Quote:
Originally Posted by toohighpsi
Adding an orifice to the bypass will impact part throttle driveability, it shoudn't have any change on the MAP at WOT (other than delay the onset of boost). I think the Edelbrock has the MAP sensor mounted in one of the ports (like #8?) if that is the case it would possibly be the cause of the erratic MAP signal that you see. Most all of the engine controls are dominated by MAF so I wouldn't be terribly worried about this.
I do think the IATs seem pretty high for what I'm used to, I normally only see a 20-25 degree rise in temp during a 1/4 mile pass (even with the small Maggie coolant tank) and don't like to see the IAT hit much over 140-150F. You were hitting 180+; from the R2300 compressor map, the delta T at 13K rpm and 7 psi is 96 degrees F, so if the SC inlet is 90F you would have engine air inlet temp of about 186 without using any intercoolers.
Now, I do find it hard to believe that you can make 560 RWHP with these inlet temps, unless it manages to stay cool on the dyno and this is symptom that happens on the street -or- the inlet air temp sensor is faulty or incorrectly calibrated. Does the IAT match ambient temp when the car is fully cooled off?
Even so I'd chack a couple things - Is your IC pump running? Double check the lines to make sure that they are connected correctly in the system. is these any lines kinked or pinched from the install?
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Thanks for the informative reply. The sawtooth pattern of the MAP readings bugs me, but you and yonson have me thinking its acceptable for now. I'll give the orifice a try since its on its way, but if I don't like it, I can pull it out.
Is the erratic MAP readings due to actual pressure pulsation from the design of the TVS assembly? if so, seems to me there's nothing to fix.
Nice info on the delta T. Gonna go with your thoughts and investigate the intercooler and its pump. My gut told me that 180+ IAT is too high, even in this heat. Never got that high on a turbo set up. In one of my correspondences with Edelbrock, I asked them if there is any upgrades available for the intercooler or "bricks" to get the IAT down. Haven't heard back yet on that.
I may temporarily install a thermocouple in-line with the intercooler and see what delta T I'm getting if the pump is working OK. I'm already thinking about an improved (or secondary) intercooler if the IC outlet temps say there is some room for improvement.
I will be also looking at an improved radiator and a 180 (170, 160?) degree t-stat. Question: Do you know if a 160 degree t-stat will keep me in open loop?
Nice technical discussion here. We need more of these.