Sasquatch Part III Audi 1.8t transplant..., PCV upgrades finally... Options

[Chris H.]

That's an older post on the limp mode thing.

So just to hijack for a minute...How much firewall cutting is required to put a 1.8T in? I'm liking the 6 speed bolt-up idea.

[Andyrew]

That's an older post on the limp mode thing.

So just to hijack for a minute...How much firewall cutting is required to put a 1.8T in? I'm liking the 6 speed bolt-up idea.

Depends on how far back you put the engine/trans. There is physically enough room to put the engine/trans in the engine bay without any cutting but you have to line up the axles with the trailing arm stub axles. if you dont want the transmission flanges to walk out of the transmission.

Brad roberts thinks that is necessary and thinks you can get away with using some material to space out the flange C pin so it retains better as thats what they are doing on the boxster/ cayman cup cars.


Personally I moved mine back about 6" (or I will). Not going to miss the space as it comes from the smallest part of the trunk. The shock towers will make the starting point for the trunk. Targa top still fits, but it will be difficult to make it work well. The rear coolant flange is the rear most item there. If you built a custom flange you could gain probably 1.5" of space. Personally I like a lot of room.

[Chris H.]

Very interesting...thanks.

[Mike Bellis]

Mine is moved back to where you see Andyrew's bar. My targa top still fits in the trunk too. The 6 speed is longer, invading the stock muffler space. The 5 speed has 3-4 more inches of space.

[Mike Bellis]

Mike,

You've talked me into it. I've been reading this build thread since the beginning. So I have a chassis and I've been looking for the right swap, now I have it. Just picked up an Audi 1.8t donor car. The problem is that mine is a 01 a4 Quattro. I can't use the transmission like you did initially. I saw that you bought a 05 -08 boxster s 6 speed and as much as I'd like to do that now I want to put a 5 speed in to get it up and running. The only question that I'm not sure about is are all the 5 speed boxster transmissions a direct bolt up or are there only certain years that will work. From what I see on here they should all bolt up. It is really like to verify that before I buy a transmission that I can't use. Any help would be greatly appreciated. Love the build!

I Agree with Andyrew, buy a Passat tranny. They are almost the same tranny. Gear ratios are the main difference. The Passat tranny is cheap. If you had a torquey motor, I would recommen the 5 speed LUK TDI version from Europe. A 6 speed in good condition will run you around $2,500 minimum in the US. I got real lucky on mine but is does have a noisy main shaft bearing. One of these days I will send it to Dr. Evil. If you do go the 6 speed route, just remember, do not buy the tranny with the circular bell housing. You need the one that looks like the Audi/VW bell housing. All Boxster, Passat and Audi 5 speed trannies have this correct bell housing. The Boxster 6 speed has 2 variants.

[Porschef]

Interesting info, would that extra 3-4" allow for installation without cutting the trunk?

[Mike Bellis]

Interesting info, would that extra 3-4" allow for installation without cutting the trunk?

The extra 3-4" is on the tail of the tranny. Trunk firewall needs to be moved to clear the valve cover and align the axles. In my case, I also run the intercooler piping in this space too.

The axle center line of the tranny is closer to the motor than on a 901. You need to move everything back close to center with the trailing arm stubs.

[Mike Bellis]

Page 3 or 4 of this thread has a side by side of the trannies with the axle locations centered on each other.You will see the longer ball housing of the 901.

[Porschef]

Gotcha. Had I been more diligent in reading Andy's post I wouldn't have been asking that question... (IMG:style_emoticons/default/dry.gif)

It's been a while since you've done the conversion, do you prefer it to the rotary from a driving/handling standpoint?

Thanks Mike

[Mike Bellis]

My car can be driven like a stock VW or Audi when not in the boost. An everyday car. Once in boost it fuching awesome and really comes alive.

I've had 3 different renditions of rotary engines. They are fun, fast, loud but lack torque. I always had to use 1st gear on the 901 with a rotary. Hated it!

The newer tranny technology is so much better. That is half the fun on the car. If I had to drive the 1.8t in front of a 901, that would totally suck. It just can't be shifted fast or smooth enough to keep the boost up.

The Boxster shifter parts are far superior to the rod as well.

Overall I love the 1.8t. It's a great motor. The Bosch Motronic 7.5 and drive by wire are awesome.

Andyrew has more power potential and that's OK. This build wasn't about maximum power. I blew up so many motors, I just got tired of it. When I saw JRust's car with the previous owner drive from Idaho to Monterrey... I knew I needed a motor that reliable. So the build is about good HP (325 @ 20psi) and reliability. The car is awesome on the street and fast as fuch on the track. I was looking for a Subaru when I stumbled on the 1.8t. All the Subaru's I found were junk needed a rebuild.

[Porschef]

My curiosity is piqued because I have a shot at a 1.8 Passat engine & tranny. I should just slap myself upside the head as I don't have a smidgen of the fab skills you've got.

But, I guess I can dream... (IMG:style_emoticons/default/blink.gif)

Great stuff Mike, thanks for sharing.

[AZBanks]

I just read through the whole thread. Awesome work on everything except one small detail. All these amazing fabrication projects and you are using angle bracket as a battery hold down????? This car needs something better.

[Mike Bellis]

I just read through the whole thread. Awesome work on everything except one small detail. All these amazing fabrication projects and you are using angle bracket as a battery hold down????? This car needs something better.

You're right. It's original to the car when I bought it. It's just so low on the list and it works great, I never changed it. I've been waiting for the battery to fail for the last few years. It just won't die. I'm sure I just jinxed myself...

[Mueller]

I just read through the whole thread. Awesome work on everything except one small detail. All these amazing fabrication projects and you are using angle bracket as a battery hold down????? This car needs something better.

You're right. It's original to the car when I bought it. It's just so low on the list and it works great, I never changed it. I've been waiting for the battery to fail for the last few years. It just won't die. I'm sure I just jinxed myself...

If Mike gave me some dimensions I'd gladly make him an aluminum hold down for it to replace the angle iron (IMG:style_emoticons/default/smile.gif)

[Mike Bellis]

If Mike gave me some dimensions I'd gladly make him an aluminum hold down for it to replace the angle iron (IMG:style_emoticons/default/smile.gif)

yey big by yonder short.

[Mike Bellis]

Time for a long-overdue update. My car had a couple of issues I wanted to sort out. First was poor crankcase evacuation. The ATW engine is one of the few variants of the 1.8t that did not have a breather attachment on the valve cover; only relying on a block-mounted PCV breather box. This would cause blowby to come out of the dipstick tube due to oil windage blocking the PCV system vent with oil. (at high boost)
The second issue was airflow to my MAF. I had a short 90° elbow in front of it causing turbulence at the MAF. To solve issue #1, I needed to send excess crankcase air into the intake system to be re-burned.
I purchased a used valve cover from eBay that has a 19mm breather attachment. To keep as much oil out of the intake as possible, I added a catch can. I already had an air pump pulling air from the PCV system and dumping it into the exhaust, post turbo. This never worked well due to windage. This did however place oil into the exhaust tubing and would drip a little at a V-band clamp after a long drive. The air pump is from a VW (smog pump) repurposed and controlled by a 3psi pressure switch. Once it goes into boost above 3psi, the pump pulls air from the top of the valve cover and PCV box, pushing it to the air cleaner.

I purchased a bulkhead fitting for installation on a silicone boot in from of the MAF. Introducing more turbulence into the stream. The MAF is located right next to the passenger side firewall, near the old battery tray location. A hole into the fender cavity provides cold air via a NACA duct. I used a longer fitting before the MAF to allow straight air to be metered. The PCV air enters closer to the air cleaner (also inside the fender)

So before when I drove and hit high extended boost, the cabin would fill up with smoke and it would look like I blew an oil line behind me. Very embarrassing and unsightly. (IMG:style_emoticons/default/headbang.gif) Now there is zero smoke and the MAF work has resulted in increased torque at low rpm that is scary. Way scary! and fun!!! (IMG:style_emoticons/default/driving.gif)

Old valve cover, no breather tube.


New valve cover in place. catch can on left, air pump on right. You can also see the 3psi switch on the right.



I had to clearance out the NACA duct due to the added length from the MAF. What you see cut out actually sits out proud from the NACA by 3/8".


The third problem, I could not get the valve cover off without dropping the engine. A couple of cuts solved this too. The top right, under the blue boot, is the MAF. the blue boot is recirculated air from the combo recirc/blowoff valve. It reintroduces air right after the MAF since this air was already metered by the MAF. Crankcase air is unmetered and must be introduced before the MAF. It's also full of atomized oil droplets. This is what the catch can is for, pulling large droplets out of the air stream.

[strawman]

Nice to see back at it again, Mike. I look forward to riding in your car again someday. Be well!
Geoff

[Krieger]

Very nice work!

[Andyrew]

Awesome! Good work! I had to run a valve cover relief as well.

I'm glad you got that torque that that setup is capable of making it's a really good setup that's extremely responsive.

[Cairo94507]

This car's development just blows my mind. I can only imagine how this car runs when you get on it. (IMG:style_emoticons/default/beerchug.gif)