4-Rotor FC Build
03-07-12, 10:17 AM
#402
mmmh can't you do something with 2 linear actuators for de variable intake.
I think you can modify it so its a little bit faster:
http://ultramotion.com/images/bugcut.gif
I think you can modify it so its a little bit faster:
http://ultramotion.com/images/bugcut.gif
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.
03-07-12, 12:20 PM
#404
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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.
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.
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!
03-07-12, 12:44 PM
#405
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.
03-07-12, 01:16 PM
#406
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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!
03-07-12, 01:17 PM
#407
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/
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/
03-08-12, 10:01 AM
#409
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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/showthread.php?t=937570
i just like the sound and it obviously performs.
half down the page:
https://www.rx7club.com/showthread.php?t=937570
03-08-12, 10:41 AM
#410
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.
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.
03-09-12, 12:22 PM
#414
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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.
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.
03-09-12, 05:03 PM
#415
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
Last edited by John Huijben; 03-09-12 at 05:11 PM.
03-10-12, 12:29 PM
#418
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lmao, i drove my 3 rotor with an open downpipe, and it sounded like a ferarri racing a ups truck!
03-10-12, 01:51 PM
#420
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.
03-11-12, 01:44 AM
#422
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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.
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.
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?
03-11-12, 04:51 PM
#424
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
