Turbo system bypass...

[deevergote]

Yes, I'm a doofus. I've been tossing the idea around of creating a turbo system, only to have it able to be bypassed at will. More of a hypothetical design, since the two routes I'm considering now are NA and SC.

Basically, my idea involves some of those motorized dump valves you can find on ebay or other performance places (Summit Racing has them, I think).

It involves running a dump valve between the turbo and the exhaust manifold, and again on the intake pipe. When you open the valves to bypass the turbo system, you're running through an alternate exhaust that doesn't spin the turbo. You're also bypassing the compressor and sucking in air afterwards.

A switchable computer chip (they make sockets that can run two chips, with a switch to select which one you want to use) can be used to run an NA map.


Basically, my main issues with turbo is that the system creates such heat and strain on the engine... something that isn't necessary all the time. Also the fact that an engine that makes significant power requires significant fuel.


I know that MRX is capable of getting the same gas mileage as me with careful driving (maybe even better), and his car has been running the stock bottom end for a long time... But I still wonder if bypassing the system completely would be beneficial.



Seeing as I'm

[slammed_cb7]

I would say your best bet is to buy an electronic boost controller and just dump the boost out the wastegate. Unfortunatley I am not knowledgable enough about these things to know what happend to your fuel maps etc. when you do that. I have seen people driving around on 4 psi and bumping it up to 12 for a quick stretch of open road and then back down to 4 with no obvious issues. If someone that knows about the tuning issues could educate me, that'd be awesome. I do know however, that those things can be kinda expensive, although not as expensive as a dump, extra chips, extra exhaust routing and all that.

[92ex]

my dad's friend actually has something similar to your idea on his sc camaro. I don't remember the specifics, but from what my dad told me, he used a magnetic switch to engage/disengage the sc. I guess it would be simply having the s/c intake and a regular intake, and have a solenoid that can change which way the air comes in. I know nothing about the elctronics

[92ex]

it wouldn't be more expensive, and as for the tuning part, it was because he was running 1bar map that he could turn his boost way up then back down. I can see how the switches would work, and that would be a good idea, but could you use it while driving? an electronic boost controller isn't gonna do much if the w/g is already set at 8psi

[cp[mike]]

Seeing as I'm

...indecisive?

[MRKIKKOMAN]

engine bays with just a normal turbo setup are pretty packed as it is. If this works yr either gunna have to get creative on fitting it all in or hack out some of the unecessary stuff. sounds cool though id love to see it done.

[deevergote]

...indecisive?

You know me

I'm not really planning on doing this...at least not to the H22. Maybe to the Volvo someday, but definitely not soon. I was just wondering if it would work!

Dumping the exhaust out of the wastegate would work as well, but for it to be reasonably quiet, it would need to have it's own exhaust piping as well. Also, that would be puttng wear on important parts, as well as not completely bypassing the turbo itself. The turbo would still be spinning, and if the bypass valve were to be used on the intake side, the compressed air from the turbine would just be dumped (and that probably doesn't sound great either!)

My idea basically turns the turbo into dead weight. Similar to that clutch-bypassed supercharger (Mercedes-Benz actually uses that clutch technology... I've been looking into MB superchargers as an alternative to the Procharger for my car, actually...)

Fitting everything wouldn't be too bad. Just mount the turbo lower. The cold side has plenty of rool for a secondary intake. Hell, stick a cone filter on the end of the dump valve!

[straightedge]

Do a y-pipe with 2 electric exhaust cut-outs. You'd be real crammed, and probably have to run the turbo open downpipe when engaged, but it would work. You'd definetly have to wire the cut-outs so that one opens and one closes at the same time to eliminate the possibility of cutting exhaust output altogether. Use a Civic half style radiator for more room.

[MRX]

I think theres a major flaw in ur concept. If u redirect all of the exhaust flow u'd wear the turbo out because the oil wouldn't be circulating around the inner seals because the turbine shaft wouldn't be spinning to prevent the oil from coking inside the turbo. Yup...there'd still be excessive heat because the turbo would still be bolted to the mani.

[cp[mike]]

i was just goign to say, get two electronic exhaust cutout pipes. flip em both to bypass both sides... interesting idea, but it may be easier to just make a dedicated W/G dump tube w/ a 0-#psi setting, though that would be forcing drawing intake air past the compressor wheel and through the IC...

[straightedge]

Like MRX said, if the turbo is getting pressure, but not doing anything, it'll just wear out and be a waste.

You could make a "sidewinder" manifold putting the turbo where the battery would go, that would allow you to run a 4-1 or 4-2-1 manifold design so you can make the cut-outs/y-pipes. Then you can just run the turbo downpipe into the fender well when you feel like boosting. You'd also probably still be able to utilize factory exhaust routing. [As far as doing it on the Accord, dunno about a Volvo]

I wish I was good at MSPaint, I'd draw some pictures. Haha!

edit: As far as the air intake goes, I guess your interCOOLER would act as an interFOOLER when the turbo is disengaged. That's whole 'nother bag of worms we could open.

[MRX]

Like MRX said, if the turbo is getting pressure, but not doing anything, it'll just wear out and be a waste.

no, going off deev's original idea he wanted to completely re-direct the exhaust flow and never touch the turbo. The only way to make this idea work is to attach this said bypass valve to the IC piping but even that would cause air leak troubles eventually.

[straightedge]

I need diagrams, now I'm just getting confused. Haha!

[deevergote]

Ah yes... you're right Antoine. The heat would still go to the turbo. Without the circulating oil to cool it, that would kill it faster than using it. Dumping the airflow after the turbo would still put wear on the turbo itself, so that defeats part of my goal. Damn.

[djcaz_aom]

Here's what you need deev:



To make it work you will need the bypasses as you said(green arrows)
And an eletric oil pump, to circulate the oil. (Purple Rectangle)