TeamSwift

Hypothetically (of course)

So, lets say I just got an 87 sprint running again after a decade of sitting. Upon the test runs, it shows I am needing just a little more fuel injector to keep up with what I am currently running. What would be the best and easiest upgrade without breaking the bank. (As I don't need much, just a little)
I have run stock stuff for so long, I really never dabbled into the wild world of slightly souped up parts.
Also, what other items usually go along with this type of upgrade?
Thanks in advance.

stock injectors flow 210 cc/min. you could find some cast off honda injectors on ebay in the 250 to 290 cc/min range pretty cheap.

_________________
1991 Blue Geo Metro Convertible highly modified 1.0L Turbo3 5 spd. - 2000 Chevy Metro 1.3L MPFI automatic. - 1991 Red Geo Metro Convertible customized 1.0L 5 spd.

My Turbo3 Project

My Cardomain Page -Ol' Blue

My YouTube Channel

My Photo Gallery

SAAB Sonett II

I have bought several sets of used injectors on Ebay with good luck.

Just look for the high impedance ones, and be sure they include the
connectors, in case they are different clips than the OE ones, you can
splice in the new clips.

The used stuff on Ebay is cheap enough that it's not a big loss if they don't
work out based on the flow rate you choose. Of course, I'm assuming you
have an A/F gauge which should tell you how the injectors are performing.
Unfortunately there's no way to monitor or adjust duty cycle if you are running
stock stuff. You kinda just gotta go with the A/F readings and pick the best size
with the overall performance.
Based on my project, 15psi boost, upgraded high flow fuel pump, and modified fuel
pressure I tried several sizes:
240 = lean under boost
275 = acceptable overall, though just slightly lean at full boost
380 = Way too rich at moderate to full boost
I've just purchased some 320, I'm hoping these will work out best

You probably won't have to worry about running rich at idle as the o2 sensor
will compensate. It's pretty much the boost setting that will determine your
needs. You can slightly tweak the way your injectors perform by changing
spring tension in the maf.


I've paid about $40-60 for a set, but you're probably gonna have to buy
a set of 4

Ebay seller zipaquio seems to have some good stuff.

Thanks guys. That is the info I needed.
I was actually looking at a set, but didn't want to pull the trigger on something that wouldn't work.

Oh yeah, forgot to mention that of course you want to
visually ID the injectors to make sure they're the same
shape/style.

Keep us posted on your results!

If you only need a minimal increase just up the fuel pressure by 10 psi so that you are getting an increase across the board. Probably work out cheaper that stuffing around with extra injectors.

Cheers
Paul

that works okay if you have an adjustable fuel pressure regulator.

the turbo3 system has a fixed fpr that maintains fuel pressure at a constant 36.2 psi above manifold absolute pressure up to the limit of the fuel pump.

_________________
1991 Blue Geo Metro Convertible highly modified 1.0L Turbo3 5 spd. - 2000 Chevy Metro 1.3L MPFI automatic. - 1991 Red Geo Metro Convertible customized 1.0L 5 spd.

My Turbo3 Project

My Cardomain Page -Ol' Blue

My YouTube Channel

My Photo Gallery

SAAB Sonett II

I understand that you would have to buy an adjustable FPR but surely that is better, easier and cheaper than stuffing around with injectors trial and error style?

there's a limit to the available headroom of the fuel pump's pressure output. if you run higher fuel pressure to trim the injectors, it cuts down on the total boost pressure you can run.

_________________
1991 Blue Geo Metro Convertible highly modified 1.0L Turbo3 5 spd. - 2000 Chevy Metro 1.3L MPFI automatic. - 1991 Red Geo Metro Convertible customized 1.0L 5 spd.

My Turbo3 Project

My Cardomain Page -Ol' Blue

My YouTube Channel

My Photo Gallery

SAAB Sonett II

http://www.teamswift.net/viewtopic.php?f=32&t=47916&start=25

Page 2 on this post, bout halfway down shows the B&M Fuel Pressure
Modifier, about $50. It's designed for Honda's, but will work fine.
You will need to shim it slightly with a thin washer to get
the housing to snug up properly.

I believe T3 ragtop has a similar setup on his current project.

The problem with upgrading injectors on the stock system (with the FPR and
upgraded pump) is that if you go too big, you will run pig rich under light
boost. As the turbo boost kicks in at high pressures, you will see a
quick dramatic drop in the a/f ratio- which will put you at a more desireable
a/f ratio. Definately not good for crusing around town, but better if
you are only doing short balls out runs. You have to find a happy medium
depending on your purpose.
Of course your results will vary based on actual airflow. If you're running
high boost with the stock turbo and piping, you'll get different results
than running a larger turbo with increased diameter piping. The stock
turbo can only flow so much air, no matter what boost you set
and there's many variables like exhuast tubing size, muffler, air filter
set up...etc.

Changing fuel pressure too much also messes with spray pattern of the injector, so you can only get so far with that modification. The larger injectors are where it's at.