Anonymous

Spotted this picture on another forum:

http://www.corsaturbo.com/forumstuff/curitiba/01.jpg



Exhaust gas comes out of the engine into the first turbo and through an external gate if there is too much for the first turbo to use.

Then it goes onto the second turbo.

Once on boost the first turbo should offer very minimal restriction to the exhaust gas flow to the second one as it will be bypassed by most of the gasses.

The two compressor outlets are then Y pieced together before the plenum, so if either of them makes any boost then the engine gets it.



What is the reason we arent all doing that?


Seems like a very good idea to me TBH, but i know very little about compounding charging other than its not common, so from that i would assume there is a reason not to do it?


DISCUSS:

keithG666

Stealth Bomber

Compound turbocharging? Shurely shome mishtake

Daviet

has there not been a few posts on compound charging before

Stealth Bomber

Exactly

Stavros

Thats not compound charging in the slightest if its how chip explained it.

More like sequential turbos.

Tony Turbosystems did summat like that for Cossies back in the day.

Shithot car tho! From Brazil! MasterPower Turbos, good stuff

Anonymous

There hasnt even been a post with a picture of a nice simple after market layour that we could all be using and look like it probably works quite well as far as im aware?

Here is picture, but you need to see it full size really i suspect:

[img:1280:960:c96b8288d4]http://www.corsaturbo.com/forumstuff/curitiba/01.jpg[/img:c96b8288d4]

digita1dragon

wouldnt that produce more boost than youve set on your actuator?
and if so, whats the point?

Rick

Karl and I wrote a fair bit on it - The problem is matching the turbo sizes, very experimental.

Anonymous

Thing is, im getting my manifold design finalised at the moment, and it would actually be VERY easy for me to do this, like literally not even a grand extra including the turbo and wastegate etc.

So why shouldnt i?

what are the downsides to it?

Stavros

[img:1280:960:780432c8de]http://www.corsaturbo.com/forumstuff/curitiba/01.jpg[/img:780432c8de][img:1280:960:780432c8de]http://www.corsaturbo.com/forumstuff/curitiba/02.jpg[/img:780432c8de]

Anonymous

Do you have a link to where you wrote that?

Perhaps im over simplifying it in my mind, but i dont see how the turbo size is THAT crucial, i agree for the absolute optimum perofrmance it would probably take a fair bit of experimentation, but for me to just get a useful bit of extra torque at low end surely even a pretty much "finger in the air" guess at turbo size (renault 5 t2 for arguments sake?) would be ok?

Plus i dont mind if i have to try a few turbos to get the right one TBH!

RichardPON

Rick,

I thought you two wrote about compound charging.

To me, this reads that you're driving the second turbo from the wastegate gasses of the first?

Stavros

This isnt twin or compound charging, this is a sequential turbo setup, been done loads, just not often on aftermaket applications.

IMO youd be better off twin charging it with a turbo and a supercharger, cheaper and simpler if you know how, and more effective too.

Or compound charge it like Dumped's saff with turbo blowing into turbo.

But all 3 ways are v.v.cool.

Love the way theyve done away with the intercooler by just injecting the nitrous into the compressor outlet too

rsnissan

iTrader: (9)

there would be two actuators............one turbo would boost up then the other would kick in and both would be controlled by their seperate wastegates when the desired boost is reached for each turbo i'd imagine. Just like a normal seqquential set up.

As Steve says its not compound charging (where one blower feeds the other)

Fudgey

iTrader: (4)

i asked this aaaaaaaaaaaaaaaaaages ago with the pic below i seen.



[img:533:800:4693ebc43d]http://www.germancarfans.com/news/2040414.009/2040414.009.1L.jpg[/img:4693ebc43d]

Stealth Bomber

Do it do it do it do it

Anonymous

Yeah but that just isnt as easy to understand as a nice picture of it simply implemented, so half of us probably didnt quite picture it right i suspect!

LOL

Anonymous

Oh and also dan, those turbos dont have their own seperate inlets, so the larger one is a flow restriction on the inlet side to the smaller one, this one isnt though!

Mongo

chip-3door

Cool idea mate

Could you use a smaller turbo to spool the larger one? Would that get around the exhaust side complexity?

Anonymous

I dont want to do that, i want to run the two seperately, i want the small one to provide boost to the engine, then the engine can provide the exhaust gas to spool the larger one

Fudgey

iTrader: (4)

its also for the vectra 2.2 dervs lol

pic was just to illustrate how its done really.

ie i wouldnt do it quite like that

Anonymous

I suspect its done that way largely to allow the use of a single inlet source, which is easier for lfow meters and filters etc.

Fudgey

iTrader: (4)

and production costs lol

Anonymous

yes Dan, thats what i mean, the production costs of not joining them

rsnissan

iTrader: (9)

if i was doing that chip i would probaly go with a small supercharger

Mongo

Probably not got enough space in the engine bay of the mini for a supercharger... Infact you'll struggle to get a second turbo in there?

Anonymous

Any, small superchargers are still very big compared to a small turbo, and also they have to be mounted in certain places (ie near the drive belts)

I wanted to supercharge the car originally (instead of a turbo not as well) but there just isnt the space, its SO tight in the bay even N/A that its not an option really for me.

I agree though that may be a good idea on something like my cossie (replica ) though, and wouldnt mind having a go doing so at a later date perhaps.

The problem with a supercharger though is they arent good at providing big torque low in the rev range and then not providing a lot of resistance at the top of the rev range dont forget!

Anonymous

Correct on the charger, wrong on the turbo.

That set up above would fit in my car perfectly

There is just about enough room for a K16 in there on the right manifold mate, and thats probably the turbo i would chose to use as a first attempt as well quite possibly

If not a K16 though i woul only go SMALLER than a K16 not bigger.

rsnissan

iTrader: (9)

ahh ok didnt realise it was for the mini

mount the charger out of the bonnet like in mad max

Mongo

How about a T15 like on my pug

I suppose you could fit the bigger turbo above the gear box.. Would you have any problems with the turbo being mounted so far away from the head?

Anonymous

Thought about that, but i would have to convert to LHD too then, as it would ctually have to sit COMPLETELY over the bonnet as the engine is only a few mm below the bonnet, and it wouldnt be possible to see past it, and it has to line up with the belts.

Did think of a "torque bar" across the car and the charger running over the gearbox, but i cant do that if ive got a turbo already sat there!


Space is VERY lmited.

Mongo

With a big red button mounted in car, that he can switch it on whilst in persuit mode lmao (more like pimp mode)

Anonymous

Thats where the turbo is going anyway mate on the new manifold me and Robbie are working out at the moment, thats how im not having to worry about space as much as Rich thinks i will

Mongo

Whos that.. My old pessamistic friend Riccardo Lewis?

Anonymous

indeed mongo, but thats VERY off topic.....









So going back to the original question, can someone (rick?) give me a good reason why i shouldnt do it?

If there is any major disadvantage then i wont bother, ive got a bottle of antilag in the car anyway, so its not like i NEED a second charger but if it brings more to the party than it drinks, then i would like to invite it along anyway!

keithG666

rsnissan

iTrader: (9)

what happens when both turbos are at full boost would the smaller exhaust housing cause a restiriction then?

as you know the exhaust housing on a turbo affects the engines flow charistics etc.

Karl

Chip,

If you have to ask on an internet formum why you should'nt use a method like above then you don't do it!!!!

It does'nt work by the way.

Shings

You in mate, might pop over in a bit for a general winge and chat