19 psi on 14b: Safe or Not

'89beretta · 06-05-2005, 06:04 PM

After installing the 190 fuel pump and setting timing to 5 degrees, the car doesn't knock anymore. However, I cranked it up to 19 psi on the stocker 14b and am still seeing no knock. Keep in mind this is on stock 450 injectors. Am I safe doing this or am I just blowing hot air after 18 psi like everyone says with the 14b?

Also, with the timing gun, the mark jumps every now and then from 5 degress up and down. It doesn't stay right on the 5 degree mark. Does this mean that the timing belt is off a tooth? Perhaps this would explain why in low rpm at partial throttle I'm seeing a lot of knock. When I do go full throttle, the knock goes away. Let me know what you guys think. Thanks.

Joesmoke · 06-05-2005, 06:34 PM

Yes, you are moving the 14b farther out of its efficiency and creating a hotter charge, but if the engine is responding favorably (no / low knock) then you're OK. Talons will run rich from the factory, and thats what you're taking advantage of with running 19 psi with stock injectors. BUT, ambient temp and good gas will start to have a real impact on knock at these levels. A couple deg. warmer outside, or a long pull, will affect knock faster and harder. Also, everybodys car will react differently to different tuning strategies. Always best to experiment yourself, using common information as guidelines.

Timing jumping around does not nec. mean belts off a tooth. Check for vacuum leaks and ignition system for optimum performance.

***Any reference to phantom knock is to be prefaced that you know your engine is sound! (fuel/air, ignition timing, combustion chambers)***

Talon knock sensors are notoriuosly over active. Most likely, part throttle knock with no knock at your torque peak, will be phantom knock. No load, low load knock (especialy max counts!), with the above ***note in mind***, is going to be garbage readings, or, so minor as to not be minded.

'89beretta · 06-06-2005, 12:19 PM

You described it perfectly. I'm getting max counts of knock at very low rpm, partial throttle when I'm easing out of 1st gear. I assumed that was phantom knock. Once floored or at higher rpm, there's no trace of knock.

Also, thanks for clearing up the timing thing. I've always assumed I've had a vacuum leak because at idle I'm only showing 14-15 on the vacuum side of the boost gauge when the norm for DSM's seems to be 18-21. I'd had a compression check recently and everything turned out okay. I'll have to take some time to plug a lot of my vac lines. Any other thoughts or suggestions are welcome.

Seat of pants does tell me I'm making more power. 2nd gear roll from 35 mph, the tires break loose on dry pavement, when they wouldn't before. Haven't had the chance to test it at the track yet. And yes, I have noticed that after a couple long 3rd gear logs, I start seeing knock counts on account of the stocker heat soaked side mount.

Joesmoke · 06-06-2005, 07:54 PM

DJ23GSX · 06-08-2005, 05:55 PM

I have pushed a 14b to 22psi with the stock injectors 255lph fuel pump and a MKIV i/c and i was seeing 6-10 counts of knock and 15- 16* timing. I could definatly feel the drop off in power after 6000 rpms. It seemed to run better at 20psi to redline. I wouldn't recomend running that boost all the time.

TheCrazyDSM'r · 06-10-2005, 07:41 AM

I will agree with the 20psi max limit for that turbo, I know some people will disagree but that is ok. I think that it pull strong with 20psi but doesn't become too inefficiant at the top end. Anything over that and it really does start to fall flat. At least that is how it felt to me.

Screamin Eagle · 06-10-2005, 08:12 AM

True it is probably out of its efficiency range, but with some race gas at the track it can be done. Just as long as you don't see the knock counts jump way up. As far as the phantom knock goes, I have the same low throttle crazy knock. It will max out at 43. I thought it was my lifters for the longest time, inspecting closer made me realize it was my loud injectors, just an idea for when you are trying to find your phantom knock problem.

xcelr8n · 06-10-2005, 04:25 PM

I run 18psi daily and it sees 18pounds more than once everyday

As long as everything on the logger is clean, meaning good timing, no knock, you should be ok.
I plan on running it over 20psi at the track in the next few weeks, and if it grenades no biggie its a 14b I can find them everyday for 125 bucks locally.
ps. curious to know what youre injector duty cycles are like, you dont want them over 90% for extended periods of time.

kevingst · 06-10-2005, 04:42 PM

I run 20psi daily with mine. However, I don't ALWAYS get on it...just mostly. But by 6000rpm it's down to like 14-16psi. I normally just end up shifting at 6k. Dsmlink says my power is pretty much peaking at around 5k.

'89beretta · 06-15-2005, 11:11 PM

So after logging a run this morning (65 degrees outside) at 18-19 psi, everything still checks out. Timing is great, no knock. However, my injector duty cycle was a whopping 98%-102% (I didn't think that it was possible, but that's what the logger said).

Time to back off? What are the long term affects of running the stock injectors that much? Thanks for your replies.

TurboAnything · 06-17-2005, 03:46 AM

Not to sound crazy but i had a friend here that had a 91 AWD. He has proof of running high 12s on free mods no exhaust 100 octane and 25psi on a 14b.