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Just looking to pick the communities brain on this to see if I'm possibly overlooking why my boost flat lines in each gear. I'm attaching an image of a log from a pass down the 1/4 mile. In gears 2-4 I'm peaking at 10.5psi and my current pulley setup should be good for 18-20+ psi based on other people's setups. I'm either getting belt slip, boost leak, or hitting a restriction in the system. The belt looks good with no signs of belt dust and tension is still really tight. I've typically seen belt slip showing boost decreasing with RPM. I performed a boost leak test and couldn't detect any leaks. I can't think of any major restrictions other than the A&A FMIC, but boost should still be higher. Any thoughts?
I'm already in the process of upgrading to a 10-rib setup with Gates RPM belt to address any slip issues and also going with a Shearer Hi-Ram A2W to address flow/IAT's.
Yes, something is wrong. First of all what map sensor and is it setup properly? Is it actually 10psi?
Besides that, sounds like crazy belt slip. Should be 20+ psi easy.
Are you referring to the lean spike between shifts? I'm ditching meth either way when I go A2W, I tuned the car without meth so even on just Ignite it's around 12:1. The only sensor that is suspect is the IAT sensor that I'm running which came from the ECS IAT breakout kit, but they didn't provide a part number for it or any reference to scaling info. I'm replacing that with an LSA IAT2 sensor now. I think it's slipping too, but the fact that it flat lines has me stumped.
It's running a ZR1 map and I'm pretty sure it's scaled correctly:
I’ve seen that happen when the sensors are being ran dry. How is it plumbed and what’s your fuel system look like? Need to address this first.
It's definitely something I'm going to look out for as the content drop hasn't shown up in any prior logs, nothing in the logs seems to suggest that the tune adjusted based on the dip either (it lasted .509 sec). Fuel system should be up to the task, but maybe fuel sloshed during the race as the tank was around 1/4 and sucked in some air? Voltage was a steady 14.0 across the pull - so I don't think that's an issue either.
Fuel System:
Walbro 450 in-tank
FPR Plugs (driver/passenger)
ECS E85 Fuel Block (-10an feed / -8an return)
Holley 12-1800 (hobbs switched)
-10 feed / split to -8 at rails
Holley Rails
ID 1300x injectors
-8 return to regulator
Holley Regulator (Boost/Vacuum Referenced - 45psi base)
-6 return to tank
Flex sensor in return line post regulator
Running dual Turbosmart 50mm - one valve had the softest spring and the other had a slightly stiffer spring. I've changed them both to the softest spring but that's really only relevant for cruise and not under boost.
That should be enough fuel assuming everything is working, I'd think anyways. Just keep an eye out for it. May want to set the polling frequency for ethanol % up a little bit, I think by default it's not updating all that often, so it would be easy for a quick dip to not show up
That should be enough fuel assuming everything is working, I'd think anyways. Just keep an eye out for it. May want to set the polling frequency for ethanol % up a little bit, I think by default it's not updating all that often, so it would be easy for a quick dip to not show up
Thanks for the suggestion - I checked and poling interval is at the fastest (0ms).
May want to set the polling frequency for ethanol % up a little bit, I think by default it's not updating all that often, so it would be easy for a quick dip to not show up
Can you really change polling interval per each PID?
Can you really change polling interval per each PID?
Hm, nice.
yes. But it doesn’t work exactly as described. It more or less prioritizes by what you’ve set to be the fastest. But you still might not get what you’ve set it to all the time, depending on the application and what all is being logged.
Running dual Turbosmart 50mm - one valve had the softest spring and the other had a slightly stiffer spring. I've changed them both to the softest spring but that's really only relevant for cruise and not under boost.
Give us a call at the shop. We can go over a few things with you. 805-278-4107
Need to confirm belt size and you might even have the BOV's pushing open and acting like a wastegate bleeding your boost off.
Give us a call at the shop. We can go over a few things with you. 805-278-4107
Need to confirm belt size and you might even have the BOV's pushing open and acting like a wastegate bleeding your boost off.
Thx,Josh
Thanks Josh for putting me in touch with your tech. I'm going to up the BOV springs from -4 InHg to -10 InHg to see if the boost rises accordingly. If this is the case it's a really simple fix and the car should pick up a bunch of power / trap speed
Interested to find out what the problem was... I seriously doubt its belt slip if it's tight like you said... I know plenty of guys making 1200rwhp on a 8rib set up from A&A without any issues of belt slip. Not at all trying to dismiss your issues...Please don't take my comment the wrong way.
Interested to find out what the problem was... I seriously doubt its belt slip if it's tight like you said... I know plenty of guys making 1200rwhp on a 8rib set up from A&A without any issues of belt slip. Not at all trying to dismiss your issues...Please don't take my comment the wrong way.
I don’t think it’s belt slip either and I’m hoping it’s just the BOV’s opening under boost with the soft springs in each. The car still made good power on the dyno at 12psi (1049/934) and should pick up a good bit if I’m able to make another 6-8 psi.
YSI Boost Flat Lines?
