Spec twin disc review

[antilag_200]

My Review/Impression of the Sheptrans and Spec Twin Disc P -trim.

Firstly, everyone picks a clutch type, that is specific to the type of racing that they do.
If you want lightning type , NLTS, banging gears -- a smaller single/triple/double clutch set should be picked, i.e a PTT, Quartermaster,spec mini, tilton

if you want driveability/strip set up --- people would go with an exedy twin

If you are made of money and want the absolute best of the best --Tilton triple carbon seems to be the choice of the masses.

In the evo community we are blessed to have a wide array of multi disc manufacturers..From the heavy hitters like TILTON, CARBONETICS, OS Giken, HKS, CUSCO, to the more common, SPEC, Competition clutches and Exedy. So making a decision for a clutch was needless to say .... Tiring ( have you guys ever shopped for a big screen TV?...) yeah its like that, because you want to get the best performance for the least amount of money.

I choose the SPEC Twin P-trim for the following features:

1) Price --it was very competitive to all of the other clutches I previewed
2) Twin disc , 1 Sprung disc, 1 solid hub disc with graphite/ceramic material of the friction surface
3)Hydraulic TOB, gets rid of that stupid pull type set up which if you own an evo, you will know what a pain in the ass those things can be
4)Rebuild cost--- SPEC is a little more expensive to rebuild I think 500 bucks for a floater plate and discs...
5) Driveability with the ability to hold lots of power
6) quietness... I don't want my car to sound like a bunch of rotating bolts and nuts

So here we are at a cross roads !!! sounds like a great clutch, what more could I ask for ?
With my initial response to how the clutch feels, there are some negatives that I have seen which could be or couldn't be due inpart to the clutch or the trans. These negatives, are so basic that I don't feel that it is even worthy to post..
the slightly more rpm to move the car and the small amount of shudder ( which IMO,is my left foots fault )

After driving the car now for about 300 miles, my left foot has now gotten into a routine, where it understands , the point of engagement and should I say "gentleness/finnesse" that is required to move the car forward. With any clutch system, it is ABSOLUTELY imperative, that you bleed the system of Air and ensure that you have a properly working Master cylinder. Don't forget to adjust the amount of throw in your system as well.

Bleeding the Hydro TOB was a breeze, I really did not understand what all the fuss was about, maybe the trick that some people are missing is to basically overfill the resevoir, that way no air bubbles can get into the system.

To give a full review of a clutch, I only think it is fitting that I try and illustrate in words how I go about driving.
Lets begin..

From the minute the starter solenoid engages, I am greeted with the warm sound of some healthy kelford cams, that are in a battle with the stock ecu, to find the perfect AFR balance, I depress the clutch, and I hear something like a swarm of mosquitos buzzing around, this is the hydro TOB engaging the Pressure plate. This sound is only audible when I am in an enclosure.. so needless to say it is minimal. Throw it in first and ever so slightly lift up on the left leg... the minute you start to feel some shudder, release quickly and give it some good right foot treatment. The Spec clutch is heavy, much heavier than my ACT HDSS and lightened flywheel, so by the laws of physics we need a little more centrifugal force ( our rpm) to move the car forward.

Once in 1st, humming down the road, stab at the throttle, 2nd gear comes on quite fast, with a simple flick of the wrist , I am in second gear, smooth effortless shift, The car is behaving exactly the way I envisioned it would.

Now for the cliff notes, if the above is too boring for everyone :
Spec clutch :

It is soft pedal feel, easy engagement, and decent shifting qualities

Shepard Trans, --- engagement and shifting is like running a plasma cutter through butter... A worthwhile investment for any dsm/evo enthusiast out there.

Hope you have enjoyed the review, and I shall post more, as I always have been.

[SparkTech]

nice review Warren.

[chaotichoax]

your written illustration is evo clutch porn haha

excellent review

[kouzman]

Originally Posted by chaotichoax

your written illustration is evo clutch porn haha

excellent review

+1000

lol

you should update this after 2-3K miles...

[4WS Tuning]

Very nice review! The couple i've driven have been pretty nice and comparable to the Exedy twin. We'll see how they do in 20-30k.

Cheers!

[linuxman51]

mm nice writeup. clearly its time for me to invest in a shep trans. it'll get a littttttle bit louder with miles on it, but its still quiet.

[TTP Engineering]

We have not seen very good performance with our customers that have bought this clutch. Shifting lockouts at high rpm, even on the dyno were symptoms of using this unit.

[antilag_200]

I am glad , that everyone enjoyed the review.

TTP, I have been keeping my eye on threads that have been popping out of the woodwork regarding the rpm lockout and shall say "suggested poor performance"

I will report back once this clutch is broken in and give my opinions whether they are good bad or ugly... Thanks for the heads up

[SmikeEvo]

Good write-up Warren.

[project_skyline]

Originally Posted by TTP Engineering

We have not seen very good performance with our customers that have bought this clutch. Shifting lockouts at high rpm, even on the dyno were symptoms of using this unit.

So far I've only seen one of your customers having issues. Doesn't he run the mini too?

[TTP Engineering]

Originally Posted by project_skyline

So far I've only seen one of your customers having issues. Doesn't he run the mini too?

No its the Supertwin P Trim.

Ever since we have given up on the Spec, we have been receiving PM's like the one below, sent about 45min ago:

spec twin disk and upgraded tilton master cylinder

Originally Posted by TTP

We have bought the Tilton 75 series master for the car, had it all ready, but Ryu has long lost interest in trying to FORCE this clutch to work.

Originally Posted by anonymous nc user

I read this and was curious if the Tilton 75 series is a direct replacement for our master cylinder as I am having some problems shifting at higher rpms and don't have money to get a second twin.

Thanks,
XXXXXXXXXXX

[pfunk47]

Updates? How's it treating you after a month?

[antilag_200]

engagement has not changed at all... the car has about 2000 miles on it,

I would say that this clutch is treating me very well... I have now become quite decent at rev matching so that makes the little grinding that the disc make when you down shift go away.

So far I am chauking this clutch up as a definite plus. I am glad that I am using it.

Now in regards to launching ... I have not launched the car, nor have I gone over 50 % in throttle. So I can not give you any information yet on how much power the clutch can hold.

[danameisoj]

Originally Posted by antilag_200

engagement has not changed at all... the car has about 2000 miles on it,

I would say that this clutch is treating me very well... I have now become quite decent at rev matching so that makes the little grinding that the disc make when you down shift go away.

So far I am chauking this clutch up as a definite plus. I am glad that I am using it.

Now in regards to launching ... I have not launched the car, nor have I gone over 50 % in throttle. So I can not give you any information yet on how much power the clutch can hold.

get some more miles on her and give it hell so we can get a review of 100% throttle lol

[Chef-j]

Nice write up.

Edit: anyone know weight of this setup?