More power please

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Have been toying with the idea of upgrading or swapping my stock engine 3.0cs coupe..it has the original zeniths. It starts up right away all the time and runs very very smooth..but it sure is lacking in the power torque department..The wheels are 16 inch,the suspension is all stock as well so basically were talking about a very smooth touring car that is not very fast. It also has the 5 speed tranny...To be honest unless I'm passing a car ..its not a very exciting car to drive.. :roll: O k maybe I'm being a bit to harsh.

The other day while on a 2 lane highway up on some country roads 1 hour outside of Montreal I was cruising at a steady 80 miles. 8) I then pulled up behind A Jeep Cherokee I waited for awhile he didn't pull out of the fast lane so I pass him on the right and slide back into the left lane and continue accelerating, now the guy I just passed is accelerating about 3 feet away from my rear end !! So not wanting to play this game and with the coupe not having the kind of power to pull away from this jerk I scoot over to the right. :oops: The idiot passes me laughs and then slows right back down again remaining in the fast lane !! Here we go again I pass him on the right again scoot over to left in front of him again and he repeats the same stupidity as before..sticking a couple of feet away from the rear of my coupe !! :evil: Err anyway we exchanged a few words showed each other a few fingers and went our separate ways.

I couldn't help thinking had I a more powerful car or motor I would have simply pulled away from this jerk :D In a perfect world or in Europe the idiot would have just drove in the slow lane and left the passing lane free..and we could have avoided this ridiculous confrontation..but that never happens here so.....
I,m thinking going the 3.5 liter root..was just wondering for those who have done the swap ..Big difference in power torque ,highway passing power.
Also was suggested by mechanic friend..he will do the work at my place ..larger cam, triple weber, bigger exhaust...will those be too drastic and change the driving characteristics of the car too much ?Or will it be a real hoot to drive ? I don't want a rally car I already have a 2002...If that's too much I 'll consider going with the 3.5 injected..Basically what I'm after is highway accelerating and passing power . My coupe right now for my driving style is under powered. highway passing right now consists of a too long gathering of speed and distance and its a 50/50 between I'll make the pass or I'll have to brake at the last second because I don't have the speed or the distance.

i was looking at Daico 35 triple weber set up in the photo gallery,looks sweet. wondering how usable this set up would be for the street?
One last question..is it normal that my tii .. smokes the coupe ? :o

Cheers
G
 
I had a 2800 with similar issues with pass and speeding up. I upgraded to the 3.5. I went straight to injection as I has told it would garner more useable power for the road compared to triple carbs. I gotta say the power is much better than the 2800. The injection makes for easy starts and idling - not to mention the drivability is incredible. I had the folks at La Jolla do all the work. While it wasn't cheap, it looks first class under the hood and brings me smiles everytime I drive the car. I am also told there is a power chip I can upgrade to. I will wait a little longer before I need to get that. But for now passing is not an issue and the car runs assume...
 
Was he by any chance American? Sounds like something some of our more idiotic citizens would do.

Not saying were all bad. I am after all, an American, but I tend to follow the German Example when it comes to driving.
 
If your tii smokes the coupe, it sounds like your coupe is not running as it should.
Some things to check:
Is the distributor timing properly set and is the advance working?
Are the secondaries on the Zeniths working?
Is the fuel filter (if installed?) clogged?

It is not clear but if you were in 5th gear, you aren't going to get very strong acceleration.
 
Finally a use for the "ugly big bumpers" on US spec '74, '75 cars. Pull up behind the jerk and give 'em a little NASCAR nudge and see how well his four wheel drive works as he's sliding down the side of the mountain.

But I digress. A 3.5 Motronic would be a good transplant. A little massaging with a mild cam, headers, wide band O2 sensor, and a chip would be just the ticket. Perhaps ticket was not the most appropriate word as there is the possibility that you might be collecting quite a few of those, what with all the extra horse power. Some suspension upgrades, chassis stiffening and if you have a bit bigger pile of $$, the big brake upgrade from Ireland Engineering.
(Although this is a BMW forum, may I suggest an early '70s MBZ 6.3. It is the ultimate sleeper and takes no sh*t from anybody. Four doors and wicked fast...and frighteningly expensive to fix)
 
Hmmn. An M30b35 transplant as Philip describes might net you around 210 bhp/225lb/ft, or about a 12% improvement over your current arrangement. If you'll be paying someone else to do the swap, you might spend a little more on forced induction for some serious horsepower.

Assuming your motor is the US 3 liter, your compression is already low enough to deal with turbocharging at, I dunno, about 8 to 10 psi. If you're willing to toss 4 or 5 grand at this, TCD sell/will install some real power. I talked to the TCD owner, Todd DeHate about installing this on an E9 a couple of years ago, and he said it would be a no-brainer:
Stage 1 kit
Stage 2 kit
 
You need an M90..

The M90 is the early euro. It has a 93.4 mm bore and an 84 mm stroke. Makes 218 hp out of the box and has gobs of torque.

I have this in my 630 Euro (1980). Driving a 3.07 LSD through a Getrag 265, this car goes 40 in 1st gear, can easily hit 85 in 3rd, and will outrun pretty much anything under about 250 HP. I have beaten Dinan M6's in the twisites (although they do pull away on the straights).

If you want a fun ride, this is what I would do.

S
 
dp said:
Malc said:
DP
The secret is "Dino-power" :lol:
Anybody know the BMW part number for the "item" next to the coolant tank?
Click to expand...

what can I say? He's a great catch bottle
(thanks to AP's daughter Katie for that!)
[Broken External Image]:http://pbskids.kids.us/images/sub-square-barney.gif

oh, the motor is a 3.5 with DCOE48's
Click to expand...

Very Nice.. :) Would you know how much " HP " your set up produces ?
It seems everybody posting on this board who's running 3 webers is having problems dialing them in properly !
Any drivability issues, idles o.k, flat spots etc..? Happy with this set up? Or do you think you would be happier with Injection ?
I'm sure the sound is awesome.. is it .. "very loud" ?
Cheers
Giorgio
 
Bill Riblett said:
If your tii smokes the coupe, it sounds like your coupe is not running as it should.
Some things to check:
Is the distributor timing properly set and is the advance working?
Are the secondaries on the Zeniths working?
Is the fuel filter (if installed?) clogged?

It is not clear but if you were in 5th gear, you aren't going to get very strong acceleration.
Click to expand...

Thanks Bill..I guess the Tii smoking the coupe was the give away that somethings not right...
Thank you for all the suggestions ..There seems 2 B more engine upgrade options than I realized :? .. the problem ended up being secondaries not opening up completely !! I can't hit reach 100 mph the way it runs now. I've only put about a thousand miles on the coupe and now realize I have never experienced it running properly...So before opening up a can of worms on upgrades etc.. "Although just thinking about it is so much fun" !.I think I 'll start with a simple rebuilt kit for the zeniths..Ill try to get it running the way it should and then decide from there whether or not it has enough ooomph ! I have a feeling I will be revisiting all these engine options upgrades again..Used to have an e34 535i and that was a great highway car, I miss having that highway pullaway torque.and having no one stuck on my rear end rather a distant sight in my rear view mirror. :lol:
Thx again
G
 
I was going to suggest getting your current setup tuned as best you can before trying the big projects. The last two coupes I had were 72 3.0's with 32/36 Webers and they were dogs. They ran good and were very reliable, but didn't have the power I thought they should have. The current coupe I have is a '69 2800 with stock Zeniths and it runs much better than the other two. I think most of it is getting the engine to breathe well (air in/air out). I have a set of 38/38 Webers that I plan to put on the car as see what happens, but if I were going to do an engine swap for power, I'd only do it for a LOT more power. ;-)

Dan
 
now this I gotta know

How do (did) you assess that you secondaries were not opening fully, or at all? Due to the linkage design you can't get the secondaries to open unless the primary is essentially wide open - which would almost immediately pass redline unless there is a serious load on the drivetrain.

So, reveal! How do you assess secondary function?
 
My 3.0 CS was converted by Carl Nelson to a 3.5 mated to a 5 speed from a 635. It's pricey as he changes many other components (and he now charges 16K) but the power difference is amazing. My coupe pulls to 60 in the low to mid 7's and at 75 mph and I can easily accelerate to 100 very quickly (which is when I brake hard and I realize that hey, if I crash, it's a 1973 technology car-- Yikes!!!). Those two point seat belts and headlight location nob would not do wonders for my anatomy...

Go the 3.5 route with the 5 speed. You'll love it and it will actually increase the value of the car despite what many people say about the original engine.

Jonathan
 
More Power

I had a 5 speed box fitted this year, and the car serviced too. Either one thing or the other has made a big difference to the 'grunt' feel in my coupe. The old four speed box had quite close gearing and the car never felt out of breath, but of course used a lot of fuel and the continuous 4k rpm on the motorway was far too noisy for me.

The 5 speed has reduced the cruising rpm, but it will not pull easily or maintain 100 mph +, you need to drop back to 4th for this. (I saw 120 in 4th before I ran out of guts).

The last post about '73 technology is very valid though. My modern BM is rock solid at these speeds, particularly in braking suddenly. Do not try this in a CS unless you want a good scare. It makes reading the old motor road tests for the car all the more funny where they praise its exceptional high speed stability and four wheel disc brakes.

I did the above speeds on clear road in the early hours - I would take far more care otherwise, the consequences don't bear thinking about.
 
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