Corrado TDI Project: Lightweight Daily Driver

A few people have encouraged me to make a thread for my car.









I'll use it to track progress and slowly share past projects.

It's a Corrado G60 with a Jetta 1Z swapped into it. I had given up on my project for a Porsche 944 TDI since I was a bit too transient and decided to go with the much easier Corrado swap. While I was shopping for a Corrado shell that was clean enough and cheap enough to swap my AHU into, I got lucky and I came across a project that I decided I would continue on with and redo all the things that were not up the challenge to maintain reliability as a long term daily driver.

My main goals are to have a great looking car, that is completely reliable, comfortable for long trips, gets fantastic fuel economy, and performs well enough to represent the Corrado name. Sort of like a dream car isn't it?

My main route to performance and fuel economy is through weight reduction. I have reduced over 250 pounds from the car so far and have maintained a stock like interior. I have another estimated 150 pounds more I can reduce with in my goals but the cost and effort increase greatly. I originally planned on limiting it to about $25 a pound to cut weight. Another 50 lbs. would be a great accomplishment.

My current project (of many ) is a PD lift pump for the Corrado G60 tank. My car came with the stock G60 intank pump and it worked okay for pass-through flow. I did not want to use the gasoline pump so I modified an MK4 ALH fuel pickup to fit and accept the G60 fuel level sensor chip.

PD lift pump project

This is the type of pump I repaired and modified for use in the Corrado TDI



It is the tan colored pump and it does not block your pick-up if the motor dies so it can be used as a pass-through without modification.

Here is a good thread on how the lift pump operate and how to repair and what parts to use.
http://forums.tdiclub.com/showthread.php?t=225672
I actually got my lift pump from Dan for free because he had not yet figured out where to get the pump motors or carbon brushes so he did not mind me cutting it up. I even think I spurred him on and got him working on his project again.

Increasing the collapsing the PD lift pump was a lot more work than the MK4 fuel pickup. It was still not difficult though. A high speed rotary tool has to be used to cut room for the fuel outlet elbow. I used 3/8" viton tubing with a medium wall thickness, to repair and replumb the lines. I later found out that a 5/16" thin wall viton is recommended. I also used a 3/8" 90 deg. brass elbow to clear from the top of the pump motor to the top plate. I had to cut the barbs on one side of the elbow and the pump motor so i could get more clearance with the shorter junction. I used an elbow from McMaster-Carr but it was not the best item since it did not let the hose slide all the way to the junction, otherwise I would have had more clearance. I was lucky enough to get a new pump motor that would work for $3 at the Asheville GTG. The pump was also slightly shorter so that made up for my loses with the brass elbow.








This photo shows the pump collapsed as I press down on it:



See how the hose drops down into the channel I cut for it.

I cut the ring for the bayonet out of the bottom of the G60 tank. I siphoned out the last 2.5 gallons and then wet dry vacuumed out the last bit of fuel. I tried to cut it with just a loose hacksaw blade but the plastic is to durable and progress was not being made. I then used a high speed rotary tool and cut parallel to the bottom of the tank. DO NOT CUT IN YOUR TANK IF IT HAS GASOLINE FUMES IN IT! Be careful to not cut through the tank floor. Once I popped the ring off I trimmed the glue that held it in place for a more flush fit though bumps still remain.

I installed the pump yesterday and it fit nicely with no leaks. I ran it for about 40 miles as a pass-though and I wired the pump up tonight. It pumps fuel well and I even had to tighten a hose clamp on the filter. I also get good flow out of my water separator instead of the usual hiss or gurgle of air. I will write more about the wiring, etc. and be looking for suggestions in the next post.


Update: Be sure to add a second elbow or you may bust the one hose. http://forums.tdiclub.com/showpost.php?p=4204315&postcount=28

Fuel pump wiring

Most of the wiring is stock Corrado. The stock Corrado fuel pump relay can be used in position 12. This feeds through the fuse in position XXX and then through the wires for the fuel pump in the trunk. Using a pin tool (bobby hair pin bent to work) you can remove the wires in the Corrado FP connector and install them in the MK4 style connector. The MK4 plug has a purple gate in the side of it that has to be pulled out before you can remove the wires. The power to the fuse and relay is run through the back of the fuse block and there needs to be a jumper wire from 30 to 30B.
The relay receives a positive voltage through the ignition switch. The ground wire is where there is a need to get creative or not. The Corrado generates a ground using the ECU. It uses this for priming the system when the key is first turned. It will reconnect the ground when the engine is cranking and disconnect it when it stops from an accident. If you make a connection that goes from xxx to the ground location behind the instrument cluster it will turn on whenever you have the ignition in the on position. This is my current set-up for now. I am planning on connecting the ground to the low oil pressure sensor. Hopefully this is a normally open switch. I can also add a momentary push button to prime the system manually whenever I want. There is also a possibility to wire it to the glow plugs/GP light so it primes every time the light comes on when the key is first turned. Any other ideas?

Fuel lines

I grabbed a bunch of MK4 fuel lines that were probably from a gasser from J&K Auto in Summerville, SC. I cut the plastic hosing from one of the connectors and installed this on the Corrado's rubber return line. One of the hoses was shaped just right for the fuel tank outlet and it met up well with the Corrado connection at the former gasoline fuel filter under the car.

Fuel level sensor

The chip from the Corrado fuel level sensor worked with the mechanism from the ALH fuel pick-up when a jumper wire was made so it should work the same for the lift pump. There is going to be a little trial and error to finding the right position so it reads from the bottom to the top. I never had it adjusted right with the ALH pick-up and the bayonet ring in the bottom of the tank.

- updated 1/17/13 - I installed my fuel level sensor the other week. It was much easier to convert the PD sensor for the G60 chip than the MK4 fuel pick-up was. The G60 chip is a little longer but a little grinding can be done and it will slip in and stay. Only 1 wire had to be soldered on. The plastic on the swinging arm had to be removed or melted a little bit to reach all the way to the bottom. I am reading at about a 1/4 tank left with 560 miles on the tank. From bone dry to the filler neck the tank held 14 1/2 gallons. Testing continues!

Purty car

Do you have a list of what you've pulled off and what each piece weighs?

Glad the you started this thread. What are some of the weight reductions you have done besides the ps delete. That's a lot of weight removed man! Nice!

There is a vortex thread that lists a lot of corrado weight reduction items and how much they help the cause.

- http://forums.vwvortex.com/showthread.php?3427836-Corrado-Weight-Reduction-Thread-Parts-List-and-Weights

- http://forums.vwvortex.com/showthread.php?3283701-Some-Weight-Reduction-Numbers

- http://forums.vwvortex.com/showthread.php?4592472-Corrado-Carbon-Fiber-Hatch-Weight-vs-OEM

I need to get mine finished and out of the garage as soon as the salt goes away...

Nice. Thanks for starting a thread!

Nice, subscribed

I saw your car twice this year. I saw it at sowo and at Landon's g2g last fall. I have a Corrado as well but it's under the knife. It's not getting a diesel engine though.

http://houston.craigslist.org/cto/3405008981.html

Just talked to this guy and he has two Corrado's on CL right now, says he has 5 of them. Says they are all project cars and he is moving. I might pick one up for a sweet tdi conversion.

deep_sea said:

http://houston.craigslist.org/cto/3405008981.html

Just talked to this guy and he has two Corrado's on CL right now, says he has 5 of them. Says they are all project cars and he is moving. I might pick one up for a sweet tdi conversion.

Click to expand...

Project corrados are everywhere if you look for them. My advice is to buy a Corrado with good paint and most of the none engine mods you want, you'll save a lot of $$$. Look for bad engines and transmissions in them.

I have updated the second post to show the PD lift pump project which was wired up tonight.

markd89 said:

Purty car

Do you have a list of what you've pulled off and what each piece weighs?

Click to expand...

Thanks! I do have a list and I will be getting to that eventually.

Houpty:

Your rado is absolutely beautiful, but if you wanted light weight, why not just build a rocco and be done with it?

Beautiful car!

What did you do to reduce all of that weight?

I updated the information on the 3rd post about the PD lift pump. There are a few minor details that I will fill in later when I get the wiring diagrams in my hands again.

Pat Dolan said:

Houpty:
Your rado is absolutely beautiful, but if you wanted light weight, why not just build a rocco and be done with it?

Click to expand...

Thanks! Did you ever get around to starting your 924 TDI?

I was pretty much focused on building that 944 or a Corrado or a FWD TT convertible. If you do not build a car that you are going to really love then you are not going to keep interest in it and either quit or sell it. I could never find a TT with a blown motor and the 944 project was to big of a project for me to take on at that time. The Rocco is neat and would be great to build and drive but I just do not have the passion for it like I do for the Corrado. There is no sense starting a project if you lose motivation and cannot follow your commitment all the way through.

Houpty: 924/2.0TD, MGB 3.5 Buick, get sleeper on F450, put HID in MkIV and put GSXR in LeGrand Mk21 to go BMod all sitting in the yard/shops waiting for me to not be gone away and trying to make enough money to sort-of retire to play with all of my junk! This gettin' old BS is gettin' old!

Here is the current list of parts removed. All were either weighed by myself or another person who posted the weight on the internet. I am replacing weights as I have been more reliable.

Weight reduction: lbs.
Al rear brakes 4
Al front brakes (10.6-6.5)x2=8.2
Lower dash 12.8
"mystery" item 16.8
Aftermarket muffler 10
"mystery" item 39
Resonator 17
Irrelevant Carbon canister 2
Fans and shrouds 25
Seat belt improvement 6
Spare tire and jack and chocks 32.6
First aid kit 2.2
Mille Miglia Spider 17 to Rial 83 18.4
Center exhaust tunnel underbody insulation 1.7
Aktive Stereo delete 1
ABS delete with wiring and computer 15.4+3.2+2.0=20.6
Rear mats 1.8
Trunk mat 4.0
Rotor splash shields- front 1.0
"mystery" device 4.6
Rear windshield wiper and motor 3.4
Power steering pump,brackets,hose,reservoir 13.9
Foglight delete with blanking plates (1.94-0.28 lbs.)=1.7
Total 247.7

It seems there was a mistake and I am under 250 again. I have also added over 20 pounds of sound deadening and insulation on the floors but this is all part of the plan.
There are also some 8 pounds of sandbags that were supposedly removed but I do not see where these could have been.
Weight varies as some items go in and out as needed.

I have been getting frustrated with the shudder in my car. Things have gotten worse with the winter fuels. I get it in fourth gear as well as fifth even at highway speed (.657 5th). I know my filters have been clogging and I was pulling air before I added the lift pump however changing the filter only reduces the problem. I have been trying to hammer mod the car to tone the problem down but have not been making progress. Injector balance is not going below a spread of 1.2 mg/stroke. It was close to 0.5 before. I am pretty certain the problem originates at the pump. I am going to pull my injectors and pop test them, check the spay pattern, and switch the highest mg/stroke injector with the lowest. If this does not make any changes then I am going to look at changing the pump. I might as well start looking for an 11 mm ALH pump.

I have been working on improving my cars comfort on long drives by reducing sound levels. I finally ran my current baseline test today using a calibrated sound level meter. 1 dB is a significant difference
77 degF. * *ambient temperature

Cold idle:61 dB
Stock 98 TDI: 65

Warm idle: 59 dB
stock 98 TDI: 59
stock Corrado: 51

60 MPH in 4th gear: 76 dB
60 MPH in .657 5th: 73 dB
stock 98 TDI: 67
stock Corrado: 70

70 MPH: 76 dB
w/ clutch in 72 dB

80 MPH: 77 dB
w/ clutch in 74 dB


The testing done with clutch in is to give an idea how much wind noise there is. It does seam that I have a lot of wind noise and it is something I have noticed as I have effectively started to quiet the engine noise. I originally set a goal of 68 dB at 70 MPH and currently even wind noise is above that.

Here are my current areas to target:
sunroof gasket near corners and the cover rattle
door seals
window frame seals
passenger foot well
cover fuse box area
remove passenger mirror
change wipers to Polo or other more aero profile
build fiberglass engine belly pan with foam insulator
hydraulic engine mount
insulate exhaust manifold
possibly different muffler or resonator
test 45deg down and 45deg out muffler tip
firewall insulation of fiberglass or foam
dampen rear buckets, quarter panels, fenders, trunk
add butyl rope to roof bracing (this worked wonders in the doors!)
line inner fenders with liquid dampener

I feel that I have done most other dampening and insulating, some more effective than others.

Wind noise at 60 MPH was 71 dB.

I installed my fuel level sensor the other week and I updated post #3 if you want the details. It was easier converting the PD sensor.

Other exciting news being the Corrado got a new goodie!



I have to say that the manifold is even more impressive in person than it is in any photos. It is just mesmerizing to look at it! I had Jamie at http://orchideuro.com/news/ import it from England for me. He was very helpful and I recommend him if you can wait for delivery.
I have some BioRem2000 soaking the manifold to clear the EGR build-up at the moment. BioRem is impressive stuff and has enzymes that actually convert oils into water and CO2. I still need to design and build an adapter for the intake plumbing. I would like to test the power and flow difference versus stock but I will not have a fair comparison. I am going to change my entire intercooler system around since it works poorly at 38degF above ambient temperature.

It was a good weekend for the Corrado. I picked up my 11mm pump that I bought for $200. I hope this will help with the shuddering that has gotten really bad. I also scored a manual steering rack with the linkage and a great condition boot from an '88 Golf at the pullapart yard. I also bought 2 BBS rims for $60 that I can use while I straighten my Rials that apear to be giving me an inconsistent shake. I may also just buy some more of these BMW 15" BBS if they fit really well on my large calipers.

The Corrado is suppose to have a duct that feeds air through the intercooler. I am buying one and expect a significant difference.

I wouldn't expect huge gains from having an IC duct, minor gains are probable. The BMW RA BBS are better than the Corrado RAs as they are wide. One thing to remember is that they bend very easily. I fully expect they will clear your brakes. Does your car have brake ducts installed?

I expect the air temps to drop at least 50% toward ambient which should net me about a 4% denser intake charge. It is just too easy for air to flow around the intercooler with no duct. A previous owner also cut out the inner fender around the intercooler so this only makes it easier for air to flow around the IC without a duct even easier. The other 50% drop in temperature towards ambient is the hard part.
What type of intake temps are you running above ambient? Check it with VAG-COM.

I have the brake ducts. I am not sure I really need these or that they help me much since I am not using my car for that much repeated braking.

What is the difference between an RA and an RZ?
Here are the 2 wheels I picked up:



This is what I would like to get and modify to fit since they are really light, have a good looking polished lip, and are cheap when bought person to person:

I have not updated this in a while and I can't let PRA4WX show me up

The BMW BBS did not work. They needed something like 13mm of spacer and they were 24 offset to begin with. Looked like something you would see on a Jetta at a car show I tried a set of the RX-7 BBS that I really wanted and they would need at least 20mm of spacer to clear because of their heavy curving on the inside corner. I am looking into a set of Corrado BBS RZ wheels now. I also now believe that the Rials are not bent and it is a problem with using them as lug centric. I bought a set of hub centric spacers and the extension for the hub (8mm) was too short and did not reach past the chamfer (10mm) on the rim. I swear I will post one day on my front brake upgrade that is making my life so complicated.

The 11mm pump swap did not go so smooth either. http://forums.tdiclub.com/showthread.php?t=378890
The car kept acting like it had an injector balance issue. I had to put my old 1Z pump Quantity Adjuster on the 11mm body. My shudder was gone for a few days and then it came back. I finished rebuilding the QA from the 11mm this weekend and am going to try and swap it back in and see what happens. There is not a lot that can go wrong with the QA or the position sensor. Here is a photo of some of the metallic debris on the QA.





The 11mm puts down good power at the lower RPM range but it feels like it does not rev as well as the 1Z 10mm pump. I also have bad clutch slip in 3rd - 5th gear now. The SBC stage 2 endurance clutch that has lived under my bed for 2 years and a new rear main seal are going to have to go in.

The intercooler duct that I installed improved intake temps somewhere between 8-19 deg.F. at 80 MPH cruise. That's worth a couple horsies.

My QA rebuild worked great and I left lots of info about adjustment in the thread above.

I split one of the viton hoses on my PD lift pump. I was having starting trouble and air in the lines as if the filter was clogged. It turns out this is not to uncommon. I am going to change the hoses up a little bit and will post a little more info for others to copy.

See it on the right. So sad

The hose looks like it broke from the stress from bending and not from the hose clamp tearing it. The hose clamp was also used to try and hold the hose round adding extra stress to the material. Like this:

Here is updated info on the lift pump to share.

You need 1 foot of hose. It is recommended by DanG to buy 5/16" hose from http://www.dudadiesel.com/viton.php?...ng_id=17:18:US Supposedly it is tougher than the McMAster-Carr Viton hose.

I had used 3/8" hose and barbs with a 9/16" outer diameter.

When I used the larger hose, I had cut one hose to 5 1/2" and another to 3 5/8". The last piece of hose from the pump to the first elbow was short enough to give just a little flex. I also think I am going to cut the elbow down on the edge it broke to only one barb and I may go to a 5/16" elbow.

The lift pump is back in and running. I used 2 elbows cut down to one barb and butting into each other. I will add a couple more photos later.

I swapped out some of my injector bodies that had significant drop in pop pressure. I balanced them and injector balance range is now below 0.4 mg/str from the previous 1.2. No significant change in shudder though.

Front end of the car comes off this weekend and a new Valeo AC condensor and fans go in as well as some dampener for the fenders and inner wheel wells and outside apron.

You got the dust off the stage 2 and installed yet?