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One MEELYUN horsepower! *in Dr. Evil voice*

Just kidding. I am feeling 379 hp though. No other guesses needed. I'll take an XL. ;)

Keep on keepin' on man! I'm really enjoying your build, and we're all rootin' for you. You've got the support of an entire forum and Warrior family.
 

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Can I ask how you chose the turbo you're running? Are you spinning the engines higher than 5000 rpm?

I assume your running at Bonneville @ 5000 ft which puts air pressure at 12.2 psi.

You're running a 3340 cc engine for a total displacement of 203.81 cubic inches. At 5000 rpm you'll have a theoretical cfm of 291. At a more realistic 80% you'll be pumping 233 cfm naturally aspirated. That equals 18.84 lbs.per minute of air flow.

Using the high desert as the facility we see we'll be at 12.2 psi so the pressure ratio will be 2.54 [(12.2 +18.8) / 12.2].

When I look at the compressor map for the GT4088 the intersection of 18.84 lbs per minute and 2.54 comes up out of the efficiency zone of the turbo. Therefore I assume you are spinning either much higher rpm or the specific turbo you are using has a much different compressor / housing than the off the shelf units.

Yes, I was actually doing math to determine what you should be making for HP. What bothered me was when I used 18.8 psi of intercooled boost and came up with a theoretical 310 hp for your machine and realized the turbo you're using is a 400 to nearly 700 hp turbo. This puts you in a very inefficient area for the turbo at best, or at worst puts you in the the surge area of the turbo. That made me realize that there is something else missing in the equation. Either the turbo sales guy didn't do his math or there is something else different from running two stock warrior engines.

Not trying to be a jerk here by the way. Please don't think I'm trying to poop on this project in any way. Just trying to understand the missing link and why you've been recommended that turbo that has that style compressor map.
 

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Can I ask how you chose the turbo you're running? Are you spinning the engines higher than 5000 rpm?

I assume your running at Bonneville @ 5000 ft which puts air pressure at 12.2 psi.

You're running a 3340 cc engine for a total displacement of 203.81 cubic inches. At 5000 rpm you'll have a theoretical cfm of 291. At a more realistic 80% you'll be pumping 233 cfm naturally aspirated. That equals 18.84 lbs.per minute of air flow.

Using the high desert as the facility we see we'll be at 12.2 psi so the pressure ratio will be 2.54 [(12.2 +18.8) / 12.2].

When I look at the compressor map for the GT4088 the intersection of 18.84 lbs per minute and 2.54 comes up out of the efficiency zone of the turbo. Therefore I assume you are spinning either much higher rpm or the specific turbo you are using has a much different compressor / housing than the off the shelf units.

Yes, I was actually doing math to determine what you should be making for HP. What bothered me was when I used 18.8 psi of intercooled boost and came up with a theoretical 310 hp for your machine and realized the turbo you're using is a 400 to nearly 700 hp turbo. This puts you in a very inefficient area for the turbo at best, or at worst puts you in the the surge area of the turbo. That made me realize that there is something else missing in the equation. Either the turbo sales guy didn't do his math or there is something else different from running two stock warrior engines.

Not trying to be a jerk here by the way. Please don't think I'm trying to poop on this project in any way. Just trying to understand the missing link and why you've been recommended that turbo that has that style compressor map.
 

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Discussion Starter #60
Can I ask how you chose the turbo you're running? Are you spinning the engines higher than 5000 rpm?

I assume your running at Bonneville @ 5000 ft which puts air pressure at 12.2 psi.

You're running a 3340 cc engine for a total displacement of 203.81 cubic inches. At 5000 rpm you'll have a theoretical cfm of 291. At a more realistic 80% you'll be pumping 233 cfm naturally aspirated. That equals 18.84 lbs.per minute of air flow.

Using the high desert as the facility we see we'll be at 12.2 psi so the pressure ratio will be 2.54 [(12.2 +18.8) / 12.2].

When I look at the compressor map for the GT4088 the intersection of 18.84 lbs per minute and 2.54 comes up out of the efficiency zone of the turbo. Therefore I assume you are spinning either much higher rpm or the specific turbo you are using has a much different compressor / housing than the off the shelf units.

Yes, I was actually doing math to determine what you should be making for HP. What bothered me was when I used 18.8 psi of intercooled boost and came up with a theoretical 310 hp for your machine and realized the turbo you're using is a 400 to nearly 700 hp turbo. This puts you in a very inefficient area for the turbo at best, or at worst puts you in the the surge area of the turbo. That made me realize that there is something else missing in the equation. Either the turbo sales guy didn't do his math or there is something else different from running two stock warrior engines.

Not trying to be a jerk here by the way. Please don't think I'm trying to poop on this project in any way. Just trying to understand the missing link and why you've been recommended that turbo that has that style compressor map.
I hear what you are saying. Normally I would pick a turbo that spools up quickly and has an airflow that plots almost all the way across the map. This setup will have a very loooong lag and it maps very close to the surge line as it comes up on boost. However, it should be at full boost around 3900-4100 and at the most efficient part of the map close to redline. 18psi @ 5000 rpm will be roughly 537 cfm. We chose a twin scroll with ball bearings to help it spool a little faster.

This is definitely not the turbo I would have picked for a street, drag or standing mile build. The biggest issue I have had with doing this in the past is if you short shift into 5th you may not be able to get back on boost. Then you have to shift back to 4th, get back on boost, run it back up to redline and the into 5th.
 
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