Bad Blu Formula

iTrader: (3)

My cam only car with 26lb. injectors maxes out injector duty (100% duty) at 5600rpm. With my TR230 it would be optimal to shift at 6500rpm. At that point (6500) my car is at a 13.9 A/F ratio with a 115% injector duty. To me that looks a little too lean for my tastes. Is there really any risk running the car like that or am I ok? A friend ran this exact set up in his car for 3 years with no problems but of course all cars are different. Plus my injectors have 127k miles on them if that means anything.

KCFormula

iTrader: (4)

If you are running 115% dc and your A/F is stuck at 13.9, I'd get bigger injectors. Your car is obviously not making max power and probobly not able to run optimum timing at that A/F. Why leave HP on the table?

tilly

iTrader: (5)

Can you say detonation :-D

GR33N GoblinM6

iTrader: (14)

i wouldnt ever take my injectors over 85% dc... thats just me..

lastcall190

iTrader: (36)

GuitsBoy

iTrader: (4)

Ive seen injectors work acceptably over 100%. 115% is really pushing it though. But what really scared me is the 13.9:1 AFR. Id get that down to 13.5 at the very most. Preferably down to 13:1 or even richer.

I was up around 112% with my stock 28# injectors. Switching to a set of matched SVO 30# redtops and now im at 85% DC max.

Kamin

never run injectors at 100% duty! that means you have NO control on the fuel going into the engine! thats called when an injector goes "static". BAD things can happen.

80-85% is the max you should EVER see.

gun5l1ng3r

I read an article a while ago regrading DC on injectors. Basically your car wants 15% more fuel than it is able to deliver at 6500RPMS. The DC is a ratio of how long the injector should be open (depending on injector flow and tuning) to how long the injector can stay open because of valve events...

Sorry if that doesn't make sense, or if you already knew that.
In the article I read, the author stated that some people say it is 'ok' to run over 100% DC, but the author would never push the injectors that far and rceommends about 85% MAX DC

Bad Blu Formula

iTrader: (3)

Has anyone ever had a tuner tell you that you're running out of injector and that it isn't safe to spin your motor too high?
I totally agree with your responses. Funny thing is that the car isn't detonating at high rpm, even that isn't making me feel ok about pushing the injectors like that. I was planning on getting some 30lb. injectors for when I install my new heads but was just wondering about the 26lb. injectors for the mean time.

Black Sunshine/ 00SS

iTrader: (1)

I've got some 28 lb injectors out of my 01, I'll give you a good deal on. PM me. About 8000 miles on them.

GuitsBoy

iTrader: (4)

If he's at 115% with 26# injectors, he'll still be at 107% with 28#.

studderin

iTrader: (28)

Just before they go static you'll have a slight rich hump. When the inj can't control itself, I wouldn't run that setup if its starting to lean out. How much power are you making?
Start with the basics, change fuel filter? Cheak your rail psi at that rpm, (pump getting weak)
We offer inj cleaning/rebuilding service, check Ebay we sell rebuilt 28s often. Or call if you need anything else.

AutomagicLS1

iTrader: (18)

Go bigger. I had a guy hook HP tuners up to my car just to see whats going on and scan it. I have 42lb injectors but at WOT they were working at 42% so either my injectors are messed up or thats al they really need to do. It was also a little rich. Those injectors are on a n/a application