Measuring pre i/c pressure
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
Measuring pre i/c pressure Can I insert a "t" in my boost ref. line to the w/g's to get an idea of pre i/c pressure? Everything on the cold side is alum and I don't have the capability to weld it. This would be a MUCH easier solution just to get a couple of readings.
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From: THORNTON, PA (NEAR PHILLY)
Yeah I was going to install a T in the reference line and then extend a hose right over to my oil or fuel pressure sender and just temporarily hook it up. Was going to that to measure PB also.
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From: Norn Iron
Only if your port for the w/g's is before the compressor, and you are not using any form of boost control that bleeds off air on that line.
And ensure anything you're using to take readings is calibrated the same as whatever you are using post IC otherwise they will be meaningless.
Thread Starter
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From: THORNTON, PA (NEAR PHILLY)
Only if your port for the w/g's is before the compressor, and you are not using any form of boost control that bleeds off air on that line.
And ensure anything you're using to take readings is calibrated the same as whatever you are using post IC otherwise they will be meaningless.
And ensure anything you're using to take readings is calibrated the same as whatever you are using post IC otherwise they will be meaningless.
My compressor cover is tapped and a line from there goes to the w/g's. I was going to T into here for pre-i/c #'s and then just use map sensor to see what the intake sees. But I see your point, I should probably use the same sensor after the i/c to get a true difference.
I just want to see how if the cheapy i/c is killing power that all. I would imagine my low boost is creating an issue with the i/c but you never know.
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From: Norn Iron
Stevie,
My compressor cover is tapped and a line from there goes to the w/g's. I was going to T into here for pre-i/c #'s and then just use map sensor to see what the intake sees. But I see your point, I should probably use the same sensor after the i/c to get a true difference.
I just want to see how if the cheapy i/c is killing power that all. I would imagine my low boost is creating an issue with the i/c but you never know.
My compressor cover is tapped and a line from there goes to the w/g's. I was going to T into here for pre-i/c #'s and then just use map sensor to see what the intake sees. But I see your point, I should probably use the same sensor after the i/c to get a true difference.
I just want to see how if the cheapy i/c is killing power that all. I would imagine my low boost is creating an issue with the i/c but you never know.
I have a few pressure sensors on my car, and each one when you use the stated calibration for them, all read slightly different than each other.
When I was calibrating them all manually for logging on my ecu, I used a cheapo mechanical gauge...which in itself raised more issues !
I had a gauge on the line, as well as the one on the pressure regulator I was using to apply pressure to the sensors to test/calibrate..
I ended up with about 5 mechanical gauges on the same line during the testing, and there was as much as 10psi difference in some of them !!
Now fair enough some were 0-30, 0-60 and 0-120psi...but the difference was ridiculous, even if they were very cheap.
I ended up using an in-car gauge which seemed the best all round to use as a base and calibrated all other sensor scaling around that.
So whether readings are technically accurate, I know they are all accurate in a relative sense which is ultimately what matters.
And as said, as long as your boost control is w/g only with no other control devices, then yes you could use the compressor port for your test.
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Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
Just need to rig up a T and I'll report back. Its just a used ~31x12X3" no-name i/c. My IAT
s are so low for some reason (turbo too big) that I wonder if I even need the i/c, or the sucker works REAL good lol!!!
s are so low for some reason (turbo too big) that I wonder if I even need the i/c, or the sucker works REAL good lol!!!
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
Some interesting data...
I only did a 5100 rpm pull at 11psi, I d!cked with the boost controller hooking this up and was worried about an overboost situation so I took it easy.
Surprising results for low-boost anyway.
Note: fuel pressure = pre-intercooler pressure
I only did a 5100 rpm pull at 11psi, I d!cked with the boost controller hooking this up and was worried about an overboost situation so I took it easy.
Surprising results for low-boost anyway.
Note: fuel pressure = pre-intercooler pressure
Thread Starter
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From: THORNTON, PA (NEAR PHILLY)
Apprx .5psi drop at this level. Closer to .7 down low.
One thing I did notice, that pre-i/c pressure jumps a bit at first then levels out. Guess air is backing-up at first and then is forced through???
One thing I did notice, that pre-i/c pressure jumps a bit at first then levels out. Guess air is backing-up at first and then is forced through???
Barely any pressure drop, nice. Are you still running the 75/83, but now on a 5.3?
What kind of IATs are you seeing?
The 75/83 finally pushed my 4900lb truck to 10.9, but IATs are 219F at the finish line.
What kind of IATs are you seeing?
The 75/83 finally pushed my 4900lb truck to 10.9, but IATs are 219F at the finish line.
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
I would have to change the springs out in the gates which is not big deal, but am more worried about pushing 16psi+ on pump fuel. I cant get this sucker to ingest any meth - she dont like it.
Yes this is the s475, 83 on a T4 and yes on a 5.3. I really can't get the IAT's to climb past 120-130 on a quarter mile pass, with no meth! Makes me wonder if I'm just not pushing the turbo hard enough to make heat, or the i/c is doing its job. For what I do a smaller turbo probably would of been more appropriate.
I'm wondering if removing the i/c would be of benefit, but seeing such a low drop I dont think its hurting anything.
GMCtrk - how much boost are we talking about for that 10.9 run? Race fuel, meth, timing, i/c??? Thanks
I'm wondering if removing the i/c would be of benefit, but seeing such a low drop I dont think its hurting anything.
GMCtrk - how much boost are we talking about for that 10.9 run? Race fuel, meth, timing, i/c??? Thanks
Yeah, you're probably right in the sweet spot for the turbo, so it's not superheating the charge.
Run was 16-17 psi, 11 deg timing due to IAT pull, E85. 20x11.5x3" ebay/china IC. New custom Garrett IC is on order.
Run was 16-17 psi, 11 deg timing due to IAT pull, E85. 20x11.5x3" ebay/china IC. New custom Garrett IC is on order.
Thread Starter
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From: THORNTON, PA (NEAR PHILLY)