Very small 12 valve tow twins

madmikeismad said:
I'd like 700 out of it.
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As long as your power goals keep going up, why not go with a small/big combo? I know Sean Gammel made 900rwhp at DPC a few years ago with a 57mm/95mm combo on his CR....Darren Morrison also made 900+ with a 62/95 setup. Just got to wastegate the small charger a lot.
 
There is a small hole into the air flow. I put a self tapping screw in it.
 
JQmile said:
As long as your power goals keep going up, why not go with a small/big combo? I know Sean Gammel made 900rwhp at DPC a few years ago with a 57mm/95mm combo on his CR....Darren Morrison also made 900+ with a 62/95 setup. Just got to wastegate the small charger a lot.
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Sorry I missed this.

I don't want to go super big because
price
still need decent spool for towing
price
I already have the 67
price
LOL

900 would be nice, but then I need rods, and I'm a 12 valve. If I had a CR I'd try it in a heart beat.
I thought darren used a 64 on that truck? (not a big deal, just thought that was what I saw)

Eventually, I might throw a gate on the manifold to bypass the secondary, and go with whatever the fancy new thing is at the time. Like a super-fmw-awesome-wheel for a 106mm.
 
madmikeismad said:
So here's how mine is going now: Side by Side setup, he351cw over s467/83/1.25 T6.

I'll port the gate, or send out the spare to get a new/different internal gate eventually. My goal with that t6 housing is faster secondary spool, and more top end out of the 67. I'd like 700 out of it.

What does the 351 gate open at stock?
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I like where this is going! If I keep my truck I may ditch the s472 and use something smaller like you have above.


I can't wait to see how this works out.

:pop:
 
Shop I hang in just got a couple 116 mm ball bearing precision turbo for the big turbo on an alcohol tractor. Nice looking turbos, really spin easy.
 
gwhammy said:
Shop I hang in just got a couple 116 mm ball bearing precision turbo for the big turbo on an alcohol tractor. Nice looking turbos, really spin easy.
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Are the alcohol's limited to 504ci where you are?
 
Update.
For Now just running a standard compound setup, but still trying to figure out the efficiency of a2w or inter stage cooling. I want to keep egts down around 800 on grades, instead of 1200 with this single 67.

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I think that's the limit and two stages. They run the 6000 lb. outlaw class I think.
 
Also, I apologize to the mods, I just realized I posted this in the competition vehicle section, and this is in no way a competition build LOL Besides wanting to be the fastest tow rig.
 
Assuming you want to make 800 or so flywheel hp (~700-740 whp depending on parasitic drivetrain losses), and assuming you want your hp to peak at 3500 rpm, and assuming the altitude and average annual temperature of Johnson City (this is the highest city you have listed), you need a primary that flows 80 lb/min and a secondary that flows 43 lb/min. The HE351CW is amazing for this and a S472 or 475 will get you where you need. A good CAC with 85% efficiency will have an outlet temp of ~115 *F (this is assuming the average temperature of Johnson City). Air to air aftercoolers work better for on road vehicles. Air to water intercoolers are generally better for low speed applications.

Edit: I forgot to mention I used boost pressures of 21 and 60 psi for the atmospheric and high pressure turbos respectively.
 
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0 Xero 0 said:
Assuming you want to make 800 or so flywheel hp (~700-740 whp depending on parasitic drivetrain losses), and assuming you want your hp to peak at 3500 rpm, and assuming the altitude and average annual temperature of Johnson City (this is the highest city you have listed), you need a primary that flows 80 lb/min and a secondary that flows 43 lb/min. The HE351CW is amazing for this and a S472 or 475 will get you where you need. A good CAC with 85% efficiency will have an outlet temp of ~115 *F (this is assuming the average temperature of Johnson City). Air to air aftercoolers work better for on road vehicles. Air to water intercoolers are generally better for low speed applications.

Edit: I forgot to mention I used boost pressures of 21 and 60 psi for the atmospheric and high pressure turbos respectively.
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Damn how'd you figure all that out?
And my 67 (primary) should flow 95lb/min. It will definitely flow enough with a t6 1.25.

For the record, my residence is now moore, ok. JC and Buffalo are just where I call home.

I'll be shooting for 30psi out of each turbo, maybe 40, using the general 1:1 ratio I keep hearing about.
 
I made a turbo calculator because I couldn't find one to properly size compounds. Unless your 67 is custom, it won't flow much over 80 lb/min (and if it can flow that, you'd be on the choke line). I don't know where you heard the 1:1 rule, but it doesn't work like that. If we use Moore, OK for your calculations, you have a barometric pressure of 14.04 psi and an average temperature of 60 *F. Let me show you the math for calculating the pressure ratios (the y-axis on a compressor map). For your atmospheric turbo you'd have the following:

(30+14.04)/14.04 = 3.14

Now your high pressure turbo will compound this pressure like this:

(30+(30+14.04))/(30+14.04) = 1.68

A pressure ratio that low is nowhere near the most efficient points of a turbo. Most turbos like a pressure ratio of 2.25 or better. Just for reference, on Cat C15 Acerts, the low pressure turbos are wastegated at 21 psi and the high pressure turbos are wastegated at 45 psi. Granted, this setup isn't as ideal at higher altitudes, but it's sort of a catch all. I hope this makes sense to you. If you don't know how to read a compressor map, I strongly suggest you learn to. It will make your life much simpler.

Using boost pressures of 21 psi and 55 psi, you'd need a primary that flows 79 lb/min and a secondary that flows 46 lb/min.
 
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I never did learn to read compressor maps. They're beyond me.

Why don't you think the 67 can flow 90+?

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0_Xero_0, thanks for posting that calculator. I'm playing with it a little right now. Also, you have some pretty cool compressor maps/flyers. I love that old school one for "upgrading your dodge to HX40 or Pro 52" !
 
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The surge line on the s467 FMW from BW barely touches the 85 lb/min line on the map. That's probably why. But it doesn't matter cause if your engine can't ingest it, it won't flow that much anyways. You have to have RPM, VE, L, PR to know what it will actually flow.
 
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