WS6 S475 official build thread.......
10-07-2013, 10:16 PM
#461
If you plot out the VE his engine is making he can push that turbo to at least 22-24psi IMO.
That same turbo on a 427 Real Street motor with much more VE than Stephen goes 5.20's and makes 16-17psi with the gate pinned shut.
A little stock headed 347 is not done at 17-18psi with the same turbo. Not even sure if it was able to hit 18psi on the dyno and the run was shut down way early.
With the gearing he has he can pull much more than 130mph on drum speed with the power it makes. The power had barely started to taper off when the run was shut down.
I'm sure Stephen is glad Jonathan didn't pull it any higher than he did though lol.
That same turbo on a 427 Real Street motor with much more VE than Stephen goes 5.20's and makes 16-17psi with the gate pinned shut.
A little stock headed 347 is not done at 17-18psi with the same turbo. Not even sure if it was able to hit 18psi on the dyno and the run was shut down way early.
With the gearing he has he can pull much more than 130mph on drum speed with the power it makes. The power had barely started to taper off when the run was shut down.
I'm sure Stephen is glad Jonathan didn't pull it any higher than he did though lol.
10-07-2013, 10:46 PM
#462
Some old fashioned facts, as always:
As is well demonstrated above, boost ≠ airflow. Choking a turbo can cost power, not only because of the asymptotic nature of the mass airflow function as pressure ratio increases and isentropic efficiency decreases, but also because of the increase in back pressure required to drive the compressor at higher pressure ratios. It is diminishing returns 101.
we were able to go 10.30 @ 134 ish with the s475 on 20lbs of boost
we had the car out with the billet 80 again sunday, and ran out of fuel at 19lbs of boost
the car has twin 255s in the tank, with a hotwire, half inch feed, and a regulator and return system
we pulled the pumps today and replaced one of the 255s with a 400lph i had laying around
removed the bottom of the basket,
installed a Y fitting instead of a brass T fitting
and used a junkyard connector with like 10 12g wires and used 5 for power and 5 for ground, ran a 8g power and ground to the connector and ground externally in the car.
the car had a 11.5 AFR on 17psi and it was quickly running away into the high 12s at 19psi
left the car the same from the track, took it out and on 19lbs its a 10.0 AFR
nice improvement hahah going to do some trimming and get back out
the firebird went 6.4x @ 109 in the 8th and then 10.66 @ 99mph in the brakes hard after running out of fuel. haha
so we will update again when we head out this weekend most likely
we had the car out with the billet 80 again sunday, and ran out of fuel at 19lbs of boost
the car has twin 255s in the tank, with a hotwire, half inch feed, and a regulator and return system
we pulled the pumps today and replaced one of the 255s with a 400lph i had laying around
removed the bottom of the basket,
installed a Y fitting instead of a brass T fitting
and used a junkyard connector with like 10 12g wires and used 5 for power and 5 for ground, ran a 8g power and ground to the connector and ground externally in the car.
the car had a 11.5 AFR on 17psi and it was quickly running away into the high 12s at 19psi
left the car the same from the track, took it out and on 19lbs its a 10.0 AFR
nice improvement hahah going to do some trimming and get back out
the firebird went 6.4x @ 109 in the 8th and then 10.66 @ 99mph in the brakes hard after running out of fuel. haha
so we will update again when we head out this weekend most likely
10-08-2013, 09:07 AM
#463
That turbo will make 22psi on that size motor....should make 800+rwhp. The restrictions I see will be the intercooler if its an ebay one. Matt Lawrence switched from his ebay cooler to a chiseled unit. Picked up over 100rwhp...lol.
10-08-2013, 09:24 AM
#464
The waste gate is still opening on Stephen's car. If it was out of turbo right now where it is, it wouldn't be opening the waste gate bleeding off drive pressure to regulate manifold pressure.
10-08-2013, 09:36 AM
#465
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Yeah its the ebay one. So assuming they are pretty restrictive?? Seem to keep the iats down under normal driving though for the 130 dollar price tag lol.
10-08-2013, 10:37 AM
#466
10-08-2013, 11:08 AM
#468
A turbo doesn't have to be at its peak pressure ratio capability to be at the maximum of its mass flow capability. In fact that is almost never the case, save for some diesel applications. Gas engines almost always suck the compressor dry before reaching the maximum boost potential. I had this exact experiment with an S465 on a 6.0. Pinned the gate shut and only made 7psi at the top of the gear, 6000rpm or so. I took that turbo off because I didn't want to overspin it and it was making garbage for power. Its now on my buddy's 5.9 cummins at 60psi...
10-08-2013, 11:49 AM
#472
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What's your thoughts on the 82 billet etr race cover all the goods for my next upgrade? On a forged engine. Will be on pump gas maybe upgrade to dual 15 gph meth nozzles. What is my limitations on using those fuels? Seeing what I'm doing now I think 1000rwhp or little more is doable with better heads, intake, little more boost, little more cubes. I may be dreamong. Or would the 82mm not cut it?
10-08-2013, 12:45 PM
#473
What's your thoughts on the 82 billet etr race cover all the goods for my next upgrade? On a forged engine. Will be on pump gas maybe upgrade to dual 15 gph meth nozzles. What is my limitations on using those fuels? Seeing what I'm doing now I think 1000rwhp or little more is doable with better heads, intake, little more boost, little more cubes. I may be dreamong. Or would the 82mm not cut it?
10-08-2013, 01:38 PM
#475
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10-17-2013, 04:32 PM
#476
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Just read through your entire thread, found it after seeing your comment's in doug's thread. Congrats on the dyno day cash and those are some awesome numbers for a cam only Turbo motor! It would be interesting to see what kind of gains you get from an intercooler swap, do you have any plans to switch it out or gonna save the cash for other items first?
10-18-2013, 07:13 AM
#477
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I'm hoping to start on a forged 5.3 this winter. I need a stronger rear end. I've got the horsepower but a lot of things are on a prayer right now. I will probably keep the same intercooler until it becomes a limitation on my next engine turbo setup.
10-25-2013, 08:07 PM
#478
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What's does 19psi, date night with the wife, and 39° outside temps equal? A 4th gear highway burnout at 100+mph.
Oh the little stock ls1 hates me!!! Lol
I'd like to know what it really puts down on a night like this and 19 psi on the gauge.
Oh the little stock ls1 hates me!!! Lol
I'd like to know what it really puts down on a night like this and 19 psi on the gauge.
Last edited by mrstepheneades; 10-25-2013 at 08:14 PM.
10-26-2013, 09:40 PM
#479
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Installed my Harlan 2step this evening. Thanks again Martin. Wired into my bottom clutch switch. At 3900 setting builds 3 psi. Can't wait to try it someday. Just afraid that at my power level if I go to track it will be BOOM!!!!!!