M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Swaps, Turbos, Buildups => Topic started by: axisofjustice on June 09, 2012, 04:40:31 AM

Title: DASC on E30 M42, tuning questions.
Post by: axisofjustice on June 09, 2012, 04:40:31 AM: I've acquired a car equipped with a DASC setup. With a Vortech SFMU that is said to be not setup and possibly not working... It is installed, but I have not verified that it was done properly. As of now the BPV is ziptied to recirculate. The car runs and drives fine during cruising pace and modest acceleration, but if I give it a little bit of push in 2nd it starts to buck. It feels like a very hard hesitiation/stumble/stutter and will not stop until I let off. I have been gentle and only allowed this to happen two brief times. The car runs pretty good otherwise.

(http://i31.photobucket.com/albums/c370/darkandroid1234/th_dasc.jpg) (http://i31.photobucket.com/albums/c370/darkandroid1234/dasc.jpg)

As may be visible in this picture, it appears to be using yellow injectors and an e36 rail/fpr, and from the look of the TB elbow bend I am assuming this is an M44 DASC (not 100%).

I am very new to e30s, the M42, and also tuning older fuel injected and S/C cars. I have had older cars (carbed), and newer cars (obdII) most have been domestic. I have owned a few turbo cars and an S/C car, but all were factory stock affairs.

Can anyone experienced or who runs this type of kit advise me on the best solution to get this setup sorted quickly and cheaply? I'd like to get started rebuilding this car (it is nearly in peices) but not until it is running well and boost is in effect.

I have toyed with a few ideas:

Try to see if this SMFU works and is properly installed, then tune with it.

Get a new RRFPR and tune with that.

Get some sort of ECU setup (MS/II, TunerPro?, Etc???)

These options, as you know, are all potentially viable, but as said, I want to get the car running well for low cost so I can build it, take what I need from my other car, then sell the other car and use that income to make this one that much better.

So, essentially I am kind of asking for a handout of free advice. I assure you I have read as much as I could understand on threads and projects others have done. I comprehend the basics for the most part. I do not know the details of how to tune this setup though.

I assume I need:

Some way to check Fuel PSI (perhaps a RRFPR with a gauge built in?)

Some way to check AFR (is is 100% needed to get a wideband?)

Some way to monitor boost (a boost gauge...lulz)

Ensure I have proper plugs for necessary heat range (wanna suggest a P/N?)

Do I need to get a larger set of injectors? A Wideband? A gun to shoot my foot for buying a headache which may or may not ever make me smile? I love the potential this car has. Given the list of mods it has and all the parts, it could be a very fulfilling project, I just need someone to calmly spoonfeed me.

Not intending to bribe here, just trying to show I do not want to rob someone for knowledge I don't deserve due to lack of research. I bought this car, and it's my problem to figure out! However, If anyone who is friendly and experienced wants to lend a hand in teaching me in-depth, perhaps I have some sort of spare part in my collection that may appease you in reward? In example, I have a 13-button OBC with the stalk, it is untested and the obc has no pigtail, but it's something I'd like to pass on to someone if they have the patience to help me figure this thing out.
Title: DASC on E30 M42, tuning questions.
Post by: bmwconnect on June 09, 2012, 08:57:41 AM: Get a Ostrich 2 and contact me with your DME# and Chip software # and I will make your a XDF & bigger injector starter file so you can tune the car via stock DME. Mega squirt or Ostrich is your best bet for tuning without getting into serious money.

Wideband is essential for tuning (LC1 works just fine) and I would get 30lb injectors for that supercharger

midnight-tuning@rogers.com
Title: DASC on E30 M42, tuning questions.
Post by: colin86325 on June 09, 2012, 10:46:44 AM: Grassroot Motorsports had a series of articles about installing a DASC on an M42. You might try to find the articles to see if they have any helpful details.
Title: DASC on E30 M42, tuning questions.
Post by: DesktopDave on June 09, 2012, 11:52:09 AM: +1 on the WBO2. They're only about $200 and will save your motor. You won't need the WBO2 for long, once you get that tune into the ballpark the WB is no longer essential. If you're on a really tight budget, pull the WBO2 & sell it used. You'll get a lot of your money back. IMHO I'd keep it - they're an excellent diagnostic for how well your motor is running. Every car should have one, a few OEMs run them stock.
Title: DASC on E30 M42, tuning questions.
Post by: axisofjustice on June 09, 2012, 02:27:38 PM: Good info, thanks so far folks. Does the LC-1 bosch sensor required a new welded bung? Or can it replace the factory o2 directly?

Quote from: bmwconnect;113093
Get a Ostrich 2 and contact me with your DME# and Chip software # and I will make your a XDF & bigger injector starter file so you can tune the car via stock DME. Mega squirt or Ostrich is your best bet for tuning without getting into serious money.

Wideband is essential for tuning (LC1 works just fine) and I would get 30lb injectors for that supercharger

midnight-tuning@rogers.com

I was thinking about the ostrich setup. If I got this I'd want to set it all up right, get injectors and wideband with it all at once. So I probably wouldn't pull the trigger yet. I'm a little nervous to try to get over the learning curve of these DIY standalone setups.
Title: DASC on E30 M42, tuning questions.
Post by: axisofjustice on June 09, 2012, 02:31:58 PM: double post
Title: DASC on E30 M42, tuning questions.
Post by: wazzu70 on June 09, 2012, 07:51:58 PM: The LC1 can be used in place of the factory O2 sensor. Same bung.

Barries suggestion is one I would go with, using the factory ECU. I am installing a VEMS standalone and it is a steep learning curve! I would advise against this route.

Another option is to contact Mike McCoy at TRM. http://www.theracersmarket.com and see if he can tune the ECU.
Title: DASC on E30 M42, tuning questions.
Post by: HaNasich on June 10, 2012, 04:20:55 AM: feel free to narrow down text and send concrete questions -
i have an M42 with DASC installed and running perfect on my E30
engine mgmt is stock 1991 E30 M42 ECU.
AFM is stock M42 AFM
Injectors are SAAB 900 (i think they are 280 cc instead of the stock 180)
and that is pretty much it
Title: DASC on E30 M42, tuning questions.
Post by: axisofjustice on June 10, 2012, 11:32:38 AM: HaNasich - Thank you for your reply! Do you run any sort of fuel pressure regulator besides stock unit? In example, the Rising Rate unit that Downing Atlanta provided? I do not have this item.
Title: DASC on E30 M42, tuning questions.
Post by: HaNasich on June 12, 2012, 03:58:48 AM: yes,
i removed the stock fuel pressure regulator and replaced it with the RRFPR that DA provided.
i understand that you can use any RRFPR, but you should check ur A/F ratio using a wide band to make sure you're not running too lean
Title: DASC on E30 M42, tuning questions.
Post by: axisofjustice on June 12, 2012, 12:59:56 PM: Last night I tore apart the Vortech peice that came with the car to see why the previous owner would say it wasn't working. It seemed solid but had two spots where it was partially clogged with debris, and the boost set screw checkball was jammed. After it was cleaned and reassembled it seems to be in decent shape. Today I'm trying to pick up an LC-1 from craigslist.
Title: DASC on E30 M42, tuning questions.
Post by: doitover on June 15, 2012, 11:44:55 AM: I have the original DASC install on an e30 that GRM did.

I don't know what size injectors they used or what aftermarket chip they put in it but it is in need of better tune. It runs fine everywhere but part throttle acceleration below 3,000 RPM under load. There it knocks or pings pretty badly.

It also can't pull the AC. With the half serpentine system and how it was rerouted the belt hits only about a 1/4 of the drive pulley. I don't know if they all have that issue or not. I've rerouted the belt as much as is possible to get more contact but no real improvement. The next step will be to make a double serpentine pulley and move the AC compressor up so that I can run two belts.

I would be much easier to do the full serpentine conversion.

I plan to go the ostrich route eventually. I had an order for 14point2's O2 sensor canceled for lack of stock and haven't gotten around to ordering another.
Title: DASC on E30 M42, tuning questions.
Post by: axisofjustice on June 15, 2012, 02:41:25 PM: Good info, thanks.
Title: DASC on E30 M42, tuning questions.
Post by: axisofjustice on June 26, 2012, 02:09:04 AM: How would one bypass the stock fpr? Never approached the concept.