Limitations of the VF11/RBH5

[dscoobydoo]

Does anyone know what the upper hp limits are of the turbo? Given a 3'' exhaust, intercooler and the usual few mods ( FCD and MBC to 15psi), what is the expected output of the engine? I know alot of people who get this far have also upgraded to a td05h or something else. And I am looking for DYNO numbers, not what you think you have. I plan on dyno'ing my 93ss and then doing the few mods. I was just looking for what the eventual outcome would be.

Thanks

D

[boostjunkie]

I'm pretty sure 15psi is out of the turbo's efficiency range. You might wanna lower the turbo to about 12-13psi. Do a search on this topic as it's been covered many times.

[DLC]

Eventually i'll get to the Cobb/MG AWD dyno after i get the turbo updated (RHB5 with upgrades) and get you all some numbers.

15PSI is definitely out of efficiency for a stock RHB5, but with a good exhaust and intercooler setup i can see the car in the 210-220HP range.

[boostjunkie]

Eventually i'll get to the Cobb/MG AWD dyno after i get the turbo updated (RHB5 with upgrades) and get you all some numbers.

DLC, what are these upgrades you speak of?

[DLC]

Larger compressor wheel, ceramic coating, porting...

That should make a little more boost possible.

[Matt Monson]

Considering JDM Legacy GT's came with the VF-10, and to my understanding ran 12 psi of boost to get 200ps, I would fully expect them to be able to push at least to 14 psi. And since the EJ22T is a slightly larger displacement motor, I am going to guess that DLC's estimated 220hp is just a touch low. But then you asked for dyno numbers, and nobody around here seems to have them. And of course, on a dyno, those numbers will be more like 160 hp to the wheels. Post back once you have the thing tested. We all want to know. I intend to get a dyno run on my EJ20G once it is in. I won't be a perfect comparison, but it will be like red delicious and granny smith apples.

[boostjunkie]

Considering JDM Legacy GT's came with the VF-10, and to my understanding ran 12 psi of boost to get 200ps, I would fully expect them to be able to push at least to 14 psi. And since the EJ22T is a slightly larger displacement motor, I am going to guess that DLC's estimated 220hp is just a touch low. But then you asked for dyno numbers, and nobody around here seems to have them. And of course, on a dyno, those numbers will be more like 160 hp to the wheels. Post back once you have the thing tested. We all want to know. I intend to get a dyno run on my EJ20G once it is in. I won't be a perfect comparison, but it will be like red delicious and granny smith apples.

You also have to take into account head flows as well as the larger displacement. Considering the turbo "might" be efficient on a 2L engine, with 10% greater displacement, the turbo "might" be efficient to 12psi on the 2.2L engine. After which, I suspect, you'd hit a point of diminishing returns with excess heat and such. Add to that the head flow of the 2.2L engine isn't as good as the 2L engines as well, which would bring that total horsepower number lower.

What injectors came on those ej20s?

[Matt Monson]

Considering JDM Legacy GT's came with the VF-10, and to my understanding ran 12 psi of boost to get 200ps, I would fully expect them to be able to push at least to 14 psi. And since the EJ22T is a slightly larger displacement motor, I am going to guess that DLC's estimated 220hp is just a touch low. But then you asked for dyno numbers, and nobody around here seems to have them. And of course, on a dyno, those numbers will be more like 160 hp to the wheels. Post back once you have the thing tested. We all want to know. I intend to get a dyno run on my EJ20G once it is in. I won't be a perfect comparison, but it will be like red delicious and granny smith apples.

You also have to take into account head flows as well as the larger displacement. Considering the turbo "might" be efficient on a 2L engine, with 10% greater displacement, the turbo "might" be efficient to 12psi on the 2.2L engine. After which, I suspect, you'd hit a point of diminishing returns with excess heat and such. Add to that the head flow of the 2.2L engine isn't as good as the 2L engines as well, which would bring that total horsepower number lower.

What injectors came on those ej20s?

Very good points. I was drawing on my memory of a previous discussion where we actually ran the numbers an placed the VF-11 at around 14spi for the EJ22T. But the head flow issue definitely would make a difference on final HP. And that sort of boost would be at the ragged end of the fuel system of a stock Legacy turbo.

As for the injector issue, there seems to be a little debate on the size of them. Some say 440cc, others say 380cc. I tend to side with the lower number from what I have been able to dig up.

[dscoobydoo]

I juts wanted to confirm what I already suspected. I was figuring about 220 at the ending. But she would get the fuel mod and better pump and possibly better injectors. The 15 psi would be the serious upper limits. 13 was more of what I would sit at for daily driving. But I had not considered the head flow issues. There is a awd dyno in Portland OR, and I should have numbers for my stock 93 ss 114000 miles. by mid may. Then I will put on all of the mods and by the end of september, I plan on another dyno run to see what the results are. I know i will have to figure out the loss for the power to all four wheels, but running a baseline before and after should give me the correct gain numbers.

I will post the graph when I get it.

D