1st>2nd shift data with JWT trimode

[Q45tech]

Did a little test today 90Q,50F, 36k remanned transmission trimode TCU, JWT ecu other systems oem stock. Set up consult to log parameters during a 1st to 2nd gear shift...........time in 100th of seconds, data updated every 0.02 seconds:

01.76 seconds: 7,000 rpms, MAF 4.38 volts, 9.5ms, 26 degrees02.03 seconds: 6,510 rpms, MAF 4.36 volts, 10.2ms, 26 degrees02.05 seconds: 6,465 rpms, MAF 4.35 volts, 10.0ms, 16 degrees*02.07 seconds: 5,125 rpms, MAF 4.34 volts, 10.2ms, 07 degrees

02.50 seconds: 4,530 rpms, MAF 4.11 volts, 11.0ms, 03 degrees02.58 seconds: 4,400 rpms, MAF 4.02 volts, 10.8ms, ZERO deg02.60 seconds: 4,300 rpms, MAF 3.99 volts, 10.7ms, 04 degrees

02.62 seconds: 4,420 rpms, MAF 3.96 volts, 10.6ms, 20 degrees*

02.76 seconds: 4,500 rpms, MAF 4.02 volts, 10.6ms, 21 degrees

03.21 seconds: 4,650 rpms, MAF 4.06 volts, 10.8ms, 23 degrees

The ignition cut for torque management was 0.58-0.60 seconds total.The total shift from peak rpm [7,000 rpm] to the time ignition advance returned [4300 rpm] was 0.80 seconds.

BY the way the VVT stayed in the 8 deg overlap condition.

Unfortunately the speed function is not up dated fast enough or the wheels were spinning as 44 mph occured at 1.04 seconds into the record and 54 mph occurred at 2.50 seconds and 57 mph occured at 3.21 seconds.The speed did not change during the shift period

Now I have to find a bad transmission to record similar data

[Jesda]

Thanks Dennis!

[HeavyDuty]

Thanks for the info Dennis, which mode was the TCU in? 1st start only or 1st high shift?

With my single mode hi shift, I'm going past 7k 1-2. (At least per the tach, and we know how accurate they are.)

[Q45tech]

Hasn't been out of 1st start/power mode in 5 years......removed the switch and have it permanent.

The tach is not very accurate in rising movement due to gravity overshoot.Heck not sure the ecu is accurate above 6900 rpm.

The point was to prove the TCU has nothing to do with the shift time lengthening as the 0.600 and 0.800 second times seem preprogrammed --------up to the transmission internals to keep up.

Next will need to monitor lines from TCU to ECU to study the signals.

[Q45tech]

As a side note the specs for Dex III have a test for shift time at 20,000 shift cycles: 0.35-0.75 seconds.

Viscosity has a lot to do with shift time [and torque convertor efficiency]...........this is useful in Summer heat as a " high temp ATF" maybe used but must be exchanged for a regular Dex III spec when the cranking temp gets down to 45-50F.

Same with Lubeguard RED which has been shown to decrease time by up to 0.03-0.05 seconds [5-6%].

Whereas [too much] Lubeguard BLACK may actually lengthen the shift time in transmission designed solely for Dex III spec.

Dex III with 1 ounce {lubeblack] per quart with approximate the overdrive TC clutch lock/slip ratio of Nissamatic D. BUT I recommend starting with half this amount 5 ounces in 10 quarts.....you can always drain and refill 3 quarts and [add no more Lubeblack] to reduce the ratio...........really the ratio depends on the clutch wear and transmission internal pressure which will change over time.

Not sure many can tell or feel the difference but it is there......using 5 ounces leaves 5 ounces to use later at next annual flush.

[HeavyDuty]

So if it took .80 seconds to effect the shift & return the timing advance, and if the speed did not change during that period, doesn't that seem like a long delay? If it were a drag race, you just gave away a lot of time, and lost ground on acceleration by not continuing to accelerate.

This is very interesting, thanks for taking the time to log this info. Did you happen to log a relatively shorter delay in 2-3?

My original point in the other post was not to blame the TCU for a longer delay than stock. Rather it was observing a confirmation from your earlier post on another thread that 6500 is where the engine stops 'pulling' (torque falls off) and that a continuation to rev yielded nothing but revs. My self inflicted complaint was a 500rpm timespan of no acceleration combined with a .80 second shift did me no good <in that gear/rpm only>.

Also, the inability to shift manually from 1-2 irks me.

At times I think I'm the most misunderstood person on the planet. Please understand the ECU/TCU did an awesome job of improving power all across the band, and in any other scenario other than WOT, the shifts are greatly improved.

FWIW, my transmission has less than 10k miles on a killer rebuild including Blue Plate kevlar clutches, new converter, all seals, etc. Even without the TCU, the shifts were crisper than stock, albeit, worn out ????? mile transmission.

[Q45tech]

There are thousands of lines of code in the TCU microprocessor memory devoted to the stock as supplied transmission.......rebuilding with different parts can change the relationship.

0.8 seconds was state of the art for 1988 when they bench marked MB/BMW, today on a modern 5, 6, 7 speed, 0.6 seconds might be considered long.

As the state of the art is 0.08 [80 millisecs for the BMW SMG auto matic manual] paddle shifter.

It appear from the graphs in the JATCO bulletin that the newer 5 speed AT shifts in 0.50-0.55 secs but there are more shifts to 80 mph/quarter mile so most of the engine weight loss is used up by the extra shift. Even though they both are quicker.

0.55 + 0.55=1.1 secs lost to shifting vs. a single 0.8.

Don't remember that the marketing for the Q ever pushed its prowness as a drag racer........."If it were a drag race, you just gave away a lot of time, and lost ground on acceleration by not continuing to accelerate."

[HeavyDuty]

As the state of the art is 0.08 [80 millisecs for the BMW SMG auto matic manual] paddle shifter.

Hopefully one day all automatics will be as cool as that. Particularly the M3 SMG Euro with the launch control. Foot on the floor, user defined rpm hold with gas pedal on the floor, release the paddle & HI HO SILVER AWAY!!!!

Don't remember that the marketing for the Q ever pushed its prowness as a drag racer........."If it were a drag race, you just gave away a lot of time, and lost ground on acceleration by not continuing to accelerate."

I know, it's a disease. :pface There's nothing more fun than spanking someone in a sports car with a boulevard bruiser though. If the TCU code has long been broken by the boys at JWT, then maybe it could be programmed to not pull as much timing out before shifts at WOT. Harsh, yes, but is it possible?

Now that I've given my car a week or so to get used to the new programming, it's not as bad as I was thinking. Maybe it's me not liking to hear a V8 scream to over 7k rpm, waiting for something to blow up. I've only punched it off the line and held till it shifts a half dozen times so far, I like to have fun, but I'm not abusive.

Thanks Dennis,

[maxnix]

If the TCU code has long been broken by the boys at JWT, then maybe it could be programmed to not pull as much timing out before shifts at WOT. Harsh, yes, but is it possible?

Yes, but only at the expense of transmission life. It wasn't just luxury that dictated the timing roll back on shifts, it was also prolonging the transmission's life.

[HeavyDuty]

I picked up a 98 XJR from the dealer yesterday for a pulley upgrade, and possibly intake mods, converter, exhaust, re-flash, etc.

Man, I gotta tell ya, the shifts were lightning quick and totally seamless. I mean I felt nothing but constant acceleration, no bumps, clunks, hesitation, nada.

I only caught off-guard once at whatever speed I was traveling.

[HeavyDuty]

I concur on the suspension and chassis integrity, it was a little "wiggly" over a railroad track & prone to wander.

As far as top end power, yeah, I haven't put it through it's paces, but it *is* only a 4.0.

I like a firm shift too, which is why I'm searching for a way to quicken the shifts on my Q. I wasn't marvelling at the smoothness, but the speed of execution as well as the timing of the shifts.

[desertq45]

Along these lines...

What JWT TCU would you recommend for a 1990 Q with a fresh transmission? I noticed in the articles section that this is recommended to eliminate the 2nd gear start, but JWT's site doesn't describe the differences in the several TCU's listed.

The tri-mode is discussed here, but if Q45tech has kept it in one mode for 5 years, is it necessary to have a tri-mode? Do they make one that will give you 1st gear start and power mode for less than $695?

I want to prolong the life the transmission, but also really hate the 2nd gear start... like dkill I find myself manually shifting the car when I really want to rely on it off the line.

Any help here is appreciated.

[HeavyDuty]

Tri mode=1) stock 2nd gear start2) 1st gear start, no changes to shift parameters. (per JWT)3) 1st start high shift, holds each gear longer, even with a light pedal, from what I can tell on mine, shifts are crisper.

(not necessarily in that order) I would only consider doing a tri mode upgrade if 1st gear start (2) would allow me to shift manually again.

[desertq45]

I'm with dkill... none of the JWT's allow manual shifting???? We need to do something about that! I want to be able to start in 1st, hold each gear longer, have crisper shifts but also be able to manually shift.

Kind of like the transmission in the 95 740 I had... in "S" mode the thing would hold the gear and "feel" like manual, but if you wanted to get serious, you could actually shift manually. However, never did it sound or feel like my 90 Q. The Q feels like a muscle car and the Beemer seemed like it had a "third party" between my foot and the engine... I guess I want the best of both worlds.

[HeavyDuty]

I don't know if either of the other two positions allow for it or not. Stock 2nd gear start did before the TCU, but I don't know if they changed it somehow or not. I would imagine those who have 1st gear start anyway stock (94-95?) can hold gears as well, but again, as part of a trimode, maybe you can't do that either.

[rahiel aziz]

i have tri mode tcu in 91 Q bought it from a friend.i have jwt ecu too.i put ecu 2 yr before tcu.with only ecu and manual ist gr to 2nd at around 7200rpm.now i am going to tell u guys things that Dennis won't agrees.the guy i bought jwt tcu from,he swears his 91Q used to hit 8000rpm.he never changed the guides and killed the Q.my experince with tri mode is kind of funny.1st mode holds the gr at 7100rpm and 2nd mode hold both 1st and 2nd at 7100rpm and make the car jerk when changes the gr,kind of uncomfortable.but in snow mode thats where things rocks i think somekind of software glitch or whatever.even in snow mode car still starts in 1st but pulls right up 7500rpm around 60mph shift to 2nd without jerk and 2nd pulls same way up to 7500rpm around 100mph never took the 3rd to 7500rpm yet.and in snow mode i can go to manual anytime.thats where i keep the Q in snow mode no more sneaky races froms beemers or lexus.ask the guy in LS430 who just saw most beautiful rearend ever put on car.

[Q45tech]

Interesting to compare the accurate rpm readings from the primary CAS [360 pulses] with the secondary CAS [90 degree pulses] to the inaccurate tachometer......to the turbine sensor.

All the readings are different in the dynamic of acceleration.

I would trust the [360 pulses per rpm] x 7300 rpm /60= 43,776 Hz...............than the resolution of some analog 5 volt meter [the tach]..........when it comes to read a 100 rpm increment as most analog meters are worse than 2% accurate at full scale.

The tach is there for looks mostly............just as the speedometer has an adjustment potentiometer for calibration at the manucturer who knows the effect age and temperature and wear has on accuracy.

For sure each one will read different by a few percent ~~ 160-200 rpms.

[HeavyDuty]

Would someone with a tri-mode drive their car in 1st gear start only (not high shift) & advise us if manual shifts are possible 1st-2nd?

[rahiel aziz]

ok Heavy Di did what u ask for . put the tcu in 1st mode shift in manual 1st took it to 4000rpm than 5 and 6000rpm from start .shift to 2nd no problem than into 3rd. is this what u asking for or something else.it took my tri tcu few dys to show its real stuff, give it some time software has to negotiate.anything else u want me to try ,i will be glad to help.always looking to explore new stuff about this car.

[Q45tech]

I think you are asking if the trimode allows manual down shifts to 1st.........yes it does, move the shifter to 1 at any speed below 90 mph after the 2nd down shift and when the speed/rpm drops to ~~ 38-40 mph it wil go into first gear..........not too good for transmission.

[desertq45]

Thanks Q45... that helps, but I still would like to get a consensus on this so there isn't any confusion... and I believe that dkill and heavyduty are on the same page I am... so here is what I would like to know:

1) Stock TCU in 1990 era Q45 starts in 2nd gear and only shifts to 1st gear if you pound the trottle at low mph or "manually" use the shifter to pull it in.

2) If you use the shifter to put the transmission in first gear... it stays in first gear until you shift it to another gear. Same with 2nd, 3rd, etc. in terms of UP SHIFTING, not DOWN SHIFTING. In other words, the transmission will not shift any higher than the position that the shifter is in... but will shift down if rpm/mph warrant.

3) Now this is the part that is unclear: IF using a 3-mode JWT TCU, and having it in 1st gear start... will it HOLD first gear if the shifter/selector is in 1st and allow you to manually shift up to 2nd, 3rd, etc.?

4) In addition, if you are using the 3-mode TCU, and you have the shifter in the D position, and you are driving about 30mph AND you decide to pull the shifter into 1st gear... will the TCU allow the transmission to shift down immediately to first, even if it is in 3rd when the shifter is moved?

Basically, I'm wondering if the JWT TCU will act just as the stock tcu, with the exception of starting in 1st gear. It would be "nice" if there was a way to make the transmission go to whatever gear you pick with the shifter at any time (thus enabling a choose at will, 1st start or 2nd start) which would be the closest thing to Manual Shifting w/o a clutch... but not too likely.

If someone who has this TCU can address these questions, it would be really helpful.

Thanks.

[HeavyDuty]

Yup, upshifts, not *necessarily* down.

My car shifts from 1-2 even if still in 1.

No trimode, just 1st gear high-shift program.

[AGM]

I have the JWT Trimode, but have not run it with my new transmission yet.

The level 10 PTS Shiftronic Shifter ONLY allows you to change mannually.

http://www.levelten.com/press12_00_shifttronic.htm

I reckon you will need a Level 10 rebuild and the Billet Torque converter to take this kind of punishment.

There has been a lot of interest in putting a manual in a Q45.This is as close as you can get with keeping the automatic.

I am currently liasing with level 10 if I can intergrate it with a relay switch, rather than having to physically plug & unplug it all the time.

I will report back with more info.

Regards

AGM

[AGM]

try

http://www.levelten.com/press/...c.htm

[HeavyDuty]

Personally I wouldn't (effectively) want a manual valve body all the time.

If I understand it correctly, it's a piggyback that you are working on the capability for auto shifting or manual shifting on the fly with a switch? That'd be cool.

[Q45tech]

The [my] trimode in 1st/2nd gear position will not shift period you just hit the rev limiter [severely] unless you move the gear selector.

[louiegz]

What would be cool is this.

http://www.bmw-paddleshift-retro.com/

This is a mod I can do to my 330i. I haven’t done it because it's a little pricey. My 330i has a Steptronic. I would have preferred a manual shift, but they didn't have one in stock. Not only that, my wife doesn't seem to miss not having a stick because she would drive to work in Manhattan and that stop and go traffic on the West Side Highway would be a bit of a pain. When I drive the 330i, I don’t use the Steptronic as much because the cool thing would be to have the F1 style paddles on the steering wheel like the BMW cars equipped with the SMG (Sequential Manual Gearbox). The SMG, a $200.00 option from the dealer, is a very nice transmission. It has five auto modes and six manual modes. In the highest manual mode, you can’t even use the TCS & the DSC (Dynamic Stability Control). On the M3 there's even this thing that you can make the car launch when your RPM hit 5000. That must be a wild ride. Read this Road & Track article. They describe it better that I can.

http://www.roadandtrack.com/ar...ber=1

I hope future Infiniti cars plan to implement this technology. It would make the automatic cars more fun to drive and not make me miss my manual transmission cars.

[HeavyDuty]

the cool thing would be to have the F1 style paddles on the steering wheel like the BMW cars equipped with the SMG (Sequential Manual Gearbox). The SMG, a $200.00??? option from the dealer, is a very nice transmission. It has five auto modes and six manual modes. In the highest manual mode, you can’t even use the TCS & the DSC (Dynamic Stability Control). On the M3 there's even this thing that you can make the car launch when your RPM hit 5000.

I hope future Infiniti cars plan to implement this technology. It would make the automatic cars more fun to drive and not make me miss my manual transmission cars.

$200 can't be right, louiegz, ya can't buy a BMW key fob for $200.

I don't believe the US spec SMG's have the launch control, do they? But it's probably an easy software upgrade.

[AGM]

dkill,

If I can set up the Steptronic via a relay switch, I will definatley get it. I will keep you posted.

Regards

AGM

[HeavyDuty]

Interesting, Q45Tech, I think I want a Tri-Mode then. Or, something's goofy with my TCU since it started out as a Traction TCU.

The TCS stuff was tuned out, supposedly. Wonder if that's a glitch?