Super sick build man. I would do things one at a time too. If you have to much going on it will be hard to pin point a problem. If this works man. I will buy a kit from you. LOL....

 

I looked at those, but it's pretty hard to use one of those in a decent way because of space limitations, there just isn't a lot of room between the intake runners and the engine.


I think you might be right, might be better to keep things simple at first, variable intake would be a nice little project to take on when everything is up and running.
I've also been busy figuring out the exhaust, don't know exactly how I'm going to do that yet
I've got the header and collector design sorted, the problem is what I'll do after the collector. I want to go with a simple single system, but don't know if I'll keep it really simple by keeping everything 3" and just having 2 absorption mufflers, or if I'll add a 3"- 3,5" megaphone, and then keep everything after that 3,5", might make some more top end power, but it's more difficult and expensive to fabricate and it will be louder.

 

dual pass muffler

 

the experience i have had with mine was that before everything was sorted its intimidating, because there is all this chaos. now that i've spent some time with it, and gotten the fuel and ignition to where the engine is happy, its actually really tame.

i'm lucky enough to get to see the 787B at least once a year for the last decade, and that exhaust is super simple, its just a 4 into 1, and then its about 80mm pipe. there is a muffler, but its like 100mm? OD and maybe 12" long? the turn out of the car is even a really ugly pie cut!

so on that, the piping is actually rather small, its short which probably helps, and the muffler is on the small side, which is odd because the car isn't loud for a rotary mazda race car

that might be a good idea!

 

Nice info on that 787b exhaust, theres no info about it in the sae paper. Maybe Ill do something like that, just with 2 mufflers instead of one. Im not so sold on the dual pass types, Ive had great results with straight through absorption mufflers myself, as long as they are build properly.

 

so far, this is the most insane thing ive ever had the joy of watching being hand built from scratch and put together, if i have the patience, knowledge, time, money and resources as you id be...idk, i dont even have a word for it... its that F%*#&G amazing, kuddos to you and more power to you, if u have a fundraiser to keep it going ill donate!

 

fitment is the biggest issue as well as complexity, but then again look at how many other manufacturers have been using multi pass mufflers on larger displacement engines as time goes on, the list keeps getting longer and longer. even the RX8 has a multi pass multi exit muffler design.

i just like the sound and it obviously performs.

half down the page:
https://www.rx7club.com/build-threads-292/non-turbo-428rwhp-fd-build-up-history-937570/

 

man this is coming along pretty nice
what a g, keep up the good work

 

Fitment of a muffler like that might be difficult, but with a four rotor with no diffuser sleeves and a tubular exhaust, it may do wonders in dampening the sound and giving it nice tone. I say go for it!

 

I know
That muffler logan made is really really nice, I would like to try to do something like that.
I think the fueltank might be in the way though, I might be able to cut away the spare wheel well and fabricate something there or something.
I'm going to pick the chassis up next saturday, mount the engine and then have a look at the bottom side of the car and see what my options are.

 

As long as you stay under the 91dba its all ok

 

with my project i plan to make 2 dual pass muffler and remove half of the heat shields in the wheel wells and try to utilize the extra space to make it all fit. that might still keep it at a streetable noise level.

 

John, you have to buy an Xbox360, Forza Motorsport4, and buy the 787B there now. I have it on idle in the background when we cook dinner

 

http://www.youtube.com/watch?v=uD-SiSStgcw

those guys need to go add more cars... this year mazda raced that white 787 against the jaguars and other lemans type things, and the 787 isn't any louder than those...

the factory GTU SA is louder than the 787, and its a little louder than a 66 Ferrari 312 F1 car, which is probably the loudest piston car, and much more pleasant to hear.

and the Car and Driver Rx2, when it had the megaphone, was louder than all of these put together, the amount of noise that came out of that little car was just astounding.

or if you look at a DB chart, it would go something like 787B, rock concert, Ferrari F1 car, jet engine, pain threshold, GTU rx7, loudest noise possible, Rx2.

 

Nice vid, not really into videogames but that rocks! We'll see how things go with my 4-rotor, I can't really imagine a car I own actually making that sound for some reason

Did some work today, I made an oilpan a few weeks ago, and with that oilpan the stock oil pickup tube wouldn't be ideal so I made a new one. It looks like a really simple part to fabricate, but it took me a few attempts. Bending the 22x1,5mm 304 tube with such a small radius just wouldn't work no matter what I did, so I ended up pie-cutting it. I smoothed everything up on the inside though so it shouldn't matter.



I like o-rings



Hopefully some more progress tomorrow

 

try getting a 90* phased rotary to not sound that smooth, this is one reason why i also will devote a chunk of my life to have a 4 rotor custom engine. it's equivalent is to an uncorked V12.

 

I found a beautiful intake that would fit our engines pretty good

 

above idle they can kind of sound v8ish too, the MX6 and FC kind of do that, the 787's don't.

lmao, i drove my 3 rotor with an open downpipe, and it sounded like a ferarri racing a ups truck!

 

well, i have yet to really hear a bad sounding 4 rotor anything. even that pos double REW slapped together with match fire rotors, the video obviously didn't give it any justice and it was a hack job but whatever.

 

Oooohhh that looks jummie!

Well they all sound wicked as hell, but the 787b, mad mike's rx7, bmi's rx8, magic's rx7 all sound a bit different. I can't wait to start toying with mine,


I started doing some chassis work, I'm an typical engineer, so it's going to be a no show all engine sort of car. Basically just a normal S4 FC with no exterior mods besides some wheels, suspension, and some stuff needed for cooling. I picked up an FC a while ago and started stripping it. The front end is totally stripped now, a lot of rusty spots, but that's normal here in the netherlands , nothings really rotted or anything, so I should be able to get it cleaned up without doing heaps of welding and sheet repairs. The rear quarters did need some of that, already welded in new pieces of sheet. I should be able to start mocking up the engine and gearbox in there tomorrow.

 

i agree they all sound different but they all nearly match once after about 6-7k RPMs with the F1 note.

 

Now I regret selling my xbox. The only reason I now currently desire to have it and F4 is to drive the hell out of that 787. The GT5 787 sounds like dump

Back on topic, so what made you choose this shell over that beautiful T2 shell you originally had, John?

 

guessing this one had less cancer.

 

This chassis I'm using now is one of the earlier s4 n/a models and it's registered as a classic car which means you don't have to pay road tax and insurance is cheap, the red TII I had is a few years newer, so it isn't registered as a classic car untill 2015, it would've cost me about 800$ per year more to own it than this one.
And besides that it wasn't in very good condition, the underside was really bad, and the interior was completely shot, it was all rotted so the inside of the car smelled really awfull. This one has some rust on the front, and it needs a respray but that's it.



Update

Engine and gearbox are in place
Looks pretty ok, everything fits the way I thought it would, oilpan clears too.
Making some extra engine mounts is going to be tricky, and I'm going to have to do some cutting to get a radiator in there but nothing that can't be fixed

 

Started modelling the intake and exhaust