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Discussion Starter #1 (Edited)
Well, I had this beautiful long post from yesterday that wasn't able to be recovered from the hardware crash. So here's the short and skinny of it. My setup is in my sig. Currently I have my ZT-2 installed, reading about 10.3 peak AFR on S2 no toys. My WGA is setup to climb to about 17-18psi at redline (can't remember cuz it's been so cold for so long). I also have a mapclamp ready to be installed.

(1) At what psi does the stock turbo start to become inefficient? 19psi? 21psi? 24psi? For the purposese of this discussion I'm going to assume 22psi.

(2) At what psi/voltage does the S2 ECU start to pull timing? I know there's the thread that relates PSI to voltage, just wondering on the PSI. I'm going to assume 20psi for this thread.

So, in theory I could up the boost to 22psi and have the mapclamp trick it into thinking it's actually 20psi. But, obviously this would put my AFRs off the charts. So, I was thinking about the PTPerformance FPR mod.

so here's my thought process for tuning this b!tch! Starting with my current setup: Up the boost to 20psi (S2 max before it pulls timing) and obviously watch the AFRs. Say @20psi I would be running 11.0AFR. Then I would install the mapclamp to run about 11.7 AFR (safer-side of the range).

(3) What would happen if I installed the PTPerformance FPR mod at this point? (remember S2 injectors)

This is where I get confused and turned around. Here's my assumption, it would lower my AFR but obviously still run @ 20psi. Say it lowers my AFR to 10.8. So, in theory, I could up the boost to 22psi (stock turbo max effeciency) and clamp it back up to 11.7 AFR. And after checking the map sensor voltages, the PCM would only think it was running at 18 or 19psi so it won't pull timing (not sure on that # though until I get into it).

Can someone make me feel better or worse about this approach? Thanks!

EDIT, I mostly need answers to (1) and (2). I think I have (3) figured out but I would welcome any input :thumbsup:
 

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I am in the exact same boat as you. As much as I would love to help you out, I have the same exact questions and similar mods. I am currently waiting on my Ptperformance FPR and Map/Tip Clamp (COME ON, JOHN!) ;) So any information that you guys could give us would be great. Thanks in Advance!
 

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Discussion Starter #3
Quicker10u said:
I am in the exact same boat as you. As much as I would love to help you out, I have the same exact questions and similar mods. I am currently waiting on my Ptperformance FPR and Map/Tip Clamp (COME ON, JOHN!) ;) So any information that you guys could give us would be great. Thanks in Advance!
Bump for any night crews?

Quicker10u - Do you agree with my hypothesis/tuning method? I think we're on the right track... But it's the whole playing with fuel levels and boost levels that scares me.
 

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Discussion Starter #4 (Edited)
Hey,

I just talked to John at PTP, What an awesome guy. The most helpful person I've interacted with on these forums.

He confirmed the thought that was in the back of my mind: The S2 injectors are more than enough for any amount of power/pressure that the STOCK turbo will produce. He said that the STOCK turbo turbine/housing is good up to 21psi.

If you're running a setup like mine, he suggested turning the boost up to 21psi and using the mapclamp to clamp it down to 11.7 AFR (or whatever AFR you want to run). The S2 PCM shouldn't pull timing with it setup that way. But, on a scale of 1-5, 5 being the most risky, 1 being the most conservative, 11.7 is probably a 2.

EDIT: The S2 injectors are enough to support this setup. Turning it up anymore "turns the turbo into a hair dryer" (that was John's comment! LOL!) Hence, a FPR mod probably wouldn't help much with our setup.

HOpe this helps!
 

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all bran,
Yea, I think we are on the right track with this. I am going to be setting for 20psi or so with my fpr. I don't have the stage 2 injectors, so the FPR will help me get the flow I need. My goal for AFR's is 12.0 at 17-18 psi at redline. All this boost scares me as I used to be a rotary engine guy and those motors were soooo much more fragile than ours. Yea, John is a great vendor and understands our cars very well. I am just so sick of the PCM pulling timing on me. I need my damn Map/Tip Clamp... :buaaaa!:

My AEM UEGO seems to be working well, however, my first tank of gas was E85 (Ethanol) so I am trying to get all of that out of the system before I hit the Dyno.

It will be good to see what the other guys on here have to say. I know there are a bunch of guys with the mods that we have on here (before they switched to big turbos) that can help us out..
 

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Discussion Starter #6
Ah, didn't know you had S1 injectors. Yeah, this should help you a lot :D
 

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wow poeple are pushing the stock turbo to 21psi these days?

ethan told us the stock turbo was a hairdryer past like 18psi back at srt nationals 2 years ago.
 

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Discussion Starter #8
vector4 said:
wow poeple are pushing the stock turbo to 21psi these days?

ethan told us the stock turbo was a hairdryer past like 18psi back at srt nationals 2 years ago.
The way John explained it to me, it depends on the exhaust you have hooked up to it. Backpressure is a key factor in turbo efficiency. Mine's in my sig.

Maybe with the stock O2 housing, and stock DP it would be 18psi? Just brainstorming...

John said he was getting efficient power at 28psi with a heavily modified exhaust.

Just going by what I was told :thumbsup:
 

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Yea, I don't think exhaust backpressure will be a problem for me. :lol:

Anyone have any thoughts on this? Maybe we should post it in the Mods secton??
 
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