How'd the turbo 535 do at the dyno, Craig? Jeff, care to share? Hmmm????

[Martin in Bellevue]

I was a wee bit disappointed with the "mild" gains provided with the reground camshaft. Oh well, at least it won't have to come out for a turbo, or trade in. It is still curious, as the car seems to pull harder above 4k rpm. Oh well, better to have too little cam, than too much cam in the familymobile.

I do think the car had cooled down too much for precise air/fuel reedings. The tech had me dialing the maf controls, over a few runs, ultimately, back to the initial settings. Should have had Jeffro do a few laps around the complex before the runs. The idle was crap when the dynojet showed the air fuel ratio to be right. The dynojet indicated lean when it was smooth. The probe up the tailpipe isn't too far away & behind the catalytic convertor to give relevant information?



Since the last dyno session, in April, the only other change was to a 3.64 limited slip gearset out back, I think.

Here's the results from that first dyno session with the stock camshaft.

[TCD]

The numbers for both the 91 M5 and the TCD 535i at 8psi are coming! Guess which had more power?
Todd

[Bill R.]

maf controller then you'll have to check the exhaust gas at the plugs in the exhaust manifold... And does the dme still overide your settings and attempt to adjust the mixture or are you on a standalone thats independant of that?
At any rate passing through the cat is going to make it read lean on the dynojet when its actually adjusted correctly... and if you richen it up enough for the dynojet to read it as correct then its way rich in front of the cat and will lope at idle... Also did you take outside air temp and barometric pressure readings for each dyno test... That will make a big difference in hp and torque on your dyno tests... the cam could be working better than you think but the air may have been cooler and denser on your first dyno test so the horsepower reading was closer to ideal...

I was a wee bit disappointed with the "mild" gains provided with the reground camshaft. Oh well, at least it won't have to come out for a turbo, or trade in. It is still curious, as the car seems to pull harder above 4k rpm. Oh well, better to have too little cam, than too much cam in the familymobile.

I do think the car had cooled down too much for precise air/fuel reedings. The tech had me dialing the maf controls, over a few runs, ultimately, back to the initial settings. Should have had Jeffro do a few laps around the complex before the runs. The idle was crap when the dynojet showed the air fuel ratio to be right. The dynojet indicated lean when it was smooth. The probe up the tailpipe isn't too far away & behind the catalytic convertor to give relevant information?



Since the last dyno session, in April, the only other change was to a 3.64 limited slip gearset out back, I think.

Here's the results from that first dyno session with the stock camshaft.

[Craig]

Here I am.

The car did very well.

[Jeff N.]

My car behaved somewhat as expected. Down on power relative to Martins. Driving the cars side by side, it's apparent that his has more oomph all around. The dyno shows where; now the question is why.

Here's the torque/hp curve. Note the lack of low end and the quick rise as the car hits 3500 RPM. Drives like this as well. The upper line is after we got the a/f mixture about right. It was a bit lean to start out with. Total power is still low.



Here's the same with a/f reading. The operator set the car a tad rich to avoid upper PRM pinging.



We also sorted out the oil consumption issue. Under WOT the car blew a pretty solid white cloud at the RPM's increased. Rings look pretty shot.

Sooo...where to go from here? Bottom end's soft it looks like and i'm not nearly getting my ROI from my head, cam and MAF. Cam just looks way too hot for motor in it's current condition. Spoke with a local BMW engine builder who's very familiar with the MM heads and cams. He basically said that this is how my head would behave without the 3.7 block with HC pistons. Maybe it's time to go "all in"?

Ah well...the journey continues...

Jeff

[Craig]

Hey Jeff it was nice to finally meet you, although for some reason you looked familiar. Maybe we crossed paths at a track day sometime.

Anyhow, I forgot to ask if you've done a compression/leakdown test? If your rings are bad that could help explain a bit of the power issues you're seeing I would imagine.

[Jeff N.]

Nice to finally meet you as well Craig. Wanted to stay longer and chat but had family in town for the weekend so the spare time was limited. I too think we have met somewhere but I can't place it either.

I've done both the tests and the numbers weren't bad. One hole - #3 I think - is definately soft with a leakdown more around 6 or 7% and the rest were about 3 or so. (This is a home test so I think we did it more or less correctly.) Can't recall the compression numbers off the top of my head; they have changed as we have adjusted the cam timing as you might expect. They are not perfectly even which tells you something.

I think the bottom line is this. High milege short block that's been driven hard and it showing it's age combined with a head that has too much cam. This Lisandro guy in Olympia is supposed to be quite familiar with this head/cam setup so I'm thinking I'll take the numbers and car down to him and see what he thinks.

Your numbers look really good. When can I get a check ride?

Jeff

[Robin-535im]

I think you've no other choice but to build a hotrod M30 from the ground up.

Did you ever decide if a M5 crank would bolt up to your block? Sounds like a perfect winter project - get started now so you know what to ask for during the holidays! You should document the process and make a book / CD out of it. Aren't there books out there about building a stroker out of a m20 or something? Pick the parts, corner the market, and sell rebuild kit for the M30. Everything you need to make your M30 a 3.7L beast, all in one box.

BTW - a 1995 535? That's a rare one indeed!

Also - question for you, Martin, others with hotter cams: What do you set your valves at? I ask because I've gone from .012 to a loose .013 and now I'm at .008 intake and .010 exhaust (w/engine at about 80 F) and the thing has a nice strong pull at the higher revs. Screw the idle! I believe I have a "+1" cam, somthing like a "274 regrind" if there is such a thing. I figured the reground cam could handle tighter clearances. Just wondering if anyone else with a hotter cam sets theirs tight.

- Robin

[Martin in Bellevue]

I have been setting intake valves to 0.010" and the exhaust at 0.012".
Since the dyno last Saturday, I've moved all the maf pots over to lean things out a scooch. It seems happier. The split second narrow band air fuel meter spends much less time pegged to rich now.

[Robin-535im]

I have been setting intake valves to 0.010" and the exhaust at 0.012".
Since the dyno last Saturday, I've moved all the maf pots over to lean things out a scooch. It seems happier. The split second narrow band air fuel meter spends much less time pegged to rich now.

There are pots too? Can you tweak both the voltage curve on the PC and the pots?

Also - now that we're talking MAFs - how much gain do you really get from one? A little bit? A lot? At $600 it seems a bit steep unless the gains are worth it. I'm toying with getting one for X-mas but I'd like to know what you think of it.