PTT clutch, pedal feels very soft...

[stockfornow]

Is this normal to have such light pedal feel? I have made the pedal stop, but the pedal still has to move quite a bit, where I was expecting it to not move much at all. I also bleed the clutch, and this is using the isuzu slave. Sorry if it's a retarded question, but I just want to make sure. Thanks to you all.

 

[Defiant]

I also bleed the clutch, and this is using the isuzu slave.

Wat? WTF

 

[SethA]

Yes the clutch requires very little pedal effort (less than stock?).

I am not sure what you are referring to when you say the pedal "still has to move quite a bit"? The Isuzu slave makes the pedal need to move farther through its range of motion to get the same movement at the throw out bearing. It makes the clutch "lower geared".

Seth

 

[stockfornow]

Sorry, I don't know how to explain this, but it just seems/feels not normal to me.

Can any of you with the twin disk clutch, let me drive your car to see if it acts the same way or not? That way I can be 100% sure. Somebody local, like "SethA".

 

[94Jettameowpsst]

Basically no pedal pressure is normal. I didnt know either until i drove it for a while and launched it....spun all 4 tires but not the clutch !!!
What kind of fluid do you run? I run the Motul stuff....thats what i've heard is "suggested"

 

[stockfornow]

So, if it feels like a stock/soft pedal it's normal? And I run just regular fluid, whatever they sell at NAPA... So, hopefully SethA is going to let me test drive his car, so I will be able to tell if it's the same or not. We will see.

 

[twicks69]

So, I hope that you have found out by now that the PTT clutch pedal pressure is extremely soft and very good engagement properties (well if you are used to driving a twin-disk at least). I use the Quarter Master twin disk on my car, but I just recently had my first experience with the new PTT twin-disk and can give some feedback about the pedal pressure and harmonics.

I drove a friend's 2G on Monday with a brand new PTT twin-disk and the pedal feel was extremely light -- lighter than my Quarter Master, and much lighter than stock. He is running a braided line from the master cylinder directly to the slave, so all the stock pressure reservoir stuff is gone (just like my setup). Very soft pedal, but suprisingly alot more harmonics were coming from his PTT clutch than I had ever heard from my Quarter Master clutch. I took it for around a 10-mile drive on the street and interstate because he was complaining about the large amount of harmonics and chatter, along with a very light clutch pedal.

He is running a street car with stock motor mounts, stock trans, built 2.4L with GT3076R, AEM EMS, etc.; 460AWHP on 18psi and pump gas on a brand new motor safe tune.

The clutch was properly installed and properly adjusted before I took it for a spin. It was REALLY soft, but had nice engagement/disengagement ~ 1"-2" range of overall pedal modulation for clutch engagement/disengagement. Very easy to use after figuring out the initial clutch pedal engagement point.

I was really impressed with how smooth the clutch was for engagement, as it was very similar to my Quartermaster. It did feel a bit flutterier than mine (and I have a much lighter rotating assembly), and the harmonics were evident through a much wider rpm band than I was expecting. I was having harmonics from 1200-3000 under light throttle and constant load cruising, and then heavy harmonics/chatter from 3000-4500rpm on decelleration. This was a brand new clutch still, so it should quiet down after a bit of break-in. It will also require a bit of pedal adjustment after break-in still. I was expecting the harmonics from 3000-4000 range, but not the other chatter under light load/cruising conditions from 1200-3000rpm. Since this was an older person's car (he is around 60 years old), he did not like the clutch chatter of the twin-disk. I told him that it will reduce overall when the clutch breaks in a bit more -- he had less than 50 miles on it beforehand. I also recommended installing a Fluidampr harmonic damper for a 4G64. If you are running a 2.0, get the damper for the 2.0L, but if you are running a stroker or anything with the 100mm 2.4L crank, be sure to get the specific 2.4L harmonic damper from Fluidampr (or whoever you use), as there is a difference.

We ended up having a Fluidampr around the shop from an employee's car, and installed it to see if it would reduce the harmonics. This dramatically reduced overall harmonics under all load conditions by at least 80% from the stock crank pulley, and has really helped smooth out the overall vibration, harmonics and clutch chatter. It will also make the crank main bearings a hell of alot happier as it is reducing crank harmonics and reducing wear on the associated parts.

I would definitely recommend installing a quality harmonic damper if you are going to run a multi-disk clutch; such as the Fluidampr or ATI harmonic damper.

As well, for clutch hydraulic fluid, I would go with a quality non-silicone-based fluid like Valvoline synthetic DOT-3/4 brake fluid, Motul 600, Wilwood 570, etc. Just remember, the Wilwood and Motul fluids are really nice, but they are extremely hydroscopic. This means that they will absorb moisture much easier, and will require flushing or fluid replacement and clutch bleeding to maintain a consistent pedal pressure and quality hydraulic system function.

Good luck with the PTT twin-disk, and please post up your comments and feedback concerning the clutch, including any characteristics that you notice from it.

 

[dragonov_elite]

He is running a braided line from the master cylinder directly to the slave, so all the stock pressure reservoir stuff is gone (just like my setup).

HI not too HiJack the thread from Stockfornow. As I am wondering about what you said here ^^^^ Do you have any good links or write up's why to do this, What parts would be needed to do it? Where would I be able to find the stainless breaded line for this mod? BTW I am looking at the quarter master clutch for my 2.3 build so every bit of info helps greatly. Thanks for all the awesome information so far.

Dragonov_elite

 

[twicks69]

The stock clutch line is a mixture of steel hard-line and rubber soft-line with a pressure reservoir between the clutch master cylinder and clutch slave cylinder on a 2G DSM. The idea behind replacing it with a single stainless line is just like removing your stock rubber lines and doing stainless brake lines for your brakes == it improves overall pedal feel and will be much more accurate for pedal engagement and clutch characteristics. It is not hard, and doesn't take too much work to do.

Just get a -4AN banjo fitting or adaptor fitting to attach to the slave cylinder (metric -- you will need to measure the size/thread pitch for the bolt going through the banjo bolt), and run a -4AN line back up to the clutch master cylinder with the proper fitting on that end.

You can purchase the fittings from Pegasus (Pegasus Auto Racing Supplies - Home Page) Pegasus - Plumbing Adapter Fittings, or Jegs (JEGS High Performance), or Summit (Summit Racing), etc. The stainless line is also capable of purchasing from the same places.

I purchased mine from Behling Racing Supply (behling circle track - Google Maps)


I don't know of any FAQ's off the top of my head for doing it. When I am feeling better in a couple weeks, I could go out in the garage and check the fittings if you haven't figured it out by then. It isn't that hard.
You can purchase pre-made -4AN stainess lines with crimped-on fittings at any length you want pretty much. Contact them, and have them ship you a catalog and price list. Otherwise, figure out your length and go online and do some searching for -4AN lines.

 

[snowborder714]

You can also purchase this line already made and ready to install. I personally haven't read anything exceptional about replacing the hard line from the master (maybe you can elaborate on this Tim?), but it's the soft line that is the culprit. It runs from the hard line (under fuse box) to the slave. With the accumulator in there, as well as it being rubber, it is a weak point of the system.

EXTREME PSI : Your #1 Source for In Stock Performance Parts - Extreme PSI Complete Clutch Line (Slave to Master Cyl.): Mitsubishi Eclipse 95-99

Select 2G (Long) for the full line:
Goodrich Stainless Steel Clutch Line - Modern Automotive Performance



I would be interested to see what fittings you used Tim. If I were to do it, I don't think I'd want the extremely long line that you buy and would probably try and route it a different way for a cleaner install. Let us know when you're feeling better!

 

[Black94DSM]

I also recommended installing a Fluidampr harmonic damper for a 4G64. If you are running a 2.0, get the damper for the 2.0L, but if you are running a stroker or anything with the 100mm 2.4L crank, be sure to get the specific 2.4L harmonic damper from Fluidampr (or whoever you use), as there is a difference.

Ok so this is making me . I have a fluidampr unit for my 2.3l engine. I couldn't find any info on one for a 100 mm crank. I got mine used from somebody with a 2.3 also and he didn't have any issue with it. They only make one for a 2.0l. Since they are neutral balanced it shouldn't matter what rotating assembly its connected to as long as the assembly was internally balanced also.

Could you give me any info on this please ?

I also have a QM twin disk.

 

[twicks69]

I agree, the short soft-line is the only one that really requires replacement; I ran the short replacement line for a few years, and only changed over to the complete line to clean up the engine bay a bit -- it wasn't necessary to run the complete line. There was no major difference between the complete line vs. the short replacement line other than the fact of less fittings and less complication.

The accumulator and the soft line is definitely the weakest link in the system.

You can also purchase this line already made and ready to install. I personally haven't read anything exceptional about replacing the hard line from the master (maybe you can elaborate on this Tim?), but it's the soft line that is the culprit. It runs from the hard line (under fuse box) to the slave. With the accumulator in there, as well as it being rubber, it is a weak point of the system.

EXTREME PSI : Your #1 Source for In Stock Performance Parts - Extreme PSI Complete Clutch Line (Slave to Master Cyl.): Mitsubishi Eclipse 95-99

Select 2G (Long) for the full line:
Goodrich Stainless Steel Clutch Line - Modern Automotive Performance



I would be interested to see what fittings you used Tim. If I were to do it, I don't think I'd want the extremely long line that you buy and would probably try and route it a different way for a cleaner install. Let us know when you're feeling better!

 

[twicks69]

Ok so this is making me . I have a fluidampr unit for my 2.3l engine. I couldn't find any info on one for a 100 mm crank. I got mine used from somebody with a 2.3 also and he didn't have any issue with it. They only make one for a 2.0l. Since they are neutral balanced it shouldn't matter what rotating assembly its connected to as long as the assembly was internally balanced also.

Could you give me any info on this please ?

I also have a QM twin disk.

I will look into the part number. All that I found quickly online on the Fluidampr site is the part number for the 4G63 (#630701). I found a few vendors (CI Peformance, Jay racing, with the #630701 part number, and then MAPerformance, Slowboy Racing, and several other vendors that have the part number as #630702 on their websites. I would recommend contacting Fluidampr and asking them specifically what the proper part number would be for your application using the 100mm 4G64 crank and if it is the same pulley or a different pulley than the 4G63 pulley. This will avoid confusion. Otherwise, I will contact them on Monday and update everyone with the proper part numbers per application for the DSM and Evo along with 4G63 vs. 4G64 crank applications.

The ATI part number is: #918251 for their damper that is used on the 4G63/4G64 applications.

 

[Black94DSM]

I will look into the part number. All that I found quickly online on the Fluidampr site is the part number for the 4G63 (#630701). I found a few vendors (CI Peformance, Jay racing, with the #630701 part number, and then MAPerformance, Slowboy Racing, and several other vendors that have the part number as #630702 on their websites. I would recommend contacting Fluidampr and asking them specifically what the proper part number would be for your application using the 100mm 4G64 crank and if it is the same pulley or a different pulley than the 4G63 pulley. This will avoid confusion. Otherwise, I will contact them on Monday and update everyone with the proper part numbers per application for the DSM and Evo along with 4G63 vs. 4G64 crank applications.

The ATI part number is: #918251 for their damper that is used on the 4G63/4G64 applications.

I have part # 630702 for my car. I think I'm going to give them a call Monday also.

 

[Black94DSM]

Just called Fluidampr. The guy that I need to speak to is not in today. I'm waiting back on a call from them.

I did find out though that my damper part number is discontinued and now the part goes by part #630701.

 

[twicks69]

Just called Fluidampr. The guy that I need to speak to is not in today. I'm waiting back on a call from them.

I did find out though that my damper part number is discontinued and now the part goes by part #630701.

Gotcha, I have a post-it note on my PC to call as well.

 

[Black94DSM]

I'm going to have to call tomorrow again, they havn't called me back since I first called. I figured I'd give them a few days to call me back since its not vital I know this info.

 

[twicks69]

Ok, I just got off the phone with Patrick over at Fluidampr. Here's the scoop.

Part number 630702 is the aluminum casing one. This part has been discontinued.

Part number 630701 is the steel casing damper; and is currently the ONLY one they produce for our applications.

I also asked them about the variations between the 4G63 and 4G64 crank setup, and they recommend Part #630701 for BOTH applications.


I hope that this clears some things up!

 

[Black94DSM]

Thanks for the info Tim. I believe Patrick is the guy who Lin?(from fluidampr) was getting his info from when I called. I had a extra question for him and he didn't know the answer so he told me that he would call back. I guess that I was lost in his notes and he never called back.

That makes me happy as I don't have to purchase a new damper now. And yes what you typed did clear things up.

I guess I have the older aluminum version of the damper. Any benefits having the steel one vs the old aluminum one ?

 

[Rocketman1000R]

If your tired of the harmonics on the PTT and the Quatermater then try the OS GIKEN R2CD for EVO 1-3, it fits and it resolves all the issues you mentioned about harmonics. I couldn't deal with the harmonics and called every clutch manufacture under the sun and OS GIKEN were the only one that knew all the flaws of the design and shared them with me. I was so impressed with the DSM clutch I replace myMKIV Supra RPS CC twin disc with the OS GIKEN R3C and love it too. The pedal is a little stiffer but you get used to it quick. I will never own any other clutch from now on. Just wish I wouldn't have wasted my hard earned money on the other two clutches. Also you don't need to modify the slave for the OS GIKEN. If any one is interested in my PTT hit me up at [email protected]

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