850 + NOS = Good God Man, thank you! (archive)

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My 91 850 auto is very happy. Its not the difference you might picture, and very smooth and 850 like... only it moves like it looks. Chips, intakes, exhaust... many of us have done it, and we've been pretty happy. But in a large 850, its still in the same "wish it would go just a bit more" range.

I'm glad I got to drive a Dinan twin turbo 850, because it gave me a range, it being the top, the Csi below that, a regular 850 an equal distance from the Csi down the totem pole. The twin turbo was fresh, smooth, and jet-like in its acceleration. I don't know how many of you really ever heard follow ups on the Dinan kit, but this particular one had a lot of repair bills... seals, idling problems. It had several previous owners, so was probably beat around a bit. But the bills scared me, so I just remember the effect of the acceleration and didn't buy it.

Dinan kills twin turbo program, the possibility gone to make my 8 feel like that. Not that I'd actually pay the 25K to do it, but wasn't it nice to know Dinan was putting out a killer representative of our great cars? When the program quit and Dinan basically yawned at the 8 series, it renewed my quest for that performance. Superchargers, stroker motors, talks of Hartge, RD, Alpina... I've been reading the board a lot, just not saying much. Then I talked to more people at NOS, about NOS.

Worries about heat, blown motors, exploding bottles on web pages (seems its the same incident everywhere, where someone basically roasts a full bottle of NOS, which also has a defective release valve, with a bottle heater gone crazy)... you name it, I've contemplated it. After finding out I'd need two BMW 6 cylinder kits running in tandom for the 12 (a dry 2 jet system, not a wet system in each cyl), I bought it and saught a good installer. That was hard. 5 people later, I went to So Cal Speed Shop in Pomona, very experienced with NOS and hotrods. 3 days, a lot of extra hours and customizations later, it was ready.

And it was just like the Dinan twin turbo I drove. Listening and feeling for any kind of hestiatation, warning sign, ping, pong or grunt, we started with two 60hp jets... 120 added to 300 = 420hp. Basically a Csi with another 40. VERY NICE. Not spastic... very controlled and smooth... very very much like the power band of a turbo ( a nice ceramic ball-bearing ultra fast spooling turbo) :) Nothing abnormal, except the notable feeling that the car kicks ass now. Although very short term in terms of testing, your initial reaction is that the NOS ALLOWED it to be tacken off that leash you feel all the time when you drive: Very brisk, but just a little short... as if its not allowed to go 100%.

For those of you that don't know, I've done a lot to get more momentum from my 8. Much of this probably adds to the overall performance as well. Currently I have the 3.91 M5 rear, a very nice improvement... I've had both the Dinan and Conforti chips in at different times, both nice but not jaw dropping. I have the Supersprint, torque master plugs, the Dinan tranny chip (still in... had to go back to stock engine chips, see post below). So, while not quite a Csi, it moved real well. So, I jumped from faster than stock, past the Csi, and into twin turbo like performance-land with the flip of a switch.

3 days later, one bottle gone. If it costs me $22 to fill a bottle and have this much fun in my 850, what a bargain. That's also why I had the second bottle installed as well. Now I'm going to carefully document every repair from here on out as I use NOS over the next several months... determine if the repairs are related to the additional power ... and not one of the semi-monthly ones I usually do in stock form anyway... they come like clockwork, don't they?

Sidenote, so funny... we're running wires back to the bottles and take the rear seat out. I remember someone mentioning gas leaks, loose bolts there, etc... sure enough, one is lose, I tighten, all better. I love this board...

So, my friends, now I know it can be done smoothly and with huge dividends in performance. When we put the 80hp jets in, which brings things to the 460-480 hp arena, it was yet another nice bit of frosting. Really, we were all impressed with how well the V12 took to it... like it was handling it without a hitch, still not challenged. I think these motors are so undertuned its a crime. Back to the 60hp jets for the next month to begin chapter 2: What's going to break and how much will it cost? The funny part is I of course had that fear going into this... sure, it may be fast for a week, but what about after a couple bottles... amd I killing it, etc.

I don't have that fear any more, and NOT because I'm worried about it. But rather, I no longer care if I have to deal with pretty major repairs down the road. Yes, potentially it could be insanely expensive... but I don't think it will turn out that way. For this much fun, its worth it... even if I have to buy one of these 15K neglected used 850s as a spare parts car, its worth it. It still can't match what I just threw away at the ol' tax collector, and life is short. And the return on the grin scale is a hell of lot better. I'll be changing fluids, looking at plugs, hooking up the air-fuel ratio meter, and finding a safe balance as best I can. The next best thing to the feeling I got blasting onto the 210 a couple days ago would be making it reasonably reliable. Lots of naysayers, but no one has REALLY tried it and monitored yet. At the very worst I will have answered this question a year from now.

I'll keep track month by month and we'll really have a good idea of the cost for this much fun. In the meantime, if anyone wants to see an 850 spank their 850, just drop me a line. I'll give you a full second head start.

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