[moved] Supercharged VR trackday issues

[FishWick 21]

Interesting. Where did you get that pump from?

I've also thought the stock pump is a bit pants. I've also thought about moving it away from it's current location so that it doesn't get so hot and fail so quickly, but it's getting round to these things!

[Phat VR6 3]

Hi very intresting.

Im enjoying learning about all this indeapth stuff. Im understanding alot of it but surtain words confuse me. Dont surpose you could explane what is ment buy "det" in

"Mon Aug 06 2007, 07:00PM" Post

"Is it normal for boosted VRs to see a tinny tinny bit of det at around peak rpm??"

Keep up the good work

Thanks Tom

[SiGainey 1]

Det = detonation = knocking = pinking

[rodney 17]

Will be interesting to see as the ambient is also much lower and if you have no more issues in October.

Is the pump a much higher flow rate??

Phat VR6, Don't mean to teach you to suck eggs here ..... This is a simple explanation. If you want more ask and one of us will fill in the blanks...as you can appreiciate I have simplified it ....

Detonation refers to the point at which the fuel air mix ignites. As you can appreciate it is a mini explosion and so as this happens it causes the piston to be thrown away quite violantly. We want to try and control that. Everytime it happens sensors can detect these mini impacts on the internals of the engine. You cannot get rid of them all so you balance the timing and fuel mixtures to get within a certain window.

The easiest way of hearing this kind of thing is with pinking. (you cant hear the knocks usually) I am sure you have been in a car and heard it make a funny sound on a hot day in the wrong gear up a hill with too much weight in etc.... this is usually caused by to little a mixture at the right time and reduces power. If you like the fuel is evaporated or made to explode before the pistons are in their correfct place... You can hear it as a warning sign on a car which is overheating....

The engine electronics are tryng to protect its' self from to high a knock count by retarding the timing. This should stop the engine failing.

Because we have a forced induction system you retard the timing anyway.... Soooo... hopefully that brings you up to speed with the quirks here...Ask away......

[Phat VR6 3]

Very helpfull. Thanks alot

[Conky 0]

Interesting. Where did you get that pump from?

I've also thought the stock pump is a bit pants. I've also thought about moving it away from it's current location so that it doesn't get so hot and fail so quickly' date=' but it's getting round to these things!

[/quote']

Hello, sorry for the massive delay, things have been a little hectic.

I got the pump new off an ebay auction for a great price.

here are few pics of it fitted.

Even though this new pump is twice as big as the VR6 one it fits in the original position nicely, with the pipe work orientated the same way just waiting for a little connector to arrive so I can use the Mercedes specific connector on the pump and have it wired up a little neater.

Also put together a little controller circuit and popped it in a little enclosure and fixed it to the side of the battery temporarily.

While I was doing all this and testing the new pump out I came across quite a nasty problem, why I haven’t noticed this before I don’t now. The Samco water return pipe that comes off the throttle body and T's into the expansion tank was blocked, well not so much blocked but when Samco manufactured the hose and added the little run of pipe to the expansion tank to create the T junction they didn’t open up the pipe that comes from the TB so the water couldn’t flow through to the expansion tank. I guess having this overflow blocked off like this would prevent the coolant system from purging quickly and possibly stall the flow of coolant if pressure rises to much, not sure exactly what it would do, but either way Im not at all happy with Samco for this stupid mistake!

Anyway now this is out the way, I can look forward to Donny this weekend

Cheers

[FishWick 21]

Cheers for the info on the pump mate, sounds interesting! Is there a part number on it at all?

The stock throttle body coolant hose has some kind of non return valve in it, is it possible Samco have done the same thing?

[Conky 0]

The PN for the pump is in my last but one post.

Ive uploaded the data sheet for all current Bosch aux pumps... http://rapidshare.com/files/60440301/Water_circulation_pumps.pdf.html

Actually wondered if it was some sort of rubber nrv, but the fact it wouldn’t allow flow in either direction and also it was quite visible that there was no break out on the main hose length, I was sure it was a manufacturing fault. Whether it should have had an nrv is another question.

Cheers

[GVK 1]

Any further with solving this? Car sounds interesting, wouldn't mind having a nose some time - I'm nr Worcester too.

[Conky 0]

Hi Gary, we haven’t really got much further tbh, as mentioned before, a nasty short in the wiring loom manages to damage a jumper pin on the ecu which we manages to resolder a good while ago. After that I’ve never trusted the original ecu so Ive sourced another one which is being sent off to stealth racing to get it socketed and rechipped. I worked out how to switch ecus over without the immobiliser having a paddy with the aid of vagcom, but I don't have the rework tools to do the socket installation myself.

When we get the ecu back (I would imagine in a week or so) your welcome to pop over and check out the car, but as the car is sat here with no ecu theres probably no point atm

Im located in Kidderminster btw.

[GVK 1]

You'll have to let me know when it's back up and running - good luck with it.

[Conky 0]

Sure will buddy, thanks

[GVK 1]

Any chance you were heading towards J6 M5 along the A449 about 8:15-8:30 ish one morning in the last couple of weeks?

Towing the mk3 on trailer with a 4x4?

I was on my way to work .

[Conky 0]

Hi guys, this maybe a monumental thread revival but we have sorted out the power loss issue once and for all!!!!! :-d

You would never guess what it was though! over 3 years we have struggled with this misfire at 4k and loss of power on track. In an effort to resolve this issue we have revised the entire coolest and lubrication system, always believing it was an engine temp issue or possible det problems. Also we have spent ages testing and replacing different ignitions components. Even sourced a new ECU, re-socketed it to take our tuned rom, but all in vain. I mean this thread has only documented a few attempts to solve this ongoing issue, I simply cant remember all the things we have tried.

Well anyway the culprit was believe it or not the Schrick variable inlet manifold control unit, not the manifold itself but the little pressure switch/solenoid that controls the actuator that swings open the manifold flap.

This pressure switch got power via the ECU harness, the switch is is basically a solenoid with a valve on the end to divert a vacuum to the flap actuator.

When the engine is at WOT this pressure switch draws power constantly as the Schrick manifold flap opens, so when on the track the engine is aways hanging around in the top rev range so the pressure switch for the manifold never turns off, Basically the combination of the pressure switch being held open for a long period of time and the high current it consumes overheated a mosfet/power reg in the ecu which also powers other critical areas of the ecu.

I only worked this out when I decided I would entirely remove the Schrick manifold and switch to a short runner.

I could have rewired the Schrick control unit correctly and ran it off its own dedicated power supply, but I wanted to change the entire intake system to accept a large charge cooler and eventually run a rotrex charger and increased boost.

Now the Schrick has been removed along with the offending control unit the engine pulls very hard above 4k much better than it did before, no flat spots and most importantly NO POWER LOSS no matter how hard the car is pushed on the track!

But now thanks to this new found top end power my 02A box has completely lunched itself! so presently I'm in the middle of installing an 02M box out of a 4motion golf which has been converted to 2wd. Once I'm happy with the box I will drop in a atb lsd

To think I thought it was the mighty VR6 engine that was to blame!!

[djmorgz 0]

shame on you for blaming the engine lol. nice to hear u got it sorted

[J5KE F 0]

I love thread revivals with regards to the 4mo box, are u keepin the 6 sp? is that a difficult conversion?

[Conky 0]

Of course, one of the great things about the DRP 02M box from the 4mo is the gear ratios and 6sp

Its really depends what you consider difficult I guess.

The hardest bit is repositioning the gearbox cup mount, it requires a bit of fabricating skills.

Off the top of my head to do an 02M conversion you need these bits off a 4mo vr golf

6speed Tranny

flywheel

clutch

starter

cable change

You also need a few custom bits...

02m mk3 tranny mount

fabricated bracket for front engine mount

custom drive shafts (if you want to be cheap you can use S3 inners and golf vr6 outers and marry them up)

02M 4WD to 2WD conversion plate

And a few odd and sods like an offside drive flange from an 02m box and a few other bits.

Thats the basic set-up to get running, when Im happy with the box I plan to replace the dual mass flywheel and standard clutch for an FST steel billet single mass fly and Clutchnet 6 puck race clutch and pressure plate. Also would like to go with fully custom driveshafts instead of using welded S3/Golf VR shafts.

Oh and not forgetting the ATB LSD which the car badly needs.

After all that with any luck the box and engine should be good for new management, fuelling, new charger and a load more boost!

[FishWick 21]

These are what you want :-) http://www.driveshaftshop.com/pdetail.php?pid=199

How are you finding the gearing? I hear the O2M is very short in MK3 Golfs etc. If it is too short, a good time to fit a taller final drive would be when you do the ATB :-)

[Conky 0]

As I said I'm in the middle of the conversion, I'm hoping I will get it finished before the trip to the ring with the club-GTI guys, if not I will have to put a spare 02a in.

Yup, those are the shafts I was talking about

very high quality parts, no need to worry about their strength and balance.

With regards to gb gearing it depends which 02M box you get, the DRP out of the 4motion has a fairly short gear ratio set when compared to the GQV/FMP/GQT 02Ms used in r32's, but some have shorter.

I always found the standard 02A to be to long on the track, most tracks I would never shift into 5 gear. I think Silverstone is the only track I have fully used 5th gear, just before stowe corner.

I also cant forget that Im running 17" wheels with wide 245mm track tires all round, which produce immense grip but have a rolling diameter much larger than the 15" 215 set-up I used to use.

If I do find that the 4motion box is to short on track I will grab a donor DRW 02m and nick its longer 5th (0.910) and 6th (0.805) gear set. There's no need to mess about with taller FD gear sets when you can change the main gear ratios, thats the beauty of VW boxes

Another thing worth noting with the early O2m boxes used in the 4motion is they are actually stronger than the later R32 units, something to do with stronger bearing carriers used in the early boxes tend to hold greater torque.

Cheers