Scum class 318 + Mtech + vortech v2 + unicorns - vortech + Turrrrbo

[s14brent]

exhaust is looking good. where did you get the oval piping? welding under jackstands is the worst!!

[2mAn]

I liked that same muffler, should sound good when done

[pandaboo911]

Got the section that goes under the subframe fabbed.



Somethings fucky with my welder though, seems to not pool anymore, just spatters and builds up weld. I cleaned the shit out of the piping with a grinder and turned the power to max, still doesn’t pool into the piping.

[pandaboo911]

Scum class 318 + Mtech + vortech v2 + unicorns - vortech + Turrrrbo

Progress on the exhaust. Working on a slanted driveway is extremely tedious.

Here’s what I’m working with





I forgot to buy exhaust hangers so I’ve been zip -tying it up, marking it, taking it off, tack welding, repeat. It takes extremely long.

I tried tacking it while under the car but got a face and body blasted with weld spatter, not fun.

I squeezed in one of these flex bellows, gotta say it makes it so much easier to get the v-band together.



For now it’s all straight through, no cat because the tune is very rich and would destroy a cat in short order, although I’d like to add one down the road when the tune is sorted out.
The oval is used where it goes under the subframe. I destroyed my last exhaust there with 16” wheels and it was round 3” so hopefully the oval doesn’t self destruct there as well.



It all goes into a borla muffler, I’ve used the pro xs on a few exhaust builds and always liked how they sound.



I’m gonna build a helmholtz resonator too once it’s all finished and try to document that. I had insane drone with the 3” exhaust I had on the supercharger setup.

[Northern]

If it lets you rev beyond 5248rpm and doesn't throw a CEL, I wouldn't be worried about the code

[pandaboo911]

41.1 from the US M52 cars doesn't depend on VSS for vanos/redline tables, but it does has a separate VSS error redline. (5248rpm is what someone says on the romraider forums, so it may be disabled already but maybe the DTC that triggers a CEL is still on?)
I think the only VSS related code it can throw is "214 Vehicle Speed Signal (VSS)"

Also, if it's a tuned ECU from like RKtunes, TRM, etc., it is likely read protected, so don't waste your time trying to get romraider installed/working in that case.

Yeah it’s from rktunes. Read protected? Bummer. Too bad they can’t just hide the fields containing their secret sauce tunes.

The code i was getting was P0500 Vehicle Speed Sensor. It doesn’t trigger the CEL but it’s stored as a code. I’ll know as soon as I calibrate my speedometer if it works or not. From what I’ve read the vems device does the same job as the speedometer circuit, converts the VR AC signal to a digital square wave. If it doesn’t work I’ll just strip down the speedometer to just the circuit board and package it nicely.

[Northern]

41.1 from the US M52 cars doesn't depend on VSS for vanos/redline tables, but it does has a separate VSS error redline. (5248rpm is what someone says on the romraider forums, so it may be disabled already but maybe the DTC that triggers a CEL is still on?)
I think the only VSS related code it can throw is "214 Vehicle Speed Signal (VSS)"

Also, if it's a tuned ECU from like RKtunes, TRM, etc., it is likely read protected, so don't waste your time trying to get romraider installed/working in that case.

[pandaboo911]

Scum class 318 + Mtech + vortech v2 + unicorns - vortech + Turrrrbo

MS41 expects VSS to come from an ABS tone ring, which iirc is 48 teeth, whereas the E30's VSS signal from the diff is 9 teeth. You're ~5.3x too slow if you feed the ECU the stock signal, but, you can change the multiplier for this with romraider (or your tuner can do it if you aren't tuning it yourself). They have a field set up to just go in and change.

Some details here:

http://www.romraider.com/forum/viewtopic.php?f=42&t=11756

Edit: I might've misinterpreted what your problem is, I guess it's more to do with lack of conditioning by the dash than what I posted about.

If your dash works and you just want the code to go away, you can (in romraider) turn off the VSS DTC/adjust revlimiter to not act weird because of it. VSS may affect vanos activation points and some rev limiter settings that work off speed in the S52's MS41.2 (but M52 MS41.0/MS41.1 don't use it to the same extent)

I knew about the number of teeth being lower, I just wanted to make sure the ECU isn’t in limp mode because there’s no signal.

I haven’t tested if this Vems converter actually works, but the engine doesn’t cut at 5500. I think the ecu had code 500 for speed signal but I haven’t reset it to see if it comes back.
I think the VSS may have been disabled on this ecu, I purchased it 2nd hand. Would I be seeing the code if it was disabled?

I have an aftermarket speedometer that works off the vems converter too, still need to test that as well.

Unfortunately the vems converter has a division option but no multiplication, and my car doesn’t have ABS so I’m stuck with using the diff sensor.

Thank you for the tip, I’ll look into romraider. I already have a cable for programming the ecu so I might as well

Edit: I think my ecu is 4.1, came from an m52. If that’s the case VSS shouldn’t affect vanos activation right? It’s just using rpm?

[Northern]

Also added a VR to Hall effect signal converter for the VSS signal. Hopefully that works. I’m not 100% sure how people get VSS to work for OBD2. I’m still getting P0500 for speed sensor. Previously I used a gutted e30 speedometer circuit to condition the speed signal, but I hated that solution. Any tips appreciated :)

MS41 expects VSS to come from an ABS tone ring, which iirc is 48 teeth, whereas the E30's VSS signal from the diff is 9 teeth. You're ~5.3x too slow if you feed the ECU the stock signal, but, you can change the multiplier for this with romraider (or your tuner can do it if you aren't tuning it yourself). They have a field set up to just go in and change.

Some details here:

http://www.romraider.com/forum/viewtopic.php?f=42&t=11756

Edit: I might've misinterpreted what your problem is, I guess it's more to do with lack of conditioning by the dash than what I posted about.

If your dash works and you just want the code to go away, you can (in romraider) turn off the VSS DTC/adjust revlimiter to not act weird because of it. VSS may affect vanos activation points and some rev limiter settings that work off speed in the S52's MS41.2 (but M52 MS41.0/MS41.1 don't use it to the same extent)

[kronus]

pipe will warp from heat and it will be a huge pain in the ass to get it mated to v-bands again. a bit of flex goes a long way.

[pandaboo911]

I’m building my 1st exhaust, but I’m not sure if I need to use flex couplers. Anyone know a rule of thumb on when to use them? I’m trying to maximize ground clearance.

I got a 1.75” flex coupling for the wastegate tube but Im not sure if it will fit where I want it. Is a flex coupling necessary if the dump tube is short? It’s only about 12” long. Is it a massive pain to install if it doesn’t have a flex?

I’m using Ryan G’s e30 m3 as a reference, and noticed he didn’t use any flex couplings anywhere. Could this cause the exhaust to crack?
Ryan G m3 pics for reference, I’m going for a very similar routing

[pandaboo911]

Scum class 318 + Mtech + vortech v2 + unicorns - vortech + Turrrrbo

Added coolant lines for the wastegate

I used the drain bolt as a feed and the throttle body heater return line as.. return







All that’s really left to do is fab an exhaust
I’m going with 3” stainless and 3” oval under the subframe into a 3” - 2x 2.5” muffler.
I had the single 3” tip previously but didn’t like how the single tip looks.

I also got an aem boost controller so I’m eager to play around with that

[pandaboo911]

Scum class 318 + Mtech + vortech v2 + unicorns - vortech + Turrrrbo

Hey man, just read through this whole build, very badass! I'm in the midst of an S52 swap so I'm hoping you don't mind if I come to you with questions!

Thanks! Feel free to shoot me some questions. I see you’re local so maybe see you around haha.

I got the charge piping finished up, went pretty smoothly. I brought it to my buddy mostly mocked up and he welded it for me.

The intercooler needed tight radius bends so I used the cast elbows on either side.







I managed to squeeze in a 16” puller fan. I had to cut the threads off the water pump. Just barely fits in there with the koyorad. There’s like 1/16th of an inch between the fan and water pump so I might do something to stiffen up the radiator mounts, the stock radiator bracket doesn’t work well with the koyorad so it flops around a bit.



New afr gauge confirms my old one was bad. It was reading extremely lean. I did read up on how to properly install a wideband so that it doesn’t turn on until the engine is started. My previous install powered it up when the key was in run, and the sensor would start heating before engine start. I read this kills sensors quickly because the thermal shock from starting a cold engine cracks the sensing element.

New gauge is powered by a relay that’s switched when the oil pressure switch opens up. Hopefully this sensor lasts a bit longer.

Car idles nicely around 14.5-15.5 AFR and gets down to around 10.8 in boost.



One other thing I noticed is the BOV is cracked open slightly at idle. I have normal manifold vacuum of around 16 in Hg. Is this normal? I know the Tial BOV comes with different springs but I don’t have them. Is the spring in there too weak maybe?

You can see the brown o-ring in there lifted up slightly.

Edit: I ordered a BOV spring meant for 16-19 in Hg vacuum. The one in there must be wrong. Thanks google!

[dadsbmw]

Hey man, just read through this whole build, very badass! I'm in the midst of an S52 swap so I'm hoping you don't mind if I come to you with questions!

[pandaboo911]

The fire ring would just make it bleed boost off so I don't think that would be the case (I ran mine once without the firing ring and had no boost). I don't know what would have caused it to explode like that. It is like it was over pressurized.

The top came off because it crashed into the pavement lol. Not sure how the wastegate came off the header though. Maybe the nut on the v-band was not a locknut, dunno