89' 325is LS3 swap

[iansane]

Thanks for the heads up on the signal!

I need to decide on tire size soon. I'd like to get some traction under it. I also need to run 17s to clear the brakes that are going on. It's becoming hard to argue with a square 255/40r17 setup. There is a huge selection of tires in that size, and I can even get all seasons. I have kamators flares on the way (which I plan to paint-to-match). I'm just having a hard time taking the plunge and cutting into the car.

I run that size in a Falken under the standard KAMotors flares and love it. Though, I don't have traction issues because I'm not LS yet. Haha

[rzerob]

I plan on getting the KAmotors flares so I would be interested in seeing how you tackle it. As far as the signals, I am still not 100% on them yet. There might be some miscommunication between me and the resident expert. I will update you if anything is contrary to what I posted.

[jeds]

Thanks for the heads up on the signal!

I need to decide on tire size soon. I'd like to get some traction under it. I also need to run 17s to clear the brakes that are going on. It's becoming hard to argue with a square 255/40r17 setup. There is a huge selection of tires in that size, and I can even get all seasons. I have kamators flares on the way (which I plan to paint-to-match). I'm just having a hard time taking the plunge and cutting into the car.

[rzerob]

I spoke with a resident expert with gauge clusters and he informed me everything but tachometer is 9 pulse. 12v 9 pulse vr signal is converted to 12v 9 pulse digital square wave and that is the signal used sent to the obc, ecm, and cruise control. The return from ecm to tachometer signal is 1 pulse 12v square wave.

[jeds]

That's the plan. I have a pair of Quick-Latch hood pins I hope will do the trick. I was going to use Aero catch, but the Quick-Latch setup seems a little more subtle.

[z28]

The radiator looks great, are you gonna keep the hinges and just add hood pins on the front?

[rzerob]

So I have been researching the operation of the speedometer circuit and I am not 100% on this but so far this is what I have:

Speed sensor is 9 tooth vr sensor in the differential.

That signal travels to the instrument cluster by connector 2 pin 12 br/rd wire

The signal is cleaned up to a 9 pulse square wave and out puts this signal to connector 3 pin 26 br/rd wire to obc. And connector 5 bl/yl wire to cruise control.
(I believe the speedometer uses this same signal to operate)

A speed signal is also sent to the dme from connector 1 pin 11 yl/wt wire.

Then the dme sends the speed signal back to the instrument cluster to operate the tachometer through connector 1 pin 7 bk wire with 1 pulse 12v square wave. The signal goes through the coding plug for proper tachometer readings.

As far as I can tell everything is a 12v reference. If you find anything counter to what I wrote please let me know as I will be going forward with my own cluster project soon.

[jeds]

The Nova was parted out. It had a custom subframe with C6 Corvette suspension, an adjustable 4 link in the back, and a full 6 piston wilwood brake setup. I kept all of this. The plan is to complete the E30, then eventually hunt for a Nova that is in decent shape that I don't need to blow completely apart. Then I'll re-use all the suspension bits.

I haven't done any ECU or dash wiring yet. I've been contemplating how to handle the speed signal. It turns out that the VSS on these transmissions doesn't produce the correct signal for the Holley ecu, so I'd probably need a converter box. Something like Dakota Digital SGI-5E.

I, for some reason, hadn't considered wiring straight to the dash from the VSS on the transmission. I need to read up on the dash input requirements and what the PPM is from the VSS.

[Anthony B]

I appreciate “its only a mild LS just 550hp”

Looks like a great build, I love the racepak setup simple & clean. Hopefully the Nova gets a new lease on life, I’ve had a few mates with builds that have gone the same way with workshops

[rzerob]

Damn man. That sucks. So what did you do with the Nova? Part it out. It looked like a solid body.

Do you have your race pack cluster already wired in? I am assuming you are using the speed sensor in the t56 for signal. If you go with the stock one in the diff. it is 9 pulse so you will need to convert it to 8 pulse or your tachometer will be off.

[varg]

That is quite a lot, I think you'll find it adequate even if it doesn't make 500whp.

[jeds]

The ls3 came from Don Hardy race engines. It's fairly mild as far as LS builds go. They built it to be about 550hp. Anxious to see what it puts down once I get everything together.

[varg]

Nice. What kind of power are you expecting/aiming for? I'm a big fan of the brake setup but I've manual swapped E30s before and the pedal box is indeed a gigantic pain in the ass to do. If budget allowed, an LS3 is what I'd put in my E30.

[jeds]

Running sans brake booster?

Yup. Booster and ABS was removed. In order to package everything and have a quality intake setup, some things had to go. I had planned to run the Nova with manual brakes, so it made sense to just move everything over.

Subscribed. That sucks about the Nova. What happened?

The Nova was getting a large amount of fabrication work done (roll cage, motor moved back 13", boxed frame and fabricated floor, etc ...) The car was at the shop for 2 years with almost no forward progress. When I finally decided to go grab the car, they rushed to get some of the stuff done. The entire floor and firewall we're removed, the cage was half completed (only tacked) and looked like a rush job, the boxed frame was partially welded and not square. The list goes on. But...the worst thing was that all the VIN information was chopped off the car and discarded. I went back and forth with the DMV trying to find a way to register the car, but they told me I was SOL. Short of me doing something sketchy and finding a body to chop a VIN tag off of, it was a lost cause. I decided I needed to move on as I had grown to resent the project.

Live and learn.

[jeenyus]

This is awesome.