Does anyone know what the max boost is on the GT20 (.46a/r turbine, .53a/r comp)?

 

Max boost is around 27 PSI... but the HP output at that level would only be around 200 hp. This turbo would be horrible for an RX-7 if that's what you're planning on using it for....

 

I'm trying to find a suitable primary turbo for a sequential twin system I'm building for an RB25. I was thinking a gt20 for the primary and a gt28r for the secondary, but I'm trying to get some info on both. Any suggestions would be appreciated.

--edit--I posted this in the single section, because I thought this would be my best chance for good turbo info.

 

double post

 

Interesting... I am not sure that you'll find great info here for Nissan motor turbo sizing

Honestly what I would do is start by looking at something that someone else already built and tested... check out where you might make improvements or do something a bit better... and go from that. Trying to just "wing it" and buy all the parts based on calculations and plans on paper is usually an expensive way to go

The ~27 psi figure I quoted would be about the MAX... not the "right" place to run that turbo anyhow... it would probably be a lot happier at 15-17 psi and would make maybe 200-250 hp... Just guessing on that based on the compressor map...

 

Thanks, As with any high dollar project, I'm not just 'winging it.' Plus, it complicates things, because I have to do it just on paper. I'm prototyping a sequential system I designed, so there's not really much real data yet to work with. The stock RB25 turbo runs a .5a/r turbine and a .6 compressor. That's why I thought the GT20 would be a good primary. Do you know any good Nissan sites for this kind of info? There's absolutley dick on nissanforums.com.

 

well i have 2 Garrett GT20's but my A/R's are a bit bigger then yours..
(.60 A/R Turbine and .51 A/R Compressor with a 52 compressor trim) on both

 

^^how do those work? (parallel right?)

 

yes in parrallel.. right now thought they're just sitting on the ground though

Frank

 

sequential will be pain in the ***, just buy a rb26dett half cut and be done with it, it will be so much better in the long run