1986 325iX 3.1L Stroker + Turbo

[downforce22]

I got the variable TPS hooked up tonight. I didn't have to splice any wires and it works ok, must be due to the pinout that is wired for it in the Whodwho MS2 unit.

I used the old tps and took it apart. Strangely it had oil in the sensor so it may not have lasted that long. I used the plastic housing and ground it down to fit the e36 tps and also mount on the throttle. No reason to turn the throttle shaft around, it fits just fine. I was worried that the sensor may not work as it was a junkyard tps but it works great and I am glad I sacrificed the old tps for the new one.

One thing I noticed is that the vtps travels about 75% of the throttle travel and moves the throttle about 50% on the MS2 unit. Then once you get that last quater of travel it transitions up the second half of the sensor to 100%. I suspect the sensor is like that to allow for good steady inputs where you spend most of the time driving at the lower portion of the map.

I will need to update my fuel map as the sensor is different from the old one at low throttle positions. I am hoping to do that the rest of this week. This was one of the last hurdles before turbo time!! ;D

[downforce22]

She runs alright now and I have been tuning to get it closer. I am at a happy medium now. Here are my fuel and spark maps. I based my spark off of tinkerputz's 3.1L stroker located here:

http://www.r3vlimited.com/board/showthread.php?t=265471

Compared to Tink's ignition map:


I seem to have a slight misfire at idle, any ideas what it could be? Do I need more advance?

[downforce22]

Here are a few pictures from the annual Ice Gymkhana with a couple other iXers.









I also got a few brochures of the early model cars and saw a few interesting differences.



The 325i Allrad is the German version. The 325iX with X-traction is the English version.



Notice the German one was printed in 1/1985 while the english was printed 2/1986. My car is older than this english brochure as the vin calls out 11/1985 production date. Also, below is another one I found online printed 2/86 in German. Note, this brochure was PRINTED in January of 85. That means the car had to be in production sometime in 1984!!






The english article calls it the X-Traction system. Who came up with that? Either way the next section calls it both the 325i 4 wheel drive (VIN Tag on my car is 325i btw) and the 325iX in the next sentence.





The english article calling out the 3.64 final drive.



Here are the official 0-60 times and fuel economy figures. Notice the catalytic model is way down on economy, down from almost 27 mpg at 120 kph (74 mph) to 24 mpg with just the cat!



And the official weight of the car listed at 1255 kg in base trim with 75 kg driver for the 2 door! That is 2767 lb! Now I want to check it officially on a scale, but that is an amazing weight savings over the stock iX. Almost 250 pounds and almost 100 pounds lighter than an '88 325is. 10 lb/hp should be easy at 2800 pounds!

[King Mufasa]

Large part of this community are young men and women (still students) looking to better their car at a low cost $$. Everybody here has the right to exercise their path they choose.

PO if you are going for it just try not to exceed its limitation like other fools do.

[AWDBOB]

I will never understand. The E30 community is one of the most educated I've been a part of, but for some reason it's the only community where it's okay to run eBay turbos (besides the Honda crowd, and maybe the driftboy 240 crowd). I know multiple locals who had seals let go during a pull and wiped out their bottom end. Why chance it? The shitty transient response alone makes it not worth it.

At least run a $200 HX35 and rebuild it yourself for $30.

[King Mufasa]

I think he'll know if it blows.. Or drops oil pressure.

[AWDBOB]

Don't use it! It's not worth it! Turbo blows, you lose oil pressure, and spin bearings. You can get a used Garrett 3076 or 3071 for next to nothing anymore.

[downforce22]

Really interesting video I found on the ebay turbos. Looks like they do advertise the measurements on ebay but the housings don't match the size. Its not really a surprise when you can get this turbo for under $200.



From an ebay ad I found, I am 99% sure this is the turbo I have and like the video, it is also the JDM Sport 'T70' with divided exhaust housing.



T70 Turbocharger
Condition - Brand New!
Manufacturer - JDM Sport
Application
Ideal for large (3.0L-6.0L) displacement engines
Features
Stage 4 turbo capable of 300-500 HP
Capable of 25-35 PSI output at peak power performance
Wet float bearing
External wastegate
Compressor
Inlet = 4"
Intake (ID / OD) = 2" / 2.5"
Inducer = 56.2 MM
Exducer = 72.9 MM
Trim = 59
A/R = 0.70
Turbine
Outlet = 2.5"
Turbo flange = T3 [twin entry divided flange]
Downpipe flange = 2.5" V-band
Inducer = 73.9 MM
Exducer = 58.3 MM
Trim = 62
A/R = 0.84
Center Section
Oil cool system
Oil feed = T3
Oil return = T3

Looking at turbo sizes, this neat size calls it out as the same size as the TO4E 57 trim or Garrett GT3037.

http://fc3spro.com/TECH/TURBO/tmodels.html

[downforce22]

The daily got some love. Apparently the old windshield seal was folded underneath and caused rust to form under the cowl, both in the corners and center near the wiper arm. The paint was pulling up from the metal and I knew it was bad. I didn't know there were rust holes underneath. So when I went to get a new windshield I was surprised to see terrible rust. I'll let the pictures speak for themselves.









A donor 325 gave its cowl to the old girl and some new paint ended with this. What is an e30 with new glass like to drive? Amazing! No glare!

[tschultz]

Cool that you have been making progress on this. I'm sure the warm weather has helped!

[downforce22]

Glad you got it sorted!

For start up cold that isn't too bad, warmed up it would be too rich. Does it seem rich at all loads? you can adjust the required fuel if so

If the jumpers on the board are set for vTPS and you are running the stock TPS it will creep, you can re-jumper for the stock one or install a variable one if you have one

FYI, if it is set for a variable one and you are running a stock TPS, on full throttle(~70ish+ %) it short the vRef and reset the ECU and the car will cutoff and come back when you let off the throttle

Perfect, thanks Keith! Thats exactly what I needed to know

My req fuel was probably too high, but I am going to keep it where it is right now and just tune.

I think I have a spare vtps I will try to hook up, but yes it will creep up and then when I was trying to calibrate it, it resets the ecu and cuts off like you described. I suspected that might be it.

Now when I install the Vtps, do I still need to cut the wiring, or can I keep the wiring the same?

EDIT: I think I found my answer on the tech. I really hate cutting wiring though...

http://www.e30tech.com/forum/showthread.php?t=98055&page=1

Also taken from diypnp site:

TPS / Idle Air Control / Acceleration Enrichments

This model does not have a variable TPS, rather an on/off style. As a result the IAC type will need to be set to "PWM Warmup" as well as the standard Accel Enrichments (not Enhanced) used.

Until a variable TPS is added, TPS SIG from the Main Board will need to be jumpered to Ground with a 1k Ohm resistor to prevent the TPS signal from gradually floating higher and possibly accidentally triggering flood clear mode.

The addition of a variable TPS will allow the use of Closed Loop Idle Control as well as Enhanced Acceleration Enrichments as both of these features look to the TPS signal for feedback. If you add a variable TPS, pin 52 connects to pin 1 (brown / blue wire) on the factory TPS wiring, and pin 53 connects to pin 3 (brown / black wire). The brown center wire of the TPS connector is grounded. We are not aware of any off the shelf TPS that matches the connector and pinout, so you will need to do some wire splicing.

http://www.diyautotune.com/diypnp/apps/b55/usdm-bmw-325-8792-m20b25-mt.html

[whodwho]

Glad you got it sorted!

For start up cold that isn't too bad, warmed up it would be too rich. Does it seem rich at all loads? you can adjust the required fuel if so

If the jumpers on the board are set for vTPS and you are running the stock TPS it will creep, you can re-jumper for the stock one or install a variable one if you have one

FYI, if it is set for a variable one and you are running a stock TPS, on full throttle(~70ish+ %) it short the vRef and reset the ECU and the car will cutoff and come back when you let off the throttle

[downforce22]

Good news!!

Firmware was updated and the base tune was good and she fired right up. Fueling was very rich, idling about 10 to 11 afr. My wideband wasn't reading on tunerstudio. I got it corrected and tunerstudio was reading it correctly.

She runs ok but my TPS isn't working right. When I put the throttle down sensor at a constant input (say 35%), the sensor keeps rising up and up and up. It goes to 200% then 300% and so on until I left my foot off the gas. Does anybody know how the TPS is supposed to work vs the VTPS from the e36? I may just try to swap in a VTPS form an e36.

Anyway, I am almost ready to start the turbo install!

[mr2peak]

One of my past E30's had a taurus sport interior, wish it had been as clean as yours!

[downforce22]

Ill just leave this here. Just for mock up at the moment.

:ST1G: