#K20-Swap - performance clutch options

fiatmonkey

fiatmonkey

Tim Hoover
I haven't had a lot of time to drive the k20 swapp'd X so took it for a spirited drive yesterday. I noticed the clutch is starting slip a tad and considering how many miles are on the engine/trans, its likely time for a clutch.

I was doing some research and it looks like the choice for K20s is the exedy exedy stage 2 and HF02

1292397005-exedy-combo-stage2-flywheel.jpg


Posted on k20a.org as well...

Thanks!
Tim
 
In my opinion performance clutches are bad news unless you need one. I'd just put a stock clutch in with maybe a lighter flywheel. Considering the X weighs at least 500 lbs less than the car the engine came out of I can't see how a performance clutch would be needed.
 
I'm with Matthew

Unless you plan on adding significant power (like forced induction) I would recommend an OE style clutch. I just did my wife's civic (D17 engine) with the exedy oem style and I'm very happy with it. Especially for under $100 for everything excluding the flywheel machining.

I did have an ACT sport street clutch on my S2000 with bolt-ons. Not sure on model # but the pressure plate was bright yellow and the friction disc looked fairly stock, not puck style. It's a good "upgrade" in feel and grab from the factory clutch, but was completely unnecessary.

I guess the question is, do you want or prefer a heavier, grabbier clutch?
 
Matthew said:
In my opinion performance clutches are bad news unless you need one. I'd just put a stock clutch in with maybe a lighter flywheel. Considering the X weighs at least 500 lbs less than the car the engine came out of I can't see how a performance clutch would be needed.
Click to expand...

Good point.

AleX1/9 said:
Unless you plan on adding significant power (like forced induction) I would recommend an OE style clutch. I just did my wife's civic (D17 engine) with the exedy oem style and I'm very happy with it. Especially for under $100 for everything excluding the flywheel machining.

I did have an ACT sport street clutch on my S2000 with bolt-ons. Not sure on model # but the pressure plate was bright yellow and the friction disc looked fairly stock, not puck style. It's a good "upgrade" in feel and grab from the factory clutch, but was completely unnecessary.

I guess the question is, do you want or prefer a heavier, grabbier clutch?
Click to expand...

Also a good point. The stock clutch does (or did) grab pretty hard when I first did the swap. I would like a smoother quicker acceleration to the vtec zone so maybe a combo light flywheel and exedy clutch (street version).

The issue is with the k20 swap, a clutch R&R requires the engine to come out. I was thinking while I have the whole engine out, might as well do an upgrade. I don't have any immediate turbo or supercharger upgrades for this car in the near future so that would not a reason to go performance clutch now...

Thanks!
Tim
 
I am using a 6-puck racing clutch in my K24 swap and I have to say it is overkill. I can't remember the brand off the top of my head, but it was about $400. I had the OEM clutch first and it was just fine. I took the transmission out to put an LSD in it and found that the trow-out bearing was broken. I figured I would just change the whole clutch assembly while I was at it, instead of just the bearing. My car is not driven on the street so its not that big of a deal, but whenever trying to start slow or reverse, it is difficult because the clutch wants to grab immediately. I think with the weight of an X 1/9 being so much less than the original RSX, that the OEM or something maybe just slightly more sporty is fine. I will not be purchasing another racing clutch for my K24 X, as it is totally unnecessary.
 
what clutch is that Tim?

Hi Tim,

I still haven't put my K20 in the bay yet (waiting on back-ordered conversion kit from MWB) but thought this would be an excellent time to do the clutch. You said "... so maybe a combo light flywheel and exedy clutch (street version)." - what are you referring to?

I'm also gonna drop a LSD in the transmission while it's out. My thinking: that much power and I'd like to limit wheelspin. Thinking of going with the Wavetrac [ame="http://www.amazon.com/Wavetrac-Differential-Acura-Limited-Slip/dp/B001FQ4Y96"]Limited Slip Differential[/ame] for street action. Has anyone done this in a #K20-Swap ?
 
I don't find wheelspin to be a huge problem

darwoodious said:
My thinking: that much power and I'd like to limit wheelspin.
Click to expand...

But I suppose it depends on your intended use.

With a FWD application such as the original RSX, you have acceleration squat working against you, but of course that situation is reversed in the X. In my experience, you really have to romp on it and do a fairly aggressive clutch dump to get a lot of wheel spin.

If you are going drag racing, then yes by all means you need this. But in spirited or even aggressive street driving I've never had a big problem with wheel spin. I imagine part of this is that the engine is not producing just gobs of torque at the typical clutch engagement RPM. That's kind of a good thing IMO. It is self-limiting to wheel spin, but the car is light enough that the engine can get up into its power band very quickly.

Have you had the opportunity to drive a K20 one on the street to assess whether you really need a LSD or not?

Pete
 
darwoodious said:
Hi Tim,

I still haven't put my K20 in the bay yet (waiting on back-ordered conversion kit from MWB) but thought this would be an excellent time to do the clutch. You said "... so maybe a combo light flywheel and exedy clutch (street version)." - what are you referring to?

I'm also gonna drop a LSD in the transmission while it's out. My thinking: that much power and I'd like to limit wheelspin. Thinking of going with the Wavetrac Limited Slip Differential for street action. Has anyone done this in a #K20-Swap ?
Click to expand...

Exedy has the OEM and the stage 1 performance clutch. I am torn between the two.
http://www.exedyusa.com/oe/HD511D

http://www.exedyusa.com/oe/KHC10

I know that LSD has been used in the k20a2 6 speed but I am not aware of anyone who has it in their swap.
 
Pete Whitstone said:
But I suppose it depends on your intended use.

With a FWD application such as the original RSX, you have acceleration squat working against you, but of course that situation is reversed in the X. In my experience, you really have to romp on it and do a fairly aggressive clutch dump to get a lot of wheel spin.

If you are going drag racing, then yes by all means you need this. But in spirited or even aggressive street driving I've never had a big problem with wheel spin. I imagine part of this is that the engine is not producing just gobs of torque at the typical clutch engagement RPM. That's kind of a good thing IMO. It is self-limiting to wheel spin, but the car is light enough that the engine can get up into its power band very quickly.

Have you had the opportunity to drive a K20 one on the street to assess whether you really need a LSD or not?

Pete
Click to expand...

Turbo or supercharger would certainly change this however. The couple of times I drove Jon's vtec swapped X, I was spinning the tires pretty darn easily. I don't recall if he had an LSD installed or not.
 
I guess I haven't been following Darin's build

fiatmonkey said:
Turbo or supercharger would certainly change this however. The couple of times I drove Jon's vtec swapped X, I was spinning the tires pretty darn easily. I don't recall if he had an LSD installed or not.
Click to expand...

Is forced induction in the picture?

Pete
 
LSD

Pete -

I've not yet had the pleasure to drive one and you're probably correct: with weight transfer it probably isn't all that important. As light as the X is, I assumed there would be some spin on acceleration - especially exiting a corner on throttle. The Wavetrac one seems to help in specific scenario (inside tire losing complete traction). However, in something like snow the oversteer is massive (the blue BMW has the LSD).

Probably not important, but thought I'd ask any #K20-Swap folks if they've done it.

Thanks,
Darin
 
darwoodious said:
Pete -

I've not yet had the pleasure to drive one and you're probably correct: with weight transfer it probably isn't all that important. As light as the X is, I assumed there would be some spin on acceleration - especially exiting a corner on throttle. The Wavetrac one seems to help in specific scenario (inside tire losing complete traction). However, in something like snow the oversteer is massive (the blue BMW has the LSD).

Probably not important, but thought I'd ask any #K20-Swap folks if they've done it.

Thanks,
Darin
Click to expand...

Hey Darin - I don't recall if you are sticking with stock or supercharged/turbocharged?

Pete Whitstone said:
Is forced induction in the picture?

Pete
Click to expand...
 
Stock to start...

Tim, I'm gonna start with stock. Not sure how one would fit a supercharger in the engine bay, but a turbo ought to work out with some tweaks (plus I've heard it can be done). I'm more interested in higher torque than more HP.

Actually, I'm most interested in getting it finished :)

I figured that since the drivetrain is all out now I'd do the clutch and LSD & I'm leaning towards something like the stage 1 kit you mentioned from exedy. Cheers, -Darin
 
darwoodious said:
Tim, I'm gonna start with stock. Not sure how one would fit a supercharger in the engine bay, but a turbo ought to work out with some tweaks (plus I've heard it can be done). I'm more interested in higher torque than more HP.

Actually, I'm most interested in getting it finished :)

I figured that since the drivetrain is all out now I'd do the clutch and LSD & I'm leaning towards something like the stage 1 kit you mentioned from exedy. Cheers, -Darin
Click to expand...

Actually the k20a2 is generally not known for a ton of torque out of the box. HP yes. Better torque can be had from the k24a2 OR a k20/k24a2 head/block combo while all motor. Bolt on torque with a supercharger for sure.
 
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I have the MFactory LSD in my K24 X and I think it is needed. The K24a2 that I swapped in has a lot more torque than the K20a2 that I swapped out (170 lbs-ft v. 142 lbs-ft). Also peak torque is at much lower RPM in the K24 than in the K20 (4500 rpm v. 6000 rpm). Even with 9.5 inch wide Hoosier slicks, I can spin the tires at will in 1st or 2nd gear, or with a little clutch action in 3rd. Accelerating through a corner is also much better with the LSD. Even a stock X 1/9 can spin the inside tire on a hard corner, it is much more so with the K engine. If you plan on driving you K20 X hard or upgrading the engine in the future, you might as well put an LSD in it now.
 
Dennisrh said:
I have the MFactory LSD in my K24 X and I think it is needed. The K24a2 that I swapped in has a lot more torque than the K20a2 that I swapped out (170 lbs-ft v. 142 lbs-ft). Also peak torque is at much lower RPM in the K24 than in the K20 (4500 rpm v. 6000 rpm). Even with 9.5 inch wide Hoosier slicks, I can spin the tires at will in 1st or 2nd gear, or with a little clutch action in 3rd. Accelerating through a corner is also much better with the LSD. Even a stock X 1/9 can spin the inside tire on a hard corner, it is much more so with the K engine. If you plan on driving you K20 X hard or upgrading the engine in the future, you might as well put an LSD in it now.
Click to expand...

Thanks Dennis for the opinion. I figure it can't hurt so I plan on doing it.

Interesting your switch from a K20a to a K24. Did you keep the same transmission from the K20a? Any issues with the ECU? Probably more cost effective to swap the engine (K20 -> K24) rather than trying to hook up a super/turbo charger.
 
darwoodious said:
Thanks Dennis for the opinion. I figure it can't hurt so I plan on doing it.

Interesting your switch from a K20a to a K24. Did you keep the same transmission from the K20a? Any issues with the ECU? Probably more cost effective to swap the engine (K20 -> K24) rather than trying to hook up a super/turbo charger.
Click to expand...

I am interested in the ECU Dennis using as well. My research tells me you can go with the haltech ECU system or a flashpro from Hondata. The torquier k24 has definitely got my interest...:hmm:
 
Kpro

I think that Kpro is the engine management system most of the hardcore Honda guys use. It took me all of about 10 seconds to change ECU maps from the stock K20 map to the stock K24 map. I updated some of the stuff about my K24 project on my thread here http://xwebforums.com/forum/index.php?threads/27825 so as not to hijack this thread.
 
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