The 'Running a Rotrex charger on a VR6' thread..

[cralstc 0]

So this has gone a bit quiet, really enjoyed following this up till now. Unfortunally my baby is in the workshop due to blown head gasket. So stuck in the 1.4 clio for a couple of weeks (honestly feel like i am missing half the engine).

 

I requested a DIY kit from SD they gave me the prices for stage 1 and 2 along with the predicted gains. I emailed them back for a list of parts included but still havent had a response. Anyone had the install or DIY kit from them so i know what i will receive if i order.

 

Cheers

[eatthis 0]

anybody got a torque graph of a rotrex? 10-15 psi preferably

[Kevin Bacon 5]

Unfortunally my baby is in the workshop due to blown head gasket. So stuck in the 1.4 clio for a couple of weeks (honestly feel like i am missing half the engine).

 

You can have my car and live here, and I'll take your place in Dubai :-)

[cralstc 0]

You can have my car and live here, and I'll take your place in Dubai

 

It cant be all that bad back there!!!

 

You know eventually you do get fed up all this sun here. Besides the c prefers the colder air and they are not too keen on all this sand.

 

But have to admit its cool having a car that no one knows.

[Kevin Bacon 5]

I bet the Corrado is a very rare site indeed amongst all those common Ferraris and Lambos :-)

[mr_fusion 0]

Hello all, been a while since i've been on here due to the C being engine-less for almost 4 months!

 

Thread about all those shenangians is here ... http://the-corrado.net/.archive/forum/viewtopic. ... 539#674539

 

**Mod Edit - Please follow the forum guidelines regarding items for sale **

[mr_fusion 0]

Ok Boys and Girls....

 

Can't seem to overcome my need to "charge-it-up" so Project Rotrex is back with a vengence!

 

Spent the past couple of months investing time and pennies getting it all sorted, been chatting with Andy at Storm a bit and have everything pretty much sorted now..

 

Current state of play is charger is all fitted, with a chargecooler this time along with the water injection.

 

Battery is in the boot and there is 9 mile of hose and ducting filling the engine bay. Finding it seriously hard to find places for everything, but it all just fits somehow.

 

Current problem is that the car is massively overfueling - MAF had been relocated upstream from the charger which has helped a tad - not entirely sure the recirc valve has the correct sping in it (it came with three different ones, currently on the second strongest one, working my way down)

 

Andy is trying to sell me a 90 degree elbow with the input from the recirc valve aimed at the compressor blades for £60ish (stops backlash against the maf) - although I may try and knock something up myself in the meantime to see if it helps.

 

Not ruling out a boost leak though - would this automatically equate to overfueling or what are the alternative reasons? Exhaust absolutely stinks when started from cold and is proper smokey

 

I would assume a part of this could be sorted in the remap - tempted to go megasquirt v3 - how easy are these to adapt to supercharger use?

 

Will try and get some pics up to show the progress...any help with the above would be appreciated!

[Kevin Bacon 5]

Welcome back!

 

What kind of boost are you aiming for?

 

The over fuelling is more than likely MAF related. Even at idle the Rotrex will be over loading the MAF. Motronic is expecting a certain mass of air at idle, but it will be MUCH higher on yours, so it will over fuel.

 

It will need a proper remap or as CrazyDave did, you can put a 10Kohm pot on the MAF signal wire to scale down the injector duty times a bit.

 

Personally I would go standalone, but not Megasquirt. I've been trying to map a mate's 16V MK2 with Eaton charger, which has megasquirt, and compared to DTA and Emerald, it's bloody nasty, to be perfectly frank. It's cheap for a reason. Save your money and put it toward a proper ECU would be my advice ;-)

 

Then you can tune it exactly how you want it and always have full control of the tune, no matter what you put on the engine.

 

I strongly recommend Sequential injection and closed loop control and you'll never look at Motronic again ;-)

[mr_fusion 0]

Hey Kev

 

Thought it wouldn't be long before you popped your head in!

I am aiming for 11-12psi boost to begin with - keep it sensible till I have confidence the car isn't going to give up again.

 

Good idea with the 10k pot - questions to answer now are :

 

1) Do you have a pinout for the old style MAF connector so I know what to connect to

2) Which pin and how am I wiring the pot - in series with the wire, or across the wire with reference point to gnd i.e :

 

On the Pot

pin 1 : signal to ecu

pin 2 : signal from maf

pin 3 : gnd

 

Thus creating a reference between gnd and the signal?

 

Or just in series (omitting the connection to gnd on pin 3)

 

Also assuming I want a lin pot, not a log pot?

 

I will drop CrazyDave a PM just in case this is something you DON'T know about the VR! ;-)

 

Cheers Mate

[Kevin Bacon 5]

LOL, yeah Crazy is the man to ask :lol:

 

I'm pretty sure it's just a common-or-garden 10K pot in series with the MAF output wire, which IIRC is the red wire on the older 5 pin MAFs (metal body).

 

Dave did that with some bigger injectors though, 359cc.

The idea of the pot is to reduce the voltage going to the ECU and when the voltage reduces, the injector duty reduces. It would probably work with stock injectors too, but the danger is you might go too lean at certain rpms. Dave's the man 8)

 

I just use a standalone now which removes any doubt :lol:

 

I have the same Bosch injectors he used with his 10K pot, which you are welcome to try if you want.

 

Another good way to get you going temporarily is to use a BEGI fuel riser and a MAF clamp. Although the boost ignition timing won't be optimised, you will have the saftey net of the knock sensors and the BEGI is boost dependant, so only increases fuel pressure when there's boost, which means the car will run like stock at idle and off boost cruising. The MAF clamp will stop the voltage exceeding 5V. If the ECU sees 5V or higher, it shuts down the injectors, which is nice of it!

 

All of those options have boost limitations, so 12psi is a good starting point. The BEGI+MAF clamp method will work up to 20psi. The 359cc + 10K pot method will work up to about 14psi before the injectors run out of flow.

 

A motronic remap will work up to 20psi with a 4" MAF body and 440cc injectors.

 

Standalones have virtually no limits and greater tuning flexibility 8)

[KADVR6 0]

hi ben,

 

i have a split second MAF clamp you can borrow if you need it.

 

karl

[Kevin Bacon 5]

Yeah i've got one of those aswell.

 

Been experimenting over the past month and Motronic defo is not the way to go with forced fed VRs ;-)

[mr_fusion 0]

I have a 6 wire MAF, is it still the red wire that performs the same function?

[Kevin Bacon 5]

Yep.

 

With the engine running, the signal wire will have a low voltage, should be around 1V, although on yours it might be double! Put a meter across the chassis and the red wire.

[mr_fusion 0]

Ok Guys, what's your opinion on this :

 

http://cgi.ebay.co.uk/Innovate-G2-or-G3 ... dZViewItem

 

I take it you can use the other analogue out put to wire to the existing lambda wiring?

 

Will prob buy this to start with if it's a good price, shame as I only just bought a new lambda...

[KADVR6 0]

i have got one of those sitting with all the other box's Ben, i got mine from the states delivered for £130 8)

[mr_fusion 0]

Ok then...

 

Got the LC-1 Wideband installed today - coupled with the resistor mod for the MAF, all seems to be running very smoothly now.

 

So far I have tweaked the resistor to show circa 1v at idle on the MAF, I think due to the larger injectors the AFR is settling at around 13.5 (rather than 14.7) and is running a tad rich across the RPM range (better than lean though), seems to be behaving though.. slides to rich on acceleration, then swings right over to lean when coming off the throttle as the injectors are cut, then back to 13.5 again.

 

I hope to get a log from the LC-1 tomorrow to upload for second opinions on how the ECU is dealing with the wideband (narrowband emulation to ecu) and the overall fueling.

 

Currently running through the chargecooler with out any water running through it and water injection is not wired up yet as I wanted to get the basics working first.

 

Any feedback on the logs tomorrow would be much appreciated..

 

ttfn

[mr_fusion 0]

Got the boot gauge installed and had a couple of runs with laptop logging the lc-1 output. Had a potter around town with a few spirited bursts on the throttle, seeing about 7.5psi before I have to slow down (major problem living in central london!)

 

Defo running too rich still, not sure if this can be fixed without remap / standalone though...

 

Here are a few pics of the install (and the LC-1 log file if anyone wants to take a look and is able to read it, you will need to rename the extension to .log (from .txt) as i can't upload .log files for some reason):

[mr_fusion 0]

Has anyone seen this box of tricks? Hooks up to the LC-1 as well to control fueling..

 

http://www.maftpro.com/tgen2info.shtml

 

I take it its something along the same lines as your Crazyfilter dave?

 

Can be had for £160 shipped.... is it worth the cash?

[Kevin Bacon 5]

Looked at the log. It's a bit hard to diagnose because the AFs shown aren't logged against RPM, or throttle position, or MAP pressure etc.

 

First thing I would do is reprogram the LC-1 cable to have a range of 10AF @ 0V to 20AF @ 5V. I think the default is something silly like 7.35AF to 22AF, which is a load of nonsense because the engine won't even run at 7.35AF and Motronic is unlikely to ever fuel it that rich.

 

Make sure the fuel type is still 14.7:1 Gasoline as it sometimes changes itself for no apparent reason, to alcohol or diesel or something.

 

I would also use the motronic lambda probe for your fuelling, and the LC-1 purely as a meter for the time being. Reason being, the Motronic lambda will be correct and reliable, the LC-1 might not be - yet. You will need to get a second lambda socket installed if not already.

 

Try running it with the aforementioned reprogramming job first and it might then show the correct AFs and drive a bit better.

 

Looked at the MAFTPRO and it seems OK, never used one so can't comment on it's suitability for your application.

 

With motronic you can only try these things until you get the results you want.

 

Let us know how it goes!

[CrazyDave 0]

Adjust your MAF signal back a bit at a time until the AF reads correct, you should be able to get it spot on 12.5 afr on WOT and 14.7-14.8 at idle and providing your DV / MAF locations are good it'll run perfect.

 

MAFT Pro, I did look at these, but didn't know of anybody who had tried them. Gave me a few ideas for my own box though :) I don't like the idea of trimming the WOT AFR in auto, not really a recommended practice, OK for setting up though. You can also get rid of the MAF and run in speed density mode with a MAP sensor, this is a bit MegaSquirt ish. But having tried that I think I'd spend the extra cash and go Emerald or DTA.

 

Been out driving the VRT today, complete with Daves box o'tricks and I'm still really pleased with it, very smooth. Hoping to try a certain FI VR thats running Emerald soon, so I'll let you know how that goes.

[cralstc 0]

Hi all,

Been a couple of months now. How are these projects coming along? I am still looking for some inspiration. :D

 

The 3.2 Audi enigne is almost ready for starting. It has been a long time since I have driven the Corrado and since I have been following this it is the only thing that has been keeping me going! LOL. The great thing about following this is it helps to iron out a couple of questions before them being asked. I have plans to install a rotrex on the 3.2 but I do have a couple of questions. :brickwall:

 

Obviously both the VR6 2.8 AAA engine and the 3.2 BUB engine are similar. But will I face the same problems with the MAF? By looking at your photos MR Fusion I guess it should be slightly easier for an install as the intake manifold and throttle body face the opposite way compared to the 12v version.

Mr. Fusion with regards to relocating the battery, eh where did you put it? in the boot? :confused4:

 

Also did you fit the charger instead of the AC compressor? as I have been trying to calculate the space needed for the charger and I think I may need to loose the AC to make it work properly. But since living in Dubai that may not be an option. I will post photos of what I have done so far.

 

Thanks

 

Craig.

[mr_fusion 0]

Hi Craig

 

Glad to see you still have the interest. I only recently got going on mine again and have got quite far along with it now.

 

Go a DTA P8 Pro ready to fit as well now as I still have overfueling issues at the moment.. hopefully this will all be on the car in the coming weeks.

 

I relocated my battery to the boot. Quite a simple job and not that pricey. Basically picked up some really thick flexible welding cable from ebay (4 metres if i remember correctly), made an MDF box (with hinged lid and breather hole) to hold the battery securely and fastened that to the boot floor with some metal brackets.

 

There is a 200amp circuit breaker attached to the box to isolate the supply if the cable shorts on the body. The cable is routed inside the car, under the rear seats and down under the handbrake etc, then up under the dash to behind the glovebox. There was already a hole in the firewall here, so i routed it through there.

 

This then goes directly to the starter motor. From here I hooked up another wire (red) to just below and behind the washer bottle where there is a distribution point / box. I then use this to tap of the 12v supply to the ancillary parts (all the wires that used to go directly to the battery positive terminal).

 

The battery itself is earthed in the boot. I did this by drilling a whole in the inside panel (below and to the right of the fuel filler cap). and bolting the negative battery cable to this point (best to file of some of the interior paint at this point to get a good earth)

 

I have had a no-start problem recently (which Kev has helped me out with). Ended up replacing most of the ignition components and it all turned out to the sparkplugs in the end. This came about after I fitted my secret custom intake manifold project that I have been keeping quiet about that I fabricated over christmas!

 

This is one thing to watch with running larger injectors on stock map as its really easy to flood the engine if the car isn't firing easily.. took me a month to realise the plugs were soaked in fuel after all the failed attempts to turn the engine over.

 

I will probably get some new pics of the engine bay up shortly as it looks drastically different now....

 

Cheers