I have the following:

Stock engine
RX6B turbo
PFS SMIC
SX fpr
walbro 255 pump
1200CC secondaries
xs ignition
midpipe
gt spec catback
Greddy pulleys

Would you keep the stock primaries or put the stock secondary 850cc in the 550cc primaries? Would I run too rich if I did that, or just keep the 550cc in there? Most likely aiming 370 rwhp.

Thanks,

Ravi

 

Also have PFC, sorry.

 

I would put the 850's in the primary to play it safe, or send them to me

 

550's are fine for 370. You can run the 850's, but it's not really necessary at that level.

 

Honestly I think that if you can do it without too much hassle, you should use your 850s in the primary spot.

2x550 and 2x1200 will not leave as much safety room as I would like if it were my car trying to make 370 rwhp.

If you get the 850s properly installed in there and tuned for it and everything you will be very glad you have that extra capacity I think.

Brian

 

Oh and just for reference... a handy little "quick calculation" I do is this...

Take your total fuel delivery in cc/min and divide by 10 and that's your rwhp you can make on those injectors.

so in your case...

(2 x 550) + (2 x 1200) = 3500

3500/10 = 350 rwhp

That's a rough calculation, and is based on 36 PSI of fuel pressure at 0 manifold pressure. So if you're running say 40 PSI of fuel pressure at 0 manifold pressure, you'd squeeze a few more out than that... but my "rule" works to be sure you're safe since it's based on 36 which is fairly low.

 

i have a very similar setup to yours, i made 378rwhp on the XS dyno with stock primaries but with 1300 cc injectors on 91 octane

 

http://rx7.com/cgi-local/3rdgencalc.cgi