boost drop - 57 trim ct26

[IndigoMKII]

and the guy who told you "The reason it was able to keep PSI to within 1 was all the restrictions in the stock piping, more restrictions=more pressure" has NFI what his on about on that part.

Really? Marvel me with your knowledge oh wise one.


Actually, I'll leave this here since I have NFI what I'm talking about. Flow is directly related to the opposite of pressure. In other words, if something flows more the pressure will decrease and the exact opposite.

The stock system is able to maintain its pressure due to shitty flowing intercooler piping, which is 2.25" except for a cast elbow which goes down to 1.75" IIRC, and the horrible flowing intercooler. Since you're only pushing this system to say in the OP's case 16 PSI, the 57 trim is able to flow that while maintaining its pressure because the capable flow is greater than the actual flow thus maintaining its pressure through the revs.

Now if you lift some of those restrictions, all the stock plastic pipes and the shitty intercooler, you're allowing it to flow more. So what was said earlier about the flow? It's directly related to the exact opposite of pressure. So if the system is able to flow more, you now need to maintain that pressure which causes the turbo to spin faster to get the desired PSI. The turbine housing isn't capable of matching the needed pressure so when the engine is ingesting more than the turbo can put out, the pressure drops.

This shows how much air the 7mgte will consume at what RPM. As you can see, if the 57 trim does flow 40 lbs/min it's more than capable of keeping up til 7k rpms but the turbine wheel can't do it.

15psi (2.02040816326)



RPM ------ NA ------------ TURBO CFM ----- lb/min
---------------- STOCK BORE ENGINE
---------- 180Cid -------- 2.020408163 ----- 14.472



2500 ---- 104.1666667 ---- 210.4591837 ---- 14.54250855
2750 ---- 114.5833333 ---- 231.5051020 ---- 15.9967594
3000 ---- 125.0000000 ---- 252.5510204 ---- 17.45101025
3250 ---- 135.4166667 ---- 273.5969388 ---- 18.90526111
3500 ---- 145.8333333 ---- 294.6428571 ---- 20.35951196
3750 ---- 156.2500000 ---- 315.6887755 ---- 21.81376282
4000 ---- 166.6666667 ---- 336.7346939 ---- 23.26801367
4250 ---- 177.0833333 ---- 357.7806122 ---- 24.72226453
4500 ---- 187.5000000 ---- 378.8265306 ---- 26.17651538
4750 ---- 197.9166667 ---- 399.8724490 ---- 27.63076624
5000 ---- 208.3333333 ---- 420.9183673 ---- 29.08501709
5250 ---- 218.7500000 ---- 441.9642857 ---- 30.53926795
5500 ---- 229.1666667 ---- 463.0102041 ---- 31.9935188
5750 ---- 239.5833333 ---- 484.0561224 ---- 33.44776966
6000 ---- 250.0000000 ---- 505.1020408 ---- 34.90202051
6250 ---- 260.4166667 ---- 526.1479592 ---- 36.35627136
6500 ---- 270.8333333 ---- 547.1938775 ---- 37.81052222
6750 ---- 281.2500000 ---- 568.2397959 ---- 39.26477307
7000 ---- 291.6666667 ---- 589.2857143 ---- 40.71902393
7250 ---- 302.0833333 ---- 610.3316327 ---- 42.17327478
7500 ---- 312.5000000 ---- 631.3775510 ---- 43.62752564

 

[ca91mkIII]

Actually, I'll leave this here since I have NFI what I'm talking about. Flow is directly related to the opposite of pressure. In other words, if something flows more the pressure will decrease and the exact opposite.

I may be new to these vehicles and turbos, but what Indigo said is basic fluid dynamics and physics.

 

[IndigoMKII]

I may be new to these vehicles and turbos, but what Indigo said is basic fluid dynamics and physics.

nah it can't be, I have nfi what I'm talking about. its impossible for a restriction to cause pressure to be easily maintained.

the same is made anytime you use a water hose. pinch the end of the hose and pressure increases.. damn you Bernoulli.

 

[ca91mkIII]

^ Haha

 

[Mikael_7m]

Really? Marvel me with your knowledge oh wise one.


Actually, I'll leave this here since I have NFI what I'm talking about. Flow is directly related to the opposite of pressure. In other words, if something flows more the pressure will decrease and the exact opposite.

The stock system is able to maintain its pressure due to shitty flowing intercooler piping, which is 2.25" except for a cast elbow which goes down to 1.75" IIRC, and the horrible flowing intercooler. Since you're only pushing this system to say in the OP's case 16 PSI, the 57 trim is able to flow that while maintaining its pressure because the capable flow is greater than the actual flow thus maintaining its pressure through the revs.

Now if you lift some of those restrictions, all the stock plastic pipes and the shitty intercooler, you're allowing it to flow more. So what was said earlier about the flow? It's directly related to the exact opposite of pressure. So if the system is able to flow more, you now need to maintain that pressure which causes the turbo to spin faster to get the desired PSI. The turbine housing isn't capable of matching the needed pressure so when the engine is ingesting more than the turbo can put out, the pressure drops.

This shows how much air the 7mgte will consume at what RPM. As you can see, if the 57 trim does flow 40 lbs/min it's more than capable of keeping up til 7k rpms but the turbine wheel can't do it.

15psi (2.02040816326)



RPM ------ NA ------------ TURBO CFM ----- lb/min
---------------- STOCK BORE ENGINE
---------- 180Cid -------- 2.020408163 ----- 14.472



2500 ---- 104.1666667 ---- 210.4591837 ---- 14.54250855
2750 ---- 114.5833333 ---- 231.5051020 ---- 15.9967594
3000 ---- 125.0000000 ---- 252.5510204 ---- 17.45101025
3250 ---- 135.4166667 ---- 273.5969388 ---- 18.90526111
3500 ---- 145.8333333 ---- 294.6428571 ---- 20.35951196
3750 ---- 156.2500000 ---- 315.6887755 ---- 21.81376282
4000 ---- 166.6666667 ---- 336.7346939 ---- 23.26801367
4250 ---- 177.0833333 ---- 357.7806122 ---- 24.72226453
4500 ---- 187.5000000 ---- 378.8265306 ---- 26.17651538
4750 ---- 197.9166667 ---- 399.8724490 ---- 27.63076624
5000 ---- 208.3333333 ---- 420.9183673 ---- 29.08501709
5250 ---- 218.7500000 ---- 441.9642857 ---- 30.53926795
5500 ---- 229.1666667 ---- 463.0102041 ---- 31.9935188
5750 ---- 239.5833333 ---- 484.0561224 ---- 33.44776966
6000 ---- 250.0000000 ---- 505.1020408 ---- 34.90202051
6250 ---- 260.4166667 ---- 526.1479592 ---- 36.35627136
6500 ---- 270.8333333 ---- 547.1938775 ---- 37.81052222
6750 ---- 281.2500000 ---- 568.2397959 ---- 39.26477307
7000 ---- 291.6666667 ---- 589.2857143 ---- 40.71902393
7250 ---- 302.0833333 ---- 610.3316327 ---- 42.17327478
7500 ---- 312.5000000 ---- 631.3775510 ---- 43.62752564

Thanks Indigo, was very informative.

 

[IndigoMKII]

No problem.