Hello everbody. I was wondering what the technical differences between shifting in manual mode vs. automatic mode are. I know there is a difference in the harshness of the shifts (D mode is smoother) but can anyone give me a technical description.

I am asking this because when shifting from 2nd to 3rd in manual mode, even though the shift is smooth, I hear a low rumbling "clunk" sound from the rear (tranny). When the D mode shifts from 2nd to 3rd, I heard absolutely nothing. Its as if extra energy is being released because the computer hasn't compensated as well in the manual mode (my theory). I would love to hear a technical explanation of how our trannies work and the difference between our tranny and a standard non-manual mode transmission.


04 Coupe Auto/DG/Prem/Nav/Perf

 

I do know that our manumatics are a lot slower on the shifts than my Acura CL TypeS was. Maybe that's what they are improving on the 05's. My shifts on my G35c take forever.
But I guess this doesn't really answer your question.

2004.5 G35c Ivory Pearl/Graphite 5AT
Premium/18inch Wheel Pkg/Front Lip/Splash Guards/NAV Viper 850 Alarm System
50% Madico Charcool Tint all around

 

reset your ecu and then see what you think of your tranny. This is common and the fix for us 5at people is to do the pedal reset or remove the battery cables for 12 hours (or touch the -/+ for a few seconds if you have stock stereo and electronics)

2003.5 DP 5AT Sedan
14.2 @ 97.18
Z-Tube
K&N Drop In & Airbox Mod
10 Wire Hyper-Ground
Crawford Plenum (V4)
UR Crank Pulley
Hotchkis Sways (M/M)
Polk EX-3500 Tweeters/Shock Sensor/H-Liner

 

So you're telling me if I reset my ecu, the shifts in manual mode will be quicker and I wont have to wait about a half a second for the actual shift to occur?

2004.5 G35c Ivory Pearl/Graphite 5AT
Premium/18inch Wheel Pkg/Front Lip/Splash Guards/NAV Viper 850 Alarm System
50% Madico Charcool Tint all around

 

Gord's 10 wire grounding kit quickens up the shifts in manual
mode. Mine shifts very quick after the ECU/TCU wires were
installed.

03 5AT Sedan, sunroof, splashguards, HKS muffler,
14 wire Grounding kit, Z Duct, Stillen HF/AB
Underbody rear diffusers, Drilled alum pedals,
Stillen sway bars H/H

 

Where can I get these, and how difficult is it to install them?

2004.5 G35c Ivory Pearl/Graphite 5AT
Premium/18inch Wheel Pkg/Front Lip/Splash Guards/NAV Viper 850 Alarm System
50% Madico Charcool Tint all around

 

I've found that the crispness of your Manumatic Mode will vary based on RPM and load on the transmission. I've run dozens of 0-60s on the exact same road, controlling for every possible condition, and have made a couple of observations related to MM as compared to full auto, when at wide open throttle.

1) The ECU reset did nothing for my 0-60 or 1/4 times, but it would set off my MIL if I gunned it too soon after the reset. I later was told by Doug at Crawfords that that I was running way too rich for 3-5 minutes after the reset because the default settings were not the most optimal for the climate conditions I was in that day. Whether an ECU reset will work for you is hit or miss and after Q45Tech explained it the other day on another thread it all makes sense to me now.

2) The 0-60 and 1/4 times were worse when I shifted manually as opposed to letting the computer do it for me.

3) The MM is useless for WOT dragging, but helpful for Urban traffic navigation.

While not at wide open throttle I've observed that I can get the MM to simulate full auto by varying the load and RPMs at which I engage the up or down shifting. I couldn't find any difference between 1-2 or 2-3 or 3-4 or 4-5 when I controlled for the RPM I shifted and the load on the vehicle. For instance down a hill with a tail wind it will behave differently than up a hill with a head wind.

This doesn't answer your question, but it implies to me that the MM does nothing more than electronically force a shift to happen the same exact mechanical way that the computer would have electronically communicated to mechanically shift.

Of course these are just my observations and the inference could be completely wrong, but I too am curious to know how the inner workings of the electronics are working. It's very difficult to actually measure the shift times, but I've read anecdotally that at WOT they are designed to take 1.5 (or 1.75) seconds, I can't remember which, but it may have been related to a Stillen product that reduces shift times.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats

 

I find that the manual mode is a bit rougher shift than when the computer fully controls it. It feels like the computer hasn't fully compensated for all variables so it makes a compromise and shifts when it can (therefore the 1.5 second delay). When shifting in D, the computer can fully compensate because the driver cannot input in when to shift...only vary the throttle which is in itself a very limited input. Now what doesn't make sense is the slight thump noise from 2-3 when in manual mode. It can't be the gears because the D mode doesn't do this. I wish I knew how the tranny compensates for the different inputs from the D vs. the manual mode and why this shift mechanism is rougher in manual mode.

04 Coupe Auto/DG/Prem/Nav/Perf

 

Yes that is what I am telling you. As much as you are getting good or some good info here - it's all more than you need.

You asked if the shifts will be quicker if you reset. The answer is yes. Before you buys the grounding kit - which 99.5% of all users say WILL help the tranny shift smoother - try the easiest cheapest and simplest way to improve it and go from there. Reset the ECU by removing the (-) terminal for 12 hours - start her up and within one run through 5 gears you will see the difference. Big difference you cant miss

As far as 1/4 miles - which is not what you asked but probably important. SOmeone made several runs with car in D and the car in MM. It was determined and proven to me anyway that the most effective WOT run for a 1/4 mile is to put it in MM 4 and leave it alone from start to finish. THis gives about a .3-.4 second difference in times - no idea why and i dont need to know. It seems true enough based on my own experience and comments made by Bossho or SFLG35 (i think), two significant contributors to this forum who track regularly.

Manually going thru MM to race a 1/4 mile is not getting you anywhere faster than the computer can do it for you.

I never had any problems up or downshifting except the 2-1 - ie the banging or roughness since installing the grounding kit. The folks with rough MM 2-3 shifts make me wonder if they should try a reset or get a grounding kit. My car shift like butter and in less than .25 seconds in MM or not when WOT after a reset. It's less than that - it seems instantanous. A month after reset the shifts take a 1/2 hour LOL

I would never shift 2-1 unless stopped all the way in any kind of car with any kind of tranny ever..but thats me

Anyone remember who tried both methods at the track (mm and at) back to back 3 times or so last fall - thinking they were in NJ or Mass. They had a good write up and I cant find it.

you'l find plenty of anti consensus and some consensus here - but you'll know whats happening when you try it. Trust your judgement!

2003.5 DP 5AT Sedan
14.2 @ 97.18
Z-Tube
K&N Drop In & Airbox Mod
10 Wire Hyper-Ground
Crawford Plenum (V4)
UR Crank Pulley
Hotchkis Sways (M/M)
Polk EX-3500 Tweeters/Shock Sensor/H-Liner

 

Yes that is what I am telling you. As much as you are getting good or some good info here - it's all more than you need.

You asked if the shifts will be quicker if you reset. The answer is yes. Before you buys the grounding kit - which 99.5% of all users say WILL help the tranny shift smoother - try the easiest cheapest and simplest way to improve it and go from there. Reset the ECU by removing the (-) terminal for 12 hours - start her up and within one run through 5 gears you will see the difference. Big difference you cant miss

As far as 1/4 miles - which is not what you asked but probably important. SOmeone made several runs with car in D and the car in MM. It was determined and proven to me anyway that the most effective WOT run for a 1/4 mile is to put it in MM 4 and leave it alone from start to finish. THis gives about a .3-.4 second difference in times - no idea why and i dont need to know. It seems true enough based on my own experience and comments made by Bossho or SFLG35 (i think), two significant contributors to this forum who track regularly.

Manually going thru MM to race a 1/4 mile is not getting you anywhere faster than the computer can do it for you.

I never had any problems up or downshifting except the 2-1 - ie the banging or roughness since installing the grounding kit. The folks with rough MM 2-3 shifts make me wonder if they should try a reset or get a grounding kit. My car shift like butter and in less than .25 seconds in MM or not when WOT after a reset. It's less than that - it seems instantanous. A month after reset the shifts take a 1/2 hour LOL

I would never shift 2-1 unless stopped all the way in any kind of car with any kind of tranny ever..but thats me

Anyone remember who tried both methods at the track (mm and at) back to back 3 times or so last fall - thinking they were in NJ or Mass. They had a good write up and I cant find it.

you'l find plenty of anti consensus and some consensus here - but you'll know whats happening when you try it. Trust your judgement!

2003.5 DP 5AT Sedan
14.2 @ 97.18
Z-Tube
K&N Drop In & Airbox Mod
10 Wire Hyper-Ground
Crawford Plenum (V4)
UR Crank Pulley
Hotchkis Sways (M/M)
Polk EX-3500 Tweeters/Shock Sensor/H-Liner

 

Thanks a lot man, I will definitely try the resetting of the ECU.
So, would you recommend resetting it once a month?
Also, did you install the grounding kit that the other person was referring to? How difficult of an install is it, and where did you get it from?
Thanks again!

2004.5 G35c Ivory Pearl/Graphite 5AT
Premium/18inch Wheel Pkg/Front Lip/Splash Guards/NAV Viper 850 Alarm System
50% Madico Charcool Tint all around

 

https://g35driver.com/forums/showfla...t=1#Post321017

BTW, You'll have to reset things every hour or so assuming city/highway speeds if you want the shift points to behave as they were previous to resetting.

If I remember correctly the tranny shifts (in full auto) when it recieves a certain voltage from (forget the part name, the blah blah sensor) at a combination of engine load and speed. It shifts in MM when you tell it to. Once it's cued electronically, it mechanically shifts.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats

 

My experiences seem to differ from several members on this board regarding the MM mode.
Shifting in MM allows you to run right up to the redline before shifting, allowing another 200 rpm or so before the shift.

I achieved my all-time fastest 1/4 mile times using MM mode, with D mode consistently a solid tenth behind. (about a car length)

Left in D, the car is FAR more consistent.......only 1 hundredth of a second separating several runs.

I believe that traction issues are at play with the folks who run slower in MM than D, causing unseen braking/timing retard to occur.

I do have AWD, so tire slip is not an issue (not being able to smoke all the tires IS, however )

FWIW, I am an avid drag racer with several years of experience at the track. I have made $$$ both bracket and street racing (when younger and dumber). I am NOT, however, the ultimate authority. I am simply relaying my personal experiences at the track.

Wayne

'04 G35X Graphite/graphite, NAV, wood, premium

 

I have a different take on things...seems the computer is kinda confused in MM sometimes resulting in a harsh shift under certain conditions. Computer seems much more comfortable in D so the tranny shifts smoother. Does anyone know what the difference between this manumatic tranny is vs an older regular tranny. Q45tech implied that it is much more advanced. Would love to hear an explanation why.

04 Coupe Auto/DG/Prem/Nav/Perf

 

I'd have to agree with ChicagoX on this one... before and after the TechnoSquare ECU.

-T

'03.5 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS - www.teamtransport.org