Jun 26, 2020 update to the Volkswagen Fox project car

Project VW Fox: Did Trading a Five-Speed for a Four-Speed Help or Hurt?

When someone talks about a transmission swap, it often involves adding a gear or two. 

Not us.

During our Lemons outing with our VW Fox endurance race car, something inside the transmission broke, preventing the box from holding fourth gear. We couldn’t find another five-speed transmission–anywhere–for this oddball application, so we went with the next best option: the more commonly available four-speed box

While the car was on the lift, we addressed the faulty wheel hub that forced us to retire at Barber. We also double-checked our front brakes to make sure they were still track-worthy.

Before we took the Fox out on a shakedown, we also needed to address our axle nuts. For some reason, the nuts come loose every single time we take it out on the track. Where most race cars will have some sort of retainer to keep the nut in place, we didn't have that luxury–perhaps due to our Fox’s pedestrian origins. Our solution, then, is to use wedge-locking washers from Nord-Lock. Their interlocking design should keep things tight even as the axle nuts try to loosen themselves under heavy loads.

All squared away, we loaded up the car and headed to the Florida International Rally and Motorsport Park to shakedown our four-speed Fox. Did the transmission swap help our budget racer?

Well, not particularly. We soon discovered that second gear was too short and third gear was too tall. We effectively made our Lemons racer even slower.

This was also the first time our crew chief, Wayne Presley, has driven the Fox, having been previously sidelined with a broken shoulder. His thoughts? Almost verbatim of our very first shakedown: "It's not terrible." However, he did admit that the Fox handles well, taking curbs at speed and dropping wheels off the road with little issue.

So, our final consensus is that, yes, we did make our Fox slower by trading one unobtanium transmission with another of unknown health, but at the same time we also had a relatively benign platform that is still holding together. 

What's left to do now on our Fox? Like any responsible Lemons race team, we're going to add power. We hope to accomplish that through an uprated camshaft, a freer-flowing exhaust and a chipped ECU from Techtonics Tuning. Look for us–sporting more power yet fewer speeds–at ChampCar’s 14-hour contest at Daytona International Speedway on July 5, the same weekend as the IMSA WeatherTech 240.

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brad131a4 (Forum Supporter)
brad131a4 (Forum Supporter) Reader
6/25/20 10:09 p.m.

Ok that's a nice big stick with a socket on the end. I can tell by just how little you moved the nut you are not even close to having it torqued down to what it needs. If my memory is correct but probably is not I feel they should be north of 260 and possibly closer to 360.

brad131a4 (Forum Supporter)
brad131a4 (Forum Supporter) Reader
6/25/20 11:11 p.m.

Did a quick search and there is a audi 80 5speed at the pick n pull in St Louis MO. It will work in the fox. Also found a few audi 4000 5speed  trans scattered around the country that will work as well. 

Honsch
Honsch New Reader
6/26/20 12:43 a.m.
brad131a4 (Forum Supporter) said:

Ok that's a nice big stick with a socket on the end. I can tell by just how little you moved the nut you are not even close to having it torqued down to what it needs. If my memory is correct but probably is not I feel they should be north of 260 and possibly closer to 360.

Nope.  172ft-lbs, no more.  We snapped the threaded end of quite a few of these axles from over-torquing.

 

Honsch
Honsch New Reader
6/26/20 12:47 a.m.
brad131a4 (Forum Supporter) said:

Did a quick search and there is a audi 80 5speed at the pick n pull in St Louis MO. It will work in the fox. Also found a few audi 4000 5speed  trans scattered around the country that will work as well. 

Many of those transmission are mismarked.

They need a 2P which is quite rare, from four cylinder FWD Audis when the five cylinder quattro was all the rage.

Honsch
Honsch New Reader
6/26/20 1:02 a.m.

I thought you guys were running CIS?  How are you going to chip it?

If you want to see what a Fox does with more power and a good transmission,  you can look here.

 

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
6/26/20 6:14 a.m.

We're running Digifant laugh

And not sure what clip made it into the video, but the nut is overtorqued if anything. 

MadScientistMatt
MadScientistMatt PowerDork
6/26/20 7:34 a.m.

Since this is a north-south motor, could you fit a later A4/Passant transaxle in there?

Extra crazy points for quattro.

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
6/26/20 9:10 a.m.

the $800 fox I had in HS was 5 speed. Had no idea the trans was unobtanium. Unfortunately I basically gave that car away when the injectors all went full open and filled up the cylinders with gas. 

stylngle2003
stylngle2003 Reader
6/26/20 9:52 a.m.

any chance to go to a shorter ring and pinion? would hurt fuel economy and enduro range, but might make 3rd more usable.

Honsch
Honsch New Reader
6/26/20 11:10 a.m.
Tom Suddard said:

We're running Digifant laugh

And not sure what clip made it into the video, but the nut is overtorqued if anything. 

Did the Nord-Locks help?  Maybe we'll get some for our Fox if they do.

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
6/26/20 11:20 a.m.
stylngle2003 said:

any chance to go to a shorter ring and pinion? would hurt fuel economy and enduro range, but might make 3rd more usable.

They should just go with shorter wheels/tires. 

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
6/26/20 1:07 p.m.

In reply to Robbie (Forum Supporter) :

Hard to go much shorter than a 195/50 15 these days. :/ 

And to the person that asked about Nord Locks: So far so good! We haven't tested much, but our impact gun can't remove the nuts anymore so that's progress. 

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
6/26/20 1:50 p.m.

In reply to Tom Suddard :

truth! maybe you need 22s to make 2nd taller...

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
6/26/20 2:10 p.m.

Axles loosening up is often a sign of weak wheel bearings.  I wonder if Audi 4000 strut housings had larger bearings.

Honsch
Honsch New Reader
6/26/20 7:06 p.m.
Pete. (l33t FS) said:

Axles loosening up is often a sign of weak wheel bearings.  I wonder if Audi 4000 strut housings had larger bearings.

They're the same wheel bearings.

VW used a friction locking nut with no other failsafe.  It's a poor design.

brad131a4 (Forum Supporter)
brad131a4 (Forum Supporter) Reader
7/3/20 3:09 p.m.

(Many of those transmission are mismarked. They need a 2P which is quite rare, from four cylinder FWD Audis when the five cylinder quattro was all the rage.)

Weird I have found a few front drive 80's with 4 cylinders that would work. Guess I need to go through my paperwork and check out the codes.

Ok the Bentley transmissions codes listed for the 4 cylinders are AKL or AUF for the 2.0ltr block. The AKT is listed for both the 2.0ltr and 2.2, 2.3ltr motors and is the quattro one. Yes there are a few but rare 4 cylinder 80 quattro's out there.

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