Jelmer's 538iS *sold*

[Jelmer538i]

Hahaha, swapping the best L-6 BMW has made for a boat anchor which belongs only in 7 series would be plain stupid in my opinion!

[Owndapwn]

Hahaha, swapping the best L-6 BMW has made for a boat anchor which belongs only in 7 series would be plain stupid in my opinion!

Depends on whether or not the boat anchor is being blown by twins.

[Jelmer538i]

yeah but it is still to heavy and placed to much in front of the front wheels in an E28.

[Das_Prachtstrasse]

I'm rather interested in this engine management option you've gone with. I require something to run this high comp ITB'd M30B35 MAFless (open throttles) and with built-in wideband lamba control, so it may be suitable for my needs. Keep us posted on how you find it to work with!

[Jelmer538i]

I will. It is Megasquirt based so easy to tune with Tunerstudio.

[Jelmer538i]

Yesterday I put new M-tech red short springs ( part number 2225645 ) in. I have new Bilstein B6's (HD's in the US) which I will send to Bilstein to be revalved so for now they are paired with my Koni yellows. I also put E90 drop hats in and this ride height is what I want! The rear are stock springs on the lowest Koni setting. I've not decided yet what springs I want in the rear.



I've talked to Bilstein UK about the revalve and asked if they can revalve it like how the OE BMW Bilstein are valved for the M-tech red short springs. If I had a BMW part number they said it would be possible! Today I will call Bilstein Germany and see what they quote me and if they can valve them the same way.

[wkohler]

I've been talking to Bilstein in the US and they will not even rebuild my BMW Bilsteins let alone valve a set of aftermarket shocks/struts to match. I don't know if it's possible to get any info or what not that I could pass along to them? They say the reason is that they cannot get the drawings. Is there some reason that with the magic of the Interwebs this cannot happen?

Your car looks fantastic!

[Jelmer538i]

I think Bilstein is not allowed to use these specs because BMW wants you to buy these shocks from BMW only. So for them it is a win-win situation. I hope Bilstein UK will do them like the M-tech Bilsteins though...

[wkohler]

Well, if they make them NLA, I don't see how that really helps. Also, on the E12 M535i shocks, they superseded the part numbers to something that supposedly fits "all E12s" and I don't want to use those.

[Jelmer538i]

What if you have them revalved for the springrate and corner weight of your E12? That is what my next step would be if they can't valve them like the M-tech ones.

[tig]

I agree. This car looks fantastic. Perfect ride height. And Arktisblau.

[Jelmer538i]

I really need to pull that chinese foil from the headlights......

[Jelmer538i]

I'm working on the standalone engine managment now. Tommorow I will wire up a wideband lambda sensor and than the tuning can start. Nice thing is that I can plug in my stock ECU and all is stock again.

[Jelmer538i]

This weekend I've put my 538iS badge on. Looks good i think:

[Jelmer538i]

The first miles are driven on the new ECU! It went well but I still need to install the wideband sensor so that it can run in closed loop. Now I can finally have it run like how it should run instead of a rev limiter coming in at 6500 rpm.

[wkohler]

That's awesome!

[Jelmer538i]

Yesterday I hooked up the Innovate MTX AFR gauge but after i had it in I didn't like how all the wires were hangeing tru the car so I took the center console out and sorted out all the wiring for the radio, digital oil pressure and temp gauges and the new AFR gauge. I've tied the box for the oil gauges nice and tight to the metal support under the dash and cut all radio wiring to the correct length and zip tied it to the correct wiring holder on the HVAC unit. Than I made connectors to the wiring so I can take out the AFR gauge easyer. So now all "aftermarket" stuff (Radio, oil gauges and afr gauge) is hooked up by connctors and everything is soldered and covvered in heat shrink. No terminal blocks or ducttape in my wiring!!!

Console out, thank God it doesn't have AC!


Oil gauges "box" tied to dash support. I don't like the "strip" of wires that go the the dash unit but this is how they come.


The connectors that I made for the AFR gauge. The brown wire isn't used so I cut it off and covered it with heat schrink.


And the AFR gauge. I absolutly wanted a gauge that has a "factory BMW E28" look so I first looked at the orange illuminated Innovate DB gauge but they where out off stock and they have a external controller. This gauge came with a silver bezel and white face plate but I swichted right away to the black/black scheme.

[downforce22]

More details and pictures of the engine please!!

[Jelmer538i]

Little update on the stanalone project. It is working great so far! We have it pretty much dialed in the way I want it. I is so easy to adjust everything that I will never mess with the Motronic again! It drives way smoother, starts better cold and warm and runs not stupidly rich like the Motronic did. I set it up that the overun fuel cut activates only above 300rpm and this makes it drive more steady and smooth in town. With the Motronic when let of of the gas for a speedbump or corner you "felt on your face" because of the braking power of the high compresion S38 but now it just goes very smooth. Next thing is to setup the ego control so that it can run in closed loop.

[Owndapwn]

Just a hunch, but the smoothness might have something to do with not having the same design as a digital sport watch in the sense that it's just a timing crystal and a mostly static fuel map.
Does the S38 already runs 91 octane, or are you having to make that change since you're no doubt messing with the ignition table? Are you feeling a noticeable difference in how hard it pulls?

[Jelmer538i]

I don't know about the US octane numbers but overhere in Holland we have 95 ron and at some gas stations 102 ron. I thinking about a second table for when I fill it up with 102.
For now it is tuned with 95.

[Owndapwn]

87, 89, and 91 in most places.
Some places have 93, but it's usually only available in rural areas where select farm equipment uses it.
Anything else and you have to buy it as "race gas" from a "race store" in "race barrels"
87 Octane = 91 RON
91 Octane = 97 RON
95 Octane = 102 RON
Near as I can tell, those measures have nothing to do with each other and are not easily calculated.

[Jelmer538i]

Uh oh! Headgasket gone between 5 and 6. Possibly detonation in combination with the small spacing of a B38.

[Owndapwn]

MHG, raised compression, and big cam time?

[Jelmer538i]

All stock.

[Owndapwn]

It's currently stuck or you're keeping it stock? I was saying to see about what your options to raise compression are, and since cams love high compression...

[Jelmer538i]

Decided to go thru some stuff:

* Clean TB's
* Replate a lot of bolts, nuts and small brackets
* Cut M88/3 manifolds and weld on 2x2,5" pipes for complete 2x2,5" exhaust
* Clean and paint engine bay
* Splice engine wire harness down to get rid of wires that I don't need anymore with the standalone managment
* Fix carbon airbox

I started with the throttlebodies. I degreased them in my parts washer and after that I put them in my Ultrasonic cleaner:

[Jelmer538i]

It's currently stuck or you're keeping it stock? I was saying to see about what your options to raise compression are, and since cams love high compression...

It will retain stock. Aftermarket cams, rods and pistons cost another $5000,- and than the engine will need extra work to take a benefit from these parts so that will be another $2-3000,-

[gazm3]

Id certainly consider raising the comp ratio but the dilemma is if you have to run on Ron95 fuel the OEM comp ratio is probably close to the limit you can run anyway. If you set it up for the ron102 exclusive you could run comp up pretty high if u had a cam to support it.
I'm running 13:1 pistons but I'm going to use a thick MLS gasket to get the comp down to very low 12's. The reason for this if I want to go and run it on exclusive e85 which is about ron107 I only have to change the head gasget down the track.

We flow tested a std b38 head and it run 309cfm @500thou (12.7mm) lift totall standard. That would be enough to support 470bhp if you are prepared to run a high lift cam.

The std rods would be fine but 1k for a set if pistons would be money well spent.

[Owndapwn]

If you religiously adjust your valves for a few tanks (Order 6-8 cam cover gaskets and go to town after every fill up), you can do cam for like $800 US. And to raise compression, you can get the shop to cut a bit extra off the head and run stock thickness gasket. It should be able to raise it at least 0.5 CR before you need to worry about clearance. And at that point, you'd just be running 91 octane equivalent with a tiny bit more ignition.