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Old 09-09-2010, 03:01 PM   #15
HPF Chris
Past Site Sponsor
Join Date: Feb 2006
Location: Portland, OR
Posts: 3,684
My Ride: 2002 M3, 2006 530i
battaM3... I'm going to make a thread about your car next week. I'm also going to start a discussion about those that may want to consider running L19's in their stage 1/2 cars. As engines age, the factory bolts stretch. This stretching can allow the head to lift under boost. Both S/C and turbocharged M3's with higher mileage engines and also older M3's 01-03 may want to consider ARP L19 head studs. These should be torqued to 100 ft-lbs. Make sure you do each one individually so you don't have to remove the turbo kit and replace the head gasket. I believe BMW may have had some issues with these head bolts in the past. I'm estimating a 3-4% stage 1-2 engine failure rate as a result of factory head bolts stretching. These L19's come standard in our Stage 2.5, 3 and 4 builds but we don't touch the engine on stage 1 and 2. Here are the ARP L19 head studs for anyone that wants them. We can provide a discount off the $495 price on our site for any HPF stage 1-2 turbo kit owner that wants them.

mtran850... Once we get your Stage 4 M3 back I'll post up the cause of the failure. It may be an injector got partially plugged, or bad gas (or dilution), or a multitude of other things that we will check for.

Commanderwiggin... Your stage 2 M3 got bad gas in it (likely 87 octane) whether you were aware of it or not. Since you can't pump your own gas in Oregon, the attendant may have put the wrong fuel in (even though it says "91 octane minimum" on the gas cap and the gas tank door) or the station mis-filled their tanks. This caused your car to knock and damaged the engine. This is why I made this video of the knock siren so everyone with our kit will know what it sounds like. We left the same gas in your car after we installed your 2.5 kit and your M3 knocked immediately and John and JP had to pull out a ton of timing dropping the power nearly 100rwhp to compensate. We then drained all your gas out and swapped it with 92 octane and put the original stage 2.5 map in the EMS. Now there is no knock and your car makes the advertised power. I then had JP take your car out and test the knock siren and it comes on as it should.

So for everyone with our kits... Please be aware of this knock siren and what it sounds like. Please also be aware that poor gas can cause motor failure in your car. For those stage 1-2 customers that have high mileage engines or just want to take the extra precautions to prevent their head from lifting can contact about doing the L19 head stud swap.


Picture of L19 Head Studs

Last edited by HPF Chris; 09-09-2010 at 03:10 PM.
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