Real Fiero Tech

My plans are to install a W-41 Quad 4 with a 93 SCX (internal slave/3.94 gears)

The Stock slave would be compatible with an earlier style external slave, using the factory slave with the "rodney dickman getrag late model slave adapter" However, i would like to take it a step further by using the internal slave, in my experience with my grand am, the internal slave was a world of difference.

The problem is the fiero slave looks so small it doesn't seem to need much fluid to operate, the internal slave looks larger, and would require more fluid.

Does anyone have any information on this topic? Or personal experience? It would make this next step in fabrication a huge deal easier.

Thanks in advance.

By internal slave you mean internal clutch release arm, right? The only internal slave was the hydraulic throwout bearing used in the 94+ (?) Getrag-equipped cars. I think the one you're referring to uses the large plastic external slave cylinder that bolts directly to the bellhousing, right?

The problem with using that part is you will have to find a way to adapt the nylon hydraulic line with the pinned end that the plastic slave uses, to the Fiero's metal line... and also add a bleeder.

The plastic slave does not have a bleeder because it is the lowest point in the system in the FWD car and its a straight shot to the clutch master cylinder. Any bubbles will go up to the master cyl. In the Fiero, the line goes down from the slave, then back up to the master. Bubbles get trapped in the slave.

Oh yeah, as for bore size, I think the Fiero master cyl is actually sized appropriately. The Fiero Getrag slave ends up with a more travel than it needs. The plastic slave has a larger bore so the stroke gets decreased. If you can make the hydraulic line work, you should be all set.

Rodney Dickman sells an adapter to use the Fiero slave on an internal release arm transmission. You'll end up with significantly more pedal effort (but shorter throw) than with the Fiero throw out arm.

I don't know about the hydraulic release bearing. I've heard that the one used on the 6 speeds works well with the Fiero master cylinder.

Some getrags were available with the hydraulic TOB in 92-94.

I have been running one of these transmissions in my 88 GT since June 2005. I am using a 3/4 wilwood slave and it is plenty big, so the stock fiero slave should work just fine.

fieroguru wrote:Some getrags were available with the hydraulic TOB in 92-94.

I have been running one of these transmissions in my 88 GT since June 2005. I am using a 3/4 wilwood slave and it is plenty big, so the stock fiero slave should work just fine.

Perfect!!!!

So glad to hear that, it will save alot of fabrication time...

However, what is this 3/4 wilwood slave? aftermarket replacement? or is that custom?

www.wilwood.com
Generic racing part.
Not sure how much work it takes to adapt it to use in a Fiero.

I was going to take a pic of the wilwood master, but ran out of daylight.

To install the wilwood requires a small adapter between the master and the front firewall. The fiero master has the mounting bolts at an angle while the wilwood is vertical. The adapter consists of 5 holes and cut/grind the outer shape. The adapter bolts to the wilwood and then the adapter is attached to the firewall.

For my last install (I have done a few), I reused the fiero clutch master push rod, but had to reshape the part that went into the master to fit inside the wilwood (for a previous installs I made an adjustable push rod).

To hook up the line, it needs to enter the wilwood horizontal at the front, so is needs to be rebent, cut and reflared.

ive heard contradicting information now... The wilwood master you used pushes more fluid than the stock, correct?

Yes, for every inch of travel, the 3/4" wilwood displaces more fluid than a stock fiero clutch master.

The Dark Side of Will wrote:Rodney Dickman sells an adapter to use the Fiero slave on an internal release arm transmission. You'll end up with significantly more pedal effort (but shorter throw) than with the Fiero throw out arm.

I don't know about the hydraulic release bearing. I've heard that the one used on the 6 speeds works well with the Fiero master cylinder.

I am using this adapter on my Q4 Fiero, and I can confirm the extra pedal effort. I have felt the clutch pedal on a Muncie 4 speed, and 2 different Isuzu trannys, and the Isuzu is light, the Muncie is about 2X heavier, and my Getrag is about 2X heavier than the Muncie. It gets alittle fatiguing while driving in downtown traffic.

Here are a couple of pics.

This one uses a steel adapter:


This one uses a slightly thicker aluminum adapter:

Has anyone tried to adapt the master cyl from an N-body car, which would be the car the slave came out of?

The FWD applications have the master and slave permanently attached to the hose between them. They come as a unit and are not meant to be separated.

actually, on the 93 olds achiva scx, (where i got the trans) there is a quick disconnect on the slave cyl end, i didn't look at the master side. However, on the 92 and earlier models there was a little pin on the plastic hose that made them separate, which could mean a custom line might be able to be fabricated by someone with the right tools...

As i look into this possibility further i will post my findings.

On mine, the quick disconnect was attached to the slave with a standard flare fitting. The disconnect just threads off and you are left with a flared end that is realtively easy to connect by reflaring the Fiero slave line and using a coupler.

I haven't a clue about the master side of the original application.

Interesting. I didn't know that.

There still isn't a bleed fitting on it, though.

If you can attach a line to it via standard fittings, you could build a bleed fitting by bringing the line above the slave and back down into the stock connection and adding the bleed fitting on a T at the highest point on the line.

the 93-on setup has a bleeder screw, right next to the input in that picture above....

The 92-prior does not, but ive seen those T-bleeders, wilwood sells them i think.

One of the benefits of these hydraulic throwout bearings is the bleeder line comes out tangent to the top of the bearing allowing any air in the system to collect in the line and be easily purged from the system.