ok im in the process of fabbing a custom intake manifold and a custom TWIN tutrbo manifold for a 6 port s4 engine, im going with a agressive street port and more then likey a wolf 3d, now i only want to run like 8 psi to start with then once all the bugs are worked out i would like to eventually run around 12-14 psi, one of my questions is when i fabb the runners for hte intake manifold should i just make the the same lenght as the stockers, of should i kinda tune then to the turbos peak eff. i posted the com map below if anyone could help me with that it would be great, now secondly i am bassically running one turbo per rotor so should i run two waste gates or just a single? also i have read in a couple place that about 16 inchs long is ideal for turbo mani runners, how long should the wastegate runners be??


thanks a ton

--joe

 

i would love to help but as of right now your way over my head. altho i think that would be badass if you pull it off

 

no one has any idea?

 

My suggestion is to stay away from the Wolf3D. It was the most painful and convoluted install that I ever did. Doesn't support stock FC ignition and the software is several levels of awful.

As for manifold runner length, you can guess or calculate. If you do a search for "calculate manifold runner" under the username "rotarygod" you will find all the info needed to calculate the best runner length and diameter.

However in my experience, if you want to guess, runners of 20CM with a 1.5" diameter work very will for the 6 port engine with a good bit of porting.

 

Intake runner length on a turbo setup only affects the standing wave resonance at part throttle, unless you include a dynamic chamber.
Emulating the stock S6 arrangement is about as good as you can do.

About the waste gate runner: Most merge the waste gate flow back into the main exhaust flow and include it with the main exhaust tune.
You raise a good question as to weather piping the waste gate flow to merge in or out of phase might make a performance difference.
Someone knows, but they probably are keeping it a racing secret.

Why twins?
Unless you go to the trouble of controlling them sequentially there’s not much gain for the trouble & expense.

A single will spool up nicely if you dump the downpipe.

 

i have the formula form the post by rotary god but i wanated to know if i would benifit form tuning the runners to the turbo,

also i went with 2 seprate turbos just to be diffrent and i just happened to get a good deal for both of them

 

the manifold if seperated into 1 runner to turbo per exhaust port (non-sequential) you would need to run 2 wastegates, 1 per runner assuming your going external wastegate. There are a few T3 turbos fitted internally wastegated. You would need to search if you dont intend to run externally wastegate. You dont need to rerout the wastegate pressure back into the main exhaust system, although it may help with noise level and resonance. The manifold should be fitted so that the turbo is relocated more foward to apply more space for the downpipe. that fits two to one pipe. unless you wana do a "true dual" (1 full exhaust per turbo) setup which makes absolutely no sense to me.

As far as the intake manifold goes, the S6 intake as mentioned above is the best you can do...ALTHOUGH i do recall that the RX8 renesis engine has a intake design thats more responsible for the increase in power (220hp N/A vs 140hp N/A) I dont know the details but you could look into the design and fab up something along the lines of that if applicable.

 

the main resaon i am fabbing a custom intake mani is to turn the way the throttle body faces for better intercooler piping

 

you can run one turbo to one rotor and the other to the other?

 

Yup - with double plumbing & waste gates.
Or - you can put two turbos on a plenum with a single (big) waste gate.

The Renesis intake has tuning for NA use.
A compressor & intercooler pretty much negates most of that.

Same thing with exhaust tuning.
The turbine pretty much negates exhaust tuning, but flow still matters.

 

ITB velocity stacks mounted to a plenum would be interesting to see for a turbo rotary

 

anything is possible with enough time and fabrecation

 

If that's the only reason, I suggest you make a custom adapter to connect the TII upper intake to the NA lower intake and be done with it. Two flanges, a few inches of tubing, two injector holders and about 8 hours of fab time.

 

Have a look at a 20B..

 

There is absolutely no need to run one wastegate per turbo. Most single turbo external wastegate setups have one pipe from each manifold runner merging to mount one wastegate, and this would be no different.

I think you'd want something better than a pair of T3's to make it worth the effort, but internal wastegates would definitely make the job infinitely easier. I know you can get internal wastegate turbos bigger than a T3.

Why wouldn't you run two separate exhaust pipes? There's room for two side-by-side pipes under the car and these would go straight to the two stock muffler locations. Two 2.5" pipes flow considerably more than a single 3" (just for example). Makes perfect sense to me.

Look at some Australian rotary websites. That set-up's common as muck.

Reduced lag isn't a gain? You don't need sequential operation to get better response than you would from a single turbo with the same power potential.

You don't need two wastegates and you certainly don't need a plenum.

A 20B doesn't have ITB's mounted to a plenum...

 

Was that a serious question?

To the OP, I think the T3 "50 trim"'s are a bit too small, if you're serious about the project.
I think the power is going to max out under 400hp unless we're talking stupid boost.
I would suggest you step up to at least a T3 "60 trim"'s for both turbos.

Yes, internally gated would make the plumbing a lot easier.
See ATP Turbo for all the flanges...

Exhaust runner length is not a big deal.
Since you're keeping everything separate, just fit everything as clean as you can.

I can't help you with the intake manifold part.


-Ted