1995 M3 Time Trial Build

[DocWyte]

Holy crap! That's seriously what you found?! I can't believe the motor was even running....

[jakermac]

You're getting new rod bolts too, right?

[yeaseth]

Wow


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[Remotion]

Wow exactly.

[BlackHawkRacing]

Holy shit, that's some FI section level bending.

[GG///M3]

So much awesome


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[darbyfam]

It's baaaack

https://youtu.be/wn0mGgzCq_4

[darbyfam]

Testing went very well today. Left with a short punch list of issues (dip stick O ring leaking, valve cover gasket has a slight leak, brake ducting torn). The car feels really strong overall. The one noticeable difference is that it pulls harder, higher in the RPM band. I previously would shift at about 6500 RPMs when it felt like the hard "pull" subsided. Today, I was shifting at 7000RPM.


http://s208.photobucket.com/user/dar...94bbl.mp4.html


Also added a MKAH Motorsports diffuser on the car.

[darbyfam]

During this process, I also added an oil cooler (see cluster fuck above). The cooler itself is installed behind the kidney grills which are also blocked off to prevent too much cooling. The S54 oil filter housing retains the stock thermostat.

[digger]

what was the cause of the buckled rod, hydro-lock ? was No6 valve(s) actually bent to or was the rod the root cause?

[darbyfam]

Our best guess is that #6 injector locked open some how and it ended up hydrolocking. The rod was the root cause it appears.

All is well now.

[digger]

yeah that's what i was thinking.

if the valve had been bent i wondered if it had been a sign the stock spring was failing to keep the valvetrain under control causing loft and bounce.

[darbyfam]

First off - FUCK YOU PHOTOBUCKET.


Now back to the car.





Here is a comparison of the last dyno in March of 2016 and today's dyno. What I take from this is that:


(1) you can't compare the two like they are direct comparisons (we all knew that). The first dyno was in March on a much colder and less humid day. The tires I was running today were a bit taller than the ones I used last time.
(2) the previous dyno had always been questioned by those "in the know" because of the crazy torque numbers
(3) the ITBs and port and polish definitely made a change.


I am going to assume that the taller tire and weather conditions made (X) difference between the two sessions. Lets just say it's 10% (27 WHP/25TQ). Yes, this is a made up number with no scientific backing, but it's for explanation purposes only. If you take the assumption and apply it to the dyno graphs (increase today's results by 10% or reduce the last ones by the same number) you will more clearly see where the two graphs differ. The most glaring would be the HP/TQ loss between 3100 and 3700 RPMS (highly disappointing. This delta steadily decreased as the revs increase. At the top end, the delta is completely gone on the graph and if you apply the 10% correction factor, today's results would be more than the last dyno. Given all of this, I am taking away from this that the ITBs robbed me of a good bit of low-end HP/TQ and gained a slight bit of HP/TQ at the top end. Overall, I consider it a failed modification at this point because of this. Had I not lost so much HP/TQ dow low, I would have been much more satisfied.


I am hoping that upgrading to Megasquirt on going Alpha-N (no MAF) will help the situation some but I cannot believe that it will be able to make up that lost HP/TQ between 3100-3700 RPMs.


I am not terribly disappointed. I knew this was a possibility of happening but sometimes you have to be the first to do something just for the hell of it. Also, dyno graphs mean nothing for how I use my car. Lap times tell the tale. I will be back at NOLA on July 19th on the long track and will do an apples/apples comparison on what really matters.

[bluptgm3]

Nice write-up, too bad no apples-to-apples comparison.


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[DocWyte]

That 255 torque number seems more valid....

[darbyfam]

That 255 torque number seems more valid....

Yeah. I wanted the old chart to be real, but......

[Pat533i]

On the plus side, you have a very nice flat power band from 5.5 to 6.5

Max hp from that low and all the way until redline can be very useful on track.

edit: although it looks like the motor leans out a bit up above 6k

[darbyfam]

Here is the dyno chart showing the first pull (on previous map tuned in March of 2016) and the last pull (after fuel and timing adjustments).

[digger]

there isn't something off like the cam timing or vanos function?

[darbyfam]

I don't THINK so. I have to change the valve cover gasket (it has a slight leak) and will double check the timing when the VC is off.

[Foda420]

Which cams are you running again? It's just so strange that power is falling off where it is. Really you should have another 500 RPMs of powerband based on the rest of your setup I think.

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[darbyfam]

Sunbelt cams, stage 2.

[digger]

Which cams are you running again? It's just so strange that power is falling off where it is. Really you should have another 500 RPMs of powerband based on the rest of your setup I think.

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yeah id expect 6500-6700rpm peak hp rpm like post 7 with power carrying well in the 7's

https://www.bimmerforums.com/forum/s...e-cams-m50-s52

[yeaseth]

Good information


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[GG///M3]

Love this thread


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