Clutch Ideas

PKFIRE

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I’m running a RST clutch and ran it with slicks for the first time. Unfortunately it didn’t hold well and started smoking on each pass. I’m seeing what other options are out there what would take drag strip launches and have good street ability. Single or Dual Disk that is around 500-1000 dollars.

605 SAE Whp 568 torque
03 Cobra 2.3 VMP 2.8 upper and stock lower 18psi of boost.
 

LethalBlake

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I would recommend one of our Lethal Performance LPX/LPXHD clutches. We use Kevlar discs instead of ceramic for smoother engagement while still having strength to hold up to power and abuse. The standard LPX would put you right around the price point you want to be at and the coverage you need for your set up. Feel free to reach out to me with any questions.
 

P49Y-CY

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the only difference between the rst and the rxt is the disc material so you might be able to just buy an rxt disc and make sure the fw is ok.

the rst is not for drag racing with sticky tires.
 

cobracide

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the only difference between the rst and the rxt is the disc material so you might be able to just buy an rxt disc and make sure the fw is ok.

the rst is not for drag racing with sticky tires.
Exactly - Send the RST to McLeod and have them rebuild the RST to RXT specs.
 

PKFIRE

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I contacted McLeod this morning. 540 to convert it to a RXT, 125 to install new heat shield in the flywheel and 125 if I want it balanced.
 

apex svt

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I contacted McLeod this morning. 540 to convert it to a RXT, 125 to install new heat shield in the flywheel and 125 if I want it balanced.
I went this route, my rst also couldn’t handle the track.

You’re getting a brand new clutch when they rebuild it.
 

apex svt

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Did your 1/4 mile time decrease and trap speed go up after the change?
Can’t speak on that one, it held fine blower only. Started rolling smoke when we put the 200 hit to it. Didn’t spray it this year, was working on the 60’. That said the car made its fastest pass on motor this year.

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geoffmt

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I upgraded the discs in my rst now that it will be having some extra power. Discs were about $500.


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Stage 4.6

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I was about to create a new post on this subject. I am on my 2nd RXT. First was installed in 2014, and had it rebuild through McLeod in 2018.

I took my car to the track for the last test and tune of the season and my clutch started slipping. I'm having second thoughts on going a 3rd round with the RXT?

For the record "I DO NOT" track my car occasionally. A couple of roll races (street car shoot outs) and dig raced it maybe 3x a year.

Wondering what kind of life span some of you that actually track your cars are getting out of this clutch?

I love the pedal feel and how it takes the power when new, but not impressed with longevity.
 

Stage 4.6

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Well I'll just say that, I installed my first RXT at 25k original miles in 2014 and my car currently has 40k and may be needing it's 3rd?

I do enjoy my car but not as much as it seems.
 

MG0h3

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Give the 1200 a shot?

You guys sure that you have clearance and the PP doesn’t have constant pressure from the TOB due to being sandwiched against the trans case?


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Stage 4.6

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Give the 1200 a shot?

You guys sure that you have clearance and the PP doesn’t have constant pressure from the TOB due to being sandwiched against the trans case?


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Your statement above has been my concern since I first got mine installed. Especially since I had a TOB (Ford OEM) go out within the first year.

On my second install, I even had them install the McLeod pivot ball adjuster, this time the TOB went 2 years before it started chirping.

Something I do find strange this time around, is that my clutch did not give a burnt smell, although it is slipping bad and engages extremely high? I thought maybe the cable stretched, but I adjusted it yesterday and it seems pretty tight?

Could the disks be glazed?
 

MG0h3

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Your statement above has been my concern since I first got mine installed. Especially since I had a TOB (Ford OEM) go out within the first year.

On my second install, I even had them install the McLeod pivot ball adjuster, this time the TOB went 2 years before it started chirping.

Something I do find strange this time around, is that my clutch did not give a burnt smell, although it is slipping bad and engages extremely high? I thought maybe the cable stretched, but I adjusted it yesterday and it seems pretty tight?

Could the disks be glazed?

Well first you need to make sure the cable is adjusted properly.

The TOB should be lightly touching the PP at all times so that it is always spinning the same RPM as the engine.

Too loose/a gap and you are taking a TOB at zero RPM up to engine RPM instantly over and over.

Too tight and of course you have heat and potential for slipping.

I ran my RXT with the stock pivot ball for over 14k miles and 7yrs. 5k or so of which was on E85 and prob @700whp. Only slipped once the PP moved back enough to sandwich the bearing to the case. Clearancing the case/fork is the only fix for this and it’s more of an issue with the magnum.

Sounds like you probably have some install/adj issues that are causing premature TOB failure. Could also be the cause of the slipping but without inspection that would be hard to determine.

Very high engagement and slipping suggests that you’re possibly too tight and have way too much pressure on the plate with no foot pressure.

I set mine with the car running and check it after oil changes. I ensure the TOB is spinning with no pedal pressure and that with one finger I can move the fork back far enough that the TOB stops spinning. Let go and it’s spinning again. Proof that leaving a gap is wrong is readily apparent as I get a puff of smoke, couple sparks, and a loud squeal when the TOB at zero rpm has to speed up to 800 rpm at idle.


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Stage 4.6

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The TOB issue has been a challenge with these cars on twin disks, I played with my adjustment a lot when first installed, to ensure that the TOB slightly touched the PP.

I was always more concern with mine being to tight, but when it was to loose the car would be hard to put into gear, so I knew I had to tighten a bit by doing small adjustments specifically while the car was running so that I can feel the engagement. Upon getting the correct engagement the pedal still felt high?

Really appreciate your input.
 

DCguy

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FWIW, i went with a Centerforce DYAD this time around....haven't had a chance to try it yet but, given the features, I wanted to give it a shot. I had an RXT before with my T56, but will be installing a Magnum and have seen that the regular RXT for these cars has a hell of a time fitting into a MagT56 - you have to grind down the clutch fork and even some of the trans front plate to gain the proper clearance for the fork and have enough travel on the pivot ball stud. This is due to the clutch stack height of the pressure plate + discs + flywheel. One of the guys with this issue said that Mcleod told him to run the RXT designed for the Magnum XL, but I can't confirm it made any difference.

I bought my DYAD when Centerforce was doing a 20% off deal (which is running right now actually). The feature set and option to select clutch material tipped me over the edge to grab one. You can either do an organic material disc in the regular DYAD or a ceramic puck style with the XDS. With these cars having crank snout issues snapping with bigger blowers i'd recommend the organic disk for a smoother engagement but I grabbed a puck style because F it.

Another major factor is that the flywheel is recessed, decreasing the clutch stack height which means you don't have to grind away at your clutch fork or brand new Magnum. The cost of the assembly is a bit higher than the RXT but it includes the flywheel AND the entire assembly is fully balanced and includes all ARP hardware.

Lot of other little things too like spring loaded indexing pins which keep chatter to a minimum and spring loaded fingers aiding in engagement.

Anyway, we'll see what it does in operation, but seems like a nice alternative to the ever popular RXT, especially if you're going Magnum.

 

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