I'm in the process of putting my car back together with a single and considering putting the 850's in the primary's. I've already got the 1600's in the secondary's and was wondering if there are any negatives to having the 850's in the primary's. The way I look at it the more fuel you have available the better. I don't want to get to the point of putting everything back together and needing more fuel. Do you guys thing 550's and 1600's is more than enough while running 22# with the GT35/40?

 

If I were you I would go bigger than 550 cc in the primaries. That turbo at 22 PSI is going to require alot of fuel. Since the stock 850's will go right in you could use them for now and see how things work out.

 

from what i have read here and by searching, you have problems with idle and everyday streetability with bigger primaries.

 

Not if the tuning is right. Friend of mine just got his T04S tuned with 850cc x 1600cc and PFC. Idles great, runs smooth.

 

go for the bigger primaries...it doesn't HURT and won't effect idle.

 

I asked the same question not too long ago and got a good response check it out:
https://www.rx7club.com/forum/showth...threadid=79614

hope that helps