twin turbo time
 

Ok its time for more air. With the fueling mods in my Sig what do u guys think would be a good setup? I put an s300 on but its still fairly small.(got it dirt cheap) When I hit overdrive I can easily choke this turbo out. Egts can reach 1400 but I don't EVER let it go that high just for safety factors. Any input would be good fellas.

My hx35 over s400 compounds worked very well with 65hp injectors. Recently I made a HX35/40 hybrid with 16cm housing and put it over the S400. It was a little lazy, but still kept things very cool. Even more recently I put 150hp injectors in, and the system works very well. Still very cool as well, never over 1250EGT but I think my Edge has issues. Actually, I know it has issues.

put a S471 under it and you would have the same thing as BDs small set of compounds, or you could put a S475 under it, both turbos usually run the same price

Idk if I want to stick with the s300 or go with a phatshaft 62 or 64 with a s475. I'll be goin into the service in a couple months ill be in Virginia so I'm hopin to find some sled pulls.

stick with what you got, even with the 475 for a primary. The size of the secondary actually has very little effect on the peak hp capability of the set of chargers as long as it isnt so small that it becomes a choke point. Many times guys go with too large of a secondary charger and end up with a slower spooling set that still makes the same peak hp

Oh ok thanks man. Good advice.

With the topic of limits being discussed, what would the limits of a S400 as a primary be? Just as an estimate, of course. These are the measurements I took off of it:
http://img153.imageshack.us/img153/1162/s400size.gif

Borg Warner S400SX4 part number 171701 and it has a 1.32 A/R T6 turbine housing. The BW catalog dosnt show the map for it so i googled it and best i could find it looks like it peaks at around 85lb/min but that would be pushing it pretty hard as in 3-3.5 P/R so i'm talking like 35psi between stages. That being said realisticly in a compound setup it could make in the 700hp-750hp range (s.w.a.g.) then its simply going to be out of usable airflow

also thats the exact turbo i was refering to as a S471 and is the same turbo that BD uses in their small kit, which i think is the R700 Tow

ie BD uses the S300G which is what cumminscwby has as their secondary and they rate that set at 700hp

hope this info helps :c:

Well, it sure is a lot of info, that's for sure. I "rescued" this one from a 12.5L Deere. 700-750 is well beyond my goals.......at this time at least.

cool so you got the JD cover on it, those are lower A/R covers and are the same thing as most "race covers"