Yo,


Yeah, me and Mark PM'ed about it. His motor is a fresh rebuild, he's in the 120's for compression, I'm in the 110's.

The numbers might seem unbelievable, but Mark certainly is. If he saids that what it did, that's what it did.

Kevin
1989 GTUs "Anyone have any Watanabe 16's?"

 

Wow I have not read this post in depth till now. First off I would like to say those are some good #’s Icemark!!! With your #’s I think it’s going to be possible to get some more HP out of Kevin’s car, you have given me hope .

We got our best HP #’s on run #15 or something like that. By the time we did that run I would not be surprised if a little bit of heat soak was not a factor. I am also tuning his car slowly and trying not to make to many major changes at one time due to the condition of his motor. The next round of tuning will be some slight advancement in ignition timing, and possibly more tweaking with the S-AFCII. But the one thing I am very interested in is the Extrude Hone. Where did you get that done? How long did it take them to do it? Did you have all 3 manifolds done? I enlarged, port matched, and polish his 3 manifolds. But there is only so deep you can go where the grinder no longer fits. I think the Extrude Hone might be an option to investigate.

Threads like this are great. Keep tuning those NA’s and one day things will all work out in the end .

- Dana “Always working on every one else’s car, not mine”

 

thats cause you drive it HARD

 

Can you explain this a little more? Are you saying that by using a pre-silencer it's going to change the temperature of the exhaust gases and therefore change the velocity of the exiting gases which effects.... what? Horsepower? or sound?

 

volocity of the exhaust gas seems to be directly related to the torque on a non-turbo rotary.

 

cant the same argument be made for pistons? the whole backpressure thing that is...

 

I don't want to get into the "how Piston motors exhaust differs from Rotary" discussion again, but a 4 stoke piston motor's exhaust is not still burning when leaving the exhaust manifold as it is in a non turbo, non-reni rotary engine.

So while some of the basic comparisons can be made with a piston engines requirement, the overall exhaust design for a non turbo rotary with a collected manifold must have some major differences including changing the size of the exhausting based on temp and velocity rather than just estimated velocity.

This is the big difference between the exhaust systems I have been playing with and not just bolting on a 3 inch cat back.

 

Icemark, you really know your shizzle on the verts. I just swapped in a Jspec and have not driven enough to feel the weight but what SS mufflers would you recommend for me to get from e-bay for the turbo setup. I plan to have a local guy weld them up with a Y pipe. Right now I have my 3" corksport DP bolted upto the tiny NA exhaust via a hommade adapter gasket plate to reduce leaks. I too want a streetable vert. that is not too loud. The Z3 S2000 thing is just what I have been going for myself, my AC, PW, and PS will NEVER be pulled out.

 

icemark, i have a s4 lim, s5 vdi + uim.....if i get them port matched, can i send it off to the same company you got yours done at, since they already have the pattern? approx how much would it cost?

 

extrudehone.com lists "mazda rotary intake" as 585.....there's several different intakes ......and if i were to go with them, id only need level 1 correct? not the level 2 which includes "gasket matching for heads, intake etc"

 

Yep, you only need level one, but I sent mine in with the middle and upper intake gaskets in, and mainfold all port matched and assembled.

To port match, I just used the S4 middle intake gasket, and lined it up on the S5 middle bottom (lower vdi section), and used a marker to show me where I had to cut. Then went at it with a dremel style cutting tool on a drill, a file, and some sand paper.

And double check the price with the location nearest to you, they did mine for about $550.

 

did you get yours done at extrude hone or somewhere else?
setup goes: tb - gasket - s5 uim - gasket - s5 vdi - gasket - s4 lim - gasket - engine correct?

s5 uim bolts up perfectly fine with s4 TB?

i think you should do a complete write up with lots and lots of pics + vac hose diagram =]


and thanks for your help so far.

 

Five stars!

More proof that porting is the king of power mods for N/T rotaries.

The manifold work is very unique. Thanks for doing this thread, Ice. I'm sick of my S4 stock manifold because of heat soaking, and have considered fabbing one up out of C/F if I can figure out how to mold the runners smoothly. Maybe I can also fix the Y section of the stock mani where the secondaries meet the aux ports and the runners collect, and tune each runner for their corresponding ports. Time for me to do some I/M research.

 

Yep, you have the order correct except it should be TB-spacer/vac router-S5 UIM/Dynamic- gasket- etc.

After moding the VDI/section to match up to the S4 LIM (as covered earlier in this thread) the only bolt up issue was with the throttle body. There was one bolt that was too short, and I had to replace it with a longer stud, and the S4 throttle body, that you will need to shave off the bottom corner so that it fits around the VDI valve.

I used the S4 throttle body since it was already set up for the MOP control.

Here is the throttle body before porting, but after the bottom was trimed with my finger pointing to the cut part:


I had my extuding done here in CA. They have offices all over.. check thier website

 

whats that material thats put on spray on truck bedliners? feel it on a hot day, it isnt hot, even if the rest of the truck is hot enough to burn you. i wonder if getting the external parts of these manifolds coated in that would keep the manifolds cooler, therefore keep the air cooler?

 

A significant source of the heat transfer in the manifold is where it bolts to the engine block, right above the exhaust manifold which is the hottest part on the engine. One solution is to use a 1/2" phenolic spacer between the mani and block, but you would need to make custom six port actuators to make up the added length.

 

A friend of mine had a company all lined up and ready to start producing phenolic spacers for the FC.. alls that he needed was 10 people to sign on, at $100 each. No one thought it was that worthwhile of a mod, so it never got off the ground

 

bed liner a bad idea?

 

Here is the final vac diagram... what I am using today:


The yellow line provides all the air for the air bleeds including the oil lines.

Dk Green is the fuel lines.

Dk blue is the lines that are pressurized from the air pump.

Everything else I think is pretty clear... the only other thing smissing from that diagram are the vac line for the Cruise (which I decided to add- heck its only 3.5 lbs including the actuator, brain, and switch) and the vac line for the boost/vac gauge that was left over from when I had the 13BT in there.

 

thanks.......

looking at that scares me.

 

Its actually much cleaner than stock now... not as clean as a complete strip... but at least a little better.

 

PHOTOS!!!

 

yea icemark, id also be interested in seeing your engine bay.

 

sorry triple post

 

sorry triple post