Has anyone replaced there secondary injectors for higher flowing units and if so what brand?
My mechanic is talking about using Rochesters which I do not know to much about.

 

I am having good luck with 1st gen GSLSE 680cc injectors. The place which cleaned them for me stated beyond a reasonable dought that they are actually rated for 760cc.

They are drop in replacements for most 1986-1987 rx7's.

 

Nope, no one has ever replaced their secondaries with higher flowing units... we just prefer to run lots of boost without any extra fuel!
Just bugging you.

RC Engineering seems to be the most popular brand that guys are using. They have every size up to 1600cc.
Putting in 680cc, 720cc, or 850cc stock injectors is also a really good upgrade, if that is the size that you need for your application. Easy to find, work good, and cheap to buy.

 

Lots of people have, but remember this is a pointless exercise if you have a stock fuel pump. The pump runs out of capacity long before the injectors, so it should be replaced first. You also need a fuel contoller, otherwise you'll just run very rich and lose power. That's just means they tested them at a higher pressure than Mazda used to rate them. More pressure means more flow.

 

Hey NZ what do you think of the FD pump, I have stock injectors but if I upgrade to 680's or 720's should I get the a walbro?

 

bump

 

The FD pump is better than stock, but Walbro is much better again. The stock injectors can flow enough fuel for 300+hp if pressure is maintained, so unless you're planning on exeeding that soon, don't bother with the injectors, just change the pump.

 

Hey NZ, what hp do you think the stock fuel pump runs out at?

 

The gslse injectors were tested at te same pressure as my 550cc injectors. The pressure was at 42 psi with a "static pulse" of 8ms. Whatever the heck that means.

The 550cc measured 174cc and the gslse measured 238cc give or take 1% between the pairs.

Now if you take 550 / 174 = 3.16... Now multiply 238 x 3.16 = 752 (cc).

This proved the injectors were indeed 760cc long before they even started cleaning them.

www.injector.com did the work.

The owner also said that there has been conflict before with what orange top Mazda injectors actually flowed at. He swore by 760cc and I have the paper to prove it to me.

 

The fd pump is more expensive from mazda than a walbro pump from bnr or rx7store.