EpitrochoidMan

Seems like a great idea, but the simplest design is usually the best.

RXciting

you mean KISS??

gdnimr0d

iTrader: (4)

I think your idea would work its just a matter of the pipping and exhaust flapper control...i had an idea like this awhile back.....having a small turbo for low end power and once i get into 3rd gear have the exhaust pulse blocked off to the small turbo and diverted to the larger one via a y pipe with electronically controlled flapper in the y pipe. still the main concern to me is actually making all this ridiculous piping fit and being able to control the boost with two wastegates through different exhaust piping for each turbo...i mean it would start to get really complicated trying to fit all of that in the small space of the fd engine bay...but then again with enough money and time you can do anything...so more power to ya if you can do it...well good luck with your setup and keep us informed
peace out

jreynish

iTrader: (2)

yeah well I am studying to be an Engineer making things work is what I like to do... LOL
But yest there is only one wastegate on this setup... the smaller turbo's control is specifically the exhaust flow control valve, which will not allow enough back pressure to spool the smaller turbo anymore... it is quite complicated if you have any ideas or comments keep them comming...
also Keeping it simple...... if everyone followed that we would not have the rotary engine... not would we have forced induction... or nitrous oxide.... or the RX-7 if you know what I am saying?...

Carl Byck

Actually, lack of sufficient flow causes surge, although it is usually the result of part throttle applications. Carl

jreynish

iTrader: (2)

Yes but the design of the tubing and angles at which they connect to the main stream of the exhaust flow, it requires back pressure for the exhaust flow to enter the feed's for the smaller turbo. But I will have to check with my prof's to make sure that is what will work... I have the math but It is again complicated and I might have made an error... but thus far I don't think so.

Carl Byck

Excellent, hope it works

gdnimr0d

iTrader: (4)

man.... the math alone to calculate that is beyond me i am an engineering major too and i will bow down to you if you can solve all of your turbo ideas with math...man thats hard but good luck either way...any other ideas i have i will let ya know peace out

scotty305

iTrader: (2)

I really like the amount of ingenuity that's taking place in this thread. Here are my 2 cents:

When you say you want a twin-turbo setup, that makes me think that your main priority is a quick response time, and you're willing to spend the extra money to accomplish it. In my opinion, twin turbochargers are not the only way to do this.

If you're goal is a streetable car, with low-rpm power, have you looked into twin-charging? Adding a supercharger will enhance low-rpm power while decreasing spool time, allowing you to run a good-sized turbocharger without complicating your exhaust manifold or having to manage the exhaust gases. How about variable-vane turbo's? I don't know much about them, but they're said to work wonders for broadening the powerband and decreasing spool times.

For track racing, I would go with a decent-sized turbo and increase the maximum engine RPM's (via different intake manifold & porting) to broaden the powerband. On the racetrack, you're pretty much going to be able to keep the car in the proper gear, so low-rpm power is not as important as a wide powerband. And a wide powerband is a wide powerband whether it's between 3-7K RPM's or 6-10K rpms, and the higher the rpm's the more exhaust pulses you have to spool the turbo quickly after shifting gears. This would take advantage of the rotary engine's ability to sustain high rpm's, and also weigh less.


If you're going to go with a parallel twin setup (similar to broken93's project referenced above), I would look into feeding both turbos from both exhaust ports. If you feed each turbo off a single exhaust port, it will be receiving half the amount of exhaust pulses, at twice the time differential since the two rotors are firing 180 degrees out of phase.

Good luck, please keep us updated,
-scott-

scotty305

iTrader: (2)

Here is a very crude implementation of twincharging, but detailed diagrams of the concept:
http://geocities.com/motorcity/lane/1231/page2.html

better implementation, less explanation:
http://shell.deru.com/~sgn1/AW11/mod/mc.htm

-s-

jreynish

iTrader: (2)

thanks I have though about twin charging but the cost for the supercharger alone is about that that this project that I am suggesting will cost.
But it is worth concidering.

hondah8er

You guys might be interested in some pics from my local shop. Its still being built but here is a sick custom twin setup with true dual exhaust fed off each turbo.

http://me.a-spec.ca:6002/Projects/FDSteve/P1020199.JPG
http://me.a-spec.ca:6002/Projects/FDSteve/CAR03.JPG
http://me.a-spec.ca:6002/Projects/FDSteve/EX01.JPG
http://me.a-spec.ca:6002/Projects/FDSteve/EX02.JPG
http://me.a-spec.ca:6002/Projects/FDSteve/P1020196.JPG
http://me.a-spec.ca:6002/Projects/FDSteve/EX05.JPG

gdnimr0d

iTrader: (4)

dude what is the specs on your car and turbo setup. I am very curious to find out more about your car and i am sure jreynish is also. So please post some info on it if you have some free time thanks and peace out

teamafx

iTrader: (4)

Ive almost got my setup done as said. Looks alot like the one in the photos above.

NYRX7

I have a suggestion...... How about 4 turbo's powering a 4 rotor ? just a matter of time before someone said it.

2a+RoN

What I want to know, is how beneficial is that twin setup rather than going with one turbo per rotor? I know each turbo would be getting more pulses since its getting one from each rotor, but would that make a large enough difference?

jreynish

iTrader: (2)

There is already.... so you seem behind the times... plus this thread is about a twin turbo setup. Not twin-twin.

Yes it would instead of every 180 degrees the turbo getting a strong plulse it will get on half that pulse every 90 degrees since the turbo doesn't really have any real time to spool down the turbo will continue to spool faster than if it were feed by a single rotor... So in short yes it would make a difference. Maybe as much as 10-20%

fdracer

by that logic a single turbo would spool the fastest for all engine configurations.

2a+RoN

but wouldn't the exhaust velocity be somewhat decreased by splitting right after port? also could heat be a problem as well?

2a+RoN

I'd really like to see some real world comparisons b/w 1 turbo per rotor and this setup

EpitrochoidMan

That's right. That's why most existing sequential systems go from 1 turbo to both. Huge singles don't spool fast.

RICE RACING

G'damn ! That is a f*king awesome idea ! Great work.... I think i need a much more complex manifold now, but there is definate merit to this and its worth the complexity

hondah8er

Thanks Peter. And everyone its not my car! LOL I'm not that rich! haha But setup is extremely badass. The fabricator of that manifold and exhaust is AMAZING! You HAVE to see the manifold in person....trust me. The idea behind the whole setup is very ingenius too I must say! The car is at getting everything put together and a power fc put in so who knows when it will be ready.

I'll keep you guys updated.

jreynish

iTrader: (2)

Yes that is right, however a single has a huge rotating mass to overcome.... the physics of this is super complex.. but because a larger single has soo much rotating mass even though it is collected and not difused it still takes a while to spool.

Hondahater
that must be a good system, what kind of porting does he have on the car?
It would be interesting to see what he puts down... do you have the specs on the turbos of his?
Thanks

hondah8er

I can try and find out. Each turbo is smaller then my 60-1 so sufficed to say...smaller then that. t3/t4 maybe? the porting on the car is a big SP with a very small bridge