what that looks like?

I think we're going to take a look at that coolant this weekend.

[FLOSS M]

If you look at the Dinan heat exchanger installation instructions they discuss the bleed sequence for that circuit. They state the coolant in there is the standard Bmw coolant. Why would anyone use straight water in that circuit is odd... that would indicate rust. Maybe it's possible the top mount was removed for some reason and they didn't have any coolant and refilled it with water ??? ECU previously flashed ?

[HP Autosport]

Originally Posted by FLOSS M

If you look at the Dinan heat exchanger installation instructions they discuss the bleed sequence for that circuit. They state the coolant in there is the standard Bmw coolant. Why would anyone use straight water in that circuit is odd... that would indicate rust. Maybe it's possible the top mount was removed for some reason and they didn't have any coolant and refilled it with water ??? ECU previously flashed ?

Water has much better heat transfer properties than antifreeze so there is a good reason to use a high percentage distilled water mix with a Redline Water Wetter or Motul equivalent.

Could be rust(you will see some floaters)or wrong antifreeze fill. A light to medium tan clolor coolant was used by MB for a long time. Red and orange too, so possibly a wrong fill? Can't tell without being there in person. What does it smell like? Feel between your fingers?

[DVC]

Originally Posted by HP Autosport

What does it smell like? Feel between your fingers?

What does it taste like?


Sorry, couldn't resist...

[HP Autosport]

Originally Posted by DVC

What does it taste like?


Sorry, couldn't resist...

Never had any so I couldn't tell you.

[scottn2retro]

As far as we can tell it is either some kind of brown or old orange colored coolant. The main radiator system has lime green coolant in it. So that isn't BMW OEM fluid either.

[scottn2retro]

Time to take out more of the A/C components. You have to remove a lot to get to it, so we thought while we have the ECU out, it's the right time. A/C compressor is under the alternator


One A/C compressor and some A/C lines (more weight out of the car) You need to replace the OEM fan belt with P/N 420K8 K-Poly V-Belt 42.63"


Nice hole in the engine bay where the compressor was

[scottn2retro]

Back to wire removal. Craig has nearly all the non-used wires out of the dash area.


Laced out the unused wires out of the right rear


Laced out wires removed


Right rear all wrapped up and ready to go


Here is the wiring removed (in addition to any I've already shown pics of). It's starting to add up to pounds of wiring.

[scottn2retro]

Put the ECU back in and started the car up to make sure our wire removal hasn't caused us any harm

The ECU bolt to the bottom of the intake manifold


Intake manifold back in place


Coolant fill tank and intercooler back in place

[Agentrs]

Hey guys, enjoyed looking through your thread.
I just wanted to share my race car build thread I started over in the photo section. Turner Motorsports is going to do most of it and it will be an SCCA Club Racing car next season...unless I go crazy and go after a bigger series..tbd!

http://f80.bimmerpost.com/forums/sho....php?t=1311479

[///Mobbin]

Originally Posted by scottn2retro

As far as we can tell it is either some kind of brown or old orange colored coolant. The main radiator system has lime green coolant in it. So that isn't BMW OEM fluid either.

Just curious, are you planning to switch over to water?