legacycentral bbs

Hey every one I am planing on running about 16 pounds of boost on my 91 turbo legacy and I know turbos are not rated in psi they are usually rated in lbs/min or cubic meters/second and i have been doing the math and figured out that one of the better turbo for my application would be a tdo5-16g big wheel from what I calculated it looks like the turbo at 16psi would start to spool at around 2200 and reach peek efficiency at 4250 of 71% and I figure that the ej22t would reach max power at 6000 which the turbo would be at 66% efficiency. I was also wondering if anyone out there might beable to get me a link or photo of the vf39's compressor map. I would like to do a vf series turbo through ihi over a mitchubishi tdo5 depending on if I will have room to grow. I was planing on either a big top mount bar and plate style ic or a front mount tube and fin ic depending on recommendations

Welcome to the BBS.

Just curious, what turbo map are you reading for the TD05-16G?

In general, turbo maps for automotive applications are not really going to tell you a lot. An automotive engine has a huge operating/load window, and will cause the turbo to do the same. Your best tool is first hand experience with that specific turbo. There's quite a few people running the TD05-16G, including myself and can give you their feedback on when boost builds, and other traits like that. Overall engine setup, exhaust, etc will also have a bearing on those factors, so you'll have to look at those pieces as well.

In my opinion the turbo maps give you a general idea of when the turbo is going to start running out of air based upon the horsepower you're looking to make, fuel injectors you're planning to use, etc.

Pretty decent site on how to read/interpret a compressor map. Plus, it has maps of lots of turbos. There is also a thread somewhere on nasioc with a bunch of VF compressor maps.

http://www.stealth316.com/2-3s-compflowmaps.htm

So the website that I used for the compressor maps is
http://www.rbracing-rsr.com/turbotech.html#ihi
They have a whole lot of different turbo compressor maps and the conversion calculator to convert from cfm to pounds/minute and more. I was planing on running the tdo5-16g large wheel since it look like it would be the most efficient turbo for my application and I was looking into getting 550cc injectors 3" turbo back exhaust and every thing else needed to run the revtronix stage 2 if I cam find them any were since I hear there not producing the chips any more. Any ideas on when boost really kicks in on the tdo5-16g large

I am 95% sure I've got the TD05-16g small wheel and I believe I make full boost between 3,000-3,500 rpm roughly. It's been almost a year since I've driven the car, so that's going off memory.

The larger compressor looks like it will make boost sooner, and give you some higher pressure ratios, but has lower efficiencies, which means you're going to heat the air up more. What sort of boost pressures are you looking to run?