2008-09-21 - UK - Pics From A Very Sunny Santa Pod

looks like a good day

Great photos Wayne, it looks as though you had a good day out. I was at Blenheim Palace for the Oxford Classic Car show and managed to get my 850Ci inn the BMW Club line up with some very nice 6's, 3's and an older CS. Fabulous weather and a big show, the folks from the BMW club were very friendly and the 8 attracted a lot of interest. I was embarrased as the car was pretty grubby as I'd driven over a 1,000 miles since leaving home on Friday and getting to Blenheim.
There was another black 8 present, I saw the photo spread that had a picture of every "interesting" car arriving at Blenheim, I could n't find this other car though despite searching, the number plate was M *** BSW

Anyone here own up to owning that car?

Hi again Wayne,
Thanks for the pics.
Was a great day (or 2 for me) and the weather helped. Never seen such ideal conditions at the Pod - no wind, unheard of !

Personally counted 8 E31's including 4 CSi's and 3 of those (including mine) in silver.

Standout (of many) things for me were the 2 side-by-side runs up the strip by 2 silver CSi's (mine and the one with the Schnitzer-style wheels) - hope someone got some pics ?? Score was one win each. Got to be a one-off moment ??
Magic
The black S800 reg 840 driver who let his girlfriend drive his car on the strip on Sunday after setting his personal best time on Sat. Then she beats his time with a blistering 14.3 sec !! His idea was to get the weight down and it worked!
"Tony" running the Montreal Blue T-reg 840 for the first time on the strip (but an experienced drag-racer in other vehicles) and managing to get his times down by almost 1 sec in a day by removing weight from the boot and playing around with just about every combination of suspension setting/traction control/tyre pressure/burnout imaginable.

A must for any owner with the vaguest interest in how our cars can perform and there were also some fabulous cars on display for the spectators too.

May post some of my own pics later, plus some performance points in a seperate thread.

More pics:-
Sorry, no videos on Youtube this year

For fans of the E24 6 series (like me), how about the red one that won "Best Original" in the show&shine....
Or the Alpina B7 Turbo ....
Or the 454ci Chevy engined racecar with an immaculate steel 635 body on top ....

And a few pics of mine on the strip (courtesy Blackett Photography)

Event official report now available on bmwshow.co.uk., including track times.
Winner on the track in our category (8 cylinder +) was 12.77 sec by one of the new V8 M3's.
Lot more quicker cars in this class than last year, first 4 were all sub 13 sec. What with the M3 V8s and the new style M5s, frankly you must have a seriously modded E31 to stand a chance in this class now !
I finished 1/2 way down the field of 29 runners, against 7th last year with a slower time ...
Never mind, it was great anyway

Just out of curiosity what were the 850CSi times?

Terry,
When we ran against each other was late in the afternoon and times had definately slowed through the day as it got warmer.
In the side-by-side CSi runs my best time was 14.73 and his was 14.86.

Earlier in the day I managed a best of 14.38, and the other CSi 14.48.
On my 14.38 run I also broke the 100mph terminal speed barrier for the first time.

My car is now slightly modified with lightened flywheel, stage 2 kevlar clutch, UUC short-shifter, adjustable clutch stop and 3.45 final drive.
The other CSI was running standard 2.93 gearing but had a "remap" with rev limit raised to 6500rpm (in all gears I think) allowing him to pull 3rd through the finish line, one less gearchange than mine.

Times for mine definately leave room for improvement in technique and to make the best of the 3.45 gearing. Got to be so careful with the revs now in 1st otherwise it just loses traction. Get better times with traction control switched on (don't need it with 2.93 gearing) but the traction control is limiting power in 1st to achieve this - can be clearly seen on my Gtech recordings of the runs.

I've got some ideas for next time and will be practicing to speed-up my gearchanges meanwhile ....
Have since tried some recorded runs on the road (private road, officer) and have equalled the 14.38 time with a 2nd gear start.....

Thanks for the information

I suppose that I need to run my 840 on the strip someday. The dyno too.

Just to see where it is now with the Wokke chip, low restriction air flow straightener and 3.64 gears.

Terry,
When you get to run it on the dyno and the strip, I think you may well be pleasantly surprised with the results...
Judging by the times achieved by the two 840s on the day (14.71 and 14.3ish) which had both had "remaps" and exhaust mods, these kind of mods seem to be achieving significant power gains putting them well in line with CSi times.
They were both running standard final drive gearing, so with your 3.64 ....?

Shame we couldn't persuade Wayne to run his 840 with 3.91 gearing. His times could have been a useful benchmark for what is becoming a common mod for 840s.

Both the 840s running had experimented to find the best combination of damper/traction control etc settings and cut weight to a minimum (spare wheel, fuel - not stripping the interior out!) to achieve their times. Don't know what these settings were exactly but I know one of the guys got his best times with the EDC set to the soft "K" setting, thereby getting it to sit back on the rear end off the line, improving weight transfer and traction.
(could be one of my problems - CSi has no adjustment for dampers, and very stiff lowered springs)

Like the idea of your "low restriction air flow straightener" (one of the 840s got some small improvement just by removing the air filter). What is that exactly and is it commercially available ?

The air flow device replaces the front plastic screen in the air flow meter. A lot more open but still an air straightener
With removal of the rear screen as well their initial gain on an E46 M3 with a 540 AFM was 12 to 15 hp. They have been sold out for a while but did make 2 sizes originally. http://www.ground-control-stor…roducts/category.php/CA=6

The leading edge is just about sharp enough to cut yourself on.

Wayne,
Once you've done your "engine work" dont forget to give it a practice run at the Pod first (to get the set-up right) before the BM meeting and let me know when you are going ?

Terry,
If not from a respected person like yourself (and the claims/guarantees made) I might have said this device seems like a gimmick ...
However .... simpler things can produce big gains !
Have you noticed a difference with it installed ?

Zitat von martinw;53969

Have you noticed a difference with it installed ?

I had to reset the computer immediately after installation to fix the idle. It was shaking like a dog so there was some effect on air flow.

Then my Butt dyno told me it was good

Take a look at the plastic factory air straightener in the AFM inlet and the screen on the back and tell me if you think the airflow is is going to be Ideal thru them. I see a serious restriction of flow there compared to the Gizmo.

All of that doesn't mean I am right. But years of "experience" designing sealed machine tool enclosures and rather exotic air pick up and flow diversion devices to contain our toxic materials during machining makes me think I am.

I've never had the inlet apart (I'll have a look one day) but I can see what you're saying about the restriction from the screens.
Like they say, if it feels right ... I'm sure you're getting some improvement.
BTW, how did you reset the computer to get the idle right ?

I may well look out for the gizmo when it comes back in stock. Do they make one in the right size for the CSi ?

In terms of "air straighteners", I was thinking along other lines - a way of getting more of a straight line ram effect to the inlet from the front of the car. Difficult from the standard air inlets by the front grille, because of the headlights being in the way.

Here are pictures of the factory straighteners used for the V8. I believe that the M70 screens are around the same diameter as the standard 6 cylinder screens but I only have M60 and M62 screens in hand.

One picture shows both an inlet and a part of the larger opening outlet straightener. The other picture is a closeup as straight on as possible of the inlet straightener that the Gizmo replaces.

The adaptive reset is done by disconnecting the connector of the ECU for a few seconds. All of the adaptive values are reset as well as any stored error codes. The engine will re-adapt in a short period of time -a few minutes and a few miles.

The Gizmo has certainly got to be less restrictive than the factory item shown ! and with the rear screen removed ....

I don't have any background in airflow but this has got me thinking ...
Is it a common thing to have an air straightener/screen somewhere in the inlet behind the airfilter ?
If so, what is it doing exactly ? I could imagine a straightener perhaps being necessary to reduce the "swirl" of the airflow, but this is after the air has passed through the airfilter. Is there going to be that much swirl there ?
If so, then to straighten the airflow, one would expect the depth of the fins in the straightener to have to be longer (certainly longer than the factory item) to have any effect ?
If its intended more as a coarse strainer/filter - whats the point ? The air has already passed through a far better filter (the air filter).

Perhaps there's more to this than meets the (uneducated) eye ?
Has anybody tried just removing the front and rear screens altogether (no "straighteners" at all) ?

It takes 12 times the diameter of the pipe for air flow to naturally straighten after a 90 degree bend. Until that distance there is a steadily diminishing amount of turbulence and swirl in the pipe.

The AFM is measuring the speed of the air as it passes that point. The computer knows the area of the pipe and the speed data allows it to calculate the total volume of air flowing in the pipe as a function of time.

The MAF uses the same data but adds the "weight" of the air to calculate mass over time rather than volume.

The distance to the meter is far less than 12 diameters but the turn is fairly gentle and the air flow is measured on the side of the tube. The sensor itself is fairly long so it is averaging over the wire length. The side of the tube will be the most stable area so it should need a lot less help than the stock straightener. Hence the Gizmo which is a truly minimalist piece of "art".

Thanks for that Terry ! Very interesting.
Wow! I knew I needed educating but .... just shows the average guy's ignorance on the subject.

I hope the company selling the Gizmo give a similar explanation of the benefits otherwise the average owner could easily ignore this useful (and well designed) device.

So, straight pipe runs to the AFM would be a good thing ? Difficult to achieve though, and maybe more expensive than the Gizmo.

Fun stuff ? It is amazing what you have to learn when 80,000 Cubic Feet per minute of building exhaust from a 135,000 square foot building comes up inadequate for point of use applications. Then you learn how to cheat with what you have

Yes a straight tube would be ideal before the meter.

The next problem is the flex tube angle into the DK motor on the 850 and then the throttle plate in the DK.

The 840 has a secondary throttle plate for the traction control and then the main throttle plate after that.

The total system flow can't be better than the flow thru worst spot so there are several points of restriction any direction you go. The usual fix is to oversize everything and let the flow be "lazy" rather than to try for "optimal".

I just thought that a smoother less restrictive flow thru the point of measurement can not hurt.

This kind of thing is why the new BMW engines have no throttle plates and use the valve opening to control the air flow into the engine.