help unleash our dog....

[dfink]

A little different situation from my normal 85' 911. Helping a friend with his 70 914-6 (I know should be in the 914 forum) anyhow the car he sold the car 15 years ago and just recently got it back. The car has not been driven much in the last 15 years. He has already had the tank drained and new fuel line installed. We just pulled the brakes and rebuilt the calipers. Late "S" on the front and were still just not quite sure on the rear. We think carrera fronts but the specs are not quite right. They have 42mm pistons with a 14mm spacer. The space where the pads slide in is 63.5?mm so the width of the pad would need to be around 62mm. They are on 24mm rotors. Just need to know what to order brakes pads for. We had a hell of a time getting rebuild kits. I still think they are carrera fronts.

Problem #2
The car starts and idles great after such a long time. I does not spit sputter or pop. It does not hesitate. It does not feel like it running out of gas. It is just a dog past 5500 rpm Here are the specs.
original 2.0 block
2.4 rods
2.4 crank
2.2 "S" pistons
electromotive crank fire ignition 7200 limiter
Weber 40 IDF carbs
Unknown jets or venturies
European George Headers
Side shift conversion

The trouble is in the upper end power. We installed two new 3" supertrapps on the ends of the old megaphone exhaust. 12 disks in each one and took the car for a test drive. It had absolutly no power above 3500 RPM. I felt the exhaust was restricted so we removed the supertrapps and reinstalled the original bannana muffler. This improved the response greatly but now it poops out around 5500 rpm. I feel the exhaust is still restricted. My friend says it used to pull to redline with the stock muffler. We are going to do an open exhaust run to test but if not the exhaust any ideas.
Also I am unfamilliar with the carbed engines. Any guesses on where this little beast might in HP numbers with the given mods.

[madmmac]

Is the distributor advance working?

[dfink]

Not sure how that works. It is a direct fire multi coil distributorless system. Any advance would have to be programmed into the control unit. That for sure is something to check however. I am going to have to learn how the ignition system works.

[911st]

Put a timing light on it, find or mark the timing wheel at abound the 35 deg timing mark, rev to 5k and see if you are getting full advance.

If it as a twin plug, should go to around 25-28 deg total advance.

[dfink]

The electromotive unit is set at 6* btdc initial advance and 20* advance at 3000 RPM for a total of 26* @ 3000. After freeing up the exhaust the car seem to pull better now to 7000 rpm then nothing. The rev limiter was set at 7500 and we turned it down to 7200 for our testing. Perhaps the rev limiter was kicking in but it didn't feel like the rev limiter in my 85' 3.2 it just sort of ran out of poop and wouldn't go past 7000. Would this be typical for the electromotive units.

[911st]

With only 26 deg total advance, it must be a twin plug???

I do not belive that is enough for a single.

[dfink]

It is a single plug system. Also finally determined how to check the advance with a volt meter. We now have determined we have 33* at 3000 rpm and 35* at 5000. It is not knocking and with the exhaust opened up some it now has more pull throught entire range. I believe the die off at 7000 is the soft rev limiter of the electomotive unit. According to what I have read instead of cutting the spark at the rev limit it just puts the timing back to 0*. You don't get the stutter of a standard rev limiter. You just don't go any faster.