the Rx8 stages the ports and runners better, at 2200rpm the Rx8 is only using the primary runners, and the long intake path, the FC is only throttle dependent, so it can be using all 4 runners

 

Update.

The harmonic I've talked about is from the trans. The first trans I bought cheap had a bad 2nd gear but the guy promised me it was a good trans. The second trans I bought was good but both have a harmonic in 4th and 6th gear. I have improved my trans mount the noise is reduced and will soon be gone.

The gps speedo is driving me nuts, it's very slow response. After looking into many dash setups, soon I will be installing a motorcycle gauge cluster. It's $50 new. Has lots of features.
12k tack
Digital mph
Wheel sensor which I will mount to rear diff. Works with all wheel sizes.
Warning lights
Shift light
Fuel gauge
Turn signal lights
Odometer and trip

I have tried going to the track but no luck. Broke a half shaft with the 5 speed and a half shaft with the 6 speed first try. 5500rpm lunch. Now saving for new LSD
The best 5 speed run was a soft lunch 15.1@93mph, next time around tried to lunch hard and broke half shaft. With the 6 speed it should go 14.5@95 or better. This is a s4 6port old 95psi per face, not running trailing. Car feels so much stronger with 6 speed and stays in its power band. Tire size is 225/45/17. Fixed all the small stuff with this car now working on turbo. Was hoping to have it done by now but will be done soon.

 

Okay I have my swap incomplete.

So the clutch is carry over, I utilize my same t2 aluminum flywheel and my t2 disc but the PP I got a hold of is from an rx8 and inn better shape than my old t2 pressure plate. These parts are interchangeable.
So it went in as ace venture says “LIKE A GLOVE!”


On the old 13b blocks cant use the rx8 trans with the rx8 stock slave cylinder since it hits the oil pedestal. HOWEVER you use the slave cylinder from a 98 acura integra 1.8 GS and viola! It bolts right in and clears.


Price is 15 dollars at oreileys auto parts, part# cs2162
But to keep the angle of the slave cylinder pin flat, you have to shim it. Extra nuts to the strut bearing work great.



ALSO the stock clutch hose has too many male threads on the slave cylinder end, but it reaches no problem.



We are not home yet! Still some issues to tackle but the engine and trans are in and the engine is bolted down on its aluminum mounts:


Also to use the rx8 trans you must use the rx8 hardware for the bellhousing. the bosses on the trans are larger than the FC ones so you will never thread anything in. the rx8 starter must be used since the rx7 starter only shares the top bolt. Rx8 start is a 2Kw electric motor while the rx7 one is 1.3Kw. Good upgrade.

Here is the difference between the two transmissions. A hole must be cut. If you have an interior or stock dashboard this could be an issue, I do not so no worries:



My mazdatrix T2 driveshaft to NA diff is just a hair too long, off to get shortened! I believe for most people a stock automatic driveshaft would work fine but I need a new yoke and u joints can use some attention. The automatic driveshaft has the same output yoke as the t2 as is common on the rx8. same diameter and spline count but the shaft is about 1" shorter.


Stock transmount does not go low enough so I had to cut it up, then cut up the poly bushing from my t2 “solid” mounts.




Did a little work on mocking up the custom trans mount, stay tuned.

Big issues to overcome:

1. Correct clutch hose

2. fab trans mount

3. new shift boot/cover misc shifter hole

4. shorten and re balance driveshaft (at the shop now)

What clutch hose did you guys use?

 

i used a off the shelf line to the slave, no rubber. all metal.

my thread is in my sig if u havent seen it.

 

Yeah i am not gonna bend a hard line he whole way to the master cylinder. I may just go in there and poke through their hoses at the autoparts store.

 

I used a one piece, generic Russell braided brake hose (20", iirc), deleted the hardline altogether and used banjo bolts on each cylinder.

 

Banjo bolts? But its both inverted flare on each end.

 

Yes but the banjo assembly seals on its copper crush washers, so the flare is irrelevant.

 

why the hell NOT?? rubber doesn't last as long as metal, my all metal line provides no room for swelling ever!

every single car on the road has brake line running longer then that?? i don't see why all cars can't have metal lines with a little coil loop for engine movement.. which is something mine doesnt have

 

Well, it sounds like you just answered your own question there. Hard metal brake & fuel line is constantly run along the chassis, where flex is insignificant. Anywhere it might encounter any flexing, such as in the wheel-wells to account for suspension motion, it transitions to rubber or braided tubing. Even with solid mounts, there's still a good bit of motion between the chassis & drivetrain, not to mention the increased vibration transmitted through all points of solid connection (including the clutch line here), leading to a lot of metal fatigue. While the metal tubing might be able to take it a few times, or even a few thousand times, any motion will damage the metal tubing at the closest joints, leading to failure. Using a loop as you mentioned will delay this failure a bit, but nowhere near as much as a soft line which is much more forgiving. Plus, new rubber lines meant for hydraulic pressures will easily last a very long time if they're properly secured from rubbing on other parts, just like metal lines will last a long time if they're protected against flexing, vibration and corrosion.

On a run of line as short as the distance from the clutch MC to the slave, its much easier to just run a slightly longer line (especially one meant for brake systems) than to add a union and bend a short length of hard line to meet up with a short length of soft line. Plus, if he's using a new hydraulic soft line that's meant for clutch or brake pressures, there's only a single line to flex, not 4 of them as in the brake system, plus clutch pressures are lower than brake pressures which gives less flex, plus any small amount of flex in the clutch line is nowhere near as noticeable or bothersome as in the brakes, plus there's less firewall flex since the clutch doesn't take as much force to press as the brakes, plus...

If you're going to try to correct someone on their decisions for their build, you may want to get your facts straight. Just running a hard line, loop or not, is rather sloppy and haphazard, and not something I'd do on any of my cars or espouse anyone else to do.

 

I hate flaring and working with metal lines anyways. The stock hose lasted 20 years so. New plan is to convert the M10x1 inverted flares to -3 AN and run an AN line the whole way. I could do braided stainless and in theory that should last 30 years

 

i'll gladly report back when it fails... imo the use of rubber in this situation is a waste. it's a car not an airplane. the dangers are nil.

 

in a early post I posted a video of how to use the rx8 rubber hose to the honda slave. Either way I use a single flare when making steel lines they always seal and never fail. I stuggle with double flare, single flare is very easy to do with cheap tools and always seals perfect.

 

I also upgraded the oil seal where my extention shaft exits the Trans. I used a dbl lip seal housed in a peice of polyurethane, a steel cover plate is used to hold it all in place. Works perfect and the shifter is in the factory location. It cost $130 to have the extension machined $5 seal and hours of cutting amd fitting using hand tools to make it fit.

 

Even if your particular install works out, that does not mean the "all hard line" concept is acceptable or best practice...because it really isn't.

The junkyard I frequent has cars from the 70's>early naughts and I'll bet not a single one has a setup like you advocate. Why would you intentionally discount the possibility of stress fracturing when the solution is cheap/easy/universal?

By using a single soft line from master>slave, you can eliminate a superfluous connection and eliminate any stress issues at the same time. No bending/flaring either.

 

Yeah I am not doing a hard line the whole way there because this is a rallycross car and sees some serious abuse off road. On road I can't imagine much of an issue aside from fatigue or poor bending (like how I would end up doing it).

 

i don't understand why you wouldn't just buy/make a clutch hose with the honda fitting on one end and the Mazda fitting on the other?

and i agree with Clokker, you will not find a car with a complete hardline from the clutch master to the slave, everything uses a length of rubber line, even BMW! BMW's are full of all kinds of engineering no no's, but they have never done that.

 

I have tried finding an off the shelf one to do such a thing, It does not exist. Current plan is to just convert the slave cyl to -3 AN and the master to -3AN and get 1 hose to connect all the way there.

 

how about using an Rx8 oil filter pedestal, and Rx8 slave?

 

its cast into the renesis rear iron unfortunately.

 

I did this on my first vehicle. The softline failed and obviously, no clutch.

I took a store bought metal brake line and wrapped a coil around a coke can and installed it. The coil could absorb the engine twist and not fatigue the line. Of course I would never ever do that at the wheels where you need a soft line.

I do however agree that without some sort of stress relief, that rigid hard line will fail. Good luck stopping.

 

Well this did the trick. 1 long 'softline'



These are the parts you need. convert the inverted flare to -3 AN and get a 40" AN hose.

 

bump/update: still works great!

I am gonna put one of these gearboxes in my 10AE whenever I figure out the shifter relocation issue.

rx8s gearboxes are more plenty than FC (turbo or NA) these days and when you have enough spare parts to throw a swap together, **** it! why not?