Definitive 24v into a (VR) Corrado thread

[VW_OwneR_85 2]

should be fun!, pics please

[matty golf 0]

Im gonna pick the block up in next couple of weeks so will make a thread up only had the car for 6 years

[Kevin Bacon 5]

I'd be interested in finding out how to get the mpg display working on my 24v conversion if possible as well (assuming I ever finish the project). I know that on the VR6 Corrado the ECU sends a signal to the clocks which is used for the mpg calculation. I presume the clocks use this signal and the speed signal to estimate mileage. I'm not exactly sure about the nature of the signal sent by the ECU, whether it is an analog voltage proportional to the fuel flow or if it is a digital pulse at the same frequency as one of the injectors and the clocks have a built in assumption on injector flow rate it uses to infer a fuel flow rate based on the injector pulse width. The early mk IV cars (pre-CAN-BUS) also have a discrete wire from the ECU to the clocks for the mileage information (terminal 81 on the 121 pin connector at the ECU according to my Bentley manuals). That terminal on the ECU connector is not used on the CAN-BUS enabled engines. I have been trying to find out if the ECU still outputs an appropriate signal to that terminal and it's just not used on the CAN-BUS cars. I have inquired about this with a company here in the US that does mk IV tuning programs but have not received any response. Perhaps one of the tuning companies in the UK knows the answer. If one of you has any contacts at a tuning company and could find out, I'd appreciate it.

I'm not sure if any of this would apply to a mk V based swap.

 

GC

 

The mpg is calculated from the injector pulse width signal. Even if you were able to feed the signal from the 24V ECU into the VR6 clocks, the injectors are different sizes, therefore the mpg reading would be inaccurate, especially with the larger R32 injectors. The 2.8 injectors might be close in size to the 12V ones, I'm not sure.

 

I can understand the desire for the mpg function for 'completeness', but it's going to take someone who knows both the Clocks and the ECUs intimately in order to get round it, and also someone who can build electronics. I reckon a PWM simulator/modifier would be required, but first we need to know exactly what signal the clocks are expecting. In the case of the Pre-CAN 24V ECUs, (AUE) and possibly the MK4 R32, it might work. No chance with MK5 R32s as it's all CAN.

 

---------- Post added at 11:54 AM ---------- Previous post was at 11:49 AM ----------

 

was told normal 2.8 with lightened bottom end flowed head and differerent cams with a chiped ecu about 245 brake so im told will soon see what its like when it goes in. say its been built by regal

 

In which case it must be a BDE/BDF 24V as you can't get any cams for the AUE. 245hp sounds a bit optimistic.

[matty golf 0]

as i said its just what i been told i had a copy of the engine spec sheet somewhere i will try and dig it up

[Sean_Jaymo 0]

I'm in the process of carrying out this upgrade (24v in replacement of 12v that is!) and i'm trying to find out how people are retaining all 4 lambda's? Contrary to what most people believe, the rear lambda's do more than report on cat health with the me7 ecu. They also influence timing. I know I could just chin off the rear sensors and everything will work more or less right but the ECU is holding the engine back a bit.

 

What i'm trying to find out is whether it's best to run twin cats and if so, what would I do about the downpipe? Would running a pair of lambda's in the stock positions on a dubsport manifold with an extra boss welded in post the single stock cat work correctly? What do others do?

[quicky1980 0]

could you elaborate about the rear lambdas influencing the timing?

[Kevin Bacon 5]

The rear lambdas look for lambda 1 (14.7:1 AFR) coming through the cats. The whole map (except the very top end) is fuelled to lambda 1 for that very reason.

 

The front lambdas (wideband) can perform a pseudo EGT function and I would expect those to retard the timing if gas temps get too hot. The rears are basic narrowbands and can't really influence much.

 

But I could be wrong. I keep reading about C2 saying you need them, and other tuners saying you don't, but neither supply us with an exact reason why.

 

I'll tell you something though, mine ran a damn site better on standalone than it did ME7. I wish I hadn't bothered converting to it tbh.

[Sean_Jaymo 0]

United motorsports, who are also C2 motorsports I believe, did the immo defeat along with SAI defeat etc on my ME7 ecu. I asked at the time for rear lambda defeat and I was advised to not get rid of them but when I pressed as to why, I was told that it can affect the running of the car but would not elaborate as to why.

 

Like a dog with a bone, I went looking for an answer and information is sketchy as to the exact methods used by the me7 and it's rear sensors but came to the conclusion the in WOT situations, they are redundant and the pre cat sensors fuel to 14.7 AFR. Under prolonged sustained conditions, such as motorway cruising where you are at less than 50% throttle, temps in a certain range, speed is in a certain range and other parameters that I don't know about yet, then the ECU actually uses the post cat sensors to control fuel to 14.7 AFR.

 

Without these sensors, on motorway trips or normal cruising about normally for example, then the ecu could steer away from the correct mapping on AFR, resulting in poorer economy. I'm not sure why but I'm guesstimating that it could be something to do with lambda temperature difference between pre and post cat sensors.

 

I know it's not the exact answer you were looking for, I know it's not what I was looking for but it is a definitely something that gives me enough reason to keep all 4 sensors and both cats.

 

I'm assuming some tuners get rid of them as they are mainly interested in headline figures and would prefer to keep their lives simpler for the cash.

 

I was thinking of going stand alone but the cost is mainly putting me off and having a "factory" feel is something that is quite important to me.

 

Might change all that though if Ii turn it into a turbo charged track only weapon. But for now...!

 

So... These leave me wondering about downpipes and how!

[20vtvw 0]

Could the post lambdas be fitted in a single cat system (both in one pipe after cat)or are they bank independent?i still have the plugs on my loom but there not connected and think they have been turned off when I had the ecu done but I'm sending my ecu off to um to get mapped and could get them to turn the post lambdas on.

[Sean_Jaymo 0]

They're not bank dependant, but they are checking lambda values against their own precat lambda sensor so if the gases are mixing into a single cat then the ecu is going to struggle to get accurate figures. I'm sure you'll get everything running there or there abouts, but long term it's going to have adverse effects on the engine and your fuel economy.

[VW_OwneR_85 2]

UM defeated my after cat lambdas without question that was only last year, im not going to lie but it does make me wonder why they suddenly decided its better to keep them? but my cars been running amazing hot or cold , short or long journey and i would find it hard to belive that my engine could run any better then it already is, only thing im not aware of yet is MPG so wether thats suffering as a result idk?.

Edited March 12, 2013 by VW_OwneR_85

[Kevin Bacon 5]

United motorsports, who are also C2 motorsports I believe, did the immo defeat along with SAI defeat etc on my ME7 ecu. I asked at the time for rear lambda defeat and I was advised to not get rid of them but when I pressed as to why, I was told that it can affect the running of the car but would not elaborate as to why.

 

Like a dog with a bone, I went looking for an answer and information is sketchy as to the exact methods used by the me7 and it's rear sensors but came to the conclusion the in WOT situations, they are redundant and the pre cat sensors fuel to 14.7 AFR. Under prolonged sustained conditions, such as motorway cruising where you are at less than 50% throttle, temps in a certain range, speed is in a certain range and other parameters that I don't know about yet, then the ECU actually uses the post cat sensors to control fuel to 14.7 AFR.

 

Without these sensors, on motorway trips or normal cruising about normally for example, then the ecu could steer away from the correct mapping on AFR, resulting in poorer economy. I'm not sure why but I'm guesstimating that it could be something to do with lambda temperature difference between pre and post cat sensors.

 

I know it's not the exact answer you were looking for, I know it's not what I was looking for but it is a definitely something that gives me enough reason to keep all 4 sensors and both cats.

 

I'm assuming some tuners get rid of them as they are mainly interested in headline figures and would prefer to keep their lives simpler for the cash.

 

I was thinking of going stand alone but the cost is mainly putting me off and having a "factory" feel is something that is quite important to me.

 

Might change all that though if Ii turn it into a turbo charged track only weapon. But for now...!

 

So... These leave me wondering about downpipes and how!

 

Interesting post mate!

 

Personally speaking, I would have loved to keep all 4 lambdas in place but it just wasn't really doable from a packaging point of view and I only had 1 cat anyway!

 

OEMs do something what's called "NOX Purging" and I know the rear lambdas are defo used for that. I'm not entirely sure what NOX purging is tbh but I would hazard a guess it's something to do with the relationship between the rear lambdas and the SAI. I guess what happens is during warm up, the rear lambdas monitor what's coming through the cat because they only really work when up to temperature, so the ECU chucks loads of air (via SAI) and fuel over the cats to heat them up super fast.

 

There could also be a curious relationship with the rear lambdas under the cruising conditions you describe and we don't know about it fully. The lengths Bosch go to to make these engines run properly is incredible.

 

Keep in mind some tuners deliberately withhold information to make themselves appear 'better' than the next tuner and hold the key to some magic potion (for a price). Many are just secretive and elusive in general :D

 

What I do know is this:-

 

MK5 engine and ME7 installed, I was seeing stock power (253hp IIRC) and I averaged 28mpg.

 

After Vince defeated everything and remapped it (also tamed the savage throttle), I saw 267hp and I then averaged 33mpg.

 

Many forums do slate the R32 (as in the car) as being too slow for it's capacity and fuel consumption, but they just haven't tried a remapped one :D

Edited March 12, 2013 by Kevin Bacon

[Sean_Jaymo 0]

If I had a spare 1500 quid knocking about, then I could be tempted into standalone, but the way my project is going and how lucky i've been on doing deals for bits, the whole project is going to cost no more than that to get to a running stage! Car included!

 

All i'm trying to do is upgrade the car to be more powerful then standard and have it done in such a way that the casual observer wouldn't know anything had been done!

[matty golf 0]

Bit off topic, I've picked up this 24 v lump, and I'm looking at using an r32 box with a vr6 clutch and fly is this possible. What are thoughts about keeping transfer box on to run equal length shafts or do I have to by that plate to cap it off, I seen something about it somewhere

[Sean_Jaymo 0]

You will need the r32 clutch and fly as the 12v versions are smaller than the 24v versions and they are not at all interchangeable.

 

You can fit the transfer box and get an adapter to stop the rear take off drive rotating, but the question is why would you want to go to all that effort if you are going to retain fwd?

The 24v stuff is much heavier and more costly to buy and the only extra thing you would have would be a 6th gear. The 6th in those boxes is only slightly longer than a 12v 5th and would like not make a huge difference, especially when you'll spend more time in and out of gears instead of putting the power down.

[Kevin Bacon 5]

I looked into the 02M conversion for mine and it's defo a classic cost vs benefit scenario!

 

As you say, there has to be a specific reason for going O2M because it's a lot of hassle and expense for an extra cog. Most people use it for it's torque handling capacity. It's actually a much better box overall too. Better shift, quieter, smoother clutch (when used with the dual mass fw) and bomb proof!

[taks 10]

Quick question about pedals...

If you had mk4 wiring but wanted to run the mk5 (floor mounted) pedal are the plugs at the pedal end the same?

I have heard rumoured that reversing the order of the wiring on the plug would do the trick

Can someone confirm?

Cheers

Taks

[Kevin Bacon 5]

Completely different plugs. There's something weird about the MK5 pedal. I think it only works with a MK5 throttle / ECU. I know you can use a MK5 throttle in a MK4 tho!

[Sean_Jaymo 0]

Can somebody post up a picture of how they mounted their Aux water pump? I have an AUE engine and can't figure where to mount it as there is a coil pack in the way and I have limited amount of loom available to me without unwrapping it a lot further. I am going straight from an OBD 1 setup to 24v. I guess AUE is the equivalent of OBD 1 in 24v circles!

 

Also, do people use the 24v waterpump and have it controlled by the ECU or do they use the 12v pump which I believe to be controlled from the sensors in the stat housing?

Edited April 1, 2013 by Sean_Jaymo

[Fanjita 1]

Mine is the 12v pump run by the fan controller, it does look a bit messy. My pump is directly under the intake pipe and the wires are pushed at a funny angle. I'll be looking at securing it better soon but ill grab you a snap.

[Sean_Jaymo 0]

Cheers mate, I'm in the process of sorting my wiring out now so trying to clear up any loose ends now!

[taks 10]

Completely different plugs. There's something weird about the MK5 pedal. I think it only works with a MK5 throttle / ECU. I know you can use a MK5 throttle in a MK4 tho!

 

I will get some plugs and pedals- have a play about and report back...

cheers

[Jim Bowen 1]

Is there an organized list of all the parts and what sort of engine is needed for the 24v conversion?

 

I suddenly found myself needing to change the engine and found an AUE engine but not sure what else i need to source? I can't go through the whole stumbling across something i didn't know about then waiting a week each time to find a part, i just don't know these things and really rely on internet folk to help :lol:

 

Took me 18months to do the rest of car, had it back 3 months and think the head gasket has gone :(

[Fanjita 1]

Sam (quicky1980) has written a fantastic guide to the conversion process, it will answer your questions about parts required.

 

http://the-corrado.net/showthread.php?50720-R32-3-2-24v-Audi-conversion-guide

[Jim Bowen 1]

Is the 2.8 24v similar install to the 3.2? I am looking at an AUE engine.

 

Have read a few of the pages of this thread, but its from 2005 and 148 pages so going to take ages :lol:

 

---------- Post added at 11:16 AM ---------- Previous post was at 11:13 AM ----------

 

Guide looks good, cheers for that, am printing it now and going to read it tonight.