outlaw2252 Posted August 25, 2020 Share Posted August 25, 2020 Hey everyone, Long time forum stalker here. A few months back my VF-40 took a dive while I was out and about. Oil analysis came back fantastic showing no bearing material so i decided to risk going ahead and replacing the turbo along with upgrading some other components. Compression and Leak down test came back good as well. Cylinder #1 (140 psi) 5% loss at 35 psi. Cylinder #2 (140 psi) 3% loss at 35 psi. Cylinder #3 (145 psi) 5% loss at 35 psi. Cylinder #4 (140 psi) 5% loss at 35 psi. The motor has 140k on it, it's an 07 LGT 5EAT. I went ahead and installed the following: VF-52 Tomei UEL Headers & Up pipe Catted Cobb DP Invidia Q300 Catback Cobb 3-Port BCS NGK One Step Colder Plugs Deatschwerks DW65C Fuel Pump Forced Performance Turbo Oil Line Kit Cobb V3 Accessport I've just had the car road tuned and my tuner was having an issue with the boost spiking on the AT shifts. Right now the tune is only running about 12.5-13.5 PSI throughout most of the powerband until it shifts, and then I see a boost spike to about 17PSI. When he started tuning it he said he was having an issue pulling back the boost and that he would like to see it peak at 17.5 psi +/- 1.0 psi but it keeps wanting to hit 19 psi. No signs of knock and it only does it on a hard pull when the automatic shifts. The injector duty is around 86% so it is all happy other than he wanted the boost to be a little lower. He said so far it has resisted letting him back it off. My question to the group is this.. I know there is more power there with only running 12.5-13.5psi. Has anyone else experienced this phenomenon (im sure some have) and have a recommendation on what I need to look at? I'd like to have a slightly more aggressive tune while still being safe on the motor and trans. He tuned it pretty conservatively and was very transparent about it. Just looking for opinions/advice on a path forward. It's my DD and I don't track it but do enjoy the occasional WOT pulls. Thanks in advance!! Link to comment Share on other sites More sharing options...
Max Capacity Posted August 30, 2020 Share Posted August 30, 2020 FWIW, my vf52 had been tuned at 21psi back in Aug 2010, on stock fueling. That was 152,000 miles ago. Since then it has been street tuned by the same Tuner and normally pulls 19+psi again on stock fueling. I have about 2 or 3 years ago upgraded to a AEM320 pump but that was just because of other gas smell issues. My Tuner is tuningalliance@gmail.com Email him and ask his advice. You can tell him I sent you. He does check in here every now and then. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
solidxsnake Posted August 30, 2020 Share Posted August 30, 2020 (edited) How is this being tuned, OpenSource or AccessPort? I know there are things the OS crowd has figured out about tweaking the 5EAT (which I've read is very much useful/necessary when putting more power through the 5EAT). I'm not sure if Cobb's implemented the same tuning capability. edit: seems this is not an OS thing after all, just a remapping of the DBW tables: https://www.romraider.com/forum/viewtopic.php?f=14&t=7539&start=30 Edited August 30, 2020 by solidxsnake Link to comment Share on other sites More sharing options...
outlaw2252 Posted August 31, 2020 Author Share Posted August 31, 2020 It's being tuned with the Accessport. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now