Volkswagen Corrado Race Car

Engine Progress Report

2010-01-18T23:36:00.003-05:00

The reground and balanced crank is in. Two of the old connecting rods were a little blued from the spun bearings, but I got lucky and found a never-used set for sale on Craig's list for $100. I got them balanced by House of Balance in Elkridge, MD - the same people who had previously balanced the rest of the engine. Here's a picture of the balance card. The pistons are attached to the new rods and I'm in the process of installing them into the block.

Fuel Rail Mods

2010-01-18T22:50:00.011-05:00

The car has braided stainless steel fuel lines with -6AN fittings all the way from the fuel cell to the fuel rail. However the one weak link was the attachment of the ss hoses to the stock fuel rail barbed steel tubes - the hoses were just pushed onto the barbs and secured with hose clamps. I decided to modify the fuel rail to accept a proper -6AN fitting to attach to the ss hoses with a swivel hose end.
I measured the fuel rail tubing and determined it was made from 8mm o.d. tubing. After some searching the Internet, I found http://www.discounthydraulichose.com who sell a line of metric compression fittings and adapters to convert them to JIC 37 degree flare fittings, which will connect up to a -6AN hose end.

The first job was to cut the barbs off the fuel rail tubing - I used an air powered cutoff tool - and filed the ends smooth. Then I removed the paint. The photo shows one of the two barbs removed and I'm holding the 8mm tube nut and sleeve.

Next, slide the tube nut and sleeve over the fuel rail tube, and screw it onto the JIC adapter.

The finished article. I jst need to add some -6AN swivel hose ends to my fuel lines and they will connect right up to the fuel rail - no more hose clamps.

Here are the part numbers from DiscountHydraulicHose:
9605S-06-L08-14 | 3/8" Male JIC x 8mm Tube / M14x1.5 Port (Steel)
9201LL-08 | DIN 2353 LL Metric Tube Nut, 8mm Tube (Steel)
9202LL-08 | DIN 2353 LL Metric Tube Sleeve/Cutting Ring, 8mm Tube (Steel)

Brake Balance Problems

2010-01-18T21:39:00.018-05:00

One of the few things we did learn on the MARRS 7 test day before the engine expired was that the car wanted to swap ends any time I got hard on the brakes. Clearly we had grossly too much brake pressure on the rear brakes compared to the front. Moving the brake balance adjuster around seemed to make no difference. Once we got the car home I put pressure gauges on the front and rear calipers and took some measurements while depressing the brake pedal by varying amounts. Plotting the results showed that the Tilton lever-style balance adjuster was not working - the output pressure was basically the same as the input pressure (minus a small constant offset due to the stock VW pressure limiter mounted at the master cylinder). See the upper graph in the embedded Google spreadsheet below. We switched out the Tilton regulator for a (much cheaper) Summit Racing knob-style regulator and as the lower graph shows, we now are able to actually reduce the rear brake pressure by an appropriate amount. Hopefully next time at the track we'll be able to use the brakes properly.

The new (working) balance adjuster. It accepts 1/8" NPT fittings so an adapter to -3AN was required on each side.

2009 Summary

2010-01-18T21:11:00.003-05:00

Well the 2009 racing season was basically a bust for the Corrado. After spending the winter converting to a megasquirt fuel injection system, and getting the broken gearbox rebuilt, we were ready for MARRS 7 at Summit Point, WV in July. Unfortunately at the test day before the race, an incorrectly plumbed oil cooler resulted in two spun connecting rod bearings. With limited time to work on the car we switched to racing our ITC scirroco for the remainder of the season. Happily I can report the engine rebuild is well underway with a crank reground by CGM Motorsports of Millersville, MD, and we have high hopes for the 2010 season.

Noodling with paint schemes in PhotoShop

2009-03-13T22:54:00.005-04:00

Hard Brake Lines

2009-02-14T22:19:00.004-05:00

I decided to rework the brake lines from the master cylinder to the rear calipers using Cunifer lines and AN fittings. I bought a Ridgid 37 degree flaring tool, which worked great. I ran the lines inside the car all the way to a point directly above the rear calipers, using a tee mounted where the rear seats used to be.

90 degree AN firewall fitting.

Brake Proportioning Valve

Oil Sensors

2009-02-14T21:56:00.003-05:00

I wanted to install new Autometer gauges instead of the crappy stock gauges, but the stock senders are 10mm thread while Autometer use 1/8-NPT. So I blanked off two of the ports on the oil filter housing with M10x1mm bolts and copper crush washers. I redrilled and tapped the third port to accept a 1/4-NPT to 1/8-NPT bushing, which I installed with a little JB weld to make sure it never comes out of the soft aluminum housing. The autometer sensor screws right into the bushing. I've heard the stock sensors (low & high pressure switches and oil temp sender) are capable of blowing out and causing a mini oil geyser, so I'm happy to have got rid of them.

Racing Radiator

2009-02-14T21:43:00.003-05:00

I managed to poke a hole in the stock radiator, so that was a good excuse to install a proper all-aluminum racing radiator. I found an Afco "Scirocco style" radiator at Summit Racing that fits perfectly. The outlets were the wrong size though, so I had to make adapters for the upper and lower radiator hoses.

Oil Cooler

2009-02-14T21:31:00.006-05:00

This shows the oil feed that comes from the oil pump, coming out through the adapter plate, into the external oil
cooler, through the brass one-way valve, and into the engine. The disconnected port on the tee connects to the line to the accusump. The one-way valve forces the accusump to discharge into the engine and not back through the oil cooler and oil pump.

The lower picture shows the oil line that runs through the car to the accusump, you can see the manual oil valve, and the thinner braided line goes to the oil pressure gauge.

Accusump Oil Pressure Accumulator

2009-02-14T21:24:00.004-05:00

Installing an accusump to protect the new engine from oil starvation in the corners. I located it at the rear of the car, just forward of the fuel cell bulkhead. This car needs all the rear-weight it can get.

Engine Swap

2008-12-04T23:04:00.003-05:00

Time to yank out the old engine & install the new one.

Cleaned up the engine compartment and painted with Rust-Oleum aluminum rattle can paint.

Body and Paint Work

2008-12-04T22:44:00.007-05:00

While all the engine building was going on, we cleaned up all the dings and scrapes on the exterior, and welded in the sunroof. This involved cutting and welding in sheetmetal filler strips about 3/8" wide to fill the gap between the steel sunroof panel and the roof, where the seal used to be. Here's the prepped car going off to MAACO for a coat of paint.

And a week later it was back with a new Silver Polyurethane paint job...

Assembling the Long Block

2008-12-04T22:02:00.017-05:00

More Short Block Photos

2008-12-04T21:52:00.004-05:00

More Cylinder Head Pictures

2008-03-23T19:47:00.002-04:00

Here are some more pictures of the work in progress on the cylinder head from Bildon.

Short Block Building

2008-03-13T14:50:00.000-04:00

A few weeks ago the short block went to A.H.M. Performance in Baltimore, MD to be machined for .40 over pistons, along with balancing all the rotating & reciprocating parts and a general cleanup. A.H.M were a pleasure to work with, and even sent us this photo of the reassembled short block.

2008-01-18T23:03:00.000-05:00

Bildon motorsports are building an IT-legal cylinder head and match-porting the manifolds to the head for us. Here are some pictures they sent us of the work in progress.

2007 Season Summary

2008-01-17T21:27:00.000-05:00

The Corrado ran five MARRS races at Summit Point in 2007. We ran MARRS 1,4, 7 and the MARRS 9 double. Evan drove in one of the MARRS 9 races, Nick drove the rest.

We ran the whole season with the stock engine with well over 100,000 miles on it. We had the 02A transmission rebuilt with a .424 final drive and a clutch-type lsd from Bildon. The car had it's new KW suspension with double adjustable dampers. WE used Kumho V710 tires for the whole season.

The MARRS 1 test day was the cars first time on track. There was a lot to learn, suspension settings, alignment etc, but it ran well and we were getting lap times around 1:33 - not a fast ITS time, but respectable for an undeveloped car. The only drama came when the driver-side inner CV joint broke. Luckily we had a spare driveshaft & John Cummins of Kearney racing swapped it in in a jiffy.

We qualified mid-pack as expected. However on the start of lap two, the expensive new transmission failed, leaving me with only 4th gear. I chose to complete the race, lapping in the 1:36's and finished near the back of the ITS field.

The transmission was sent back to its builder who discovered a stripped 3rd gear. Meanwhile for MARRS4 we found an 02A transmission from a Jetta with a quafe lsd. Unfortunately its final drive ratio was ridiculously tall, so during the race we were changing gear in the middle of turns, using 2nd gear where we should be in 3rd, and never getting into top at all. Despite this the race went well and we collected a 4th in class finish with a fast lap of 1:31.677

For MARRS7, we were still using the makeshift transmission. The car was still running well however, but during the early part of the race the left rear tire wore through to the cords which didn't help handling at all. However we managed a 3rd place finish with a fast lap if 1:31.912

MARRS 9 came along and we had the repaired race transmission back in the car in time for the practice day. It lasted a couple of laps before we lost 3rd gear again! Luckily we had brought the backup, misgeared-but-reliable gearbox, and an all afternoon thrash ensued to swap it in. Evan discovered that replacing an 02A transmission in a Corrado is a different sort of job from replacing an 020 box in a Scirocco!

Another problem was caused by us installing a brake bias adjuster and somehow getting air into the abs system. We never got the brakes properly bled, despite repeated attempts at the track. At one point during Nick's race the pedal went to the floor approaching turn 1 resulting in a brief visit to the mud outside of turn 2.

With the backup gearbox in the car we got through qualifying with no problems. Evan ran the first race and quickly got up to speed, coming in 8th in class with a 1:31.415 fast lap. Nick ran race 2 and also came in 8th in class with a 1:31.670 fast lap.

Due to the various gearbox problems and our limited schedule we didn't really make the progress we'd hoped for with the car's suspension setup. One thing we learned is that the nose heavy weight distribution and fwd makes the car very hard on the front tires. In the later stages of the races they were really overheating. I'm hoping suspension setup changes along with adjustments to driving style can keep this under control. We might experiment with different types of tires too.

There's lots of work to do to get the car ready for 2008, not least build an IT race motor with a lot more horsepower, but we're determined to come back with a much faster car for 2008.

Video from MARRS 4 2007

2008-01-16T23:25:00.000-05:00

Here's the video from MARRS 4 again, this time uploaded to the blog.

Dyno Graphs

2008-01-16T23:19:00.000-05:00

In preparation for building a race motor, we dyno'd the stock high mileage engine we ran in the car during the 2007 season. The ECU had a GIAC chip in it.

The dyno showed we were getting about 156 HP at the wheels.

2007 Race Videos

2008-01-16T22:19:00.001-05:00

Here are links where you can download in-car video of some of the races we ran with the Corrado in 2007. These are full-length, so may take a little while to download.

MARRS 4 2007

MARRS 7 2007

MARRS 9 2007

Front Ride Height

2007-04-15T10:17:00.000-04:00

The front was too low, even with the coil-overs set to maximum ride height. The solution is to switch from 6" to 7" front springs.

Welded in Camber Plates

2007-04-15T10:04:00.000-04:00

The car went back to Kearney Racing in Landover, MD to have the camber plates trimmed and moved back by about an inch in order to add more caster. They were then welded in place.

Rear Sway Bar

2007-04-15T09:58:00.000-04:00

The 1-1/8" rear sway bar from Bildon mounts inside the rear beam axle, alongside the stock 21mm bar. It is installed by drilling four holes in the beam axle.

Height Adjustment

2007-04-08T11:07:00.000-04:00

Coil-over set at maximum ride height.

Front Ride Height

2007-04-08T11:04:00.000-04:00

View of front right control arm with coil-over set at maximum ride height.

Cooling

2007-04-08T10:51:00.000-04:00

Here's the new radiator, the lightweight SPAL fan saves a ton of weight compared to the OEM dual fan assembly. The oil cooler is mounted to the radiator with some custom brackets.

Assembling Strut

2007-04-03T23:07:00.000-04:00

Bolting up the new carriers, coil over struts, half shafts & brakes.

Hub Carriers

2007-04-03T22:55:00.000-04:00

Brand new hub carriers, with bearings, hubs and wheels studs installed by Bildon.

Control Arms

2007-04-03T22:49:00.000-04:00

Here are the new control arms, with spherical bearings (rear) and delrin bushing(front) preinstalled by Bildon. The bearings are Aurora part # COM-12T, 3/4" bore with PTFE liner. Bildon designed and supplied the bearing housings that press in to the control arms. The housings have a grove for a circlip that retains the bearing.

Subframe

2007-04-03T22:10:00.000-04:00

The front suspension is starting to go back together. First thing is to reinstall the sub-frame that the control arms attach to, and upon which the engine mounts sit. Here's the subframe with the original control arms and transmission stay-rod attached.

Camber Plates

2007-03-19T22:47:00.000-04:00

To install the Shine Racing camber plates, the raised areas on top of the strut towers have to be cut off with a reciprocating saw. Here are before and after pictures.

After some grinding, drilling, and a little hammering to flatten the top of the strut tower, the bolt holes were drilled using the camber plates as a template, and the fore-aft position of the plate was set to be exactly the same on both sides, to try to get the caster consistent. The camber plates will be bolted in using grade 8 1/4-20 bolts. We'll then make sure the caster is the same on both both sides before welding the plates to the strut towers for extra strength.

Crack Pipe

2007-03-19T22:36:00.000-04:00

Here's the new plastic coolant pipe and thermostat housing. They're made of special German plastic that self destructs after about 8 years, so it's a good idea to replace them any chance you get.

Installing the Transmission

2007-03-19T22:20:00.000-04:00

Installed New clutch master and slave cylinders. Here's the slave, ready to install on the transmission.

A good time to fill the transmission with Redline MT90

Rebuilt Transmission

2007-03-09T20:47:00.000-05:00

The rebuilt transmission arrived from BSI. They installed a clutch-type limited slip differential, .424 ring & pinion (both sourced from Bildon), and replaced synchros, bearings etc. They turned it around in only a couple of weeks.

Oil Cooler Sandwich Plate

2007-03-09T20:34:00.000-05:00

Bildon Motorsport provided a nice kit for installing an oil cooler - including the sandwich plate, hoses, fittings and the cooler itself. Here are some photos of the plate being installed on the stock oil cooler in place of its cover plate.

Removing the cover

Pull off the old cooler for a quick look and cleanup.

The stock cooler, cover and sandwich plate with threaded pipe that replaces it.

Final Assembly

KW Coilovers

2007-03-09T20:24:00.000-05:00

This is a shine racing upper strut mount (camber plate), next to one of the front struts. The KW upper spring perch is too bulky to work with the strut mount without being modified, but Shine sent some of their own spring perches which we'll use instead.

Here a photo of 2 of the KW coilovers the one on the left is for the rear, the other is for the front.

Installing race clutch

2007-03-05T22:04:00.000-05:00

I Torqued the 12-point pressure plate points to spec. (14 ft-pounds), and used loctite on them. This was also a good time to clean up the TDC mark on the flywheel and highlight it with a white permanent marker.

Messy Engine Compartment

2007-03-05T21:57:00.000-05:00

After pressure washing.

Here's the greasy mess in the engine compartment. I broke out the pressure washer shortly after this photo was taken.

Front bodywork removed

2007-03-05T21:53:00.000-05:00

Took off grill, headlamps etc. Will be replacing radiator, installing Bildon oil cooler, Samco hoses.

Front End Work

2007-03-05T21:49:00.000-05:00

Entire front suspension is to be replaced. Bildon are supplying new control arms with spherical bearing bushings preinstalled. Also they are rebuilding my bearing carriers with new wheel bearings, hubs and wheel studs. They also ordered KW 2-way racing coilovers for me.

Since the transmission has to come out to be rebuilt, I just supported the engine and dropped the entire front subframe with suspension attached. After that it was simple to remove the transmission.

Phase 1

2007-03-05T21:17:00.000-05:00

The plan is to put in a racing suspension - coilovers etc., install a limited slip differential, 424 ring & pinion, racing brake pads, plus maintenance & safety gear, and race the car with the stock motor for a while. Later we'll build & swap in a 2.9 liter IT motor.

A core engine and 02A transmission were found on eBay. The transmission has been sent to BSI for rebuilding and installation of a clutch-type lsd and the 424 ring & pinion (both obtained from Bildon). Here's a photo of the core engine that we'll turn into a race motor.

Roll Cage Pictures

2007-03-05T20:53:00.000-05:00

Roll cage custom fabricated by Kearney Racing of Fairmount Heights, MD (just outside Washington, D.C). Kearney do great work at reasonable prices and Linda, John and Dale are a pleasure to work with.

Seat & Steering Wheel

2007-03-05T20:28:00.000-05:00

Kearneys did a great job fitting the removable wheel and racing seat. Seat is a Sparco EVO L. Seat and wheel were sources through Bildon Motorsport, who will be providing most of the important racing parts for the car.

Fabrication work

2007-03-05T20:25:00.000-05:00

Took the car to Kearney Racing in January for custom roll cage, seat mounting. Here's John Cummins (left) of Kearneys, with Evan Webb, who'll be a co-driver of the car.

Gutting

2006-12-17T11:15:00.000-05:00

Removing interior so the car canhave its roll cage installed. SCCA says you can remove carpets & interior panels. Gutted doors for NASCAR style door bars.

In the Beginning

2006-11-25T23:35:00.000-05:00

Here's my 1993 VW Corrado SLC. 126,000 miles. Worn out suspension, trashed interior. It's going to become an SCCA ITS race car.