Chasis 138 checking in from Alberta, Canada.

[gwnwar]

Has the clutch system been bleed out good no weeps master or slave under rubber boot.. Right free play at pedal 10mm.
No slop at slave push rod..

[Trenon]

The issue with the clutch is that to mount the RX7 T2 transmission I have to use a 1/2" thick aluminum plate to make an adapter. So the throwout bearing is now 1/2" further away from the pressure plate. I spaced out the pivot point a bit to try and make up a bit of the 1/2" and then added an extension to the arm on the slave cylinder to take up the rest. But it wasn't enough.

From what I've read it sounds like there are 2 options. Either space out the clutch fork pivot point by 1/2" or modify where the throwout bearing sits so its 1/2" closer to the clutch. The pivot point just threads into the T2 tranny so it should be easy to extend a bit more. I spaced it out by 1/8 - 1/4" but it wasn't enough.

So off the tranny comes again so I can space the clutch forks some more.

[gwnwar]

Maybe if you can get another pivot ball unit you can cut the stud almost off and weld a longer stud on with a lock nut to lock it at the right length. Or would just a longer rod off the slave to fork work.. and maybe use a light tension spring to hold the fork to the slave to keep the rod in place.. I would try that before pulling trans again..

[Trenon]

I tried the longer rod off the slave, i machined an adapter that extended it by ~5/8" and it still wasn't enough. That was about the maximum I could get to fit in there. 

Extending the pivot bolt is the way to go like you said. I should have something the right thread here so the plan is to just extend the bolt and use a lock nut like you mentioned. 

[gwnwar]

What clutch master and slave are you using MX5 or RX7?? If you use a large bore master it will move the slave more with less pedal travel.
Were are the slave mounting ears.. at boot end of slave or mid cly.
What flywheel and pressure plate are you using..
Did you have to make a spacer between the back of crank and flywheel to change distance to pivot of throwout bearing face and pressure plate because of the thickness of the adapter plate..

[Trenon]

Clutch is a 6sp (matched RX7 splines) pressure plate is FM stage 2 for a 1.8 and i have the lightened 1.8 flywheel.

The clutch slave and master are stock NA miata (94)

The flywheel fits inside of the 1/2" adapter, there is no spacer in the rotating assembly at all. Just on the belhousing to engine.

[gwnwar]

OK so the problem is the trans with pivot ball is 1/2" back farther away from the pressure plate fingers then if bolted directly to the engine..What is the distance from face/mount surface to engine of RX7 and the MX5 trans to pivot ball.. then add the 1/2" plate to that number.. Does the RX7 use a bigger master bore then a MX5 That would move the slave more with less pedal travel.. Have you compared the master and slaves differences between the 7 and 5 units..

[Trenon]

I have no idea on the measurements. I don't imagine they would be easy to get short of having the car.

The plan is to space out the pivot point and recheck the engagement. As I am using a miata clutch, the miata slave should have the required throw length as long as the dimension of the clutch forks / pivot location are similar.

From what I can find searching the interwebs there have been a few people posting about doing it this way.

[Trenon]

Picked up a new throw out bearing and a VSS from a RX7 FD, supposedly it fits in the T2 tranny, you just have to take the gear off of the mechanical pickup and epoxy it onto the VSS. I hope it works or I'll have to use a GPS speed sensor.

[Trenon]

Had a somewhat productive day. Made an extended clutch pivot point. Switched out the input and output tranny seals, and put in a new throwout bearing.



I don't have a transmission jack so I had to wait until a buddy came over to help throw it in so I started working on mounts for my newly acquired kirkey seats. I wanted to mount them through the bottom and have the bolt heads in places I wouldn't feel them. 



We lifted the transmission back in place then it was beer'o'clock and productivity dwindled. I hope to find out tomorrow if this fixed my clutch engagement issues. 

[Trenon]

Took the car for a test drive, clutch engagement seems good. It's winter here (Canada after all) and all the roads are covered in ice. The skinny 185 winter tires I have on it right now are not sufficient for the car. Between the lightened drive train and the extra power it generates its quite terrifying to drive on snowy / icy roads.

[Trenon]

Well got to take the exocet out for a decent test run out today. Everything seems to work well.

I only have some skinny 185 winter tires on it right now so I can't really see how it deals under load but nothing fell off so thats a good sign.

I am switching to an aftermarket digital dash and I have a question about the altenator light. The miata electrical wiring shoes a diode in there. Any idea on what I need to wire up to make sure the car is charging correctly? Right now the altenator seems to be going full tilt all the time.

[Trenon]

Got the speed sensor working. I took the gear off of the cable sender and epxoied it into a VSS from a FD RX8. Works like a charm. I now have an accurate speedo from the T2 transmission.

next thing I need to do is figure out why it doesn't run great before boost kicks in. timing or tuning are the only options left really.

[Trenon]

Haven't updates anything in a while. The transmission needs some work. Does not appear to have a syncro in 3rd or 4th.

I had the car on a dyno today. 285hp. But far more importantly than power was he fixed my engine issues pre boost. The car is entirely different to drive. I don't have to drop the clutch at 2000rpm anymore from a stand still. It is awesome. The little engine that could wants to generate so much more power but my stock coils were not up to the task. They crapped out around 14 psi of boost. We could only get one run ever time we'd take the plugs out and let them cool down. Luckily I happen to have some LS coils just sitting in my garage waiting to be installed. ~350hp should be pretty easily obtainable.

[Trenon]

Here's the dyno plot.

This is what my tuner said about my engine issues below boost:

"The running issue at 1500rpm was a combination of a lean spot in the map, along with a requirement for more accelerator enrichment. The low rpm areas of the map required a large increase in accelerator enrichment. During the initial testing, the problem area was so lean that the AFR reading was off the end of the scale in this region, causing a misfire. RPM would then drop to the adjacent cell in the map where fueling was adequate and RPM would climb again. The problem would be less pronounced with the stock manifold because overall airflow is lower in the same RPM and MAP conditions, giving a less drastic lean condition."