First, sorry I've missed out on this thread for so long. Been a busy busy few weeks, even more than normal. Lots of really good info.
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Originally Posted by PGreenSVT
I have been out of this thread for a while and there has been some good information and some misconception. A smaller nozzle that is sized correctly for the injector size is going to yield the best overall results. Note that I said overall. Obviously if you size the nozzle so that you have to advance the timing to dangerous levels to empty the injector you are going to have dangerous cylinder pressure. You have then also sized the nozzle incorrectly. You need to size the nozzle so that your SOI is not to far advanced and the injector has sufficient time to empty as it nears the lower portion of the power stroke, thereby applying force to drive the piston throughout the power stroke. If you have an overly large nozzle the injector empties (just for example) in the top third of the power stroke. You will get a more violent combustion with higher cylinder pressure and now the power stroke is relying on that initial burst to drive it through the rest of the power stroke.
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Again the key is to size the nozzle to the injector size so that you can empty the injector within the allotted PW window without having to advance the SOI event to dangerous levels without using a nozzle that is so big that it empties the nozzle prematurely. Yes if you have a larger nozzle the tuner can cut back the pulse width and inject less fuel but it will do so with less atomization than the smaller nozzle which results in higher temps and an incomplete burn causing it to smoke more.
Now how many of you spend your time running your engines in excess of 3000 rpm? So how important is it that your engine be tuned and injectors sized to have its best power above 3000? If you are a Drag truck or a Puller then yeah, I'll buy that. If you are looking for a street truck with great all around performance that runs cool with minimum smoke and best throttle response the smaller nozzle is the way to go for most.
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Way back on like page 3 I was gonna post something very similar, and my phone flipped out and it didn't post it, then I've been out of touch for a few days since then, and wow this has blown up. I agree whole heartedly, that mirrors what both bill and Jesse warren told me.
Quote:
Originally Posted by Tuscany
I don't see why anyone who is towing anything heavy would consider spending the extra $600-$700 for nozzles when the peak hp isn't going to be that much higher than stock nozzle 175's. Bill has already proven that a 175 stock nozzle is just as good as a 175/75 for peak power (minus a few hp, but considering the cost to hp gain to me it's not worth the extra money) and better for towing heavily without anything special needed such as a larger turbo and special tuning to haul heavy with.
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You indeed can empty a 175 inj on stock nozzles, but at higher rpm where pw is limited, that means starting the injection cycle earlier to dump the fuel 'in time'.
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Originally Posted by Six0~Stroker
It might not make WAY more power, but it will make a noticeable power increase. Whether or not it justifies the cost... Well that is my choice (and everyone has to make that choice themself) Not have someone tell them what is justified or not.
Also, you have not even touched on the topic of nozzle quality. Because a 175/stock nozzle is just that a STOCK, USED nozzle that is worn out. New nozzles will flow better/more even because they are new!
THAT is really what the $600-700 is really paying for... The added power is just a bonus  |
That's the only real reason I went with aftermarket bigger nozzles in the first place. I've seen what worn out nozzles and poor atomization do on some of the core engines we get back. Melted pistons, cracked pistons, bad stuff.
Quote:
Originally Posted by william_ace
I'm very excited to see Eli's setup once tuned properly. Has gearhead upgraded his turbo at this time? I believe he has 175/30s correct?
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yes, I have 175/30's at the moment with stock turbo. I called jesse askin about his stock plus, or 155/st inj, and he quickly pointed me to the 175/30. I told him I dont tow really often, maybe once a month or so over the summer for a mud bog, and its around 10-12k lbs. You can always pull fuel out, but as mentioned with really large nozzles, you loose atomization when doing so potentially. Thats why Jesse steered me towards the 30's instead of the 75's. I trusted him after talking with him, smart man. I told him I didnt want to set any hp or land speed records, just something fun to drive that was still practical, and he agreed that that was what most of us want. I personally think 175's will he a great alternative to the 190's as you don't immediately have to get into the rest of the fuel system upgrades right away.
Stock tuning temps were fine, 1100 max, wot from a stand still. Temps only got bad when I had the hercules ficm tuner on it, paired with the looney wild. Great throttle response also came with the herc ficm tune, and i only needed like 15-18% throttle to totally pull away from traffic at a stop light. It'll hit 33psi, stock turbo at like half throttle rolled in with the tc locked. However, it'll also hit 15-1600* at half throttle from a stand still with the herc and looney wild. It's fast, and I know for sure I could tow fine with it as long as it wasnt on the Hercules setting. I could probably tow most loads around here on looney and atlas 40. I love the setup personally, now i need more turbo. Talking with Adrian about that now, I might do some work for him in exchange for a hybrid, but part of me really wants a stage 3, but I feel like that would cause a hair more lag than the hybrid. I'll get some dyno numbers up really soon, as soon as my trans is fixed, still haven't had time to look at that yet. Maybe I can do a before and after with 175/30's and stock vs hybrid turbo, I think theres a few people who'd be interested in the results...
12-04-2012, 05:17 PM
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