Recommended / Preferred charge pipe?

[ArmenLS1]

I'm seeing mixed suggestions on the charge pipe factor. Power gains seem minimal to zero. However, reliability factor is another question. If running an OTS Stage 2 map, targeting 22, 23lbs boost. Would it be wise to swap out the stock charge pipe for an aftermarket one? If so which one is better designed to seal properly and not vlow off.

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[kyle9]

Stock charge pipe is fine for OEM or hybrid turbos. You’ll only need an aftermarket charge pipe if you get a new intake manifold (oem won’t quite fit right with most) or if you want to run meth injection.

 

[ArmenLS1]

Stock charge pipe is fine for OEM or hybrid turbos. You’ll only need an aftermarket charge pipe if you get a new intake manifold (oem won’t quite fit right with most) or if you want to run meth injection.

Appreciate the feedback. The stock one looks compressed and narrow in certain parts, (likely for clearance), none of that is a restriction?

 

[kyle9]

Appreciate the feedback. The stock one looks compressed and narrow in certain parts, (likely for clearance), none of that is a restriction?

I don’t think you’ll find a single person that has any data to show that it makes any difference.

At some point I’m sure it’s a restriction, but you’ll have already upgraded your intake manifold by then (and maybe added meth)if you’re pushing 800+ whp.

 

[PikkaGTR]

Ran the FTP pipes on the S55 and now the B58
They have been nothing but good products

 

[Tsuki8]

I don’t think you’ll find a single person that has any data to show that it makes any difference.

At some point I’m sure it’s a restriction, but you’ll have already upgraded your intake manifold by then (and maybe added meth)if you’re pushing 800+ whp.

I vote for the stock chargepipe.

Not advocating Mishimoto's chargepipe, but they had some data.
I'm sure its a good pipe, but have no experience with it.
https://www.mishimoto.com/engineering/2021/06/toyota-a90-supra-charge-pipe-production-sample-2020

 

[razorlab]

Over 40 track days on the oem pipe, now making over 500whp and 27psi.

Also fits just fine with the Wagner intake manifold.

 

[Extreme Power House]

The stock one is not prone to failure, so you do not have to change it now.
But the FTP is better quality and a little larger in diameter.

If you decide to get an upgraded charge pipe, my vote goes to FTP

 

[Supra Jr.]

Over 40 track days on the oem pipe, now making over 500whp and 27psi.

Also fits just fine with the Wagner intake manifold.

Hybrid turbo or just running E blend?? I'm guessing at 27psi you have a hybrid or your stock turbo would fail!!!

 

[razorlab]

Hybrid turbo or just running E blend?? I'm guessing at 27psi you have a hybrid or your stock turbo would fail!!!

Pure700

 

[Shelby Miles]

Stock is fine. Only do it if you like the look or have a true legitimate need as mentioned by others.

 

[i3igpete]

Not advocating Mishimoto's chargepipe, but they had some data.
I'm sure its a good pipe, but have no experience with it.
https://www.mishimoto.com/engineering/2021/06/toyota-a90-supra-charge-pipe-production-sample-2020

Ok, so let's convert this plot into layman's terms. First, let's figure out what the typical output is from the stock turbo. Since the stock turbo has a compressor inducer of 50mm, this is roughly equivalent to the GT3076 which has a compressor inlet flange of 51.8mm. Looking at the GT3076 compressor map, the 74% efficiency island has a right edge of ~40 lb/min. Let's just go with this for now - most of the time stock turbos are undersized, so you'll running further to the right when you turn up the boost.

From there we need to know what is the uncompressed volumetric flow rate. Let's convert.
40 lbm = 18.1 kg
air density @ STP = 1.225 kg/m^3
1 m^3 = 35.3 ft^3
18.1 kg * (1 m^3/ 1.225 kg) * (35.3 ft^3 / 1 m^3) = 521.5 CFM

Now, that volumetric flow is uncompressed. The air in the charge pipe is compressed. What is a typical boost pressure? According to this post, stock ECU map has a limit of 2.5 bar absolute (1 bar = 1000 hectopascals). Since this is a limit, let's round down a bit for sake of argument.

2.4 bar absolute = 1.4 bar gauge = ~20 psi gauge

Now that volumetric flow we calculated was uncompressed. How do we find the new volume? Let's assume an ideal adiabatic compressor which means no heat transfer in or out, and a compressor at 100% efficiency.

p1 * v1^gamma = p2 * v2^gamma
1 bar * 521 cfm^1.4 = 2.4 bar * X cfm^1.4

X = 278 compressed cfm

On this map, let's lookup the pressure drop at 275 cfm. 27 inH2O -> 16 inH2O. Converted, 0.067 bar -> 0.039 bar.

Since the ECU will target maniform pressure to be the same, this means the compressor outlet will be slightly higher to compensate. Let's quantify the additional delta-T which comes from the work done on the air. By using the adiabatic equations again, this time targeting P and T:

P1^(1-gamma)*T1^gamma = P2^(1-gamma)*T2^gamma

For both conditions, P1 and T1 will be room temp and sea level (give or take). P1 = 1 bar, T1 = 25 degC = 298 K. We will try P2 with 2.467 bar and 2.439 bar, and compare the T2's.

if P2 = 2.467, T2 = 385.7 K = 112.5 degC
if P2 = 2.439, T2 = 384.4 K = 111.2 degC

Therefore, we can conclude that for the stock turbo, the decreased pressure drop will reduce compressor outlet temperature by ~1.3 degC. While the real number will certainly be different, the exercise here is to show that you can either be roughly right or precisely wrong. All estimates are on the correct order of magnitude, so I expect my estimates to be 20-30% wrong.

Edit: yes, I know that there are estimates on how to estimate flow rate based on target whp. I avoided using that rule of thumb. We ended up in the same ballpark anyway.

Edit 2: did I expect the results to be more substantial after investing all that time writing it up? also yes.

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