650cc injectors, how's your idle? (Minimum pulse width?)

[Really_Soaked]

For anyone running 650 cc injectors, what's your minimum pulse width like? How is the idle?

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[el~sharko]

I've got modded stockers and my idle is pretty nasty

[LatentWagen]

^^^ ditto, but only on coldstart

[SBW]

Originally Posted by Really_Soaked

For anyone running 650 cc injectors, what's your minimum pulse width like? How is the idle?

if you mean pe650's, they're a pain, I screwed around with my 0% column for a while in order to get idle right. I just kept changing 0% column and watched delta dash basically.

[Really_Soaked]

I do mean the PE 650s. I'm hearing a lot of conflicting opinions on how much fuel I'm really going to need for ~350 hp. The calculators on the net (all of which I think come from RCEng) are pretty conservative. So it's either STi pinks or PE650s or UR 680s. If the pinks will do me, I don't want to deal with crappy idle issues of larger injectors. I'll be running the AEM EMS.

This one's a toughy, I just can't decide.

[SBW]

I've heard different opinions on what to use for BSFC. So im not sure what to tell you regarding that. I also used the same calculator and spoke to marren fuel injection (since its a town over in derby) and they explained a lot of things to me, they explained to me that my sti pinks would be enough for the 400 crank hp I was trying to make. But with wrx's anyway, it just didn't work, not if your trying to go no higher than 11.2afr at peak torque to redline on 93 pump gas.

I do not like the pe650's, they took a lot of fuss to get them to run right. Some people believe a reflash of the ecu is necessary to get them to run right, while others believe a utec will take care of them as long as you just take the time to tune out the odd things they'll do sometimes. I think sti pinks should be fine for 350 crank hp.

[skywalker]

Originally Posted by Really_Soaked

I do mean the PE 650s. I'm hearing a lot of conflicting opinions on how much fuel I'm really going to need for ~350 hp. The calculators on the net (all of which I think come from RCEng) are pretty conservative. So it's either STi pinks or PE650s or UR 680s. If the pinks will do me, I don't want to deal with crappy idle issues of larger injectors. I'll be running the AEM EMS.

This one's a toughy, I just can't decide.

This is highly dependant on what octane you plan to be using. If you were going to run 100 octane I would say the STi Pinks would work fine for 350WHP. Though if you are going to be running on 91 octane then you will need some bigger injectors and an efficient turbo.

As for crappy issues with larger injectors I don't believe we have had a problem yet getting the idle smooth on PE, Ultimate Racing, STi, Perrin Modified, even the infamous cut injectors, etc... It is all possible to get a perfectly smooth tune/idle, though years of tuning helps to know what to look for.

Cheers,
William T. Knose Jr.
Lead Programmer
I-Speed USA

[WRX-Blue-Mica]

I use PE 650 with UTEC, Jun Cam, TGV Delete, 2.35 ltr block, Fp Green and my idle is fine and not difficult to tune it with UTEC. Only when the engine cold, the engine become lumpy and sound sooo nice like the race car.
No problem at all with PE 650 cc ...

[mantra1]

I installed PE650's about a month ago for a future turbo upgrade. I'll I can say is I miss my pinks. Car occassionally stalls and idle is lumpy. Idle fluctuates around 750 then drops to 600 and almost dies. Pulse rate has been adjusted per PE specs. My tuner will have another crack at it this week and see if we can smooth it out. Also, intitial throttle input is abrupt, not smooth like the pinks. Tuned with ECUTek. Just my $.02

[4830DeuceWRX]

^^ agreed, I just got rid of my 650's and and going w/ some pinks...650's would do if I couldnt get by on pinks (No sure why I got 650's in the 1st place)...cant wait to have a nice idle again...