Tell me why I should get bigger injectors??

[TurboDave]

Yeah, guess without using DirectScan or a powerlogger I am flying on the blind side. I just feel so inadequate when people ask what injectors I am running and tell them 37lbs:biggrin: Guess I could always fib.

One way to verify if there's any more in them. Just crank in a notch or two or WOT fuel via your Translator +. See if that brings your WOT O2's up any. You should be trying to get it a littel richer anyway since you're running alky.

 

[Grumpy]

I say do a Fast system ( for the cool effect with the laptop on the seat at the car shows ) and leave the damm car alone .. we went mid 11s for years with ol blue tops (36's)

 

[tom j]

maybe some straight methenol, instead of 50/50 mix for some head room

 

[TR Custom Parts]

maybe some straight methenol, instead of 50/50 mix for some head room

Just went to straight meth. :smile:

 

[GNVYUS 1]

What no Scanmaster and you even sell those cool shades for it. :tongue:

But before we get too carried away with suggestions you do need to know what's going on to find the proper solution, DC% first.

 

[TR Custom Parts]

What no Scanmaster and you even sell those cool shades for it. :tongue:

But before we get too carried away with suggestions you do need to know what's going on to find the proper solution, DC% first.

I DO have a scanmaster but that is it!

 

[GNVYUS 1]

Oh, well I think the fast update gives you the DC window but it sounds like you don't have that huh?

 

[bison]

I still cant believe this thread is going. If hes not lean now and hes running straight meth instead of 50/50 then he sure as hell does not need more injector. Ive gone 116-117mph on old blue tops like Grumpy without the fp being turned up over 45. I bet i could have run 118+ with them if i turned up the fp. That was with out alky. The best thing to buy instead of injectors is a wideband and something that will read it or an egt readout. Injectors are clearly a waste. I see a lot of guys running 60's in their 12 second cars. Thats some funny $hit. At about 35-40%DC. Put 60's in. Put 60's in. Why not 83's or 96's? Might as well they are all fairly cheap. Even though 95% of the guys on here never need more than 50's .If you dont plan on running your car over 118mph then you dont need more than 42lb/hr injectors. Thats without alky. With it even less.

 

[PaCemkr86]

What's your duty cycle? If you do upgrade, might as well go straight for the 60 Mototrons. Good for 10's and idle very well. Replaced a set of 55's with them and it was a night and day difference in idle.

excellent advice..

but if you not gonna race it much, leave well enough alone.. If it aint broke dont fix it

 

[disco stu]

If the DC is good, you're good. But if you are maxin out the 36's, which don't take much, then there is no need to go less than 60's. I've played the injector ladder game, starting at 40 red stripes and going up. Back then the bigger injectors did not trim down as well, and chip burners were nowhere near where they are now. The 60's idle better than alot of other older style injectors. Just sayin, if you have to upgrade, no sense in going 42's, 50's, or 55's or whatever. The 60's drive better, and leave more to grow into. Without putting your pump in the ~75psi range, where pump volume numbers really drop off, under alcohol boost levels.

 

[GoldHawg]

several of the posts suggest that 60s idle a lot better than other injectors. I am about to upgrade (considering a set of flow-matched 50s) but I really want the regular street manners to be very stock. Can someone explain why 60s are better (or alternatively, why others are worse). I have stock injectors now, and will get a chip to match the injectors. Help me get the "knee in the curve" as far as performance potential and idle characteristics.
thx!

 

[PaCemkr86]

I can tell you from my past experience the 60's have way better manners then the 50#..

This info from Ken Mosher

The 60s are a nice solution for most ...

They use the new technology "pencil" design and have good low pulse width manners (which means they cruise nicely and idle nicely), yet really deliver the fuel at high demand (as the boost comes up and the airflow increases from a bigger turbo).

At 52 psi base pressure, I had a set that made 650+ HP (engine dyno) ... they were delivering about 71 lbs/hr, yet it was SPOT ON 14.65:1 AFR at idle.
__________________

 

[Mr.Spool]

mark,those 37lb injectors are more than enough with meth.i agree on the wideband to get a more accurate reading although 740 on the narrowband is lean.do you see 740 wot all the time or after the car has been street driven a bit?try adding fuel to bring the 02's up to 780's.

 

[Detroit Turbo]

The best thing to buy instead of injectors is a wideband and something that will read it or an egt readout.

Exactly, without knowing the actual AFR for your combo throwing bigger injectors in will do you no good. You'll be starting all over with a tune unless someone has your exact combo, but even then you'll have to dial it in with a WB O2.

 

[Nasty Wendy]

Mark if it ain't broke don't fix it. You know as well as we do that it is only a matter of time before you make some chrome fuel injectors. Upgrade when you change out to the chrome ones....until then enjoy life.

 

[SRGN]

I'd only change them if they're acting up. If they're acting up, throw in some 60s just so you'll never have to upgrade again, a lot easier than the 12 step turbo and injector program when you want to go faster.

 

[TR Custom Parts]

Just an update, got down with a Powerlogger install on the GN as well as the new model SM with 2.2 update chip. Seeing mid 90's on the duty cycle readings. 22-3 lbs of boost and this was at around 80-85mph.

Alky was set at 5 setting on the remote, 02's were around 800 so I guess I can lean it out a bit? At least I know where I am now.

 

[wickedtt]

I think I might have gone with the 50's or 60's so you could have had Eric Tweak you a widebandchip

 

[GNRick]

I just got my Directscan up and running. Went for a blast but rear end wanted to fishtail, so I got out of it, then put the pedal back to the floor. I have 009's, alky, TT chip. Also a brand new Cotton's front mount intercooler just to make you guys jealous :smile: When TPS showed 4.24 volts, injector duty cycle is 95%, O2's were 720, blm's were in the 135 range. So I guess I should add fuel pressure, right? I was thinking maybe I need bigger injectors but I read in another post that duty cycle is programmed into the chip. Is that correct? If so, then any injector will always show 95%, right? Oh, I had no knock, so maybe I should leave everything alone? Boost gauge showed 22-23 psi. Thanks for the help.

 

[TurboDave]

I just got my Directscan up and running. Went for a blast but rear end wanted to fishtail, so I got out of it, then put the pedal back to the floor. I have 009's, alky, TT chip. Also a brand new Cotton's front mount intercooler just to make you guys jealous :smile: When TPS showed 4.24 volts, injector duty cycle is 95%, O2's were 720, blm's were in the 135 range. So I guess I should add fuel pressure, right? I was thinking maybe I need bigger injectors but I read in another post that duty cycle is programmed into the chip. Is that correct? If so, then any injector will always show 95%, right? Oh, I had no knock, so maybe I should leave everything alone? Boost gauge showed 22-23 psi. Thanks for the help.

No, duty cycle is not specifically programmed into a chip. Parameters are set that can make them run that hard. You are definately running out of injector if you're running that high a duty cycle with such low O2's.