Turbos Without Wastegates

[Lextreme II]

Hey Gang,

Lets imagine this. Two turbos max out at 1000 rwhp and the engine can handle 1000 rwhp easily. Do u think i still have to put in wastegates?. What if i install the wastegate somewhere in the inlet pipe and release pressure at a given psi. For example, if i want to run 30 psi and the wastegate (located in the inlet) and set for 30 psi. Would this setup work?

I am try to eliminate space occupy objects to save space. What do u think?

 

[BlownV8]

Lex,
the problem with this type of setup is that your turbo impellar speed will always run at a maximum speed. With wastegates, the impellar only spins up enough to create the required boost. Using pop off valves to control the boost, will mean the turbos will run at full impellar RPM and will created excessive heat, and fail earlier.

Stick with the wastegates. If your using custom manifolds, you can install the wastegates anywhere.

 

[R-Jay]

or you could go with variable vane turbo's..... electronically controlled "vanes" control the angle the exhaust gas hits the turbine... this controls the speed in which the impeller spins at...

this tech has been around in turbo diesels for awhile, but i hear it's been trickling into petrol engines alot more now.... i still dont know a heap about it, so i'll do more reading...

just something to think about

 

[toad007]

The new ford 6.0L powerstrokes have use that type of turbo..(variable vane..) might want to look at aftermarket powerstroke turbos..

 

[chrisman]

yes, you do not need wastegates--but for long term use wastegates are the way to go..
but,i have always thought from a "race only" point of view, you would be better off keeping that turbine spinning and regulating the intake psi just like you had said. i think boost between gears would come on much quicker--good for drag racing... you could even use a waste gate actuater to help you accomplish this by making a pressure realse or ""poppet" valve or "pop off valve" like already mentioned.. im sure it has been done, and i think it was used for f1 or some open wheel racing..
il be the first guy to say" try it" just because its not a common doesnt mean you could not get this setup to work well...

 

[1UZ-HZ]

Having the turbos setup like this wouldn't be ideal as shaft speed could not be varied which would more then likely push the turbos out of thier efficiency range. How about internally wastegated items?

 

[Sparky]

Variable vane all the way. Otherwise without a wastegate how would you cruise?

 

[Red Supra]

http://www.honeywell.com/sites/ts/tt/

 

[bobadrift]

The only problem with the variable vane turbos is the fact that running them in a gasoline engine can shorten their lives greatly.

The amount of heat produced by a gasoline engine is much higher than those found on a diesel engine. That is why these turbos are primarily used on diesels only.
Now perhaps the technology has changed to allow the use of them in gasoline engines and I know their was a twin turbo kit for the Toyota MR2 using variable vane turbos, however they cannot be runt at high boost and thus the power gains aren't as great.
In trying to produce 1,000hp I just don't think you will find a variable vane turbos large enough to use on a gasoline motor that can withstand the high heat produced.

As for the wastegates they aren't needed and you'll see this alot in Japan. The only drawback is the possibility of compressor surge which can damage the turbo over time.
I'd like to hear what setup you end up using as it would provide great tech for everyone here.

Edit:
Well I just went through the Honeywell link posted above and I guess there has been greater development in using these turbos in gasoline engines.
The only drawback now is $$$. From reading it seems these turbos won't be for average people cost wise.
If you look into pricing let us know what you find out. In a few months I may contact them regarding specs of the turbos and just how much boost they'd be able to handle.

 

[chrisman]

boboadrift, is there a link-site were i can chck out the japan setups .. id like to see some in action--btw, i cant read japanese..but even pics would interesting.. and couldnt a bypass valve be used to keep compressor surge from destroying the turbos.. i know alot of factory supercharged setups use a bypass to keep from having problems..banks also uses a great design-bypass built into the intake plenum..

 

[BlownV8]

boboadrift, is there a link-site were i can chck out the japan setups .. id like to see some in action--btw, i cant read japanese..but even pics would interesting.. and couldnt a bypass valve be used to keep compressor surge from destroying the turbos.. i know alot of factory supercharged setups use a bypass to keep from having problems..banks also uses a great design-bypass built into the intake plenum..

With superchargers they only spin as fast as the crank pulley ratio will allow. This is setup on install so the supercharger impellars never over rotate. A Turbo does not have that limitaion on it. A bypass valve on a supercharger only vents excess boost out of the intake manifold at high rpm once the throttle is closed. It is basically the same as a blow-off valve for a turbo. It would not limit shaft speed of the turbo.

 

[bobadrift]

boboadrift, is there a link-site were i can chck out the japan setups .. id like to see some in action--btw, i cant read japanese..but even pics would interesting.. and couldnt a bypass valve be used to keep compressor surge from destroying the turbos.. i know alot of factory supercharged setups use a bypass to keep from having problems..banks also uses a great design-bypass built into the intake plenum..

I'll have to find a link that shows the setup. I've seen plenty of actual film showing this and have friends here in southern california that have run a setup without wastegates, but eventually they install wastegates in order to avoid premature turbo failure.
A bypass valve could be used although I have yet to see this done on a turbo import vehicle. As you said the Banks system uses a bypass valve however the easier method that I know of is to use a wastegate.

 

[JBrady]

wastegates or variable vane turbines are the best way to control boost. By control boost I mean reach full boost as soon as possible and maintaining or even adjusting the boost relative to RPM all the way to redline.

If you run a boost bleed the problems are many. Turbocharger overspeeding is probable. Also, you are moving MORE air than you are using so the efficiency will change dramatically and you use more exhaust energy to do this. Typically this means less efficiency on both the compressor and turbine side.

Integral wastegates work very well for simplicity and space savings... they are also cheaper than remote wastegates and they are easier and require less exhaust plumbing. Don't worry about the efficiency differences unless the design you are using is struggling to maintain proper/stable boost. This condition, if present, can often be solved by reworking the WG port in the turbine housing.

 

[JBrady]

boboadrift, is there a link-site were i can chck out the japan setups .. id like to see some in action--btw, i cant read japanese..but even pics would interesting.. and couldnt a bypass valve be used to keep compressor surge from destroying the turbos.. i know alot of factory supercharged setups use a bypass to keep from having problems..banks also uses a great design-bypass built into the intake plenum..

It is easy to translate most Japanese pages using any of the many online page translators.