Audi S1.5 [OEM+] - (10-valve turbo B3 Coupé)

[LeafBox]

INTRO
I've been thinking about this project since I was 15, but until recently, a place to work and money have never been available at the same time. I could write books about this, but it feels best to keep it short. So I thought I would share some quick info and put some pictures up so you guys can see what we're working with.

WHAT?
In the end it not more complicated than putting a 10vt in a B3 Coupé. But since it's going to be road-legal there are some other part that's going to need work. And then there's ofc stuff I want to change other than the engine.

WHY?
I suspect alot of people are going to wrinkle their nose over some of my decisions.

"Why are you building on a FWD?"
"Why not just buy a S2?"
"Why not use [another engine]?"
"Bork! Bork!"

It might happen that I actually do a video solely to adress this topic, because it's just to much to type out, but most of the questions can be answerd with a simple; "Because this is how I WANT it to be."

HOW?
So, how do we get a Audi 100 turbo engine into a Coupé? It's quiet the puzzle as you might know. I bet there's stuff I haven't thought of, but here's a rought draft

Engine&Gearbox
MC2 (Audi 100 turbo -88>)
”Mac14” ECU
8,4:1 Compression
K24 turbo
Knocksensor (x2)
Other IC
MC2-gearbox (because of emission-rules)

Front
20v hub-housing (same as S2 according to ETKA)
A100t hub (5x112 ET45, same dimension as S2 according to ETKA)
A100t brakes (276x25mm, same bracket and caliper as S2 according to ETKA)
A6 (-94-97) [O]CV-joints (38O,30i,59,5Ø)

Rear
A100t hub (5x112 ET45, same spindle as coupé according to ETKA)
Standard disks (245x10mm, same dimension as A100t and same bracket/caliper according to ETKA)

Wheels
Avus 17x8” (5x112 ET35, Audi S6 V8 (-98 -04), +8mm spacers?)
225/45 (-1,15% omkrets)


OTHER
There might be alot of mix between Pics/Text and Video, because sometimes video is just simpler. So it might look like some kind of weird documentary? We'll see, I already got some video I wanna do something fun with.

PICTURES

Project-car
In it's prime!


Parked in the garage


Donator-car
A proper square!


Relativly low milage


Garage



INTERNATIONAL
If you're reading this on a international forum I want to point out that I will only update on this forum IF there's enough interest. Because these take quiet some time to translate. And also, if videos do appear, they will be texted in english.
So if you find this interesting, let me know to stick around.

[Takumi]

go for it

[Nuvo]

Great project! Subscribed with much interest. Looking forward to reading about your efforts.

[igor136]

That's it. 10V power

[rxl]

thats a big garage.. subscibed

[gavs20v]

Loving some of these home brew 10vt projects coming through lately

Gav

[rxl]

It's something different.. And not often.. And also very interesting becouse of that

[LeafBox]

It seems to be some interest brewing here. Noted.

I'll swing by tomorrow with more details about the project and my plans, and then again at the end of the week with some actual progress-pics.
I do have the old engine out already, so there's a bit of a backlog.

If you have specific questions, feel free to leave a comment, and I'll adress it tomorrow.

[LeafBox]

Let's go into a little more detail about what's planned and why I chose too do so

We'll start off with a little backstory and a short overview of the donor-car, and after that go into more details about what and why.

Coupé
Ordinary 2.3E, tach shows ~225km.
FWD without any fancy options, I didn't even get power windows.

First time I bought it was back in 2009


Had to sell it 2011 because I had just moved out and spent all my saving on furniture and then lost my job. (Last in, first out!)
In the spring of 2013 I saw an ad for it again, and my situation was a little bit more stable, so I just couldn't resist buying it back.


Even tough the car isn't anything special or out of the ordinary, the sentimental value is off the charts.
It was my first car, with all the implications. Alot of memories and experiences had not been possible without it. I got 2 canvas-paintings of it in my apartment. One of them is my wedding photo...
So, it's not worth much, but at the same time irreplaceable.

Donator
Audi 100 turbo from 1989, 175km on the clock. This is an "MC2" I don't think you guys need further explenation.
It spent the last 3 years standing under a tree, but the engine seems to be in good condition.
Packed with extras! Cruise-control, onboard-computer, autocheck, gas-heater and a weird extra backseat that folds into the trunk? I don't know how much I'll move over, but I'd atleast like to get the computer working.


BECAUSE!
I thought we'll take a closer look on why I chose some parts.

Engine&Gearbox
MC2 (Audi 100 turbo -88>)
I wanted a 10vt for severals reasons. First and foremost because I think they're way cooler than the overused 20vt. Ofc a 20vt is a better choice for almost every reason, but it kinda steps on the toes of "OEM+." I dont see a world where the 20vt would be an option for a FWD. A 10vt however would fit like a glove, and I don't understand why it wasn't a factory option.

MC2-box
More or less only because of swedish build-rules, but it feels better to have the proper gear-ratio, and it's also nice to not have to spend time figuring out the clutch/flywheel.

Front
20v hubhousing
I wanted 5x112, and they needed to be changed anyways to make use of the turbo brakes. Which are obligatory according to swedish build-rules. I was going to use S2-stuff, but that was surprisingly hard to get a hold of. But I found these, and according to ETKA, they're the same. Time will tell.

A100t hubs
As I said, I was going to use S2-stuff. But since I couldn't get a hold of housings, I started to look for alternatives, and once again ETKA says they're the same dimension, and since I already have them I might aswell try.

A100t brakes
I'm just trusting ETKA at this point, they supposedly fit, and once again I might as well try

A6 (-94-97) [O]CV-joints (38Y,30i,59,5Ø)
I needed something that fit both the standard driveshaft aswell as the new turbo hubs

Rear
A100t hubs
It was either this or A4B5 hubs, and they looked complicated and annoying. And once again, I already had these available. So it would just be stupid not to use them. The turbo uses the same spindle as the Coupé and A4, so it shouldn't be a problem.

Standard disks
The standard disks are the same dimension and uses the same bracket/caliper as the turbo, so no need to change anything here.

Wheel
Avus 17x8”
5x112, looks great, comes from Audi, and 17" feels like the proper size.

225/45
Simply the dimension closest to stock.

These are all stuff needed to be changed because of either swedish rules or as a result of one of those changes

CHANGES
Stuff I want to change that's not obligatory

Power
1Bar WG-spring + Chip
We do want a little more than stock 165hp. As you know this is very common and atleast puts us on the right side of 200.

2.5" Exhaust
This would have to wait until after registration, but when you have a 10vt you have to be able to brag about it

Chassie
Harder buschings
Not all of them, but a selected few.

40mm lowering
An H&R-kit is already mounted on the car since the first time I owned it, looks good and is already there so...

Exterior
Remove light-washer(?)
Looks like 2 warts on the bumper, never liked it and does no good. So off they come.

Interior
S-wheel
A very appropriate upgrade in regards to our new found sportiness

The sound system is also in for an overhaul, but noone cares about that

FUTURE
When everything is 100% said and done, it's not just these changes that are done, but a near complete restoration. Everything from paint so missing bolts will be replaced.
This is ofc a massive project, so to not run out of motivation, and to avoid unnecessary headaches, it will be done in steps.

Step 1 = Planning

Step 2 = Make the car drive with the new parts and get it registered

Step 3 = Restoration

Doing it like this has 2 benefits. I get to enjoy my hard work and relax, and I get to properly test everything and make changes accordingly before restoration-season begins.

END
I was going to answer some comments, but this post kinda dragged out, so we'll skip it for now.

Now when I've told you a few more details, it's time to make progress. As I said, I already have a backlog of stuff to show you, so coming the nearest weeks I'll make regular updates until you guys have cought up with me. After that I'll just roll them out as I work.

[K Simmonds]

I was going to do the exact same as what your going for with my old 10V FWD Coupe, I got as far as picking up a doner Audi 100T with a cracking engine and breaking it then I changed my mind and decided to put the engine in a B2 quattro. Then I ran out of time and space

Be great to see this finished, the only real hurdle I found was getting the offside tie rod to clear the wastegate, not a big issue though as you'll see.

Will be keeping an eye on this thread.

[igor136]

10V sounds better, like S1. This Audi 100 is a great car.

[LeafBox]

I was going to do the exact same as what your going for with my old 10V FWD Coupe, I got as far as picking up a doner Audi 100T with a cracking engine and breaking it then I changed my mind and decided to put the engine in a B2 quattro. Then I ran out of time and space

Be great to see this finished, the only real hurdle I found was getting the offside tie rod to clear the wastegate, not a big issue though as you'll see.

Will be keeping an eye on this thread.

Ha, small world.
Yeah, I am aware of the tie-rod issue. My first thought was to buy a bent rod from 034, but they're kinda pricy. So my current plan was to just see how bad it was before making a decision.

10V sounds better, like S1. This Audi 100 is a great car.

100% Agree, 10v sound is so much better.

[LeafBox]

Video-update

I had a lot of material from when me and my buddy went to buy back the car that I wanted to do something with.
It's basicly 10min of us complaining and doing kareoke.

(subtitled in english ofc)



If you like this kind of update, let me know, and I'll try to film more than take pictures in the future.

[S2central.net]

Certainly an unusual approach in these parts where all things 20VT is the norm... but as pointed out - with FWD then anything more than 200bhp is just going to be silly, so unless you wanted to go really crazy and convert the chassis to quattro it would be a waste fitting the 20VT motor.

I must say the MC2 engine bay looks very disorganised and busy with all those old school systems - good luck making it all fit in the B3 without drama.

I used to have a KV engined B2 Coupe (FWD) so I too love the 10V burble and curious K-Jetronic systems - that was my first Audi... not my first car sadly. Back in the day I wanted to do the 2.5L conversion on that motor but funds never allowed !

[LeafBox]

Certainly an unusual approach in these parts where all things 20VT is the norm... but as pointed out - with FWD then anything more than 200bhp is just going to be silly, so unless you wanted to go really crazy and convert the chassis to quattro it would be a waste fitting the 20VT motor.

I must say the MC2 engine bay looks very disorganised and busy with all those old school systems - good luck making it all fit in the B3 without drama.

I used to have a KV engined B2 Coupe (FWD) so I too love the 10V burble and curious K-Jetronic systems - that was my first Audi... not my first car sadly. Back in the day I wanted to do the 2.5L conversion on that motor but funds never allowed !

The MC2 really is a complete mess, without a doubt the most cluttered enginebay ever
It kinda looks like they designed most of it as an afterthought. It's gonna be horrible to move