Injectors- Evo 8 work???

[Punish'nRice]

I have a set of 660cc evo 8 injectors that a friend gave me when he upgraded to 1000cc injectors.

Has anyone ever ran evo 8 injectors before?

As long as they are low impedance will they work with a '89 Smec?

Thanks
Mahlon

[turismolover22]

Im pretty sure they will work and fit, but man those things are huge.

[Punish'nRice]

Im pretty sure they will work and fit, but man those things are huge.

Well +40 injectors are 556.5cc at 53lb/hr. So an extra 103.5cc would be too much?

[wheming]

Wouldn't that be good then? Means you could drop your fuel pressure down.
That would kind of help me out right now.
What year Evo?

[turismolover22]

But at a certain fuel flow and pressure you begin to drop off flow and your spray pattern. You need a minimum pressure to maintain a sufficient spray pattern to optimize fuel atomization.

[wheming]

But at a certain fuel flow and pressure you begin to drop off flow and your spray pattern. You need a minimum pressure to maintain a sufficient spray pattern to optimize fuel atomization.

Do we know what that is for said injectors? With the Evo bring a 2.0 I can't see where we couldn't run close to their base fuel pressure. It has to be less than 55, no?

[cordes]

Do we know what that is for said injectors? With the Evo bring a 2.0 I can't see where we couldn't run close to their base fuel pressure. It has to be less than 55, no?

I'm sure they're running the lower 43?PSI base pressure. That really frees up a lot of headroom for the FP.

[Punish'nRice]

Wouldn't that be good then? Means you could drop your fuel pressure down.
That would kind of help me out right now.
What year Evo?

Evo 8's are from 2003-2005. His is a 2003. I'll see if I can find out what fuel pressure his car runs at.

[wheming]

I had an 03 Evo 8. But I never had s fuel gauge on it.
I like the sound of doing this. Just, I don't have the knowhow to rescale and make any other required tuning changes.

[turbovanman²]

I've tested injectors down to 20 psi, still had the same spray pattern as 55 psi. We could lower our fuel pressure like everyone elses, would save the fuel pump.

[wheming]

I've tested injectors down to 20 psi, still had the same spray pattern as 55 psi. We could lower our fuel pressure like everyone elses, would save the fuel pump.

That's my big thought. Gus used +40's in Slug but with the stock computer and 25psi base pressure. It would idle around 20ish. Never seemed to be a problem.

Does anyone have the part number for those Evo injectors mentioned? Were they stock or an Evo upgrade injector?

[tryingbe]

Using big injectors by only lowering fuel pressure and not adjusting the injector pulse time on the computer is a waste of time and money.

Given the same pulse time width, why would you want your big injectors to flow the same as your stock injectors? You just effectively made your big injectors to became stock injectors, along with all the stock injectors' limitations.

The proper way to use big injectors is to decrease the pulse time via computer control, so you can add boost and/or up the RPM.
Lower the fuel pressure if you're running of fuel pump, which doesn't apply to most TMers as they are making less than 400hp.

[wheming]

RRFPR.
I know its old school and not optimum but it works.

I'd want the big injectors to act like stock injectors, but with less fuel pressure.
Or rather big injectors scaled to run about 30-40psi base pressure via cal.
The big hangup is I'm not a calibration writer/expert.

[jonnymopar]

As long as they are low impedance will they work with a '89 Smec?

I've been running high-impedance injectors (SRT Stage 1) on my 89 SMEC for 5 years now. The only problem I have is a code 26 that won't go away, but other than that, it works fine. If anything, the driver ICs in the SMEC are probably running cooler now with the decrease in power.

[tryingbe]

Or rather big injectors scaled to run about 30-40psi base pressure via cal.
The big hangup is I'm not a calibration writer/expert.

Type the number in, click ok, save, burn chip, profit?

[tkelly27]

EVO 8 injectors are 510cc. I know this because I am looking at a tephra V7 map for a stock EVO 8 right now. Your friend may have 660's but those did not come stock on an EVO.

I ran 550cc's in my van and I had to compensate a pretty significant amount in MPtuner for them. I think I ran them at about 70pph, 55pph when I was running E85. 510cc's will be about 69pph. It makes sense, my friend ran 450cc DSM injectors at about 65pph in mptuner.

If those are really 660's you will want to start around 85pph in MPtuner. If you drop the base pressure it will obviously be smaller.

EVO and DSM base fuel pressure is 37.5psi (2.5bar) where as a dodge is 55psi (~3.5bar), that's why there is the difference between the size in cc's and pph in mptuner.

It is good to drop the fuel pressure for the fuel pump. at 55psi base with 25psi of boost you're at 80psi at the inlet of the rail. With stock dodge fuel lines and an old fuel filter you could easily be at 90-100psi at the pump. A wally 255hp will drop flow dramatically at 100psi. If you drop the base pressure to even 40psi you could be at 85psi at the pump, which makes the wally happier.

With 510 or 550's you could drop the base pressure to 40psi and still safely make 350ish to the wheels, maybe more. You can get bosch regulators that bolt on in the junkyard off of euro cars like volvos.

You have to shave down the O-rings to get DSM style injectors to work. It takes an afternoon, but I get 450cc and sometimes larger injectors for free, so it's worth it for me. Sounds like your free EVO injectors will work too.

[Punish'nRice]

Thanks for all the input.