I corrected my turbine size above but wanted to make it clear I have the 178's I would be happy to send logs to Aerocharger and see if we can get together on a conference call with them to discuss the two turbine choices. My feeling is the 178's will have no problem with 10 or even 12 PSI, I think the issue will be more to do with high RPM CFM's and this is where they will be able to help out. My sizing was simply their best guess based on displacement and estimated VE's as no one had used a large frame Aerocharger on a NSX when I did mine.
I am making 430whp at 8.4lbs peak and that is measured before the intercooler so there is likely a .4 to .5 pressure drop across my WTA core. I am adding yet another sensor to measure post cooler so I know the pressure drop, but this will require me to drill and tap the upper part of the intake and I have been too lazy to get it done. I am making this boost with the blue spring 2nd lightest they have for the controller, the next spring up (orange) made 10.2psi, and there is still 1 more spring heavier that ships with the controller. At the 10.2 level there was no sign of pressure drop at the higher RPMs and the controller had very good control as the boost peak was constant from 5-8K RPM.
I did not tune for peak power at the 10 PSI levels and my testing was early on in the process. I made the change to the lighter springs after the first full pull. I was only wanting to run 8 to 8.5lbs of boost and my whp goal was for 400. With fairly rich AFR and limited timing the 10PSI pull made 440 whp. So I decided to reduce boost and start the tuning process again. I ended up at the blue spring and 8.4PSI peak @430whp AFR's at 11.7 avg and IAT's of 110-117 degrees. Timing retard at these boost levels in the FIC is 6.5 degrees at 8PSI and 7 degrees at 9PSI.
From my last dealings with Meth, I think if I did nothing but add Meth at 50/50 and pulled my car it should make about 440-445whp, lean it out a bit and try for more timing as the Meth is increased and the car could make 450-460whp maybe more depending on the Meth mix. So with your engine build at 10PSI, Meth, and no intercooler restriction I think you will make more like 480-500whp. It will get harder to pull more out as the Aerochargers are still small compared to other turbo options, but with twins I think they move enough air to support 550-600whp. Just a guess and without more info from Aerocharger it will have to stay that way. My bottom end is stock and unless there is a major mechanical problem forcing a build I will stay at the 430whp level. I am thinking about adding Meth as another layer of protection in case I get the desire to track again, it will be cheap insurance.
Dave
next thing is to put this stuff outside and degrease/steam it. It's not in that bad of condition right now though:
(they'll be replaced with the updated style anyways), but I have a few slight wear marks on just one location on each camshaft as shown:
