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Thinking of going bigger turbo + injectors...


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Send me a PM on how you calculated this please :) Ive got most of it - but where you picked up the PR values and worked out the ratios :) Carl said not to bother with the turbo wastegate opening unless your over 600HP. Yes I need both gauges :) But its pretty nice as it is - so just havent made it a priority yet and Im in the process of ordering 7x0.010 :) Unregulated air to the elbow to see when WG opens you mean ? I think it was 28 psi ...... I think Carl also said that when you run it though it will open earlier due to backpressure from exhaust flow. So then not sure how to tell when its opening at RUNNING conditions. :think: (sorry Rogan - hijacking more than I intended - get back on track soon )

I'll put it here for the masses. I googled HE351 and S472 compressor MAPs for the best PR ratio's. Which is why that is peak airflow, and that's compressor potential, the turbine plays a role in total effectiveness. So pressure at sea level is 14.7 psia (ambient) and 0 psig (gauge). A compressor works with ambient pressure. The widest part of the S472 MAP is at a 2.75 PR, meaning it will compress the air 2.75 times. So 2.75*14.7 (psia) gets us 40.4 psia output, now subtract the input pressure (14.7) and you have 25.7 psig. Now when you get into compounds the secondary works with psia again, so were back at 40.4*3.0 = 121 psia output, subtract 40.4 and we are at 80.8 psig. The other numbers are derived the same by looking at the compressor map and picking PR's that will have good flow/spool, which is why it's not quite even. Who is Carl, and what wastegate is he talking about at the 600hp level, S472 or HE351?
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So, John (FAK) has been expressing various options with reasons (offline discussions) and I thank him for that. But I think a lot of good info will get lost that other members may be able to benefit from, so I brought the convo back public.Basically, I think I'm leaning towards the option of keeping the HX35 and throw in some small sticks (50 or 75s), to be honest.. BUT, here's my question/concern.. Right now, my truck with the Edge on 4 will smoke light a freight train (as previously mentioned) pretty much, at will. Won't this only get worse with bigger sticks? I understand I'll need to dial my box back. The biggest point of confusion for me is how M73M and others can run a bigger injector (rv275, etc.) on a stock turbo, and their box on 5x5 or greater... No way in hell I can do that, especially with a trailer on, and keep EGTs below 1100+ on any real type of engine load.

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I may have missed it, but what kind of boost do you build?

John, right now, the highest I've ever seen is 32psi for a split second. On average, it's max boost seems to hover around the 28-29psi mark.. Climbing the 6% grade, pulling ~9000lb trailer, 5th gear (nv5600) at 55-60, it's about 23-25psi, easily 1100*F+, but only hazing, if that.. That's with the Edge on 3x5 or 4x5. I've never towed in 5 or HotUnlock. Same hill, same speed/gear, with Edge on 2 or 3, it'll hover around 1000* and 22-23psi. Around town, rowing through the gears, it'll haze heavy at gear change/acceleration of 3, 4, and 5 on any Edge setting > 2. On 4, empty, it'll really bellow the smoke on gear-change accelerations til about 8-10psi. Think my stock sticks are wore out? 180+k miles on the truck.
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I'll put it here for the masses.

I googled HE351 and S472 compressor MAPs for the best PR ratio's. Which is why that is peak airflow, and that's compressor potential, the turbine plays a role in total effectiveness.

So pressure at sea level is 14.7 psia (ambient) and 0 psig (gauge). A compressor works with ambient pressure. The widest part of the S472 MAP is at a 2.75 PR, meaning it will compress the air 2.75 times. So 2.75*14.7 (psia) gets us 40.4 psia output, now subtract the input pressure (14.7) and you have 25.7 psig. Now when you get into compounds the secondary works with psia again, so were back at 40.4*3.0 = 121 psia output, subtract 40.4 and we are at 80.8 psig.

The other numbers are derived the same by looking at the compressor map and picking PR's that will have good flow/spool, which is why it's not quite even.

Who is Carl, and what wastegate is he talking about at the 600hp level, S472 or HE351?

Thanks I was trying to find the original thread I read about tuning all this - here it is for everyone else

http://www.competitiondiesel.com/forums/showthread.php?t=107957

Thanks for the walkthrough.

Carl builds twins on CF - Crazy Carls Turbos - hes one of the main builders :) And where I sourced my kit.

He was saying no value in porting out the wastegate on the he351 until your over 600hp.

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Right now, my truck with the Edge on 4 will smoke light a freight train (as previously mentioned) pretty much, at will. Won't this only get worse with bigger sticks?

Yeah - but bigger sticks push more fuel means more boost and when your operating in the key mart of the MAP longer then more efficient. So its not always that simple that it makes it worse.

Something doesnt sound quite right though ........... boost leaks ? Injector problem ? Intercooler ?

I am VERY (overly) conservative with EGT. With my he351cw and +75 sticks as well as HOT UNLOCK level 6 - I could only push black smoke at initial acceleration - as soon as rmp kicked in and spool started NO smoke and EGT at full acceleration up hill at WOT was about 1200.

Towing up hill was same - I could push 1250-1300 if I went too fast .......... thats why I went twins ....... but I dont pull a hill at 35 ..... Im generally doing 55+.

I have also sinced learned that I am probably overlyconservative on EGT - more than I originally thought. But I still feel better knowing I can pull all day long under 1200.

Do what John said - switch out your injectors first ...... and go from there on the turbo. And finally I really do think all the turbo choices are good .... (hx35/he351/hx40/hybrid/s300) ...... problem is noone has run ALL of them so we aere just going off MAP and what we ave read. But properly tuned they will all support 375-400HP and some 500HP :)

In meantime - someone build and run one of these before I do - I want a tester !!!!

http://www.pusherintakes.com/24_valve_intake_horn_manifold_3_inch_2nd_gen_p/24vs2gca.htm

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I am really thinking I'll just stick to the 35, and start gathering parts for a primary s47x addition.

as for sticks (75s), I'll start looking. I just hate that I have these 155s that are not being used, and will need to spend an additional 3-500$ for a set of 75s..

Just thinking out loud, here. :)

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images I found on DB site..

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