B4Q 80-AEB TD04HL-15T->16T 630-> 1150cc

[ChrisAudi80]

Glad to see you found a solution.

I follow along, but try to only post when I have something to add so as to not clutter up your thread. Usually I'm stumped, or learning something new!

Yes, it was a relief to see things go back to normal. Another thing I have learned is that the Forge BOV/DV/ splitter whatever, does not work well on this car.
Stock 710n is where it's at. It's quite loud as a blow off and my wife does not really like the sound. This thing has been on the car for ages and just works.
All this noise about it's plastic, cannot hold the pressure/temperature blabla is BS.

[ChrisAudi80]

Been working hard to rewire a bunch of things on the car.

-Coil harness.
-Fuel pump wiring. Found toasty wires in the relay holder from the bad pump pigtail.
-engine bay subharness (WBO2, Fuel pressure sensor, K-type TC for post turbo temp, aux analog in).
-Motronic to VEMS adapter harness. A serious PITA, but had to be done. See pic of old adapter. It worked, but on inspection it was clear it needed replacement.

Several issues with the adapter harness, but got it to work properly today. Worked for two days to build it. Fucked up a few connections, but managed to fix them all.
I forgot to take a picture of the new finished adapter...

[Afterthought]

I don’t buy the diverter thing either . I think they criticized the plastic in order to market the billet ones.
I remember when the b5 guys were all going to forge diverters and later down the road people were having issues and going back to 710N . I was running over 600 WHP with those 710 and never a problem with the plastic ones, some seasoned runners argue they react faster, and they also don’t stick or require any servicing .

In that same car I ran two fuel pumps (dual 044 ) which was overkill I think. If sitting in traffic with a tank level was on the lower side (3/8 or less) it would actually heat up the fuel enough that it would cavitate because the fuel was just taking a free ride in a circle to the rail and back to the tank.


I need to develop he patience to build nice harnesses like that . Btw what is that material (not the heat shrink but the nylon looking cover)?

[ChrisAudi80]

I don’t buy the diverter thing either . I think they criticized the plastic in order to market the billet ones.
I remember when the b5 guys were all going to forge diverters and later down the road people were having issues and going back to 710N . I was running over 600 WHP with those 710 and never a problem with the plastic ones, some seasoned runners argue they react faster, and they also don’t stick or require any servicing .

In that same car I ran two fuel pumps (dual 044 ) which was overkill I think. If sitting in traffic with a tank level was on the lower side (3/8 or less) it would actually heat up the fuel enough that it would cavitate because the fuel was just taking a free ride in a circle to the rail and back to the tank.


I need to develop he patience to build nice harnesses like that . Btw what is that material (not the heat shrink but the nylon looking cover)?

It is called expandable wire sleeve or something. You can find it on Ebay. It does take a lot patience and planning. Make diagrams and tables. I'm still a n00b.

Might just be psychological, but it seems the car runs just a tiny bit smoother now.

[PRY4SNO]

That's a major update, well done. Wiring is certainly not my forte, so hat tip to you.

[ChrisAudi80]

That's a major update, well done. Wiring is certainly not my forte, so hat tip to you.

Thanks, man.

It was nerve wracking... My hands were shaking, bad butterflies in stomach, when connecting the last connectors.

[ChrisAudi80]

Decided to redo some of the fuel lines.

The feed now goes into the rear of the rail instead of over the block through a 180.
Return much shorter from the front.

And most importantly shortened the signal line to the Fuelab FPR by like half. Hope this makes a difference with control and eliminates the small ridge at around 2800 in the VE table.

See pic. It looks way cleaner than that stupid shit I had before.

[ChrisAudi80]

A small but critical part failed. This cause me to chase my tail for a long time even though it ran OK, but could not really maintain boost target. I put that down to the wastegate actuator being 0.5bar stock. I had been hearing a hissing sound from the ECU for a long time, but thought it was normal. Silly me.

However, it tuned out that the little tube inside the ECU to the sensor was borked big time. Luckily, a tuner I have befriended recently from Lithunia is visiting Thailand so, after fixing the issue by just replacing the tube with a silicone hose, we went for a drive where he live tuned the VE table because it was completely wrong.

Before, it idled at 60kpa, now 45. Cruise on hwy before 76kpa, now 60. Boost for days. Maintains 200kpa flat to 6000.

See pics of culprit.

[lorge1989]

glad you figured it all out! Those nagging things are nice to figure out.

[ChrisAudi80]

glad you figured it all out! Those nagging things are nice to figure out.

After all the work with the turbo swap, the rewiring and replumbing, it is a relief to find the lost piece of the puzzle.

Also fixed a nagging fuel leak today. Right at the return side of the rail. Just a smidge, but not cool. Hopefully it has the right O ring now.
Buddy of mine just polished the mating surface with some 1200 grit paper.

Also, I suddenly have some injector head room. Used to be 85% DC @ 180kpa and 5000+, but now easypeasy 70% at 200kpa at 5300.

[PRY4SNO]

Gotta love when one fix results in a cascade of improvements... nice work!

[jbrentd]

Nice find and fix on the tube. Gotta love cheaper fixes like that.

[ChrisAudi80]

Gotta love when one fix results in a cascade of improvements... nice work!

Yessir, and super easy to fix.
Thanks again.

[ChrisAudi80]

Nice find and fix on the tube. Gotta love cheaper fixes like that.

Yep, cost nothing but about 20-25 liters of E85 to rough tune the VE table. Done in an hour or two while a pro tuner with 10 years of VEMS experience sat next to me with the laptop.
It was so cool...

[ChrisAudi80]

Forgot to post these shots. If you compare the fuel pump wiring from before to now, so much better and cleaner. I spent a lot of time on the previous config too. Shit house
Moar better now. The relay and fuse are under the back seat now.

Bottom of fuel tank looks bad, but it's just dirt and weld discoloration. No rust.
The sticker is from a hilarious YT channel called juiceboxforyou. Some dudes in Ireland who are crazy about AE86s and other JDM cars.

[ChrisAudi80]

Just to summarize after the fixes:

Tune is now on point. Follows boost target (after spool up of course) and VE is within 4% margin of target.
Only thing left really is a dyno session to dial in ignition timing.

[Afterthought]

I would be so stoked to have someone locally who could dial my tune in! Too hard(impossible) to do it by myself

Fuel system looks good

[ChrisAudi80]

I would be so stoked to have someone locally who could dial my tune in! Too hard(impossible) to do it by myself

Fuel system looks good

Thanks.

The hard part is the rough table, starting from scratch. He is in country temporarily. Fine tune is not too bad. I do it all the time.
Do you have a standalone ECU? Then you can do it. Not impossible. I was a total noob 3 years ago. Still at elementary level IMO.

[ChrisAudi80]

More adventures with wiring and config.

After scratching my head about the weird voltage drop issues and erratic voltage reading in VEMS, it has been partially resolved.
Changed the ground for the fuel pump. Measured 12.6v between FP + and -, but 13.0-13.1 between FP+ and chassis. Weird. Had FP- going back to Battery -. Now chassis under back seat. Done.

Voltage at Batt + & - 13.5-13.6v. Voltage reading in VEMS was erratic. Varied between 11.8 and 13.2v. My Lithuanian friend suggested to power ECU direct from Batt+. Hey presto: 13.5v stable. Fark. So, quickly wired in fuse/relay circuit to power ECU. Looks shithouse so will have to tidy it up next week.

Had a weird issue with fuel pressure reading. Did not follow boost 1:1, but no lean spots or increase in requested VE. Just needed to recalibrate the sensor in VEMS, by moving from 0.497v = 0MPA and 4.497v = 0.689MPA to 0.5v = 0bar and 4.5v = 6.9bar. I is an idiot. I had that before but thought it wrong.
Base pressure = 3bar. If idling at 50kpa, should say 2.5bar. Duuuuuh At 200kpa FP = 4.0bar. On the money. Job done.

Will log tomorrow to see what effect the smooth voltage has. Hopefully an improvement.

This is Kaizen.

[ChrisAudi80]

Some maintenance. Had an annoying oil leak for a while. I was fairly sure it was the front crank seal. Not quite.
It was time to do the timing belt set I figured. Good thing I got it done. The water pump belt was about to go. Dry rotted and cracked.

However, it was not the crank main seal that was leaking. I had that replaced about 3-4 years ago, so thought it weird it would leak so soon.
Turns out i was the gasket between the block and the bracket that holds the front main seal.

So, while in there, changed out the timing belt, idler, tensioner and accesory belts.

Pics... Includes gratuitous picture of my dog.

[ChrisAudi80]

When you think, finally, it's getting somewhere, something else happens.
These cars are old and stuff corrodes/wears out. Like the fuse/relay board. Cooked one of the fan relays. Man, that stinks!

So, bought a replacement board, a bunch of 214 relays, fan resistor pack and a fuse box cover that still has the sticker on it.

I THINK I have figured out the ridge thing in my VE table at 3100 rpm. Partially it is signal hose length to sensor causing resonance, but also my pick up point is right at the throat of cyl #2. Not only that, cruising at 3100rpm is around 120kmh. TPS is then 21%. So, the resonance probably reflects off the throttle blade right up the signal hose fitting. This is only under 100kpa, not in boost.

Will probably relocate the 1/8" NPT fitting to between runners for #2 and 3 in the plenum.

[ChrisAudi80]

Relocated the MAP signal position on the plenum. Made no difference really.
Staring at the logs every time confused about WTF is going on.

Still have oscillation in my VE current and so corrected VE. I don't see any oscillation in MAP or fuel pressure.
It could be the MAP signal filter is not showing any rapid jumps in MAP. At the moment, this happens from 3200 to 3400 RPM.
After 3410rpm stable and back to a reasonable VE value. It wants like 7-10% more fuel in that rev range between 50 and 90kpa.
So, I get a hump in the table.

I guess next step is to switch back to a as short a silicone hose as possible for MAP signal to see if the harmonic moves up the rev range.

[PRY4SNO]

That's a complex issue I have no grasp on how to fix, but am glad you're posting here because it's valuable for a n00b like me to follow along.

[ChrisAudi80]

Don't feel bad. Thanks for the comment. Consider myself a n00b too.

It is starting to look like it's not MAP signal related. Fuel pressure and MAP is stable everywhere. However, lambda does suddenly look like a saw.
Target VE is stable, but corrective VE is also jumping. So, it would seem logical that EGO corrective VE follows the saw tooth pattern of actual lambda.

This leads me to believe there is some kind of resonance in the down pipe. I would have to tap in a pressure sensor right next to the WBO2 to check.

[ChrisAudi80]

Because I am a data geek and love coming up with overly complicated stuff, I am working on a study project that will take some time.

Have been ruminating about the hump in the VE map, so thought "what if there is some kind of resonance in the DP? How would I find out?" Ah! Measure pressure next to the WB sensor! So, down the rabbit hole I go...

Just bought a 2nd hand Pneumadyne vacuum manifold with 4x 1/8" npt ports and 2x 1/4" npt ports, 3 pneumatic switches and will get a whole bunch of adapter fittings, a Honeywell 100 psi sensor and bundy material hard line to make a switchable port manifold.

It will measure:
1. Down pipe back pressure. For purpose mentioned above.
2. Exhaust manifold back pressure. To see where max effective boost is at. EMAP/IMAP ratio.
3. Post turbo pressure. To correlate to IMAP and double check for leaks and IC pressure drop.
4. Possibly crank case pressure, but need to make sure the block adapter seals properly.

Only one sensor because they are expensive and I only have one (usable) analog in left on VEMS. The sensor will have a pulse damper/muffler on it. Top tip from HP Academy.

Will this net moar powah? Nope. Is it fun? Yessir!