Injectors, old topic but what's new

[cougar]

If you have been following my other threads, I'm trying to lower my EGTs for better towing. I would like this topic to be about what are the new theories concerning injector attributes. Please keep in mind when answering mine is a work truck not a street racer, even though I've gotten the undivided attention of a few 3rd and 4th gen drivers. You can see in my signature what I am currently running. The DAP 7X0.010 injectors have served me well for a long time. But, after the Scheid IP upgrade EGTs are difficult but not impossible to control. I'm still working with Turbo Lab to get the missing parts to install the 62mm compressor. That should also help, but what could a change in injectors do for me?

[Richie O]

I still have the smoky 6x.016's in my 93 from JL machine. My 92 has stock sticks a 60 cool side 16 hot side H1C with 4 inch exhaust and only the cone ground mod ( no fuel screw adjustments ) and it gets hot towing. Timing is stock as well. I am so far out of the wrenching loop on these I have to call Philip to get me out of trouble. Forgot what little I did know.

[cougar]

Those 7X10s started out in my 91.5. It had a 5 speed and a big HTT turbo as well. That setup worked quite well for the most part. Had to run in 4th on a grade with a load to keep the EGT down without any loss of speed. Once I get the 62mm upgrade on I'll see were I'm at. I'm thinking 6X12 or 13 may be the next step, but I'd like to know more about the latest theories.

[1STGENFARMBOY]

My 93 was very hot towing with everything in my sig line, I did the power stroke intercooler, GDS 60mm/16 mod, and Tims cooler tubes at the same time so I don't know what helped the most, but those three upgrades absolutely fixed my high EGT's, now if anything starts getting warm on a long grade it's the coolant.


just for reference, before the wheel, intercooler and tubes on a flat out run my EGT's would blow by 1600 like it had no intention of slowing down, now 1200 is max.

[cougar]

At one point in time I was attempting to do the PS intercooler upgrade, but found the fabrication more difficult than I could handle in both equipment and time. I suspect, but can't prove of course that the added fuel forced through small holes is now being over atomized because of the Scheid injection pump. That is why I'm thinking fewer larger holes, but about the same flow rate as I have now. Mishimoto offers an aftermarket intercooler that is not too badly priced. So that, along with water/meth injection are things possibly on the back burner.

[KTA]

On my crew cam I am running 7x.011 sac nozzles from power driven. I switched from an hx35-12 to a s300g57mm 80ar and dropped egts over 500 degrees. It still can hit 1500-1600 on a hard pull but it is running mid 40's for boost so I am about 400hp to the tires I would say. At 350hp the s300 could probably keep it cool. Radiator capacity at that power level is also an issue. I plan to twin it which should cure the egt's. Even over 600rwhp old yellow would not go over 1300egt after I put the twins on.

[Richie O]

On my crew cam I am running 7x.011 sac nozzles from power driven. I switched from an hx35-12 to a s300g57mm 80ar and dropped egts over 500 degrees. It still can hit 1500-1600 on a hard pull but it is running mid 40's for boost so I am about 400hp to the tires I would say. At 350hp the s300 could probably keep it cool. Radiator capacity at that power level is also an issue. I plan to twin it which should cure the egt's. Even over 600rwhp old yellow would not go over 1300egt after I put the twins on.

I have a stock s300G 57mm on my 89. It is at 300 hp with an auto but it can still get 15 to 1600 too. Mine boosts around 35. Stock non ic injectors. My timing is bumped a bit on that truck. I am fine with it, it never tows.

[cougar]

Well, looks like my only solution is to seriously turn down the fuel, getting boost down to around 35. If the turbo won't spool, I still have the 60mm compressor. Maybe a set of 5X12 injectors. As far as other stuff goes, physical limitations and funds prevent other probably more useful changes. Shop rates around here are around $150 an hour.

[cougar]

I pulled the trigger. Ordered a set of "flow honed" 6X0.009 injectors from THD. Was looking for 6X0.010, but those that were on the market are now off. By the time they get here, enough of the snow should be gone I can pull my truck out.

[spencerdiesel]

I just installed my PDD “Stage 2” injectors yesterday, was running THD 6x10s w/ pump at runaway. I backed the fuel screw out 2 turns while installing the PDD sticks.

I wasn’t expecting much power gain as I’m STILL running a stock H1C, but there is definitely some added power. I’ll have to do some timed 40-70 mph runs (my “standard” of testing) and see where we’re at.

[cougar]

Not a happy camper, not happy at all. THD has seriously let me down. I ordered the injectors March 25th and it turns out they never had them in stock. This was supposed to be an exchange. They have my money; they have my OEM cores. Their reply to my latest inquiry " thank you for reaching out to me. I haven't had a chance to call you yet. However, the nozzles that we get from this hone shop don't seem to be ever getting done. Are you ok with changing your order to 5x12 nozzles?" If I had wanted 5X12 I would have ordered 5X12. I have requested a refund and return of my cores as I sent them to them, in running condition. I hope that is what I get back.

[spencerdiesel]

Not a happy camper, not happy at all. THD has seriously let me down. I ordered the injectors March 25th and it turns out they never had them in stock. This was supposed to be an exchange. They have my money; they have my OEM cores. Their reply to my latest inquiry " thank you for reaching out to me. I haven't had a chance to call you yet. However, the nozzles that we get from this hone shop don't seem to be ever getting done. Are you ok with changing your order to 5x12 nozzles?" If I had wanted 5X12 I would have ordered 5X12. I have requested a refund and return of my cores as I sent them to them, in running condition. I hope that is what I get back.

Sorry to hear that, Ive only done 8-9 WOT pulls with the PDD Stage 2’s but so far:
Previous 40-70 mph w/ stock H1C/ maxed pump/ THD 6x10s/ timed to the head: 6.8 sec best case (winter). Summer heat usually yielded 7.0-7.5 sec

After PDD sticks, same timing, fuel screw BACKED OUT 2 turns from previous, all else identical: 6.0 seconds flat in 75 deg w/ 85% humidity.

Best things so far, these injectors are even cleaner than the 6x10s, less smoke at all throttle positions, SAME EGT’s but remember it’s making substantially more power. I’ve been skeptical of the PDD Powerjet injectors because everything appeared to be a classic “too good to be true”, and also being a newly released injector design.

However, so far I’m impressed as the 40-70 times are just barely trailing a stock 5.7 Toyota Sequoia, and the Yota is 1200 lbs lighter than my 1st gen.

[cougar]

Eric called me later yesterday and we talked. He said the vender he uses for flow honing is not sending him nozzles and no longer answers his phone. He said he will make it right by sending me a set of 6X.010s from DAP. Should be equal to or slightly better than the flow honed 6X.009s. The reason I'm going backwards in performance is to take the stress off the truck and get rid of the black cloud that always follows me around. Fun days are over. I will be turning down the pump and probably go back to the stock fuel pin. Nothing more I can undo to the pump without replacing it. That would cost too much $$$$.

[cougar]

Just received the injectors and they came with seals. Thanks to THD for working to make it right and kudos to DAP for working with THD and picking up the fumble. I would say this erases any remaining bad blood between me and THD.