big-phil Posted January 21, 2006 Share Posted January 21, 2006 I had to lean out my AFM 16 teeth! to get it to pull smooth, but it now pulls hard, and there is no ping at 14 psi Is 14 pounds of boost to much for my set up? Plus I just got a P90 head, should I put it on? Will it flow alot better? will it lower my compression? Will my motor last longer with it? Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted January 22, 2006 Share Posted January 22, 2006 ummm.. turn it way down.. the stock turbo ECU will max out at 10psi.. it cant think anymore after 10psi! Quote Link to comment Share on other sites More sharing options...
EZ-E Posted January 22, 2006 Share Posted January 22, 2006 Actually after 3500 rpm and WOT the ecu doesnt really do much anymore. Quote Link to comment Share on other sites More sharing options...
big-phil Posted January 22, 2006 Author Share Posted January 22, 2006 it pulls hard to 5000rpm and my air fuel guage is pegged "rich" I know they are not very accurate but it feels great. I don't want to blow it up, so what psi should I turn it down to?? 10? Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted January 22, 2006 Share Posted January 22, 2006 ummm.. turn it way down.. the stock turbo ECU will max out at 10psi.. it cant think anymore after 10psi! doesn't really matter at that point, with larger injectors he's kinda taken the stock ECU out of the loop anyways. stock ECU, 370 cc injectors, a decent intercooler, and 14psi of boost should be fine. Can't know for sure w/o dynoing it, unfortunately, and some people have seen the car start to run lean at 5000rpm or more. Remember, that narrowband gauge you're using is looking for 14.7:1 air fuel, so anything richer than that will show rich, but really, you could be at 13.5:1, peg that guage at rich, but that's still way too lean. You want a good low 12:1 air/fuel really. But just going on the experiences of others, those 370's SHOULD be giving plenty of fuel. When you tune the AFM you're not even adjusting the top end, you're really only tuning the part throttle driveability, at 14psi and WOT the AFM is pegged at full open anyways and the ECU is just following a preprogrammed fuel map. Again, with the 370's it's kinda out of the loop anyways. I ran 14psi on the stock injectors at increased fuel pressure, I did the math a while back when I was trying to figure what pressure to run, and at the pressure I ended up at (about 75 psi at WOT full boost) my injectors ended up equating to about 330 cc's, and my air/fuel ratios on the wideband were in the 10:1 range at 3000-4000rpm, 11:1 4000-5000, and 12:1 5000-6000 (it leaned out because boost was dropping so the RRFPR was lowering fuel pressure). Never once heard it ping on the street or dyno. You should be fine. Quote Link to comment Share on other sites More sharing options...
big-phil Posted January 23, 2006 Author Share Posted January 23, 2006 I was thinking the same thing, at WOT the afm is open all the way, and those 370's are dumping the fuel. plus my fuel pressure at WOT is about 55-60poundsBut I would like to get it on a dyno with the wide band, but from the seat of my pants, it's pulling damn hard, I'm going to race my freind with the 5.0 again, just to see how much farther in front of him I can get hehehehe! Quote Link to comment Share on other sites More sharing options...
EZ-E Posted January 23, 2006 Share Posted January 23, 2006 From looking at your car your going to need better tires to stop all that wheel spin you are going to have. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted January 23, 2006 Share Posted January 23, 2006 yeah dyno it just to be sure but especially with increased fuel pressure I would bet money, literally, that your a/f ratios are perfectly safe, you may even be on the rich side. I had a friend with a mildly modded '90 Stang LX notchback 5.0, when I was at 9psi and no I/C, we raced and he beat me bad off the line, I bogged so bad, in 2nd gear I was right at his tail not gaining or losing, in 3rd gear I walked past him so bad I asked him afterwards "why'd you let off so soon???" only to find out he was still on the throttle until I was 4-5 cars AHEAD of him and pulling. We went at it again after I got my I/C, RRFPR and 12psi of boost and it was a SLAUGHTER. Since then I have uh... 'inspired him'.... (more like pissed him off) to the point where he's now 'serious' and is in the process of installing a supercharger. Should be fun. Big-phil, any way I could talk you into doing me a favor? Just a little experiment for me. I want to get some comparisons of how quickly other people with similiar setups to mine are getting their turbos to spool. If you could time yours I'd be really grateful. Take your car up to like 3500rpm in 3rd gear (that's where I've been timing mine from), just hold it steady at 3500 and then punch it and time exactly how long it takes your turbo to reach full boost. I've been timing mine with a stopwatch... if you can't do that at least try to count one-one-thousand-two-one-thousand and give me an estimate. I'd really appreciate that if you could. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted January 23, 2006 Share Posted January 23, 2006 hmm i was under the impression the stock turbo ECU maxes out at 10psi.. bastaad is right though.. more fuel pressure will handle it .. or a rising rate FPR or adjustable fpr.. sweet.. rock on! Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted January 24, 2006 Share Posted January 24, 2006 well the stock EFI 'maxes' out at 10psi... sure... at 9-10psi you will start to run lean above 5000rpm or so. At that point, the AFM is open as far as it will go and the injectors are at their maximum duty cycle. If you upgrade to larger injectors, the ECU doesn't know this, and will still max out the duty cycle at WOT and 9+ psi of boost. But now, you're dumping in... what... like 40% more fuel? For that same duty cycle. The ECU doesn't compensate for the larger injectors in any way... that's why you need to tighten the AFM spring or the car runs like crap off boost. So he doesn't NEED the extra fuel pressure, the larger injectors on stock EFI would probably be enough, and guys have run on a wideband up to I think like 14 or 15psi of boost on bone stock EFI with just the 370cc injectors and found it to be perfectly safe. Since Phil is running higher compression, the added fuel pressure is probably a good additional safety net. But as I keep saying, until he gets to the dyno no one can know for sure. Quote Link to comment Share on other sites More sharing options...
big-phil Posted January 24, 2006 Author Share Posted January 24, 2006 bastaad525, next time I have the chance I will do the 3rd gear @ 3500rpm punch for ya and let you know, its funny I remember you saying it took 1.5sec to reach 14 psi. I tried that tonight but the car started sputering under boost. I think I fouled plugs while tuning the afm****bog after bog after bog untill it felt right*** OR I'm still to rich out of boost that its fouling plugs, It just started doing it tonight only in boost, so I'm going to get some new plugs, and maby go a couple more teeth leaner on the afm. Oh and my clutch might be slipping now? I have a new one, just don't look foward to putting it in. Quote Link to comment Share on other sites More sharing options...
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