Question about injectors

[Excessum]

When is it the proper time to upgrade injectors? I've been reading about different sizes and such, but I haven't seen much about when they should be changed and how big they should be for which application. Plus, would it be worth it to convert the fuel rails to top-feed for the SR20? Just curious about that is all. Thanks.

[TatII]

it depends on how much power your looking to make. if your goin to stay with the stock turbo, then the stock 370cc injectors will be. ( this is assuming you have a SR20DET ). if your looking to make around 300whp reliably then a 480cc sidefeeds from a S15 will do fine. if you want to make around 350whp on street gas and 400whp on race gas, then you can get 550cc injectors. i have a set off SARD side feed injectors that are 550cc that is waiting to be put in my car. you can also find nismo sidefeed 555cc injectors also known as tomei injectors. they als0 720cc side feed SARD or Tomei or Nismo injectors that are good for 450whp.

the cost will run you around 400-600 dollars for 550cc to 720cc. it seems like alot but for those injectors in top feed, it will cost around 120-150 per injectors and the fuel rail will cost around 200 bucks and for 720cc's you need resister packs for each injectors.

[Excessum]

Now would the bigger injectors work well with the stock turbo or with an upgraded one? I had a figure I wanted to achieve, which was about 300 whp/300 tq but after reading about some higher numbers, I decided I was gonna see what I could get with the money I have for the SR20DET project I have set up. I was considering getting at least a T28 installed after I got the money for it but if I can make some decent power without it, I can focus on other stuff.

Sorry for all the questions folks, I'm just trying to find out how much money to put aside for my project.

[TatII]

for a stock turbo 370cc will be fine as you will not hit 300whp. if you get larger injectors, you need a SAFC to tune them anyways. so if your running the stock turbo with larger injectors, it will be a waste of money to tune it, just to have to tune it again when you get a larger turbo. the other alternative is to have jim wolf write you a program to run larger injectors so no tuning is required. but that will require you to take out hte ECU and send it to them and you won't get it back till a month and 600 dollars later.

[S13wanabe]

hey TatII, when are you going to dyno your car again. I'm curious to see how much power you are making now. Also if you wouldn't mind, could you send a list of the parts to the turbo kit you pieced together. You could send it to my email if you don't want to post it.

[driftking777]

just to add my 2 cents...just as a helper..for injector sizing every 1 horsepower (to the crank) should have 1cc...so for 300hp you should have atleast a 300cc injector...going above that is usually better though...like for 300hp...a 370cc should be fine...if im wrong someone correct me

[TatII]

i had the car redynoed and i'm making only 214whp. i have no clue why. i checked my compression and its perfect. i think its from a clogging cat, and for some reason i'm only running 7 psi now so i guess i got a pretty big boost leak. also i think the software they used got changed so the readings are not consistance anymore.anyways i'm goin to fix all that problem over time, i'm goin to redyno my car after i'm completely done with it and running 17 psi. then i should be in the 350whp range on street gas and close to 400whp on race gas running 19-20 psi.