Gorilla RE

iTrader: (1)

ANd your magical way is?

-J

GoRacer

iTrader: (2)

^ are you going to build it? ...i'm waiting for a quote from A-Spec.

Dual parallel GT25 Tial turbos (w/internal gates)
Dual manifold (single flange, dual pipes - 1 per turbo)
Dual Down pipes - One per turbo.
True Dual exhaust (with X pipe) - each turbo gets it's own exhaust.

I've been wanting to do this since I bought the car and saw Border Racing's kit.

Gorilla RE

iTrader: (1)

Hmmm Can I ask why? What makes "this way" so good? Why wast money on twin setups like these at all?

-J

GoRacer

iTrader: (2)

^ It's actually quite simple (in my head). It has been proven on a twin turbo corvette (years after I thought of it). One turbo per half of the engine (v-twin block). Just as I releived back pressure on my 4x4 changing from 4-1 to true dual exhaust it was done on the vette with one turbo per side. They actually stuck each turbo in the recess made for the muffler and no muffler was needed. There are other high HP piston cars that have one turbo per side but I would have to research to tell you if they use true dual exhaust.

First the turbos would have to be smaller then gt28. I would think two small gt25 with seperate exhaust would spool very quickly (like two 1 rotor turbo engines) and have no lag time. I saw gt25 with internal gates but not sure if they would work woth Tial snails. it would be like running the stock twins in parallel but with no back pressure and without the lag, like in series. Each rotor's A/F & temp would be controled independentally. Dual 2" pipes would equal a single 4" pipe on a single turbo. If you can run 1 turbo per half of a piston engine then I don't see why it cant be done per rotor. I wish I had software to test it on. It seems so simple to me but then i'm not a fabricator. There would be exhaust pipe clearance issues, but the muffler would be a dual magnaflow truck can which is dual in/dual out and takes no more room then a single can. It makes perfect sense and seems so simple in my head. maybe it would be marginal but why did that twin turbo corvette get huge gains? I should have went to Vegas on veterans day.

Chaotic_FC

well, no actually.

twin 2 inch exhaust is half as much as a single 4 inch.. we're talking area here, not diameter.

however, i like the rest of your idea.

JDriftM

iTrader: (9)

I am a fabricator...I have had the same plan in mind for about a year now. The way around exhaust clearance issues is staggering....Stagger your flex sections, stagger your inline mufflers/presilencers, and use/form oval tubing to reduce actual area being consumed. You can then stack 2 oval tubing sections atop one another and split them in a Y once under the car. Just ideas I've had floating around. GT28R's would probably be a better bet, same to similar spool as the GT25R, but more top end power so that you're engine isn't panting like a fat kid running from a diet plan when it gets over 6000rpms.

-J

DelSlow

iTrader: (2)

Goracer, so your saying that your setup will see huge gains over every other twin setup just because you might have slightly less post-turbo backpressure?

Personally, I think twin-turbos are a complete waste of time unless your going with a sequential setup or there are packaging/plumbing issues (ex. V8s). A single turbo will be more efficient for several reasons. If you are going to put that much time and effort into it, I think you should try a sequential setup.

GoRacer

iTrader: (2)

Chaotic_FC - Most likely tubing would be 2.25" since that is most commonly used by sport compact piston cars. In fact there is a muffler shop around the corner that can only mandrel bend 2.25". You can do the volume math but you get the concept.

JDriftM - Doing a "Y" defeats the whole purpose, that is my point. You also don't want GT28's for a single piston engine. Each rotor is treated indepentantly, again my point and joining them defeats the concept. What are you gaining by merging two pipes in to one? You aren't, the exact opposite you creat a bottle neck. Get it?

DeSlow - You don't get the point. 4-2 headers yield more power then 4-2-1, that's already proven. v-twin piston engines yield more power with true dual exhaust, that's already been proven. Pistons fire at different intervals and dual exhaust with an X pipe takes advantage of that by scavenging and two 2.25" pipes will yield more volume then one 3" pipe. You can use two metalic cats with the same restriction as one cat on a single pipe. Rotaries fire indepentantly as well, so dual pipes with an X will improve efficiency. Rich (Gotham Racing) already proved a 4" exhaust yeilds 2lbs of boost effiency.

If it was so good it would have been done alredy? - WRONG! If that is the case NOTHING new would ever get invented and NOTHING would ever be improved!

Narfle

iTrader: (16)

Your major breakthrough is in all likelihood dealing with insignificant performance gains over patented twin turbo systems; which show insignificant gains over much less expensive, complicated, redundant, failure proned single systems. Not to mention that you already have a perfectly good single setup.

DelSlow

iTrader: (2)

I disagree with your hypothesis. On a naturally aspirated engine, yes, I can see the dual exhaust having an effect, but on a turbocharged engine the turbine will act as a one-way check valve. The exhaust pulse will be reflected by the turbine. Post-turbine exhaust should be evacuated in the most efficient method possible, which is one large exhaust if the turbos are located in the engine bay and the exhaust exits the rear. Why? Because the single exhaust will give the best volume-surface area possible. This will minimize drag and heat loss.

GoRacer

iTrader: (2)

A single exhaust is a bottle neck. A dual exhaust would be the same as a strait pipe. Each rotor fires independant of each other and at different times. Thus they would benefit from having their own (spereate) exhaust. This is similar to pistons firing at different times. The exhaust gas pulses exit at different times and would benefit in velocity and scaveging with the X pipe connecting the two.

Again, this is not new and has already been proven.
- 4-to-2 headers yield more power then 4-to-2-to1 on both cars and motorcycles.
- True dual exhaust releives back pressure from bottle neck of Y connection.
- True dual exhaust yields more volume for exhaust to escape
- X pipe scavenges pulses from each rotor (v block piston) as they fire at different times.
- This has already been done multiple times on piston engines and yeilded more power. The Corvette is only one examble of dual turbo in parallel with true dual exhaust. One turbo per side of v-twin block and one exhaust per side. All you have to do is transfer this simple logic to rotory. 1 rotor = 1 turbo + 1 exhaust.

GoRacer

iTrader: (2)

Sequential twin turbo has nothing to do with this thread. This is about dual single turbos running in parallel.

JDriftM

iTrader: (9)

I think you misunderstood me. Each turbo has it's own pipe, by using oval tubing you can stack them atop one another to save room and then once under the car the piping is routed to its respective muffler. Totally separate piping, I proposed an X-pipe section in there as well, only to equalize out the sound of each rotor. Hopefully that clears it up some. Not disagreeing with you, just trying to help sort out how you can do it and save room in the engine bay and right at the firewall.

J

Narfle

iTrader: (16)

At exactly which point did i mention sequential twins? I didnt.

Gorilla RE

iTrader: (1)

I think we should just let HIM build it if he want's..... Most the issues mention about "his" setup I already thought about but made no comment. That was the main reason I asked my question, just to see him spell it out to me. If he is SO sure it will be the best thing since swiss cheese then let 'em find out.
I like when folks are trying "new" things. And I'm really glad you're so into "your" setup but honestly you'll just be wasting your time and for sure a lot of money.
-J

Miata_mx5

I would love to see a properly worked twin setup.

I think engine management is very crucial too.

spiritrmazda

iTrader: (3)

I'm going the custom twin route too. We'll have to see how it goes the next few weeks. I have twin T3/T04E's by Garrett though. It will have dual exhaust piping all the way to the back with HKS carbon TI mufflers on each side. I ripped out my gas tank and will install a Fuel Safe fuel cell to be able to run a 2nd exhaust. Its a pain in the @$$ waiting, I've been waiting for years to get this set up(fabricator lags like hell).

spiritrmazda

iTrader: (3)

Oh yeah, forgot to mention my HKS GT 50mm wastegate and custom twin core(one per turbo) v-mount intercooler.

spiritrmazda

iTrader: (3)

I'm waiting to order a new water pump with block off plate for my set up. Seems like I keep having to order new parts each week. I'll keep you guys posted on my set up.

silverTRD

iTrader: (36)

howard coleman already has a setup like this. i'm not sure if its true dual exhaust al the way out but i know each turbo has its own manifold, wastegate and down pipe. he did tons of calculations and figured it to be enough for 620ish hp. i'm not sure if thats wheel hp or not. but his setup is with 28's

twint789

Pretty sweet

dregg100

iTrader: (34)

no, its twin to4s'

silverTRD

iTrader: (36)

thanks for the correction