APS Extreme Twin Turbo Build
Joined: Oct 2011
Posts: 115
Likes: 13
From: California
You're welcome Marty! I appreciate all the help, effort, and updates with the project 
Spoke to Howard @ Techno Square yesterday and I think we've got the boost controller working now. I was reading the manual for that thing and I think they made the EVC a bit more complicated than is necessary (for me at least lol!) I will try to make it down in a week or so and get the car back on the dyno. Will update everyone with numbers and an actual dyno sheet.
Thanks for all the positive feedback! I can't wait to bring the G home
So 507whp on 8.5psi? I have never see that before, then only 70whp gained with another 6psi? Something seems off. Not saying that it didn't happen, it's just that the numbers seem a bit weird. The 570whp at 15psi seems on par with other builds.
The build looks awesome though, hope you enjoy it for a long tim.
The build looks awesome though, hope you enjoy it for a long tim.
Thanks for all the positive feedback! I can't wait to bring the G home
Joined: Oct 2011
Posts: 115
Likes: 13
From: California
For sure! Another dyno session has been scheduled. Will keep you posted!
Joined: Oct 2011
Posts: 115
Likes: 13
From: California
Small update to report. Attached below are the dyno sheets from Jan 21st showing a couple diff dyno pulls. One of the issues we had during that session was misfire in all 6 cylinders under higher boost (see curve for ~12 psi and ~15 psi). We tried to remedy that by gapping the plugs (ngk iridium) to .023 ... Today the car went back on the dyno and still getting misfire ONLY at higher boost like 12 psi etc. Pulls at wastegate 8.5 psi - no problems. I think the next thing we are going to try is just swapping out the plugs all together. Possibly running too rich fouled the plugs. Anything else you guys can think of please chime in.
Picked up the dyno sheets today as promised!
Picked up the dyno sheets today as promised!
Joined: Oct 2011
Posts: 115
Likes: 13
From: California
Update. I got new ngk iridium 1 step colder plugs and gapped them down to .023, did an ECU reset and still getting misfire under higher boost. At about 8 psi the car pulls through the RPM range without misfire. A third gear pull at about 12 psi, 6400rpm or so, hesitation is felt and I can hear it misfire. AFR is in the 11.5 range. There are no CEL/codes from the ECU.
Car will be going back to Technosquare to rule out any vacuum leaks, check fuel pressure, etc. We've also discussed the possibility of upgrading to Haltech.
Any thoughts/input?
Car will be going back to Technosquare to rule out any vacuum leaks, check fuel pressure, etc. We've also discussed the possibility of upgrading to Haltech.
Any thoughts/input?
Joined: Oct 2011
Posts: 115
Likes: 13
From: California
We have ruled out ignition related misfire. I've had a chance to look over the data log with Shawn at Church Automotive and there is something strange taking place.
MAF
AFR
Intake timing R/L banks
are all reading/behaving as expected. However on the Exhaust timing we are seeing erratic changes in the timing for one bank only (can't recall if its R or L side) jumps +/- 10 degrees several times within a matter of a split second. Sometimes it does it under laod and other times we see it after a gear change. A spare ecu was brought in and reflashed without any luck. I believe this helps us narrow it down to possibly a bad EVT sensor, a bad EVT control magnet, or a bad/pinched wire. But again no CEL/codes other than recently a random misfire while I was backing the car out of the driveway (which may be from running more aggressive cams).
Correct me if I'm wrong but I think I was misinformed before about having misfire in all 6 cyl. I would imagine this would only cause misfire in one bank. And the misfire would happen only if the exhaust gas remaining in the combustion chamber was not allowing intake air and fuel to combust.
I really hope we are a step closer to getting this sorted out. If the above EVT solutions don't fix the problem is there a way to just disable the variable timing on the exhaust side - basically make it a non-revup?
MAF
AFR
Intake timing R/L banks
are all reading/behaving as expected. However on the Exhaust timing we are seeing erratic changes in the timing for one bank only (can't recall if its R or L side) jumps +/- 10 degrees several times within a matter of a split second. Sometimes it does it under laod and other times we see it after a gear change. A spare ecu was brought in and reflashed without any luck. I believe this helps us narrow it down to possibly a bad EVT sensor, a bad EVT control magnet, or a bad/pinched wire. But again no CEL/codes other than recently a random misfire while I was backing the car out of the driveway (which may be from running more aggressive cams).
Correct me if I'm wrong but I think I was misinformed before about having misfire in all 6 cyl. I would imagine this would only cause misfire in one bank. And the misfire would happen only if the exhaust gas remaining in the combustion chamber was not allowing intake air and fuel to combust.
I really hope we are a step closer to getting this sorted out. If the above EVT solutions don't fix the problem is there a way to just disable the variable timing on the exhaust side - basically make it a non-revup?
