Competition twin sizing

[DCreed]

is there a simple way to measure ALL brands of turbos? seems everybody uses different specs! I'm looking to try a pair (not compounds)of maybe 57/8s do they make such a thing? I'd like to put them sideways/side by side in the truck so the compressor inlets face the pass. fender outlets toward under ex. manifold. Garret/scwitzer/tubonetics all use diff #s. need to know whats what. anybody got a clue? THANKS.

 

[Forrest Nearing]

what size engine? surely not a 5. 9



the problem is that our engines need pretty high pressure ratios, and usually the smaller you go on a turbo, the worse it does at high boost



a pair of 57mm compressors on a 5. 9 would be a bit like putting a 90mm single turbo on it. it's gonna be a dog



don't try to reinvent the wheel... and if you just HAVE to reinvent it, don't make it hexagonical shaped

 

[DCreed]

thanks Forrest, but I'm really just trying to get a handle on the #s different manufactures use so I can compare/ cross reference correctly.

 

[Forrest Nearing]

garretts list most of their wheels in standard inch measurements. they list their turbine housings in A/R ratio vs. metric area.



not quite sure what you're wanting to do, but you don't need sizes and measurements, you need compressor maps, and I think you're going to be bummed when you start looking at them.



you're not going to find anything that does 5:1 PR... probably not even 4:1 (45psi) that's that small.



if you do, let me know, I've got some applications I'd like to use them on, but like I said, usually the bigger the turbo, the better the map at higher pressure ratios.



you can bolt on a single turbo that'll spool similar to stock and support over 50psi. You're not going to be able to build a set of parallel twins that'll do that. Not even close.



Will you have some wow factor? yes, but not while sitting in the driver's seat.



parallels HAVE been done on these engines, but you don't hear much about it because those that have done it are embarassed by the results

 

[DCreed]

thanks again for savin me some time, always like to learn more! I sketched some up ,looked pretty neat!

 

[Forrest Nearing]

like I said, plenty of wow factor



I love thinking outside the box, but sometimes you realize why everyone's inside it