What gauges is a must for tuning new twins

I have Rips twins s300/s400 the 64 with the small 12 outlet, flux 2 tips and a stock cp3 and a Smarty with the standard programing (not TNT). Yes I guess I will only be adj the one waste gate.

Charles thanks for the explanation on drive pressure. I don't think I will have enough fuel with the stock cp3 to build much drive pressure, do you?
 
Charles said:
The animation on the left is actual throttle position.

2934225320082519711S600x600Q85.jpg
Click to expand...

And the actual size of Charlie's calf!!!!:hehe:

Sorry buddy...............couldn't resist:kick:
 
Now THAT is some kind of funny ^^^^^.

What software is that ?? While I am in no way some kind of computer geek, I could get into something like that, or give it one he!! of a good try learning how to use it.

Carol
 
Charles is this a set it and forget it kind of thing (balancing the compounds), or is this something a person needs to keep an eye on?
 
dieselduck said:
Charles is this a set it and forget it kind of thing (balancing the compounds), or is this something a person needs to keep an eye on?
Click to expand...

Both...

It's set if and forget it...... until you blow a reference line and snap a 100lb gauge before you know it.

That's when having the needle movement meaningful holds merit IMO. I've blown signal lines multiple times, on first and second stages having boost jump up to 70, 80, 90 and higher on me. The truck feels different, sounds different and within the second I know it's boost when I see one of the gauges way out of whack, either high or low. High if it's a blown signal line, low if it's a blown boot.

If you run a setup for enough years lines are going to blow, and boots are going to pop.
 
I'm a little slow, but I think I'm finally getting it.

I've always heard in a twin turbo configuration, you want the primary and secondary to each do half of the work. That's true.

I've also heard from everyone (except Charles) that this means you want to adjust the wastegate so the primary is making half the boost of the secondary. This is where everyone gets it wrong!!! Somewhere along the line, someone wrongly made the assumption that boost is the same as work, and everyone else repeats it. Thanks for getting me thinking Charles.

So, if I have this right in my head, "work" is equivalent to pressure ratio...and NOT boost. Thus, in simple terms, a balanced twin turbo system will have each turbo doing equal amounts of work...or they will both be operating at similar pressure ratios.

Pressure Ratio is defined as: Pabsolute,in / Pabsolute,out

So, assuming atmospheric pressure of 14.7 psia, the PR formula for the primary is (PSIg + 14.7) / 14.7.

The PR formula for the secondary becomes (PSIg,secondary + 14.7) / (PSIg,primary + 14.7).

Assuming I'm finally getting a grasp on this, resultant PRs for the primary and secondary would look like this:

Primary Turbo Secondary Turbo
Boost PR Boost PR
0 1.00 0 1.00
1 1.07 3 1.13
2 1.14 6 1.24
3 1.20 9 1.34
4 1.27 12 1.43
5 1.34 15 1.51
6 1.41 18 1.58
7 1.48 21 1.65
8 1.54 24 1.70
9 1.61 27 1.76
10 1.68 30 1.81
11 1.75 33 1.86
12 1.82 36 1.90
13 1.88 39 1.94
14 1.95 42 1.98
15 2.02 45 2.01
16 2.09 48 2.04
17 2.16 51 2.07
18 2.22 54 2.10
19 2.29 57 2.13
20 2.36 60 2.15
21 2.43 63 2.18
22 2.50 66 2.20
23 2.56 69 2.22
24 2.63 72 2.24
25 2.70 75 2.26
26 2.77 78 2.28
27 2.84 81 2.29
28 2.90 84 2.31
29 2.97 87 2.33
30 3.04 90 2.34
31 3.11 93 2.36
32 3.18 96 2.37
33 3.24 99 2.38
34 3.31 102 2.40
35 3.38 105 2.41
36 3.45 108 2.42
37 3.52 111 2.43
38 3.59 114 2.44
39 3.65 117 2.45
40 3.72 120 2.46

(I can't get the columns to display correctly. The first column is Primary turbo boost, second is Primary turbo PR, third is Secondary turbo boost, fourth is Secondary turbo PR)


Thus, if I'm wanting to run a total boost of 60 psi as measured by my gauge at the intake manifold, I want to wastegate the primary turbo to approximately 17 psi...since this is where the pressure ratios are equal.

If I went with conventional thinking, I would run 60 psi total, and 30 psi in the primary. However, doing so would put the primary at a PR of 3.04, which is more than likely well out of its highest efficiency range on the compressor map.

...and that's why Charles says to use a 35 psi gauge for the primary and a 100 for the secondary!


Comments?

--Eric
 
Last edited:
ENafziger said:
I'm a little slow, but I think I'm. finally getting it.

I've always heard in a twin turbo configuration, you want the primary and secondary to each do half of the work. That's true.

I've also heard from everyone (except Charles) that this means you want to adjust the wastegate so the primary is making half the boost of the secondary. This is where everyone gets it wrong!!! Somewhere along the line, someone wrongly made the assumption that boost is the same as work, and everyone else repeats it. Thanks for getting me thinking Charles.

So, if I have this right in my head, "work" is equivalent to pressure ratio...and NOT boost. Thus, in simple terms, a balanced twin turbo system will have each turbo doing equal amounts of work...or they will both be operating at similar pressure ratios.

Pressure Ratio is defined as: Pabsolute,in / Pabsolute,out

So, assuming atmospheric pressure of 14.7 psia, the PR formula for the primary is (PSIg + 14.7) / 14.7.

The PR formula for the secondary becomes (PSIg,secondary + 14.7) / (PSIg,primary + 14.7).

Assuming I'm finally getting a grasp on this, resultant PRs for the primary and secondary would look like this:

Primary Turbo Secondary Turbo
Boost PR Boost PR
0 1.00 0 1.00
1 1.07 3 1.13
2 1.14 6 1.24
3 1.20 9 1.34
4 1.27 12 1.43
5 1.34 15 1.51
6 1.41 18 1.58
7 1.48 21 1.65
8 1.54 24 1.70
9 1.61 27 1.76
10 1.68 30 1.81
11 1.75 33 1.86
12 1.82 36 1.90
13 1.88 39 1.94
14 1.95 42 1.98
15 2.02 45 2.01
16 2.09 48 2.04
17 2.16 51 2.07
18 2.22 54 2.10
19 2.29 57 2.13
20 2.36 60 2.15
21 2.43 63 2.18
22 2.50 66 2.20
23 2.56 69 2.22
24 2.63 72 2.24
25 2.70 75 2.26
26 2.77 78 2.28
27 2.84 81 2.29
28 2.90 84 2.31
29 2.97 87 2.33
30 3.04 90 2.34
31 3.11 93 2.36
32 3.18 96 2.37
33 3.24 99 2.38
34 3.31 102 2.40
35 3.38 105 2.41
36 3.45 108 2.42
37 3.52 111 2.43
38 3.59 114 2.44
39 3.65 117 2.45
40 3.72 120 2.46

(I can't get the columns to display correctly. The first column is Primary turbo boost, second is Primary turbo PR, third is Secondary turbo boost, fourth is Secondary turbo PR)


Thus, if I'm wanting to run a total boost of 60 psi as measured by my gauge at the intake manifold, I want to wastegate the primary turbo to approximately 17 psi...since this is where the pressure ratios are equal.

If I went with conventional thinking, I would run 60 psi total, and 30 psi in the primary. However, doing so would put the primary at a PR of 3.04, which is more than likely well out of its highest efficiency range on the compressor map.

...and that's why Charles says to use a 35 psi gauge for the primary and a 100 for the secondary!


Comments?

--Eric
Click to expand...



Exactly. Half and half is the easy way. Starting figuring PR's and its a different ball game. Charles is smart as fvck!
 
Exactly. Half and half is the easy way. Starting figuring PR's and its a different ball game.
Click to expand...

I guess...but it seems like if you're going to resort to guessing rather than figuring, that 1/3 and 2/3 is a lot closer than 1/2 and 1/2?
 
joelc79 said:
well hopefully when these stand alone ecm come out they will have the data logger features nailed down as well. I would rather spend the 4K on that then acomplete datlogger system with all the extras for the same price.
I do agree that this is the true way for now
Click to expand...


hey joelc79 ur from kent ohio im from ravenna and im going to put a set of twins on my 12v we should hang out some out.
 
I did'nt realize it was this difficult to tune twins. I'm gonna run my super b over a s472 and from the sound of it i'll be trying to tune them for months! LOL
 
KoalRolr said:
I did'nt realize it was this difficult to tune twins. I'm gonna run my super b over a s472 and from the sound of it i'll be trying to tune them for months! LOL
Click to expand...



I need to tune mine again, since changing the WG actuator. It sucks for me.

Even untuned they kick a singles azz.
 
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