best injectors for PMR's

[juniort444e]

Tuning is a must if you want them to live. And treat them better than i did. My heavy foot and crazy nights of chasing deer didnt help them out. But in my honest opinion, if you are worried about blowing them up, dont add any power. If you dont care and have plans for another build or motor then by all means do what you want, just dont break the block like i did.

Tuning is the most important part like others have said already. And dont go to big of a turbo either. I still believe and was told that that was partially the problem.

 

[juniort444e]

Every time I see one of these threads about "what injectors are best" for whatever unstated purpose - I want to answer 400/400s.

I knew there was a reason i liked you. :grouphug:

 

[big_stroker]

It was explaned to me buy a tuner a while ago that 238/80 hybrids are probably the best choice for guys with PMR's. With out going into great detail its because it takes less timing and everything in the tuning to make power with these injectors than it does with others. I was also told 400hp PMR truck with 238/80 with good tunes is safer than a 300hp stock PMR truck with just tunes.

Maybe I was told wrong I dont know just throwing that out there.

 

[juniort444e]

I would agree with that, but the one major problem in the equation is PMR's. They have blown apart stock, with injector, turbos, mild tunes, safe tunes, and they have held together for some over the 400hp mark for longer than anyone could imagine. Its a gamble when you have them, your taking a risk no matter what you do to the motor power wise with those rods.

But you are correct big stroker. The tuner i talked to some time ago even told me that my 250/200's were better than stock sticks, BUT my big turbo would cause unburnt fuel to be left in the cylinders in certain situations and when it decides to ignite not only do i have the freshly injected fuel but i have extra fuel that was already in the cylinder that is hard to tune around and get rid of. Now that i have a forged rods and when the money gets here im going with a different tuner and i will see how big the differences are. Should be interesting.

And a side note, my pmr motor finally blew up around 180000 miles. I would say it lasted long enough with the abuse that it endured. But im sure with better tuning, and maybe even a smaller turbo it could have kept on ticking.

 

[CurtisF]

But you are correct big stroker. The tuner i talked to some time ago even told me that my 250/200's were better than stock sticks, BUT my big turbo would cause unburnt fuel to be left in the cylinders in certain situations and when it decides to ignite not only do i have the freshly injected fuel but i have extra fuel that was already in the cylinder that is hard to tune around and get rid of.

Huh?

 

[TyCorr]

Huh?

How has your truck been doing.Curtis? You ever dyno tune your setup and find out.what kind.of.power you're making?

 

[juniort444e]

Huh?

Pocket, im not the best at describing some things. But that is what i was told. He even told me that he wouldnt tune my truck until i got a forged rod motor, which i can respect a ton.

I will try to explain it a little better. The tuner told me that in a CERTAIN condition or situation, there would be too much fuel injected and not enough air to burn it, most would go out as black smoke but some would be left wet in the cylinder. It wouldnt do this all the time or in all the cylinders, but just a little bit of extra unburnt fuel left from the previous cycle along with the freshly injected fuel would be enough to cause more than enough cylinder pressures in that one cylinder to blow the pmr up.

I dont know how else to put it. Just trying to relay what i was told.

 

[CurtisF]

How has your truck been doing.Curtis? You ever dyno tune your setup and find out.what kind.of.power you're making?

I dyno'ed right before Truck Fest in August. Made right at 408 hp on the rollers with some uber-conservative timing. Timing was pulled back so far that I hit a point where increasing PW was netting zero increase in HP, but just pouring out black smoke.

So I re-addressed the timing, and bumped it up since then. Time slip at Bandimere suggests around 425-430 hp (14.4 @ 92 mph on a 8000 lbs lifted truck). Since Truck Fest I've addressed various tuning strategies and many tweaks, but never have I increased the fuel pulsewidth above what I used to make my last run. However, ICP and timing changes obviously have had an effect on overall power, so I'm not really sure right now if I'm higher or lower.

Other than that, it runs fine. I'm still dialing in the tuning, although it's been slow lately, and I only get to it every now and then. It runs fine overall, except some idle quality issues. Other than that, EGT's are low, there's very little smoke, and it runs like a beast. Even cold starts in single digit temps aren't too bad for such large nozzles. Used to be worse, but I've significantly reduced it over the past few weeks.

 

[CurtisF]

Pocket, im not the best at describing some things. But that is what i was told. He even told me that he wouldnt tune my truck until i got a forged rod motor, which i can respect a ton.

I will try to explain it a little better. The tuner told me that in a CERTAIN condition or situation, there would be too much fuel injected and not enough air to burn it, most would go out as black smoke but some would be left wet in the cylinder. It wouldnt do this all the time or in all the cylinders, but just a little bit of extra unburnt fuel left from the previous cycle along with the freshly injected fuel would be enough to cause more than enough cylinder pressures in that one cylinder to blow the pmr up.

I dont know how else to put it. Just trying to relay what i was told.

But in that case it would be simply pulling the fueling back at lower RPM and/or lower boost levels. Seems that if there's enough fueling to cause a rod to break, then it was too much to begin with... regardless of the turbo.

 

[TyCorr]

I dyno'ed right before Truck Fest in August. Made right at 408 hp on the rollers with some uber-conservative timing. Timing was pulled back so far that I hit a point where increasing PW was netting zero increase in HP, but just pouring out black smoke.

So I re-addressed the timing, and bumped it up since then. Time slip at Bandimere suggests around 425-430 hp (14.4 @ 92 mph on a 8000 lbs lifted truck). Since Truck Fest I've addressed various tuning strategies and many tweaks, but never have I increased the fuel pulsewidth above what I used to make my last run. However, ICP and timing changes obviously have had an effect on overall power, so I'm not really sure right now if I'm higher or lower.

Other than that, it runs fine. I'm still dialing in the tuning, although it's been slow lately, and I only get to it every now and then. It runs fine overall, except some idle quality issues. Other than that, EGT's are low, there's very little smoke, and it runs like a beast. Even cold starts in single digit temps aren't too bad for such large nozzles. Used to be worse, but I've significantly reduced it over the past few weeks.

This is excellent news!

430hp is a fair amount of power in my book..does that make a heavy, lifted, cc truck feel fairly nimble? You are running stock fuel if I remember correctly?

Would it be asking.too much if I asked you to post a cold start video? Im interested to witness what you experience as a bad or rough idle. My truck with high mileage injs idles.choppier than my.buddies 02 that has 126k on it. I think mine are getting near their useable limit at 256k miles.

Everytime I see that youtube video from beans where Charles does his burnout I become jealous ofhis rolling idle quality. It almost gallops and doesnt have the clattery diesel quality. I picture your.idle being similar to this.

 

[big_stroker]

I would agree with that, but the one major problem in the equation is PMR's. They have blown apart stock, with injector, turbos, mild tunes, safe tunes, and they have held together for some over the 400hp mark for longer than anyone could imagine. Its a gamble when you have them, your taking a risk no matter what you do to the motor power wise with those rods.

But you are correct big stroker. The tuner i talked to some time ago even told me that my 250/200's were better than stock sticks, BUT my big turbo would cause unburnt fuel to be left in the cylinders in certain situations and when it decides to ignite not only do i have the freshly injected fuel but i have extra fuel that was already in the cylinder that is hard to tune around and get rid of. Now that i have a forged rods and when the money gets here im going with a different tuner and i will see how big the differences are. Should be interesting.

And a side note, my pmr motor finally blew up around 180000 miles. I would say it lasted long enough with the abuse that it endured. But im sure with better tuning, and maybe even a smaller turbo it could have kept on ticking.

Pocket, im not the best at describing some things. But that is what i was told. He even told me that he wouldnt tune my truck until i got a forged rod motor, which i can respect a ton.

I will try to explain it a little better. The tuner told me that in a CERTAIN condition or situation, there would be too much fuel injected and not enough air to burn it, most would go out as black smoke but some would be left wet in the cylinder. It wouldnt do this all the time or in all the cylinders, but just a little bit of extra unburnt fuel left from the previous cycle along with the freshly injected fuel would be enough to cause more than enough cylinder pressures in that one cylinder to blow the pmr up.

I dont know how else to put it. Just trying to relay what i was told.

I understand what you are saying... Bigger turbo = harder to light = cant push out unburnt fuel = PMR's get some fresh air.

 

[golfer]

I understand what you are saying... Bigger turbo = harder to light = cant push out unburnt fuel = PMR's get some fresh air.

eh...

my take is that a larger/slower to spool charger would prevent the low end hp (ie, torque)...that the PMR's don't want to be subjected to...

say the turbo lights off ~2200rpm...hitting its stride @ 2700...that would keep the tq in check, and reduce the lower rpm, high cylinder pressure from a quick spooling charger with large(r) injs...

 

[CurtisF]

This is excellent news!

430hp is a fair amount of power in my book..does that make a heavy, lifted, cc truck feel fairly nimble?

Yes it does. Ass end likes to swing around pretty quickly if I hammer on it.

You are running stock fuel if I remember correctly?

I'm running a stock 17 degree HPOP, but the fuel is from a Walbro pump along with the fuel lines completely replaced and stock fuel bowl delete with a remote mounted fuel filter and W/S setup.

Would it be asking.too much if I asked you to post a cold start video?

That's a great idea.

Im interested to witness what you experience as a bad or rough idle. My truck with high mileage injs idles.choppier than my.buddies 02 that has 126k on it. I think mine are getting near their useable limit at 256k miles.

Everytime I see that youtube video from beans where Charles does his burnout I become jealous ofhis rolling idle quality. It almost gallops and doesnt have the clattery diesel quality. I picture your.idle being similar to this.

What's funny is my idle is actually very smooth after a cold start, and while the engine is below NOT. Only after it's fully warm does the idle quality start to chop a bit. That's the part I'm still trying to figure out.

 

[big_stroker]

eh...

my take is that a larger/slower to spool charger would prevent the low end hp (ie, torque)...that the PMR's don't want to be subjected to...

say the turbo lights off ~2200rpm...hitting its stride @ 2700...that would keep the tq in check, and reduce the lower rpm, high cylinder pressure from a quick spooling charger with large(r) injs...

I understand were your coming from... But I also wouldn't want a big turbo sitting there than cant clean up the fuel siting in the cylinders at a little lower RPM... I could be wrong but wouldnt that cause high CP as well?


I guess what i'm saying is I would want a turbo that can light when ever you tell it to and just control the fuel with the tuning at what RPM's you want it to be at to keep CP down.

 

[Hotrodtractor]

How in the world did a bigger harder to light turbo equate to high cylinder pressures down low?????

What is this stuff about unburnt fuel and wetted surfaces in the cylinder causing sudden cylinder pressure spikes under certain conditions???? If there are wetted surfaces - then you had too much fuel to begin with... the only time you get to that level is perhaps initial turbo spool up on an unlimited single truck...... that isn't what we are talking about here....

I'm not even sure I know where to begin.

 

[big_stroker]

Thats why i asked... I really dont know. Ive just always been under the impression that to big of a turbo makes things worse.

All just go back to working on setting up my new server here at work and shut up now.

 

[Chvyrkr]

Pocket, im not the best at describing some things. But that is what i was told. He even told me that he wouldnt tune my truck until i got a forged rod motor, which i can respect a ton.

I will try to explain it a little better. The tuner told me that in a CERTAIN condition or situation, there would be too much fuel injected and not enough air to burn it, most would go out as black smoke but some would be left wet in the cylinder. It wouldnt do this all the time or in all the cylinders, but just a little bit of extra unburnt fuel left from the previous cycle along with the freshly injected fuel would be enough to cause more than enough cylinder pressures in that one cylinder to blow the pmr up.

I dont know how else to put it. Just trying to relay what i was told.

Who tuned your truck? DP?

 

[juniort444e]

Yes chvyrkr.

Jason, teach us something bud. Im only spitting out what i was told over a phone. I dont fully understand everything yet. Im still a dumbass learning here and blowing motors up as i go along.

 

[MINK]

lolz

 

[golfer]

I understand were your coming from... But I also wouldn't want a big turbo sitting there than cant clean up the fuel siting in the cylinders at a little lower RPM... I could be wrong but wouldnt that cause high CP as well?

no sir