Honda / Acura K20a K24a Engine Forum banner
1 - 19 of 19 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter · #1 ·
So I'm reading through the magic of Google that the 5 speed might be better for high HP applications

Regardless of the trans I still plan on cryo for the gears.

I want to go with the si transmission due to the longer 6th because I want to be able to street and track the car or I'll put 6th from a tsx in a type s. But I'm hearing that the longer hearing of the 5 should be better for high HP. So which trans should I go with? Considering the 5 is a lot easier to get I'm tempted to try it
 

·
Registered
96 civic HX K24a
Joined
·
2,024 Posts
So I'm reading through the magic of Google that the 5 speed might be better for high HP applications

Regardless of the trans I still plan on cryo for the gears.

I want to go with the si transmission due to the longer 6th because I want to be able to street and track the car or I'll put 6th from a tsx in a type s. But I'm hearing that the longer hearing of the 5 should be better for high HP. So which trans should I go with? Considering the 5 is a lot easier to get I'm tempted to try it
The si trans has a 4.7 FD. You will be spinning the hell out of your tires. The 4.3 type s trans or the 5 speed would be better as far as acceleration and traction with high hp/tq on a turbo car. With a 5 speed and a 9,000 + rpm engine you could pass the 1/4 at the top of 3rd on the right size slick.
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #3 ·
The si trans has a 4.7 FD. You will be spinning the hell out of your tires. The 4.3 type s trans or the 5 speed would be better as far as acceleration and traction with high hp/tq on a turbo car. With a 5 speed and a 9,000 + rpm engine you could pass the 1/4 at the top of 3rd on the right size slick.
Tempted to go 5 speed but I'm not sure about what mods would get me 9000rpm with a turbo
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #5 ·
Not saying you need that, just an example. The 5 speed will be less shifting in a race.
The FD on the 5 and 6 are the same but I wonder with a different FD ratio would the 6 be better 🤔

I'll probably go with whichever is stronger for boosted application. It's coming apart for cryo anyways so I can swap a LSD into the 5 speed
 

·
Premium Member
Joined
·
908 Posts
my old Jackson Racing M62 non-intercooled 2005 "Trainwreck TSX K24A2" shifting @ 8,000rpm

Modification List:

1) Zero mile Complete 2005 K24a2 longblock ( factory longblock )
3) PRB Type S flywheel
4) Exedy Twin Plated Clutch
5) AMSOIL MT transmission fluid
6) EP3 5speed 4.7 FD (No LSD)
7) DC Sport Customized exit Race Header w/ 2.75" exit (no cat)
8) Custom 3" exhaust
9) 3" intake
10) RC 650cc

1st gear = 0-32 mph

2nd gear = 32-64 mph

3rd gear = 64-92 mph

4th gear = 92-124 mph

5th gear = 124-156mph

Using a tune made for VP 103oct Unleaded Oxygenated mixed with some 93oct left over in the tank.
 

·
Registered
Joined
·
6 Posts
Is the 5 speed a direct swap into a 6 speed car, or are the axles and jack shaft different lengths or spline sizes ect... I'll search around on here but figure since were on this topic someone may know what is all different. Thanks!
 

·
Registered
96 civic HX K24a
Joined
·
2,024 Posts
Is the 5 speed a direct swap into a 6 speed car, or are the axles and jack shaft different lengths or spline sizes ect... I'll search around on here but figure since were on this topic someone may know what is all different. Thanks!
All bolts up the same as long as the 5/6 speeds are both k20 transmissions. The tsx 6 speed and accord 5 speed require different parts to work in the chassis but all the engines and transmissions share the same bolt pattern for the common k series engines.
 

·
Registered
Joined
·
6 Posts
Thanks for the quick replay, the car is a 2006 RSX-S, I bought it with a bad trans, I have a 2007 Accord 5 speed available. The car is for my son and I am not looking for it to set any speed records, just be a good daily driver.
Sorry for the questions, just trying to figure out all my options. The current trans was run low on oil and 3rd gear welded itself to the main shaft, so Im sure when I pull it apart it will need lots of parts being run without oil.
So, no issues with bellhousing and clutch setup... From what I read there are differences in the shifter and linkage, what are the other parts that are needed to work in a RSX chassis. Thanks!
 

·
Premium Member
Joined
·
908 Posts
Hi RuppMagnum --

I ran out of time cross referencing part numbers of the RSX Type S and the 2007 Accord 5speed. So when I have more time later I will look at the subject more.

What I did find out was the left axle & right axle assemblies are different part numbers, the spindle nut size on the DC5 is 24mm and the Accord is 22mm. The halfshaft part number's are different also. I would continue to cross reference parts and find out why they are different part numbers. However the oil seals and the set rings are the same part numbers. I hoping the reason is because of length.

Just because they are different part numbers does not always mean the parts are not interchangeable.
 

·
Registered
96 civic HX K24a
Joined
·
2,024 Posts
Thanks for the quick replay, the car is a 2006 RSX-S, I bought it with a bad trans, I have a 2007 Accord 5 speed available. The car is for my son and I am not looking for it to set any speed records, just be a good daily driver.
Sorry for the questions, just trying to figure out all my options. The current trans was run low on oil and 3rd gear welded itself to the main shaft, so Im sure when I pull it apart it will need lots of parts being run without oil.
So, no issues with bellhousing and clutch setup... From what I read there are differences in the shifter and linkage, what are the other parts that are needed to work in a RSX chassis. Thanks!
The accord transmission would need a different mount to make it fit with the chassis I believe. I know it does in 92-00 civic /integra swaps. Or you could replace the outer bell housing on the k24 transmission with the original k20 one so it bolts right in the same and you retain your original speed sensor. 02-04 have a different speed sensor vs the 05-06 and newer transmissions so that’s something to consider as well. If the RSX trans case is good still that would make the swap a lot easier and even use your original cables and shifter box.
Edit - I see the k24 trans is an 07 now 👍
 

·
Registered
Joined
·
6 Posts
If I understand all this correctly I should be able to swap the 07 K24 guts into my 06 K20 cases... I'll start pulling the trans out of my RSX and when I have them both on the bench I'll post up the differences.
 

·
Registered
Joined
·
6 Posts
After pulling the trans out of my 06 RSX, I found the damage limited to the 3rd / 4th gear needle bearing and collar that was pressed on the shaft. If I can find these parts I will just rebuild the 6 speed and unfortunately for the K series community I wont be able to verify details on the swap.
However I am having trouble finding these parts, what is the best place to go. I have not been able to find the needle bearings or the collar they go on.
Household hardware Gas Auto part Cylinder Nickel
 
1 - 19 of 19 Posts
Top