zfaylor
Comp Diesel Sponsor
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- Nov 21, 2010
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It is 71mm.... 99% of them come with a 75mm from the factory whether they are TMF based or GTA42 based. Low horsepower units came with a 71mm GTA42 base typically.
w/m for 12.7 detroit
- Thread starter allan5oh
- Start date
It is 71mm.... 99% of them come with a 75mm from the factory whether they are TMF based or GTA42 based. Low horsepower units came with a 71mm GTA42 base typically.
Yeah I'm a nerd. I have all the software and flash it probably a couple times a week. I've opened the valve cover dozens of times playing games with different clearances on the valves. I even have a digital egt gauge. Divorced compressor intake. Walker mega flow muffler straight out the rear (weed burner). Fun!
As far as spooling when you're shifting hundreds of times a day yes it's important when you drive through the back roads of Wyoming at high elevation yeah it's important. Don't forget not wanting just to dump a **** load of fuel getting your truck and oil dirty. You're wasting fuel at and richer than the smoke limit. Not to mention soot is an abrasive.
But you're likely right about my expectations.
Hey if there's something wrong with my engine I'm all ears.
jfaulkner
Douche Hunter
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Basically it seems you started this thread wanting to hear answers that supported your ideas. Obviously that has failed miserably and you don't want to take any advice of anyone that might actually know what works. Leon forgot more about the 12.7 than most will know and you took what he did, and has done for a ton of trucks and screwed it up.
If you want to mess with W/M then go ahead but your going to need a huge tank. Meanwhile you'll get your butt handed to you by a mildly tuned truck running the correct parts.
If you want to mess with W/M then go ahead but your going to need a huge tank. Meanwhile you'll get your butt handed to you by a mildly tuned truck running the correct parts.
Ok but it's the compressor map that matters. How do those compare?
425 volvos came with a 62mm inducer
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BRE
Active member
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I just wanna make you aware, because I don't think you know this...
You're arguing with a turbo manufacturer that does a great deal of work with class 8 stuff, and a top notch high hp class 8 engine builder/truck owner/ and I've heard rumors he's drove one like twice.
These guys aren't Tom and Jerry at the coffee shop. They are well aware of how these engines work and how to make them run.
Might take that into account. I realize you don't like their answers, but it doesn't make them wrong.
SmokinCAT
Cheap and Easy.
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That is until the FL actually has a cat in it.
BRE
Active member
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Nah I didn't screw it up I tweaked it for my own purposes. His tune was great for the larger turbo but it also smoked at times to get that thing to light. It definitely made more power before. I highly recommend him and have given him lots of business.
I want need a huge tank like I said before because I only need extra power on one or two passes. Mostly this is about experimenting and I haven't seen anyone respond "Yes I tried it worked good" or otherwise yet. But what I can do is share dyno verified numbers here. I have nothing to lose if it works or not.
I actually don't see much arguing? I see a difference in what we define as an ideal engine. Mine is just different than most. I hate smoke. I like a turbo that isn't lazy. I'm not willing to give that up for more power. Some people are. To each their own.
Also about the turbo inducer vs hp, that has more to do with the rpm limit of the engine. 1800 vs 2110. Again matching the compressor map to engine needs.
Now here comes the interesting part.
Detroit rated their engines quite strange. The HP rating is not peak. It is at rated rpm if it's 1800 or 2110 rpm.
But it gets even more strange!
For different ratings of the same engine, say 430, 470, and 500, the difference is only at rated rpm. Below that there is no difference whatsoever. None. As long as the ratings are the same torque.
So that means if you're never near rated rpm you will never notice the difference between different hp settings.
Hey weren't you on TTR in the past? I recognize the handle.
Who says it's a 400 hp turbo? Also I'm definitely putting more than stock fuel to it. It's cool now but won't be in the middle of summer at high elevation.
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After docking around with matchbot for way too long. Way too long. I've found a few things:
- the 71mm is probably the best choice for stock or near stock 12.7s. Especially ones with an 1800 limit.
- the 75mm is a better choice if you want to make over 40 psi or want to run over 1600 rpm. It's obviously moves a lot more air.
- if I could have sex with a compressor map, it would be with that 72x96 fmw one. Where have you been all my life? I bet you can't get it with a 96mm hot side though right? This might be the replacement for the 171701/171702 plus fmw means it's stronger. Holy **** look at how flat the islands are at higher boost!
- the 71mm is probably the best choice for stock or near stock 12.7s. Especially ones with an 1800 limit.
- the 75mm is a better choice if you want to make over 40 psi or want to run over 1600 rpm. It's obviously moves a lot more air.
- if I could have sex with a compressor map, it would be with that 72x96 fmw one. Where have you been all my life? I bet you can't get it with a 96mm hot side though right? This might be the replacement for the 171701/171702 plus fmw means it's stronger. Holy **** look at how flat the islands are at higher boost!
OR idiotic. I just love when a driver tells me he picked up mpg changing hp ratings. Not a tune, just changing ratings. Because it "works easier" or something.