Can’t shift smoothly after 1 year

SoCalCivicSI

Car Addict
First Name
Jerry
Joined
Oct 13, 2018
Messages
303
Reaction score
168
Location
South Carolina Near Spartanburg, formally So Cal
Car(s)
2018 Aegean Blue Civic SI, 2006 2.4 5 Speed EX Accord Sedan, 2007 Red 5 Speed Pontiac Solstice
Country flag
I have a 18 SI and a 2006 2.4 Accord....both manual.
The Accord shifts smooth as butter....the SI is VERY notchy.



Advertisement


 

Hoang_Honda

Senior Member
First Name
Hoang
Joined
Jun 21, 2017
Messages
76
Reaction score
40
Location
Orange Country CA
Car(s)
15 Accord V6 Touring. 17 Civic Si Coupe.
Country flag
31k miles on my Si. I've learned that If I want a butter smooth shifting from 1-2-3 I will release the clutch very very slowly and start to add gas around 80% at the end of the clutch. Im no expert Si is my first manual car, I still remembered my gf and her mom really hate to have a drive with me but now they can even sleep in my Si during trip :) btw I always shift at 3k - 3k9 rpm.
 

SiGeddy

Senior Member
First Name
Geddy
Joined
Jul 1, 2018
Messages
130
Reaction score
51
Location
Bakersfield
Car(s)
2017 civic si
Country flag
It's funny I've driven numerous manual cars in my lifetime (my favorite being my 1986 accord) and I swear it varies day to day.. some days every shift is smooth and other days I'm rocking back and forth like I'm on a bull lmao.

25k miles in it might be time to change the transmission fluid because there have been numerous times in the past month I have a hard time getting into first gear and reverse :dunno:
 

A2typeR

Senior Member
Joined
Oct 14, 2016
Messages
515
Reaction score
476
Location
Ann Arbor
Car(s)
2019 Honda Civic Si sedan (TSP stage 1) 2016 Mazda Miata Club (Brembo BBS pack)
Country flag
This car has bad rev hang, I have to slow my normal shifting technique by 2 times compared to my ND Miata.

I literally and to say keep the clutch depressed in my head and then release other wise I will get the RPM dropping from 3-4K RPM to 1.5-2k RPM everything. I find it easier if I actually go up to around 5k RPMs or higher and then the upshift usually feels much better.

But yeah if I drive normal for me, rather quick shifts I’m always beating the engine before it drops the RPMs to the proper level.

now my car is TSP stage 1 tuned so I can’t quite recall
 

yyalb

Member
First Name
Albert
Joined
Oct 9, 2017
Messages
46
Reaction score
29
Location
Michigan
Car(s)
10 gen Civic Si
Country flag
After deleting my clutch delay valve, I can shift a lot smoother and quicker. The clutch is much easier to modulate and the jerk I sometimes got before doing 1-2 and 2-3 is no longer there.
 

amirza786

Senior Member
First Name
A
Joined
Oct 4, 2018
Messages
3,524
Reaction score
3,368
Location
Northern California
Car(s)
2006 Camry SE V6, 2013 Toyota Sienna LE, 2010 Lexus IS 350 Sport, 2018 Honda Civic Si (SOLD)
Country flag
After deleting my clutch delay valve, I can shift a lot smoother and quicker. The clutch is much easier to modulate and the jerk I sometimes got before doing 1-2 and 2-3 is no longer there.
I'm not saying you did the wrong thing, but here is a possible reason doing a CDV delete can be problematic down the road. According to Wikipedia:

"A clutch delay valve is an automotive component added to the clutch system of an automobile to standardize clutch engagement speed. Its purpose is to engage the drive train of an automobile without introducing shock to the drive train components by engaging too quickly. By preventing drive train shock, CDVs also prevent an automobile's balance from being upset, which aids in handling characteristics.

Clutch delay valves operate on the principle that engagement only needs to occur at a certain rate to be efficient and that engaging at a quicker rate can damage the drive train components of an automobile. Engaging the drive train to the engine too quickly can damage drive train parts, including the transmission, differential, half shafts, axles, and CV joints. Engaging the drive train too slowly can damage the clutch friction disc and cause clutch slippage"

Basically after doing a CDV delete, you have to be very careful not accidentally let off on the clutch to hard or letting off to soon, something most of us have done one time or another. My mechanic recently had a car in his shop that had drive shaft damage caused by a cdv delete, so I would be careful when doing it or advising others to do it
 

yyalb

Member
First Name
Albert
Joined
Oct 9, 2017
Messages
46
Reaction score
29
Location
Michigan
Car(s)
10 gen Civic Si
Country flag
Thanks for reminding! I am fully aware of these risk but still decide to do it. I did it not to dump the clutch and chirp the tires, but to make the car smoother to drive. After the mod, the shock I feel when shifting is much less than before, which also should mean less shock and wear to the drivetrain. I will be more careful when releasing the clutch since doing so wrongly will cause my wear to the drivetrain, but I don't think it will break anything as long as I don't do it on a daily basis or doing something really stupid.
 

Maroco

Senior Member
First Name
Martin
Joined
Oct 22, 2019
Messages
624
Reaction score
532
Location
Tulsa Oklahoma
Car(s)
2012 Honda civic lx 2020 civic si
Country flag
I'm not saying you did the wrong thing, but here is a possible reason doing a CDV delete can be problematic down the road. According to Wikipedia:

"A clutch delay valve is an automotive component added to the clutch system of an automobile to standardize clutch engagement speed. Its purpose is to engage the drive train of an automobile without introducing shock to the drive train components by engaging too quickly. By preventing drive train shock, CDVs also prevent an automobile's balance from being upset, which aids in handling characteristics.

Clutch delay valves operate on the principle that engagement only needs to occur at a certain rate to be efficient and that engaging at a quicker rate can damage the drive train components of an automobile. Engaging the drive train to the engine too quickly can damage drive train parts, including the transmission, differential, half shafts, axles, and CV joints. Engaging the drive train too slowly can damage the clutch friction disc and cause clutch slippage"

Basically after doing a CDV delete, you have to be very careful not accidentally let off on the clutch to hard or letting off to soon, something most of us have done one time or another. My mechanic recently had a car in his shop that had drive shaft damage caused by a cdv delete, so I would be careful when doing it or advising others to do it
This is why im hesitant to do this mod. Not because it WILL hurt anything but because it CAN. And the only deciding factor on if i break something will be human error. I feel like im pretty good at driving stick. But, im human and sometimes i fuck up. The idea of having that cushion of safety helps me relax while driving. Maybe once the car isnt so new....
 

yyalb

Member
First Name
Albert
Joined
Oct 9, 2017
Messages
46
Reaction score
29
Location
Michigan
Car(s)
10 gen Civic Si
Country flag
This is why im hesitant to do this mod. Not because it WILL hurt anything but because it CAN. And the only deciding factor on if i break something will be human error. I feel like im pretty good at driving stick. But, im human and sometimes i fuck up. The idea of having that cushion of safety helps me relax while driving. Maybe once the car isnt so new....
I also had hesitated for a year before pulling the trigger. There are two main reasons why I eventually did it:
1. When the car is cold in winter, I contantly grind gears at 1-2 shift, sometimes 2-3, even though I was doing everything right, shifting smooth and slow and keeping RPM before shifts under 2.5k. I know my brake/clutch fluid are 32k miles old, but this gear grind is still unacceptable for a stock drivetrain. (My trans fluid is newly replaced). I did some search and found it to be very similar to the infamous type R gear grind. And the solution for that seems to be a CDV delete. Here is a video: 2. Only some BMW, Dodge, VW and Honda has this mechanism. I don't think/believe that these companies install the CDV in order to make the drivetrain weaker. If other manual cars can live without CDV, why cannot our SIs?
I know it's a bold conjecture, but I'd love to take that risk. I'll keep an eye on it and let you guys know if anything goes wrong on my car.
 

Siiick

Senior Member
Joined
Oct 28, 2019
Messages
292
Reaction score
533
Location
Texas
Car(s)
2020 Civic Si, 2019 Corvette Z06, 2017 Fiesta ST
Country flag
Only 300 miles on my Si so take my opinion with a grain of salt...

I find the Si tranny to be extremely notchy. I have noticed though if giving it moderate acceleration and then shifting, the stick slides into the gates smooth as silk and feels amazing. Since the car is still not broken in though, I've been going pretty easy on it and can usually feel the gears engage on each shift. Not an issue IMO, just different compared to my other rides. I do anticipate it will improve as I rack up some more miles though.
 

amirza786

Senior Member
First Name
A
Joined
Oct 4, 2018
Messages
3,524
Reaction score
3,368
Location
Northern California
Car(s)
2006 Camry SE V6, 2013 Toyota Sienna LE, 2010 Lexus IS 350 Sport, 2018 Honda Civic Si (SOLD)
Country flag
Only 300 miles on my Si so take my opinion with a grain of salt...

I find the Si tranny to be extremely notchy. I have noticed though if giving it moderate acceleration and then shifting, the stick slides into the gates smooth as silk and feels amazing. Since the car is still not broken in though, I've been going pretty easy on it and can usually feel the gears engage on each shift. Not an issue IMO, just different compared to my other rides. I do anticipate it will improve as I rack up some more miles though.
I know this sounds like a broken record, but once you break her in and do your first oil change (please don't do one of those "I change my oil every 3K" silliness), my advice is to also change your OEM manual trans fluid to Amsoil Synchromesh. You wont' be sorry
 

Zeffy94

Senior Member
First Name
Matt
Joined
Mar 26, 2017
Messages
1,288
Reaction score
968
Location
Doylestown, PA
Car(s)
2018 Honda Civic Type R
Vehicle Showcase
1
Country flag
I just got orthopedic inserts for my shoes to help with flat feet issues and because of the very foreign feeling (after walking around on flat feet for over 8 years), it's taking a lot to get used to (which I was warned). My issues are that there's more weight in my shoe thus my smooth clutch movements have become less smooth. Took a while to get 2nd gear shifting to be smooth too, but it is my first stick shift vehicle ever.

Sucks though, I am getting a lot more jerky shifts in 2nd, 3rd and 4th and it's just like "great, how long will this last".
 

DRuby

Senior Member
First Name
Dave
Joined
Jun 28, 2018
Messages
145
Reaction score
102
Location
Westchester NY
Car(s)
2018 Si
Country flag
I've found in leisure driving, skipping 2nd and going to 3rd seems to match the rev hang delay. Same going right into 5th from 3rd. As long as accel. isn't an issue,
 

pinhead66

Senior Member
Joined
Jun 6, 2019
Messages
118
Reaction score
54
Location
Bay Area, CA
Car(s)
2019 Civic Si Sedan, 2018 Odyssey EX-L
Country flag
After almost 6 months of ownership with this car my experience is that the heavy dual mass flywheel causes revs to drop very slowly especially in 1st and 2nd. Thus the long pause to let the clutch out to get smooth shifts. Rev hang is also a factor but the main culprit is after the rev hang the revs still drop too slow. After I installed a CTR RMM, I found that it was easier to make smoother shifts in those lower gears since the stiffer mount prevents the engine bucking if you release the clutch too early. I think to truly get smooth shifts though without having to hesitate in between the shifts is to get a lighter flywheel that will allow the revs to drop faster. It sounds like all the owners with emans CTR retrofit flywheel love it since the revs drop normally and the drivability is excellent since it’s OEM. It’s a shame though that a lighter flywheel solution is not cheap for parts and labor.
 

REBELXSi

Señor Member
Joined
Aug 12, 2018
Messages
1,968
Reaction score
1,781
Location
215
Car(s)
'18 Si coupe
Country flag
Still on the OEM fluid at 37k and mine shifts smoothly. I must be lucky :rolleyes:
 

                           

Top