Click to go to Forum Home Click to go to maXbimmer Home

Go Back   maXbimmer Forums > maXimum Tech > Forced Induction
User Name
Password


Welcome to Maxbimmer.com!

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

Reply
 
Thread Tools Rating: Thread Rating: 3 votes, 3.67 average. Display Modes
Old 07-18-2011, 09:03 PM   #61
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,733
Back from the dead....

Any MS guys here have any experience with the LM1815 VR Conditioner circuit?

Last year I had an issue with my DIYPNP where the car wouldn't rev past 2500rpm. I checked my tooth log and noticed some irregular noise and I was getting sync loss error code #2. I tried noise filtering to no avail. After speaking with Matt Cramer he recommended switching to the LM1815 circuit. However winter rolled around and the car got put away.

Fast forward to this year, I took the car out of storage a few weeks ago. It fired right up with no issues, still with the same problem as last year not being able to rev past 2500rpm. So I decided to try and switch over to the LM1815

Last year Matt had pointed me to this application document for an example of how to implement the circuit (http://www.diyautotune.com/diypnp/ap...-5vzfe-mt.html). I wired the VR+ input on the connector board to the VR+ on the LM1815 circuit and the VR- input on the connector board to the VR- on the LM1815. Then I wired the LM1815 Out to Relay 3 In and Relay 3 Out to Opto+ and I installed the Opto ground jumper. I tried starting the car and now it's not getting a cranking signal so the car won't start.

Is this the way it's supposed to be wired? Was I supposed to keep the 18k resistor in series with the VR+ input (I removed it)? Do any changes need to be made in the TunerStudio Settings.

Any help advice would be greatly appreciated
__________________

Last edited by Bullet Ride; 07-18-2011 at 09:15 PM.
Bullet Ride is online now   Reply With Quote
Old 07-18-2011, 09:14 PM   #62
dcramer
5th Gear Member
 
Join Date: Nov 2010
Location: Orangeville
Posts: 1,103
that link is dead.
dcramer is offline   Reply With Quote
Old 07-18-2011, 09:16 PM   #63
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,733
Quote:
Originally Posted by dcramer View Post
that link is dead.
Fixed. Sorry about that.
__________________
Bullet Ride is online now   Reply With Quote
Old 07-19-2011, 06:42 AM   #64
dcramer
5th Gear Member
 
Join Date: Nov 2010
Location: Orangeville
Posts: 1,103
are you talking about this http://www.aaroncake.net/rx-7/megasq...AndModding.asp circuit ?
dcramer is offline   Reply With Quote
Old 07-19-2011, 07:53 AM   #65
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,733
The DIYPNP has the circuit built into the board. I'm just unsure about where the output of the circuit is supposed to go.
__________________
Bullet Ride is online now   Reply With Quote
Old 07-19-2011, 09:27 AM   #66
dcramer
5th Gear Member
 
Join Date: Nov 2010
Location: Orangeville
Posts: 1,103
I'd have to see the circuit.
dcramer is offline   Reply With Quote
Old 07-19-2011, 09:56 AM   #67
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,733
Quote:
Originally Posted by dcramer View Post
I'd have to see the circuit.
I guess there is the potential for the chip itself to be dead, but assuming the circuit is fine I'm only concerned with the inputs and outputs. I picture the LM1815 circuit as a black box. I input VR+ and VR- and I get an output.

The application guide shows the output going to a relay. I'm guessing that's to trigger the relay to power the chip. If that's the case would a pull up resistor be required? The application doesn't specifically state this.
__________________
Bullet Ride is online now   Reply With Quote
Old 07-31-2011, 04:50 PM   #68
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,733
UPDATE:

I was able to get the LM1815 circuit figured out (thanks to Matt Cramer). The Opto GND needed to be off, and the Relay 3 output needed to be wired to Opto -. with a 470 ohm, 5 volt pullup in the R3 slot.

However the I still had the same issue as before when using the LM1815, I was getting a sync loss which was preventing the car from revving past 2500rpm.

So I switched back to the original circuit and started playing with the resistor in series with the VR+ signal. Originally I had a 16k resistor. The application guide on diyautotune said 18k, which I didn't have, so I tried the next highest one I had which was a 22k. No change, same issue. So I tried the next highest one which was 33k and with that it was even worse, the car would experience the sync loss around 1500rpm. So that made me figure it's not an issue with the voltage in the signal being too high, it was being pulled down too low. I tried switching over to a 10k resistor and guess what.... she can rev freely now!!!

I was so relieved to get past this hurdle. I took the car for a quick rip up the road so I could finally feel some boost. It pulled nicely, but I wasn't in it too long until my car all of a sudden wanted to rev up to redline by itself. I shut it off and pulled over, a quick look at the engine showed that the tube from the ICV popped out of the manifold, I shoved it back in and drove the car back home. Time to buy some RTV, make sure everything is sealed up and start tuning
__________________
Bullet Ride is online now   Reply With Quote
Old 08-01-2011, 01:16 PM   #69
e30_kid89
The Afro-stig
 
e30_kid89's Avatar
 
Join Date: Nov 2005
Location: TDot West End
Posts: 4,589
Send a message via MSN to e30_kid89
Sick! Good work man get er done! We need more turbo BMWs on the roads
__________________
e30_kid89 is offline   Reply With Quote
Old 08-02-2011, 11:26 AM   #70
everlast
if I lived . I would be ~
 
everlast's Avatar
 
Join Date: Mar 2004
Location: Ottawa
Posts: 5,847
SWEEET great perseverance to get 'er running!
__________________
everlast is offline   Reply With Quote
Old 08-02-2011, 01:06 PM   #71
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,733
Thanks guys. I was getting pretty frustrated with the thing… I was almost at the point where I wanted to install an adjustable pot because I was sick and tired of swapping resistors. In hind sight however, installing an adjustable pot for the VR+ signal might be a good thing to note for future applications. The reason I say this is because I was in contact with the guys at diyautotune to try and help me troubleshoot this problem. They were recommending installing the larger resistors because they’ve had feedback from some other customers that required resistors anywhere from 18k to 30k+ on their M20 applications. However I also saw some discussion online where people needed to use a smaller resistor (like me) to get things to work properly. Having an adjustable pot would make things easy because you can just turn the adjustment screw until you get a nice stable signal with no sync losses.
__________________
Bullet Ride is online now   Reply With Quote
Old 10-24-2011, 01:52 PM   #72
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,733
Back to the issue with the ICV tube popping out. I'm going to be coming back from europe in a week and want to get back to work on the car. I was thinking about just getting rid of the ICV all together, pipe tap the hole and plug it. Have any of you guys done that or read of people that have done that? I figure I can just use the screw on the throttle body and just crack it enough that it will idle. The car doesn't need to be e-tested so I don't really care if it has to idle a bit higher. The reason I'm asking is because I'd rather just eliminate potential leak points than create them. If I run the ICV then I need to plumb it back into the charge piping because it will leak boost and in order to do that I need to weld on a bung and have another coupler with two clamps.
__________________
Bullet Ride is online now   Reply With Quote
Old 11-03-2011, 08:24 PM   #73
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,733
So now that I am back in the country and currently unemployed (just starting to look for jobs) I'm making a bit of a push to get the mechanicals of my turbo car finished before the winter. I've been sitting on the car for two years now, it's time I get it done.

First thing I wanted to do was weld in a flex joint. For some reason the PO was ok with having an exhaust shop weld up his exhaust solid with no flex joint...

Easy fix, cut a section out and weld a flex joint in




I spent today working on the brakes, ended up having to grind out one of the screws that holds the disc in place because it was seized and it stripped. Because of that I only got the front brakes done before deciding to call it quits. Also spotted that one of the rubber flex lines must have been rubbing on a tire at one point because it was all chewed up so I'll have to replace that.

Upon inspecting the car further... there's a hole in the floor pan on the driver's side. I'll probably just chop a bit out, rivet a plate in and slather a few pounds of tar over it just so my feet don't go through the floor.

I've also go 6 of these on order since the 24lb injectors currently in the car are nowhere near sufficient... 42lb bosch design III injectors ftw.


After that, all I have left to do is plumb the ICV into the charge piping and clean up a bit of wiring. Then the car will more or less be done and I can start fiddling around with tuning it. As it sits with its very conservative "get it running" tune and it's undersized injectors it feels like a low 5 second 0-100 car, so I'm definitely looking forward to getting it tuned better... and having to replace the clutch because of the power
__________________

Last edited by Bullet Ride; 11-03-2011 at 08:28 PM.
Bullet Ride is online now   Reply With Quote
Old 11-04-2011, 02:15 AM   #74
DIY
Permanently Dirty
 
DIY's Avatar
 
Join Date: Aug 2010
Location: Etobicoke
Posts: 528
Its sounding awesome! Although with those bigger injectors your probably going to want a bigger downpipe. Good luck looking for a job!
DIY is offline   Reply With Quote
Old 11-04-2011, 08:14 AM   #75
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,733
Quote:
Originally Posted by DIY View Post
Its sounding awesome! Although with those bigger injectors your probably going to want a bigger downpipe. Good luck looking for a job!
Yeah, I would have gone at least 2.5" all the way if I had done it. The car currently has a 2.5" down pipe that necks into a 2.25" along the bottom of the car. I'll just have to live with it for now because I don't want to spend money redoing the whole exhaust.
__________________
Bullet Ride is online now   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 12:21 AM.


Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.