Clutch parts

[repiv]

(Reprint series)

Question: What are the required parts to do a clutch swap. I recently purchased a ACT clutch kit that has the HD PP and the performance street disc, but that was all that was in the kit. I plan on turning the flywheel, but need to know if there is anything else I need/should replace besides the throw out bearing and pilot bearing. Also is it a good idea to switch my clutch line to a braided one with the added pressure that will be required to disengage the PP?

Reply: I think you've got it all covered. You might have some high temp grease on hand to lube up the TO bearing and release fork fingers and end socket.
While you're in there, inspect the engine rear main seal and change it if it's showing any signs of leakage. It's a small part but very extensive work if you have to replace it later.
There's really no need to go with a braided steel clutch line. Even a HD PP doesn't have that much resistence to make a difference. The ACT is only about 40% to 50% more pedal pressure. Think about the brakes. Those lines get several times the amount of pressure going through them and only a few people elect to go with braided steel lines there. The stock brake and clutch lines do a good job. However, if your clutch line is getting old or looking damaged, then the choice is yours on if you want to go with an upgraded line. Nevertheless, the clutch line is not a high pressure, high heat line.

Q: I have another question would I see any benefit going to an AP1 flywheel my S is an 04?

R: Not really, unless your old flywheel can't be re-surfaced. I doubt you will feel any difference. The weight difference is marginal.

[SpitfireS]

Ehh... MY04's (= AP2) have the F22.. right?
The AP2 FW is a lot heavier as far as I know.
(isn't it?)

:yo:

[raymo19]

But does it really make a significant difference? I've got a CC stage 2 clutch with a lightened flywheel on my CT/AC boosted AP1 and the only difference I've noticed is that the shift points change - the RPMs drop more quickly so you can mash the gas more quickly.

And that's with the same Richmond 4.57s you've got as I recall.

It seems to me flywheel weight is just another change you have to allow for when modding this car.

[repiv]

Ehh... MY04's (= AP2) have the F22.. right?
The AP2 FW is a lot heavier as far as I know.
(isn't it?)

:yo:
It's heavier, but by how much, I don't know the exact difference in pounds (if it's even that much). I doubt the difference can be felt in performance numbers nor could it be felt by the average driver.

[dc_35]

acording to SOS

the ap2 weighs 21 pounds compared to the AP1's 14....i would say that A LOT...

here's some food for thought....

http://www.uucmotorwerks.com/flywheel/how_a_lightweight_flywheel_works.htm

[repiv]

acording to SOS

the ap2 weighs 21 pounds compared to the AP1's 14....i would say that A LOT...

here's some food for thought....

http://www.uucmotorwerks.com/flywheel/how_a_lightweight_flywheel_works.htm
First of all, I'll have to take SOS's word on the weights, since I gave my old flywheel away and can't weigh it myself. If it is 6 pounds, then yes, it is quite a bit. One has to ask why Honda would make the flywheel so much heavier after running a much lighter one for so many years? We all know that the front crank pulley is weighted because it's also used as a damper. We also all know that the F2x series (and most inline 4 cyl engines) have a natural harmonic vibration. Some designers put in counter rotating shafts to dissipate these vibrations. On our engines, Honda chose to use weighted spinning objects like the front crank pulley and I suspect, they are using the flywheel (and pressure plate) on the back of the engine to further act as a damper. If we reduce the weight of the flywheel, what are the negative consequences of doing this? Having said this, I can tell you that I myself, have installed a Comptech lightened flywheel. Along with myself and all other S2000 owners that I've talked to or PMd with, who have lightened flywheels, we can all attest to the fact that a lightened flywheel produces no noticeable gains on the butt dyno. Not scientific, I know, however, in the real world, that's the dyno we use day to day on the street. I've always suspected that many car enthusiasts who expends the money and effort into putting aftermarket parts on their cars, will tend to say that their money and time was well spent. They have a tendency to say what a great product it is for various reasons, be it that they don't wish to admit to spending money for nothing or that they feel money spent must equate to performance gained, especially when posting on a world wide forum. When you speak to them in private, their real feelings come out. This is not to say it's always the case, but let's face it, in the world of car mods, owners don't like to admit they "fell for it". I can list all the expensive mods I've done to my car that does absolutely nothing.
Additionally, when you consider the weight of the flywheel, then combine to that, the weight of the pressure plate (which is bolted to it and spinning with it), a reduction of 6 pounds (if that's what it really is), really is not as significant.
Now, I'm not saying one way or the other about the UUC page, but let's not jump over the cliff with the other lemmings just yet. It sounds an awful lot like the old Duralube commercials. UUC gives us "calculations", not actual dyno numbers. Where do they get these formulas from? Remember how CAI manufacturers give us "dyno" numbers for their products? In reality, everyone knows that you can't dyno a CAI. Also, what about grounding kits and what their manufacturers claim to be "gains"? These people are trying to sell product, so unless the tests are conducted by independent sources, I tend to be a bit on the sidelines on these claims. It may be "food for thought", but till we can determine if it's health food or junk food, a little objectivity might be in order.
Your input is appreciated and it certainly does give another point of view.

[SpitfireS]

Going by Billman's (from S2ki - I am alowed to use that word here.. am I? Ha!) line of thought: the F22 has a lower redline but the about the same vtec crossover point so the heavier flywheel was used to keep the engine revs up, IOW "in the powerband" during redline shifts.

I have to agree with what was said about the difference between lighter than AP1 OEM FW's when accelerating, with the Comptech I've noticed nothing.
My take on it: the weight difference of the accelerating FW is only a very tiny little small ;) fraction of the weight of the car that has to be accelerated.
That's why "you" don't notice it.
Maybe one does notice it a little bit during shifts and maybe during downshift & trying to revmatch.

The things mentioned above are all with lighter than OEM flywheels.
And the weight difference isn't as much as the 21 > 14 (like 14 > 11with OEM > CompT)
(Weights are IIRC)
Maybe a heavier than AP1 OEM FW will make a small noticable difference during shifts.
Not while accelerating.

The differences between a 4.10 diff and a 4.57 diff are... huge:lol2:
IMO you can't compare it with weight differences between FW's.

The 4.5X (4.57 or 4.56) final drive ratio should have been used for the S2000 from day 1.
In My Honest Opinion.

:yo:

[Bieg]

.........Having said this, I can tell you that I myself, have installed a Comptech lightened flywheel. Along with myself and all other S2000 owners that I've talked to or PMd with, who have lightened flywheels, we can all attest to the fact that a lightened flywheel produces no noticeable gains on the butt dyno. Not scientific, I know, however, in the real world, that's the dyno we use day to day on the street. I've always suspected that many car enthusiasts who expends the money and effort into putting aftermarket parts on their cars, will tend to say that their money and time was well spent. They have a tendency to say what a great product it is for various reasons, be it that they don't wish to admit to spending money for nothing or that they feel money spent must equate to performance gained, especially when posting on a world wide forum. When you speak to them in private, their real feelings come out. This is not to say it's always the case, but let's face it, in the world of car mods, owners don't like to admit they "fell for it". I can list all the expensive mods I've done to my car that does absolutely nothing.........



Wow! You sound like you are singing from my songbook! :)

[Bieg]

All joking aside I believe the heavier the flywheel the less effect each power stroke will have on the overall engine balance and also lighten the load on the main bearings. Correct me if I am wrong but I believe the heavier the flywheel when rotating at any given RPM the harder it is to deflect the crank from its center of rotation. This should mean the bearings have an easier life with a heavy flywheel correct?

[repiv]

The 4.5X (4.57 or 4.56) final drive ratio should have been used for the S2000 from day 1.
This is the opinion of many. I've always thought that if Honda came out with this in the first place, there would have been no need to go to the 2.2 and revised AP2 transmission. The AP2 powertrain is a vast improvement, but I still feel the best is the AP1 with a 4.5x rear end. My AP1 with AP2 tranny and 4.44 is perfect for me, but what a lot of fiddling to get it right. If only the 4.57 was available at the time. I would have had no need for an AP2 tranny.

[Wanderer]

. My AP1 with AP2 tranny and 4.44 is perfect for me, but what a lot of fiddling to get it right. If only the 4.57 was available at the time. I would have had no need for an AP2 tranny.

Dave, , now I am confused. I thought that you went with the AP2 transmission because your cruising RPM was higher with the 4.44 ratio. Wouldn't the 4.57 gears have made this "worse" (with the AP1 transmission)?

[repiv]

Dave, , now I am confused. I thought that you went with the AP2 transmission because your cruising RPM was higher with the 4.44 ratio. Wouldn't the 4.57 gears have made this "worse" (with the AP1 transmission)?
Here are the some of the numbers that outline what happens depending on what one does ........
The AP2 tranny has an altered secondary reduction gear (1.16 for AP1 vs 1.206 for AP2). This gives a similar mechanical advantage as having ~4.3 final drive. However, Honda saw this as a detriment to highway cruising rpm and hence, they altered the gear ratios for 5th and 6th. Consequently, gears 5 and 6 is "like" having a FD ratio of ~4.02 (not too different from the stock AP1).

At 70 mph, a stock AP1 runs at ~3750 rpm in 6th.
At 70 mph, a stock AP2 runs at ~3750 rpm in 6th. (may not be exact but very similar)
At 70 mph, AP1 with 4.57 FD runs at ~4200 rpm in 6th.
At 70 mph, AP1 with 4.44 FD runs at ~4050 rpm in 6th.
At 70 mph, AP1 with 4.44 FD and AP2 trans runs at ~4000 rpm in 6th. (also very similar with AP1 tranny).

What in essence happened when I went to an AP2 tranny (with the pre-existing 4.44 FD) was that for gears 1 to 4, I now have the equivalent FD of about 4.62 while still retaining a FD ratio as though I still had 4.44s for 6th. I guess the real reason was to get way more "grunt" in the first 4 gears without sacrificing any further increase in cruising rpm. In fact, cruising rpm dropped marginally. I may have tried to justify in my own mind that the reason for getting the AP2 tranny was to drop cruising rpm a bit, but it was really for the more "get up and go".
So yes, 4.57 in an AP1 would increase cruising rpm by about 450 rpm to 4200 at 70 mph. However, our 2.0L engine is working not much harder than the same engine stroked to 2.2L and running at 3750 rpm in terms of piston speeds. My before and after highway fuel economy improved from 36 to 38 miles per imperial gallon. (I was getting 40 when the car was completely stock.)
I don't know if this addressed your question but ............................. :)

[Wanderer]

Thanks Dave!

I see that there was more to the story than what I thought. Thanks