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Old 11-30-2009, 02:05 PM   #1
ludo
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Default M44, DASC, 3.4 pulley, TT S3 tune, snow performance=> Kaboum

First post here, I was reading you from time to time (as I do on many US based BMW forums, not too much info on boot bimmer in France). I am posting on behalf of a friend who owns a Z3 1.9l roadster fitted with DASC. I personnaly own a Z3 coupe 2.8l and an E36 M3 3.0L (euro spec)

so set up is as follow:
90k miles engine on a Z3 1.9L
DASC kit, 15k miles on it.

fitted during the week:
NickG tune stage 3
pulley 3.4"
snow performance stage 1

The first issue we had:
that was with the snow performance kit, we did not order the solenoid valve and find out about the requirment for this with DASC (due to the injection being after the throttle body and subsequent risk of siphoning) set-up while fitting it. Upon realising this we decided not to run with the sno performance on the road.
Yesterday the car was driven down to the road track, 200 rouble free miles. Before that 2 or 3 run down the road were done with no problems.

once at the track:
reconnected snow performance before going in. All went ok for 8 miles when the low level alarm for methanol/water tank went off. Seing that and in order to protect the pump, my friend shut off the injection (in car switch) right away.
Immediatly a very strong smoke came though the air vents and smoke out of the exhaust so he decided to proceed to the next fire man pit. on the way he felt the car was sluggish (more on that later). the fire was quickly put out and only located on the exhaust just after the header.

the car was brought back to the pits and the findings were:
-snow performance tank level was in fact low, so around 1 gallon was injected in 8 miles
-blown filler cap seal (seal couldn't be found but was there the day before, re ), so that explained the oil everywhere in the engine bay area and was probably the source of the fire
-flexy hose between MAF and throttle body was partially disconnected, no idea how did that happen
-we tried to restart the car, sounds like there is no compression
-looking at pistons through the spark plug holes, they look like brand new pistons (shiny)
-engine turns freely by hand
-oil pressure and temp, water temp were ok on the way to the fire man pit.

what we don't know (amougst other things):
-AFR: no meter, will be fitted for the rebuilt
-boost pressure: gauge wasn't looked at

Basically looking for opinions on what went wrong before rebuilding. My feeling is that the injection rate of methanol/water was much too high, almost as much as petrol. When I thought of the siphoning effect before I only thought of it at idle, now in insight, it also takes place everytime the throttle is closed.
I still can't understand how the filler cap seal could be blown like that though

Car is still at the track, we will collect it during the week, and open the engine after to have a good look at the pistons, after having done a compression test.

Original theorie of mine was:
the methanol injection was cut off in th middle of the straight at 7000rpm. Very high revs and closed throttle butterfly lead to partial vaccum being created in the intake manifold, correct? if so, the siphoning of the methanol/water goes on but as the pump is not running, it is not under pressure anymore so no atomisation of it, just dripping. Than goes into the piston chamber and probably vaporised immediatly => Hence the white exhaust fumes that could be seen as soon as the methanol injection system was shut-off. That might also have washed the bores and blown the piston rings.

Looking at pictures my friend just sent me, I think that my original bore wash theory is out the window, definitely looks like pinging to me.
Car was running on 98 RON fuel (I think it's 93 of your octane number which is an average of RON and MON). Should we be running higher octane fuel at 10psi?
I am getting my friend to check that the pulley size is correct and that the MAF he fitted was the correct one too. If these two check out, then I am a bit at loss so once again, any suggestion welcomed.













the headgasket was found to be ok during diassembly.
Pistons appeared to have melted on the exhaust side, too high EGT?

anothr Q: what octane petrol is run by those running 10psi on stock engine? we wre running a 98 RON (93 for US octane rating I think)
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Old 11-30-2009, 04:18 PM   #2
projekt EPiK
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high exhaust temps usually are a result of severely retarded ignition timing.. new to BMW, but is there a failsafe in the ECU to yank timing under certain conditions??

the methanol mixture super cleaned the pistons and bore.. possibly it pooled in the cylinder, leaked down the exhaust side on fire and created a heat pocket? grasping at straws there..
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Old 11-30-2009, 04:44 PM   #3
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You dumped too much Meth and washed the oil off the pistons and cylinder walls. With a 3.4" pulley you really don't need any Meth spray
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Old 11-30-2009, 04:49 PM   #4
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+1 on that. Also, your injector is likely way too big. I run meth injection before the TB (in the rubber intake boot). I don't use a solenoid but rather a checkvalve.
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Old 11-30-2009, 08:53 PM   #5
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Quote:
Originally Posted by pnosker View Post
+1 on that. Also, your injector is likely way too big. I run meth injection before the TB (in the rubber intake boot). I don't use a solenoid but rather a checkvalve.
Yep sorry to see the carnage. Those are washed pistons and I've seen a few on my outboards that run Meth. Meth is a perfect solvent for oil. You need Castor Been oil to run with it in high amounts or you get exactly what you have pictures of

Last edited by xxxJohnBoyxxx; 11-30-2009 at 08:57 PM.
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Old 12-01-2009, 02:49 AM   #6
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Quote:
Originally Posted by pnosker View Post
+1 on that. Also, your injector is likely way too big. I run meth injection before the TB (in the rubber intake boot). I don't use a solenoid but rather a checkvalve.
we can not run it before because it seems that roots blower internals don't like it too much.

What fuel onctane are people running with 10psi pulley? what about the compression ratio, do people fit thickier HG?
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Old 12-01-2009, 04:30 AM   #7
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I have a roots blower too. So did John. We both ran before and that's where you have to or else you inject streams of water. Running before the blower allows it to vaporize with the blower heat and it seals the rotors better anyhow. I am running 15 psi with meth injection with 93 octane fuel (US grade, approx 98 in europe?).

I have the stock head gasket.

As long as you don't run anything other than water or methanol your blower will be fine. I just opened mine up this week and it was pristine. It has over 10k from when I put meth injection in and the blower has been on the car for almost 90k now. I'll probably have it rebuilt just to have the lube replaced and plastic pieces redone and the coating reapplied within a couple of years.

I also have NickG's tune.
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Old 12-01-2009, 07:45 AM   #8
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I thought I read it here or on bimmerforums of case where the internals of the blower had been eating away.

What compression ratio are you running @ 15psi?

Last edited by ludo; 12-01-2009 at 07:49 AM.
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Old 12-01-2009, 03:28 PM   #9
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Stock motor. dustenT ran methyl ethyl ketone in addition to methanol and that ate his coating. Make sure you don't do that and you will be ok.
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Old 12-01-2009, 06:24 PM   #10
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Quote:
Originally Posted by ludo View Post
I thought I read it here or on bimmerforums of case where the internals of the blower had been eating away.

What compression ratio are you running @ 15psi?
10:1 stock compression. Need to run Meth if your going to try it. No issues with internal blower eaten away thats BS or you used the wrong stuff.

I've run 92% Meth with 8% Nitromethane with no rotor issues put 33,000 on my blower and stock motor at 15psi with no issues. Retired the motor at 173,000 miles in excellect working condition...
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Old 12-01-2009, 06:57 PM   #11
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I'm not sure meth is 100% required, though I run it to be safe. When I was installing it, I kept having a check valve problem which made it not inject for the first few days. I eventually fixed it but my motor seemed to run fine for that short amount of time. My compression is the same in all cylinders so I'm not sure how long it would last without meth injection. I don't stay under high boost for long periods of time though.
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Old 12-01-2009, 10:30 PM   #12
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You should run a 50/50 mix of meth and water. Actually they say 49% meth/51% water so it is not flamable
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Old 12-03-2009, 03:27 PM   #13
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Could there also be a tuning issue with the TT S3 tune? Doesn't it require at least us grade 93 octane? Which I think with the way it is measured in the US, makes it more like 98 octane in Europe.

Does Nick have his tune set up to use the gas from different countries? I think an AFR to determine if the tune is good on your setup is the best place to start.
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Old 12-03-2009, 04:05 PM   #14
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Quote:
Originally Posted by mohaughn View Post
Could there also be a tuning issue with the TT S3 tune? Doesn't it require at least us grade 93 octane? Which I think with the way it is measured in the US, makes it more like 98 octane in Europe.

Does Nick have his tune set up to use the gas from different countries? I think an AFR to determine if the tune is good on your setup is the best place to start.
OP posted he was running 98ron or same as US 93 octane. Nick's tuning is pretty good and I doubt there are any issues with a stage 3 since it would have his injectors. Fuel pump maybe but it looks washed. Everything is so clean it looks like the Meth washed off all the oil and it stuck the skirt and then it was friction city and melt down very quick. Only my opinion.

I've seen this a lot on meth motors I run. Meth cleans the oil off the rings and cylinder walls if not evaporated and there is no lube and this is the result.
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Old 12-04-2009, 05:14 AM   #15
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At the moment I have no reason to blame NickG tune, his service has been second to none and I never read any issues with his tune so no real reason to question it at this time

Now the rebuilt is starting, that's what we are thinking of doing:
Forged pistons
forged rod
ARP head studs
fitting a solenoid valve to meth injection and smaller nozzle (probably the smallest one available)

and my friendsalso want to take the opportunity to fit a ported head (probably VAC stage 2) and cams. The downside is that this means another mapping will be required and might need to do it locally which could prove hard to find and expensive

On the monitoring front, EGT and wideband will go on.

Being all new on this FI things, could you advise which parts/brands are good, especially for pistons and rods?
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