Too much back pressure?
05-20-2021, 11:54 AM
#81
I had a well known tuner tell me that he had tuned a 5.3 with the exact same turbos. At 7psi the back pressure was 1.6:1.
when he swapped to the .82 ar it went to 1.2:1 and picked up 40whp
when he swapped to the .82 ar it went to 1.2:1 and picked up 40whp
05-20-2021, 12:28 PM
#82
05-20-2021, 12:50 PM
#84
If you have an aftermarket ECU a 0-100psi transducer is $16 on Amazon. Def worth the $. Either way, as seen guys are making silly power... regardless of back pressure readings.
Also fwiw here are the numbers at lower boost levels.
727/882 @ 22
624/796 @ 20
630/737 @ 17
573/674 @ 14
Also fwiw here are the numbers at lower boost levels.
727/882 @ 22
624/796 @ 20
630/737 @ 17
573/674 @ 14
05-20-2021, 12:50 PM
#85
05-20-2021, 02:09 PM
#86
If you have an aftermarket ECU a 0-100psi transducer is $16 on Amazon. Def worth the $. Either way, as seen guys are making silly power... regardless of back pressure readings.
Also fwiw here are the numbers at lower boost levels.
727/882 @ 22
624/796 @ 20
630/737 @ 17
573/674 @ 14
Also fwiw here are the numbers at lower boost levels.
727/882 @ 22
624/796 @ 20
630/737 @ 17
573/674 @ 14
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Fallguy (05-20-2021)
05-20-2021, 02:21 PM
#88
At that time, those cast baby GT3582's were $109 shipped! Pretty great value for turbos capable of 500+ crank each. The T4 versions do better on power, but the response isn't there.
I always wanted to do 3 of them just to be different. Cheapest set ive seen these days is $129 shipped.
05-20-2021, 02:33 PM
#89
While I was swapping the housings I went to rebuild them. Apparently these steel thrust bearings aren’t the best idea. So it’s an upgrade to go copper.
05-20-2021, 03:14 PM
#90
That was kind of my point, those little bad boys should be putting out some power! Should be MUCH more efficient than the baby GT3582 china clones. I'd check your cranking compression. Ensure plugs are gapped way down at .015 or less and see if makes a difference. Something seems "off". I don't think it's a bad thing you went larger on the housings. Hope it solves your issues. Just bacuase china says .063 T3 def doesn't mean it specs out to that. While I'd assume precisions are accurate in sizing.
05-20-2021, 03:22 PM
#91
That was kind of my point, those little bad boys should be putting out some power! Should be MUCH more efficient than the baby GT3582 china clones. I'd check your cranking compression. Ensure plugs are gapped way down at .015 or less and see if makes a difference. Something seems "off". I don't think it's a bad thing you went larger on the housings. Hope it solves your issues. Just bacuase china says .063 T3 def doesn't mean it specs out to that. While I'd assume precisions are accurate in sizing.
I hope it’s just the housings lol. But it could be something else. I’m running BR7ES factory gap at .024
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06-01-2021, 09:08 PM
#95
Very impressive gains! That is fantastic. That is one really impressive car.
You know, looking at the torque rise in your dyno plot with the old turbine housing, it looks like you gave up very little on spool response. After driving it around off the dyno, how does it feel on transient response compared to the old housing?
You know, looking at the torque rise in your dyno plot with the old turbine housing, it looks like you gave up very little on spool response. After driving it around off the dyno, how does it feel on transient response compared to the old housing?
06-01-2021, 09:28 PM
#96
Very impressive gains! That is fantastic. That is one really impressive car.
You know, looking at the torque rise in your dyno plot with the old turbine housing, it looks like you gave up very little on spool response. After driving it around off the dyno, how does it feel on transient response compared to the old housing?
You know, looking at the torque rise in your dyno plot with the old turbine housing, it looks like you gave up very little on spool response. After driving it around off the dyno, how does it feel on transient response compared to the old housing?
06-01-2021, 09:48 PM
#97
FWIW - I have a Ford 8.8 in my LS1 Miata. It uses a Ford Explorer aluminum IRS housing, and an Allison Truetrac differential, with a 3.55 R&P. The Truetrac is a very worthy differential for street or track. People even drag race with them. I am very happy with mine.
The limited slip Getrags are another good option. A friend of mine has one in his dedicated road race LS Miata, and does well with it on the track.
The limited slip Getrags are another good option. A friend of mine has one in his dedicated road race LS Miata, and does well with it on the track.
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Fallguy (06-01-2021)
06-01-2021, 10:20 PM
#98
FWIW - I have a Ford 8.8 in my LS1 Miata. It uses a Ford Explorer aluminum IRS housing, and an Allison Truetrac differential, with a 3.55 R&P. The Truetrac is a very worthy differential for street or track. People even drag race with them. I am very happy with mine.
The limited slip Getrags are another good option. A friend of mine has one in his dedicated road race LS Miata, and does well with it on the track.
The limited slip Getrags are another good option. A friend of mine has one in his dedicated road race LS Miata, and does well with it on the track.
06-02-2021, 09:09 AM
#99
Why does boost / tq seem so laggy? Not hating on you or car!
I had a tune that looked like this before and turned out the timing was super low on the bottom end going up to like 4psi. Got it retuned by someone else and he said need low end timing to get turbos going. Car is 600+ tq by 4000rpm now. Night and day. Same setup but diff tuners.
I had a tune that looked like this before and turned out the timing was super low on the bottom end going up to like 4psi. Got it retuned by someone else and he said need low end timing to get turbos going. Car is 600+ tq by 4000rpm now. Night and day. Same setup but diff tuners.
06-02-2021, 09:11 AM
#100
Why does boost / tq seem so laggy? Not hating on you or car!
I had a tune that looked like this before and turned out the timing was super low on the bottom end going up to like 4psi. Got it retuned by someone else and he said need low end timing to get turbos going. Car is 600+ tq by 4000rpm now. Night and day. Same setup but diff tuners.
I had a tune that looked like this before and turned out the timing was super low on the bottom end going up to like 4psi. Got it retuned by someone else and he said need low end timing to get turbos going. Car is 600+ tq by 4000rpm now. Night and day. Same setup but diff tuners.
I’ll take a look.