Power-curve straightened...

[Ether-D]

I'm thinking of starting to get back on the turbo side of this thing. Does anyone have any advice as to which specific turbos will run large amounts of air, efficiently, at low boost? Like Varg said?

It's just that every time I look in my engine bay, the passenger side just looks so empty. And all I can do is imagine how nice it would look if there was something filling some of that space.

Bump

[TheTacoMan]

Have you considered how you will pipe your turbo to the super and vice versa? Im not sure what sort of turbo budget youre looking at however I would go with the most efficient platform as possible.
Alot of work is being done between the turbo and supercharger that will create massive heat.
What is the supercharger currently putting out as far as boost pressure goes?
For example from what Ive read, 12 psi out of a Super and 6 psi from a turbo does not equate to 18 psi, if I can find the graph showing this I will update. If I remember correctly its net pressure output would be 22-30psi roughly.

[varg]

Start looking at compressor maps. You want to find maps with broad efficiency islands at low pressure ratios and generous surge lines. You need to know how much air you'll be flowing to do this correctly, so power goals are kind of necessary to know.

For instance, with a 1.6 pressure ratio target you can see that a T04E-50 is a better choice than a T04E-57 because it is much more efficient at that pressure ratio on the far right of the map. Note that at 36lb/min mass flow and 1.6 PR the 50 is on its 65% efficiency island, and the 57 is well past its 60% island (it's actually off the map). That means lower adiabatic efficiency, which means more charge heating, and managing intake charge temperature will be a challenge with a compound forced induction setup unless you are constantly using water/methanol injection. It's not a large difference, but the inefficiencies multiply just like the pressure ratio does so it's worth considering.

http://www.not2fast.com/turbo/maps/all.html

Have you considered how you will pipe your turbo to the super and vice versa? Im not sure what sort of turbo budget youre looking at however I would go with the most efficient platform as possible.
Alot of work is being done between the turbo and supercharger that will create massive heat.
What is the supercharger currently putting out as far as boost pressure goes?
For example from what Ive read, 12 psi out of a Super and 6 psi from a turbo does not equate to 18 psi, if I can find the graph showing this I will update. If I remember correctly its net pressure output would be 22-30psi roughly.

The pressure ratios multiply, I think I posted something about that earlier in this thread. To minimize the heating of the charge it would be best to run lower boost from the supercharger than the turbo instead of vice versa. Superchargers tend to be less efficient at a given pressure ratio than a turbo.

[TheTacoMan]

Thank you varg, explained it better than I could.

[Ether-D]

Thanks Varg. So what I gather is that I'm going to be fighting heat.

My current plan was to have the turbo feed the supercharger. It would go like this: air filter-turbo-FMIC-blowoff-throttle body-supercharger-methanol-plenum with bypass back into supercharger's butthole.

Also I should say I really just want this to work in a way that's not necessarily super high strung. Going for proof of concept, then proof of radicality. I honestly just want to see a turbo in there functioning with the SC because I like building machines that look cool and go fastish.

What might be a fairly mild (safe, at the expense of ideal) turbo? Just looking for a ballpark to start off in.

[Ether-D]

Supercharger is currently putting out 6.5 peak at 5000-6000rpm.

Edit: there's another post at the end of the last page that is pertinent.

[Ether-D]

Thanks Varg. So what I gather is that I'm going to be fighting heat.

My current plan was to have the turbo feed the supercharger. It would go like this: air filter-turbo-FMIC-blowoff-throttle body-supercharger-methanol-plenum with bypass back into supercharger's butthole.

Also I should say I really just want this to work in a way that's not necessarily super high strung. Going for proof of concept, then proof of radicality. I honestly just want to see a turbo in there functioning with the SC because I like building machines that look cool and go fastish.

What might be a fairly mild (safe, at the expense of ideal) turbo? Just looking for a ballpark to start off in.