I just installed an HKS TO4E kit on my FD, with a PFC, and a Greddy Two Row FMIC. I have asked about injectors because I need to upgrade soon. Many of you have said 1200, 1300's or even 1600 secondaries. I talked to Chris at Rotary Performance today, and they will be tuning my car in two weeks. He recommended only replacing the primary injectors with 850's and then tuning. What do you guys think?

 

How much power you looking at making?

 

I would like over 400 if possible. I think it is possible with the TO4E, but Chris said it probably won't be able to produce over 450. What do you think?

 

Get 1600s

850s wont be enough, or will be close to max duty cycle. With injectors, secondaries at least, bigger is better and safer.

 

Jason,
Look at the Rx7.com catalog in the fuel section and there is a calculator there for trying different injector sizes and duty cycles to find out how much hp they can support.
Jack

 

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

 

I was running 4 x 850cc with a To4E A/R .84exaust and I was hitting about 94% on the injectors at 1kgcm boost with a good size port and 45psi fuel pressure. I would recomend using larger injectors...

 

just run the stock primaries, and get the fuel rail/ 1600cc injectors from Rx7.com, very nice peice, possibly one of the best upgrades anyone has come out with, its simple, and gives you the fuel you need, with a turbo that size, you definetely wont have to worry about running out of fuel, and if you decide you ever need to run a different/bigger turbo, youll have enough fuel for that also, saves you money in the long run, you'll want more power from a larger turbo eventually, the T04e is just slightly better in peformance than the stock twins, its just great for a little more power and a simpler turbo system.
Rob

 

thanks for the advice. I think the TO4E is really all I will ever want. You never know though, my car may sometime seem to slow for me though, and I will want to upgrade the turbo.

 

I give it 6 months

 

I talked to Chris at RP again, to ask him exactly why he recommends replacing the primaries with 850s and here are the reasons.
1. Many people have recommended 1200's or 1300's but they are simply bored out 850's, and the components of the injectors are not made to support being modified like that.
2. The 1600 secondary upgrade would work though, he said it would be overkill with my setup, and they are really made for large turbo setups and would likely be ineffecient to a certain degree at some rpm levels with my setup. He said they would cause the system to hiccup at some points.
3. The 850's have been a tried and proven, safe, reliable and effective upgrade, and would be the best way to go with my car.
I guess if I go with a really large turbo later on, I can always upgrade the secondaries at a later time.

Anyway, that is what I was told.

 

1. True. Make sure you get OE larger injectors, not boed out smaller ones.

2. I would prefer overkill when it comes to injectors. The second part about hiccups sounds like a dud tuner trying to cover his **** or trying to cover the bad tunability of his chosen brand of aftermarket ECU.

3. Why buy 2 lots of injectors? Just buy the big ones to begin with and you wont have to worry about them again.

 

get your 1680cc (160lbhr) injecotors here for $75 ea
get your fuel rail here http://www.k2rd.com/Online_Catalog/FD3S/FD3S-index.htm for $220
Then go to radio shack and get the 2 10 ohm resistors for about $0.20 each

 

I have had mine for 2 years. It's not the biggest but it's doing the trick. I have yet to run into that *** WHIPPIN that I know for sure is out there when I do then I'll think about upgrading, I know cars are out there with much more power then me.