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Best Twin turbo setups? by pttransamdriver
Started on: 09-18-2013 04:24 AM
Replies: 14 (418 views)
Last post by: Slowbuild on 09-22-2013 12:10 PM
pttransamdriver
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Report this Post09-18-2013 04:24 AM Click Here to See the Profile for pttransamdriverSend a Private Message to pttransamdriverEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm putting the engine back into the car with some fresh new headers and I was wondering how to setup the turbos. I want to pull fresh air in from the side vents but how to do that without kinking up the exhaust flow. I am still puzzling over it and just wanted some sage advice.

The setup is a V6 transverse mounted and the headers are turned down. Forum links? similar setups?
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Fiero84Freak
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Report this Post09-18-2013 08:31 AM Click Here to See the Profile for Fiero84FreakClick Here to Email Fiero84FreakSend a Private Message to Fiero84FreakEdit/Delete MessageReply w/QuoteDirect Link to This Post


I've been messing with Fieros for a long time, and cannot recall anyone ever doing any sort of twin-turbo swap using a six cylinder engine. Not only does it seem that tuning may be a potential issue, but you could probably make similar numbers using a single turbocharger as you would using two.

You need to post exactly what engine you have however for anyone to help you. "V6 transverse" tells us pretty much nothing.
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darkhorizon
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Report this Post09-18-2013 03:02 PM Click Here to See the Profile for darkhorizonSend a Private Message to darkhorizonEdit/Delete MessageReply w/QuoteDirect Link to This Post
I would run dual PT6767 turbos with ball bearings mounted in the rear bumper.
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BillS
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Report this Post09-20-2013 10:40 PM Click Here to See the Profile for BillSClick Here to Email BillSSend a Private Message to BillSEdit/Delete MessageReply w/QuoteDirect Link to This Post
Wasting time so you have bragging rights about having twin turbos is still wasting time.

A single properly sized turbo will make all the power you could get out of 17 turbos........
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IROCTAFIERO
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Report this Post09-21-2013 05:56 AM Click Here to See the Profile for IROCTAFIEROSend a Private Message to IROCTAFIEROEdit/Delete MessageReply w/QuoteDirect Link to This Post
the best dual turbo setup is a single turbo setup.
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Joseph Upson
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Report this Post09-21-2013 08:38 AM Click Here to See the Profile for Joseph UpsonClick Here to Email Joseph UpsonSend a Private Message to Joseph UpsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by pttransamdriver:
I'm putting the engine back into the car with some fresh new headers and I was wondering how to setup the turbos. I want to pull fresh air in from the side vents but how to do that without kinking up the exhaust flow. I am still puzzling over it and just wanted some sage advice.

The setup is a V6 transverse mounted and the headers are turned down. Forum links? similar setups?


Sage advice; Put it out of your mind son.

But if you must, look up my twin turbo build with the 3900 for an idea (good or bad).
Having performed the feat at least twice before realizing that my ambition had far exceeded practicality, I suggest you consider using two T25s with .48 turbine housings for a 2.8L and .63 for a 3.1L and above.

Fresh air in from the vents is a bad idea in my opinion since you are going against normal airflow. Just optimize the side scoop and plumbing into the turbos, you'll need those vents clear to relieve the heat from twin turbos as well as a single.

Good luck and note what I did in the end and wish I had done from the start.
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pttransamdriver
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Report this Post09-22-2013 03:11 AM Click Here to See the Profile for pttransamdriverSend a Private Message to pttransamdriverEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks for the replies. Sorry for the lack of detail. Just a note to those like Bills up there, I'm not doing this for bragging rights guys. I'm doing this to wipe the smiles off of GTR owners (and the like) and win many for all the "Built not Bought" guys everywhere.

Relavent Details:
- Engine = 2.5L DuraTec (Why??? Because it was the lightest V6 Engine I could find, and because porsche designed it)
- Turbos = Audi/VW 1.8L Diesel Turbos. (Why??? Explanation below.)

Okay, the reason for two turbos rather then one in a nutshell: Small turbos give you boost early on for good power to start out with. Big turbos give you lots of top end power. So I chose to get two very small diesel turbos and put one for every three cylinders. The Idea is that since they are large relative to only three cylinders they will give good top end power. And since they are small and meant for a diesel, that they will spool up early with low exhaust pressure for low end power. The only problem is I don't know how they will handle the higher RPMs. But at least they are relatively cheap to replace, only $200 new.

My Question to all of you, Which Joseph did a great job in answering by giving his example, was this:

- What are the Best Airflow Ideas out there for the Twin turbo setups?
- Will I need to setup some kind of intercooler? Or will getting fresh air from the Side Scoops be enough?
- Ideas for good muffler setups that won't heat up the engine bay?
- How to hookup the exhaust. (Where the Turbo should be in the line for optimum output, ie:Closer to the engine or further away like the STS setups) ???

Thank you all again for your sage advice. Also Please feel free to tell me if you think this setup will even work (but say objectively why)

-Tim
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darkhorizon
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Report this Post09-22-2013 04:13 AM Click Here to See the Profile for darkhorizonSend a Private Message to darkhorizonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Okay, the reason for two turbos rather then one in a nutshell: Small turbos give you boost early on for good power to start out with. Big turbos give you lots of top end power.


Simple physics proves this wrong in both theory and reality. Whoever told you this couldnt be more wrong.

 
quote
I'm doing this to wipe the smiles off of GTR owners


Good luck.. You'll need closer to 6 of those diesel turbos to hang with a $100k supercar.

[This message has been edited by darkhorizon (edited 09-22-2013).]

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darkhorizon
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Report this Post09-22-2013 04:16 AM Click Here to See the Profile for darkhorizonSend a Private Message to darkhorizonEdit/Delete MessageReply w/QuoteDirect Link to This Post

darkhorizon

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Member since Jan 2006
 
quote
Okay, the reason for two turbos rather then one in a nutshell: Small turbos give you boost early on for good power to start out with. Big turbos give you lots of top end power.


Simple physics proves this wrong in both theory and reality. Whoever told you this couldnt be more wrong.

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pttransamdriver
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Report this Post09-22-2013 05:41 AM Click Here to See the Profile for pttransamdriverSend a Private Message to pttransamdriverEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm an Engineer Dark.... if it's one thing I know, its physics.

 
quote
Simple physics proves this wrong in both theory and reality. Whoever told you this couldnt be more wrong.


I don't see where your getting that..... since you want to be a physics patriot tell me how this is flawed? The Mazda RX-7 had a specially designed sequential turbo system with a small turbine and a large turbine. Because the engineers (that according to you knew nothing) knew that at lower engine speeds the engine doesn't produce enough exhaust gas to spool the turbo therefore resulting in (the of course fictional to you) turbo lag.

Here, I give you an opportunity to educate yourself, because I know you don't want to continue on through life sounding like an ..... I'll be kind, an uneducated individual.

http://www.autozine.org/tec...ced_Induction_3.html

[This message has been edited by pttransamdriver (edited 09-22-2013).]

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tampalinc
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Report this Post09-22-2013 08:47 AM Click Here to See the Profile for tampalincSend a Private Message to tampalincEdit/Delete MessageReply w/QuoteDirect Link to This Post
Considering the engine you are going with you should take a close look as the Noble M10, M12, M400. Noble has done a lot of the R&D work for you.
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Blacktree
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Report this Post09-22-2013 09:13 AM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
I personally wouldn't discount Darkhorizon's advice. After all, he's been there and done that. His own car has a turbocharged 3800 which runs low 10's in the quarter mile.

Also, keep in mind that technology has advanced since the days when you needed sequential turbos to combat lag. Nowadays, you can have your cake and eat it too, i.e. a big single turbo with only minor lag.

But hey, it's your car. Do what you want with it. If the twin turbo idea works, that's great. And if not, then you learned something.
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Justinbart
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Report this Post09-22-2013 10:24 AM Click Here to See the Profile for JustinbartSend a Private Message to JustinbartEdit/Delete MessageReply w/QuoteDirect Link to This Post
If you were so concerned with low end power perhaps you should have chose an engine more capable.

x2 on this never being within a city block of an R35.

------------------
Turbo 3800 E85 F23 5spd spec5
11.17@132.6

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bmwguru
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Report this Post09-22-2013 11:22 AM Click Here to See the Profile for bmwguruClick Here to visit bmwguru's HomePageClick Here to Email bmwguruSend a Private Message to bmwguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
The Audi 1.8t is a gas engine and the 1.9 is the diesel. The 1.8t uses K03 and K04 turbos depending on the year and model. The 1.9 uses a turbo built into the manifold (and I can't remember the specifics), but won't be usable in any other application.

Dave

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www.hausofguru.com

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Slowbuild
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Report this Post09-22-2013 12:10 PM Click Here to See the Profile for SlowbuildSend a Private Message to SlowbuildEdit/Delete MessageReply w/QuoteDirect Link to This Post
I think the only good reason to go twin would be if you can't get a single big turbo to fit in you car, or you can't find a big enough turbo to match your needs. Unlikely!

The following decrease spool time:

1)Ceramic ball bearing turbo
2)Twin scroll turbo
3)Smaller exhaust turbine housing
4)Smaller turbine trim wheel
5)Smaller compressor housing
6)Smaller compressor trim
7) To some extent (trial and error), smaller diameter turbo manifold diameter piping


All of the above are at the sacrifice of high end horsepower.

So really, whether it is single or twins, or triples, really what you want to decide is where you want your power. I went with a smaller turbo for street use, because it builds boost early. I don't expect to hang at 7krpm with a supercar, but in autocross point to point speed it's pretty good (I'm a terrible driver, but that's another story).

I think what the guys are trying to tell you is that turbos are scaleable. Big twins will act like a massive single, middle twins will act like a single big single, tiny twins will act like a middle size single. There is little gain in real effectiveness, but a massive gain in complexity given the plumbing, etc.

Just totally not worth it!!

Incidentally, I just wanted about 5psi. After installing my 'small' turbo, I have it cranked to near 10psi and it pulls like a freight train. It's sometimes difficult to properly estimate the airflow you will require to satisfy the engine's requirements. In my case, I overestimated my engine's req., so my 'smallish' turbo ended up being a good compromise for both spool and top end. It's a twin scroll mitsu, and spools very quickly!


The best page I've seen for engineering info on turbos is this:


www.my3kgt.insel.de/gt-file...turbochargers.pdf‎


Hope it helps.

Chay
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