Turbo 90Q!! Cont.

[SilverCQ]

It’s about 395hp @ crank. I’m happy for about the torque curve, means I can run more power on the rods.

It’s not completely gutless, it’s similar or faster than my stock 10v NG when off boost.

Off-boost is as expected BUT the spool sounds amazing, it can reach 5psi when under 3000rpm but really kicks at +3000rpm.

Funnily enough I’ve already ordered a water pump so that will get fixed fairly quickly.
Although I’m also thinking of the spark, I don’t know what a stock alternator Amp’s are. Read it might be 120A, but looking at R8 & RS3 they have like +180A.

 

[SilverCQ]

Some time has gone by and a few issues have come up and they just HAD to be annoying to solve.

It had a weird mis/cut when boosting which was the worst thing in the world and it would get worse in higher gears and it took a while to solve... Thought it might've been alternator letting go or some weird Knock limit cutting -5° timing out of the table. But it turns out it was Boost cut kicking in, tuner sent a fix table but it hits about 17-15psi according to the gauge, so I've been doing some adjustment to the wastegate trim to see if I can make it stay around 20psi (which it's meant to be at).

There was a few issues with boost... Solved (hopefully) after water pump, but there was 1 point where it would keep blowing off:

Really annoying but we fixed it with some cut, bend & weld.

So far its been kinda working with cut still kicking sometimes but after the drive I realized I was trying to set it around 250-260kpa which is about 22psi boost (cut is 265kpa) instead of ~240kpa which thankfully I think I've solved. So now it should hit 20psi in all gears and not get stuck sitting under 20psi when trying to go in 3rd or 4th.

But thats been the current challenge, the one just before this was much harder, annoying and painful. Water pump leak was fixed after 3 pumps combined into 1. Initial pump we got was the fixed tension 2.2L one which at first leaked because the O-ring was the wrong size, then we got the proper one with slides (7A & NG had water pump do the tension for the timing belt which is pretty smart). Went on fairly well, only trouble was the blades being longer than the others so it was a struggle but it worked nonetheless. Until I tried to get the belt on and figured out the gear/cog was wrong and didn't mesh with the belt (different tooth gaps) which was even more annoying...
So then I tried the fixed tension one again but with the good O-ring from the adjustable pump, which then got 80% of the way until I turned the car on & it started whining extremely loud.. Fixed tension doesn't work with this setup

So in a last ditch effort before going insane was: Swap the gear from the fixed tension one into the adjustable tension housing... Surprisingly enough, after some screwing around on a press it had actually worked.
Went on, no leaks, no whining, literally perfect. Instead of the 2-3h it should've taken, it took 3-4 days & lots of cuts on my hands (one of which cut a few mm in my thumb)

Aside from the most annoying water pump ever seen, and me actually taking a plunge into learning how to tune the car is going fairly well. I think it has some torque steer when boost hits but that could be the "Unpowered-power steering" doing some wandering but eh.

The car sounds insane, it looks really unassuming, but it goes like nothing I've ever been in before.
Next on the list... Redo coil wiring, up the alternator to +120A, actual fuel tank. Criteria for next time it gets tuned after these things is: Higher Revs (7.5k lim), More Boost, Less Timing Advance (I'm staying with 98 Octane).

 

[jnrdavo]

do you think the very tight bent could be causing you some issues?

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[SilverCQ]

While I was doing water pump, we took that bit of pipe off made a few cuts & bent the sections then welded them together so its making a very good flare.

The bend is actually fine funnily enough. It's a 130° bent hose already so it is fine, and that side doesn't have a flare cause its never blown off.
I got a tune sent to me that should fix the boost cut issue and it works, but it doesn't quite hit full boost so I have been making some adjustments and worst case I go back to that tune.

At first I was trying to set it at ~255kpa when it was supposed to be 240kpa lol. Boost cut is set at 265kpa and trying to balance 20psi in 2nd & not over-boosting in other gears is was difficult. Especially 3rd gear @ ~5000rpm it would build boost literally immediately..
Then I had a look at his and thought I'd take some notes and change my mindset on how to set it up properly and I figured it out. Instead of trying to open wastegate at a different time to allow for maximum boost in all gears, I finished with a setup which gets to 20psi based on load. So in 2nd it hits 17psi because it doesn't have enough load in 2nd, but in 3rd & above it hits 20psi through the entire rev range AND it doesn't over-boost when giving it at higher rpm so its extremely good.

Now its just insane driving it with no cut. Its faster than I keep thinking it is, 1st & 2nd is crazy. One moment your at low rpm in 1st, then your at the limiter making ~15psi and 2nd just throws you to 80kmh as you lift cause you just saw speedo jump to 60kmh... Much like what dad's said about the UR, this one also pulls in 3rd like you wouldn't believe.

So far its been good things until yesterday. In traffic the heat on the drivers side usually does make the brakes feel funny but there was extra bad traffic and it was in the heat and everything. Brakes got real bad and luckily it started doing it when I was 2mins away from home (still in traffic, but handbrake is cable & works). The solution is vents near the reservoir.

you can only wonder how we solve heat issues.

It's in 'stage 1' because it was a 5min fix between multiple things but it might work:

My idea is to not bother with the bonnet (maybe in future) but we're gonna drill another hole (same size) then use a grinder to cut between the 2 and make a large duct. Bonnet vent is suspicious, the heat should be able to escape well (also make airflow better so it doesn't just get trapped back there). We might do the same on the battery side one day (once fuel tank is done & we redirect battery back into the boot) just so radiator flows better and just to get trapped heat out from the engine bay (also while keeping it fairly well hidden).

I'm also having a thought about how much power could be made on this setup by taking timing out and throwing more boost in. It makes nearly 400hp at motor with a 500hp capable turbo :| but I think I have some reasoning behind it cause I plotted roughly where the turbo goes on the graph:

I'd be hoping at some point to maybe, just maybe, take it to ~2.75bar boost (3.75 ratio = ~54.5psi atmospheric) but I dunno how long a turbo (and hose clamps) hold on at that boost

 

[quattro5v]

Drilling holes like that into your firewall usually results in an unroadworthy vehicle.

 

[SilverCQ]

I'd say that as well but theres quite a few things on this car thats... roadworthy... Audi firewalls are kinda weird though, to make it more permanent we could weld in a piece of metal next to where the vents breathe so it acts as a firewall (between lambda/fusebox & vents).

I'd say it was already not great because someone drilled holes to fit a 'coil rack' of LS1 coils and now it doesn't use LS1 coils, so it has like 3 ~1/4" diameter holes behind the reservoir (the big hole cut one of the little ones out).

Truuuust me its a way better option than what I had in mind for the bonnet if I couldn't drill through...

 

[SilverCQ]

So, there is a slight problem and it could range between new wires, a new part or a new car...

I tried to leave to go to a car meet. Turn on the car, sounds fine, open gates, back out, close gates, plug in music, everything seems good. Back out to turn around and go and as I stop the car dies... Completely, no lights, no starter, no nothing almost as if there wasn't a battery. Checked battery and it was smoking, part of it was hot & the wires were really hot.

Pull battery and put it somewhere incase it decides to explode, put in the battery from the UR and still nothing, although the wiring wasn't hot thankfully but still weird. Thought maybe that battery is dead so we give it a go at jumpstarting.

Connected properly and yea... The clip started glowing red after 3s so there is some major wiring issue at the moment.
Because its completely dead, I've taken the battery out and let them both sit just incase the UR's battery is now completely ruined but I have like 2 theories as to what it is:
Starter motor wiring is broken/melted
OR
Alternator is completely ruined

Only things I have to go off what might be causing it is:
At night all the lights would change brightness (like go dim then back to full brightness) and it would do that at idle and go away at higher revs.
The starter is separate from the ignition, so having no ignition & no starter is bad (cause I can usually use the starter with no ignition)

The reasoning for either new wires, new part or new car is fairly simple.
New wires is starter side, new part is alternator/regulator. Now I'm not very interested in moving into a new car even if the entire loom was forgone because the 20v just has that something special but there is a point you get to.. And it does JUST so happen that alot of parts work pretty well with a certain Coupe Quattro lmao but I also just so happen to have $0 for something.

The verdict will be given shortly. Its rego runs out on the 2nd so it'll be by then.

 

[jnrdavo]

First things first. Make sure you have fire and theft insurance!

Apart from that , I'm not going to be any help, it's beyond my skill set...

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[SilverCQ]

It’s on comprehensive, we don’t drive a car unless it’s insured.
I’ve been able to narrow it down slightly:
Alternator won’t matter, cause you can drive a car without one, voltage regulator is not sure (ECU shuts down when outside of voltage parameters)
Fuses are fine, alternator seems fine, but strange how it doesn’t cut power when it’s just ignition…
So far the biggest suspect is starter motor wiring.

I can turn the car over without turning fuel, spark & ECU in. Except now I can’t because of some weird issue.

The big wire is loose, small seems fine. I haven’t traced the wiring back to see if there is any damage BUT I do know where it goes

 

[SilverCQ]

This car I swear... Always some serious issue that is a somewhat easy fix and isn't difficult enough to pull out and setup for a Coupe Quattro
So it was starter motor wiring. And of course this is how we find out about the random 2 wires that were kinda in the way when installing the turbo...

It left a scuff on my turbo it could've been really bad. I think the main thing that saved it was the battery was already low on charge, it would've detonated the battery I reckon if it was full charge.

Ran an entire new wire from the battery terminal to the starter, it follows its old route then takes a detour and follows the intercooler pump wiring for a bit before going straight to the starter. Also re-routed the small wire to follow a similar path, but also taped it in certain spots then put some conduit around it (both power & switch) wires just to absolutely minimize potential damage in future.

But from what I can see, its fixed and works well:
Finally, an internal video

I noticed when close to the wall the flutter sounds awfully IMSA-esque. Now we are just going to do lil 'reliability' things, like new power steering hoses and finally get a fuel tank made for it, maybe a 120A alternator from a B4 V6.
Next tune it gets I won't be able to tell how much power it runs. Because I'm planning on having a go at tuning it myself later on, after I do a ~$800 tuning course & get a knock headset before I try and up the boost.

 

[jnrdavo]

sounds great, even off my phone...

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[Tas_Audi]

This car I swear... Always some serious issue that is a somewhat easy fix and isn't difficult enough to pull out and setup for a Coupe Quattro
So it was starter motor wiring. And of course this is how we find out about the random 2 wires that were kinda in the way when installing the turbo...
View attachment 32996
It left a scuff on my turbo it could've been really bad. I think the main thing that saved it was the battery was already low on charge, it would've detonated the battery I reckon if it was full charge.

Ran an entire new wire from the battery terminal to the starter, it follows its old route then takes a detour and follows the intercooler pump wiring for a bit before going straight to the starter. Also re-routed the small wire to follow a similar path, but also taped it in certain spots then put some conduit around it (both power & switch) wires just to absolutely minimize potential damage in future.

But from what I can see, its fixed and works well:
Finally, an internal video

I noticed when close to the wall the flutter sounds awfully IMSA-esque. Now we are just going to do lil 'reliability' things, like new power steering hoses and finally get a fuel tank made for it, maybe a 120A alternator from a B4 V6.
Next tune it gets I won't be able to tell how much power it runs. Because I'm planning on having a go at tuning it myself later on, after I do a ~$800 tuning course & get a knock headset before I try and up the boost.

I learnt my lesson many years ago with batteries and 12/24volt systems. Batteries are a vast store of energy and a 12 volt wont blow clear like a 240V fault.

Any high current connection to batteries especially if it is an add loom I always install a wire fusible link right at the battery. The fusible links just looks like a short piece of wire, but rated to a specific current. Any more than the rating and the link goes open circuit. You need to replace the link to get things going again.