400i Shifting Questions

Auto I assume- Automatic transmissions use "Torque Converters" to shift gears- so your shift points will be dependent on how hard the pedal is pressed to the floor. A stock TH300 should let the car get somewhere near redline if you drive aggressively- My 412 has a "shift Kit" installed which will keep the car in the lowest gear possible as long as you are inputting any reasonable amount of throttle- in man ways it makes the car more fun to drive than my 5-speed 400i.

A good service by any auto transmission shop should improve the crispness of your shifts and the amount of throttle you need to input to get it to kick down.

I just did the tranny service myself- and really enjoyed paying under $10 for a gasket for a Ferrari!

 

Enrique
My 84 400i shifts 1 to 2 and pretty low speed, maybe only 25-30 if at low to mid throttle, higher if pushed. Again at modest throttle it goes from 2 to 3 (D) at about 50. I usually keep in 2 for standing starts and use the throttle to make the shift from 1 to 2 and than let it rev in 2nd until I am ready to line out my speed and then push into D. It sounds like your set up might be a bit more fun!
Ken

 

Th eturbo 400 relies on a vacuum signal which indicates throttle opening for shift points.
If you feel the shifts are late I'd investigate for vacuum leaks or a failing vacuum modulator.

 

Shift points on the T400 can be moved up or down in several ways: 1.
the vauucm modulator on the bottom side of the tranny is adjustable with a very small screwdriver in-situ. If ours is not adujsable, buy one for about $15USD.2. Torque converters can be purchased with specified shift points built-in from B&M, TCI, ect. for $100USD upward. 3. Shift kits. The street kit is what you need, as the drag kits kick
in too hard and the the shift points are just too high for the street and they are just down right uncomfortable. Last year I had my tranny re-built from the ground up, using the factory rebuild pakage from Rebestos. It's how they came from GM. They are without any doubt in my mind the best. We also added a treet shift kit. Also, we put in a higher stall-speed torque converter. Mine is around 2200rpm if I remember. Most importantly of all, the internal pump was shot. This is the very heart of the tranny. It's about $100USD. 4. Lastly..inspect all of the vacuum lines, especialy the 3 foot long line that goges from the vaccum amplifier( that golden colored disc on top of the engine, it's right there in your face.. it feeds the vacuum modulator on the tranny housing. This line is what actually shifts your car). My line had been routed down the back of the engine over the exhaust manifold... gulp. It had of course deteriorated and had been supplying nearly zero vacuum. I replaced mine with a length of copper tubing..problem solved...forever (10 years+). I hope that this is of some value to someone. Thank you. Jacques.

 

Did the car come with a Smog Check "pass"? If not, are you in a Smog Check II zone? If so, who are you dealing with it?

I bought my 400i at about the same time and for the intervening 3.5 months it's been in re-wiring jail. So I am just now about to undertake the Smog Check process. Hence my curiosity.

 

I am glad you are working with the OE engine. Actually I don't know how the DMV would react to an LSX swap in a car that's still subject to Smog Check (i.e., 1976 or newer). I don't think they'd give it a "like."

On the other hand a nice 600 lb-ft 454 ci LS motor would sure help move those 4,000 pounds off the line. http://www.mastmotorsports.com/2010/news-view.php?id=55

 

You could always swap engines for the check and then put the original engine back in. I wonder how these engines would run with modern injection and ignition systems?

 

I'm going to file that away. $8300 for a 430 hp, 424 lb-ft 6.2 liter efi engine is a very interesting alternative to the $15K to $35K costs you see bandied about for a Ferrari V12 rebuild. (Here's a GM web page on the E-Rod LS3: http://www.newgmengines.com/e-rod_ls3_crate_engine.html ) I have a 2004 Pontiac GTO (actually a Holden Monaro with the steering wheel on the wrong side), with a 350 hp 5.7 liter LS1. It's a great engine, pulling happily, and rapidly, to 6000 rpm. The extra 70 hp of the E-Rod 6.2 liter would be all the better. In fact, in a 4000 lb car -- compared to the 3700 lbs of the GTO -- it should make the 400i slightly quicker. (The 2004 GTO is generally a 13-second car.)

I've had only two or three short joyrides with my '83 since I got it back from the shop. But that's enough to appreciate the unique virtues of the V12. Mine already has a pair of 2-in, 2-out catalytic converters where the first pair of resonators are supposed to be. I want to get straight pipes to replace the second pair of resonators, in hopes it will turn up the volume a little more. If that doesn't make it loud enough, I'll look at aftermarket mufflers too.

Mine had a verrry long list of those. But my man Tim at Select Electrics in Berkeley worked his way through all of them. Not with great speed -- 3.5 months -- but with efficacy. I'm very pleased with the results. For one thing, my multi-function switch (headlights, turn signals) was almost completely inoperable. Some guy on eBay was asking iirc $1800 for rebuilts, *and* he wanted your core. Tim rebuilt mine for 4.25 hrs labor. With a "nice guy discount," his rate was $61/hour. Not bad, compared to $1800.