reduced boost after new FPR install
#1
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1988 944 Turbo S,
Car was running very rich with 3.0FPR and autothority chip set to +12.5%. Reduced it to stock setting at +0%. Was boosting to 14-15psi.
Had a 3.0 FPR, and just installed a new FPR (2.5), no other DME changes, now the boost is barely 10-11. Would a 2.5 (vs 3.0) FPR reduce the boost like that? Again, have not changed the DME setting, so it's still at stock 0%.
Car was running very rich with 3.0FPR and autothority chip set to +12.5%. Reduced it to stock setting at +0%. Was boosting to 14-15psi.
Had a 3.0 FPR, and just installed a new FPR (2.5), no other DME changes, now the boost is barely 10-11. Would a 2.5 (vs 3.0) FPR reduce the boost like that? Again, have not changed the DME setting, so it's still at stock 0%.
#4
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1988 944 Turbo S,
Car was running very rich with 3.0FPR and autothority chip set to +12.5%. Reduced it to stock setting at +0%. Was boosting to 14-15psi.
Had a 3.0 FPR, and just installed a new FPR (2.5), no other DME changes, now the boost is barely 10-11. Would a 2.5 (vs 3.0) FPR reduce the boost like that? Again, have not changed the DME setting, so it's still at stock 0%.
Car was running very rich with 3.0FPR and autothority chip set to +12.5%. Reduced it to stock setting at +0%. Was boosting to 14-15psi.
Had a 3.0 FPR, and just installed a new FPR (2.5), no other DME changes, now the boost is barely 10-11. Would a 2.5 (vs 3.0) FPR reduce the boost like that? Again, have not changed the DME setting, so it's still at stock 0%.
Get a good 3 bar.
#5
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the possibility is that you are getting less fuel, causing a lean condition causing knock and the ignition is being retarded
#6
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thanks to the responses...to clarify though, will setting the FQR to +12.5% potentially help given the FPR is a 2.5 bar and not a 3.0? I'm just not clear on that point. I could get another FPR 3.0bar but having just dropped $100 on this one, I'd like to avoid it if simply changing the FQR would help, so just curious before I go rip it out again.
#7
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thanks to the responses...to clarify though, will setting the FQR to +12.5% potentially help given the FPR is a 2.5 bar and not a 3.0? I'm just not clear on that point. I could get another FPR 3.0bar but having just dropped $100 on this one, I'd like to avoid it if simply changing the FQR would help, so just curious before I go rip it out again.
No disrespect intended but read what Lart said.
If everything is set up like it sounds like it is and you do not have a proper 3 bar you could potentially damage the engine. Get a working 3 bar. If there is an issue I would look at vacuum leaks.... Then at adjusting the fqr. I'm pretty sure that's not for that though. Swore that was for if you are at a different elevation compared to sea level.
Lart is acting like the grim reaper right now. He warned you. Heed it or he will materialize and spirit your Porsche away...
![bigbye](https://rennlist.com/forums/graemlins/xyxwave.gif)
A 3 bar is the most standard and basic change we make when doing any modifications to the engine. Even with just an autothority chip and nothing else you use a 3 bar.
https://rennlist.com/forums/944-turb...regulator.html
Read each post closely in that thread.
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#8
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No disrespect intended but read what Lart said.
https://rennlist.com/forums/944-turb...regulator.html
Read each post closely in that thread.
https://rennlist.com/forums/944-turb...regulator.html
Read each post closely in that thread.
So sounds like a 3bar is in order given I have it chipped.
Anyone need a brand new 2.5bar??
#9
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hey man, no disrespect taken or inferred at all, I appreciate all the help and input! This forum is awesome. Just wasn't sure with my setup if it was a problem, with a 2.5bar which is stock, and stock boost is around 11 (all of what I was seeing), it sounded normal just not as great as it was with the 3 bar and FQS dialed up. And, my prior setup was running so rich I failed emissions and fouled new plugs in 2 months. So I was thinking with the reduced boost and stock 2.5 FPR...oh, so this is what a "normal" turbo should feel like. Which kinda sucked to be honest...I lost the feeling of putting you in your seat.
So sounds like a 3bar is in order given I have it chipped.
Anyone need a brand new 2.5bar??
So sounds like a 3bar is in order given I have it chipped.
Anyone need a brand new 2.5bar??
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#10
Rennlist Member
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You need to get a new 3 bar FPR, since the Authority maps are based on 43 PSI of fuel.
Using a 2.5 bar FPR and increasing the FQS to +12.5% does not increase the physical amount of fuel available, beyond the max. limit of your 2.5 bar FPR. It only increases the scaling used in the maps, not the absolute amount of fuel you get to the injectors, which is mechanically limited by the FPR.
Using a 2.5 bar FPR and increasing the FQS to +12.5% does not increase the physical amount of fuel available, beyond the max. limit of your 2.5 bar FPR. It only increases the scaling used in the maps, not the absolute amount of fuel you get to the injectors, which is mechanically limited by the FPR.
#11
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hey man, no disrespect taken or inferred at all, I appreciate all the help and input! This forum is awesome. Just wasn't sure with my setup if it was a problem, with a 2.5bar which is stock, and stock boost is around 11 (all of what I was seeing), it sounded normal just not as great as it was with the 3 bar and FQS dialed up. And, my prior setup was running so rich I failed emissions and fouled new plugs in 2 months. So I was thinking with the reduced boost and stock 2.5 FPR...oh, so this is what a "normal" turbo should feel like. Which kinda sucked to be honest...I lost the feeling of putting you in your seat.
So sounds like a 3bar is in order given I have it chipped.
Anyone need a brand new 2.5bar??
So sounds like a 3bar is in order given I have it chipped.
Anyone need a brand new 2.5bar??
I do not have emissions here though. To pass I would put stock 2.5 and stock chip.
Then 3 bar and chip back in.
Pretty sure several venders modified set ups can pass. I would look at upgrading to have more power but also more control and safety features.
#12
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thanks to all the input above, I ordered and received my new 3.0bar FPR today. Car is in TN and spent most of its life in SC. I passed emissions fine with 3.0 bar, chip and 0% FQS setting. So installing the new FPR now to get back to that setup.
Question: procedure calls for removing fuel pump relay and running it out of gas. Is this necessary or just one of those recommended things? Just wasn't sure how much fuel would actually spray out once I unclamp it. TIA.
Question: procedure calls for removing fuel pump relay and running it out of gas. Is this necessary or just one of those recommended things? Just wasn't sure how much fuel would actually spray out once I unclamp it. TIA.
#13
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thanks to all the input above, I ordered and received my new 3.0bar FPR today. Car is in TN and spent most of its life in SC. I passed emissions fine with 3.0 bar, chip and 0% FQS setting. So installing the new FPR now to get back to that setup.
Question: procedure calls for removing fuel pump relay and running it out of gas. Is this necessary or just one of those recommended things? Just wasn't sure how much fuel would actually spray out once I unclamp it. TIA.
Question: procedure calls for removing fuel pump relay and running it out of gas. Is this necessary or just one of those recommended things? Just wasn't sure how much fuel would actually spray out once I unclamp it. TIA.
Where in Tennessee are you?