I have a 95 z28 supercharged and I'm trying to get more fuel past 5500rpm. The MAF is maxed and the PE values are maxed so how can I program more fuel?

Thanks in advance,

Dave

 

If the engine is going lean past that point i would say a bigger fuel pump, adding an external pump which you should already have or bigger injectors. As far as programmming i have no idea. What unit do you have and how much boost are you running?

 

I have 75# injectors which are more than adequate and a TREX pump that keeps the fuel pressure good. So I need to know how to program it. The heads are fully ported so I'm showing about 10psi with a maxed s-trim.

 

i am having the same issues. are you using edit? if so try the pe vs coolant temp. i started with 44 degC and up and increased it by 25%. it helped but it still needs a bit more. once it is richened enough up top i can go back and lean the lower rpm's back out.

 

Interesting. I haven't tried that. I have LT1 edit and I just got the new version of tunercat.

 

Its not about the fuel pressure so much as its about volume. Sounds like your running out of pump. Large injectors won't help that either if there not getting enough volume. I had the same issues, even with a 255 and an inline NOS pump. Still ran out up top even though my fuel pressure looked good. You may need to go to dual 255's but they have to be in a parallel setup to get good fuel volume. Series setup wont work as that will only flow the volume of a single 255 pump. If your adding a bunch to your WOT tables in the rpm range that your leaning out and not really seeing any difference, then your probably running out of fuel.

Ken R.

 

Good info Ken. I did think about that but I didn't realize it was an issue even if the pressure looks good. Besides it's hard to watch the gauges and the road and shift at the same time. LOL!!

 

My 383 setup was running out of fuel at around the same hp numbers that your putting up with 60# injectors. FP looked good but just started leaning out up top no matter how much i added to the WOT tables. That was with a single 255 in tank and inline 255 (in series). I put dual 255's in the tank (in parallel) and I ended up having to take a ton back out of my WOT table up top just because it was running so rich. Definitly something to keep in mind. Do some more searching on here and you'll find more info on it also.

Ken R.

 

Yeah I think that is the problem now. A local buddy entered 1/2 the injector size and MAF values and adjusted the rest to compensate. I copied his settings for my tune but it looks like it's still going lean up top. Time to upgrade the fuel system. Thanks for the info guys.

 

BTW Ken, how do you like the T-trim? A local buddy has one but I'm not sure if I want to get it. I wanna keep mine a street car and the s-trim is already very impractical.

 

Your 383 will like the T a lot better. You could always pulley down if you want to keep it somewhat tame on the street. When i had my s-trim, i had it maxed out, but to make decient boost, it was running well past it's max efficency. The T matches my setup a lot better, plus i'm not overspinning it to get good boost either and pretty much running it right at max efficency on the top end. A 4" intake pipe improved on that even more. I think the T-trim is a solid street head unit for strokers assuming your in the Vortech crowd.

Ken R.

 

What cooler are you running? I've got the vortech aftercooler which was necessary. The pully swap is a good idea. I just worry about breaking my T-56. :/

BTW your car is sweet!!!

 

Thanks for the complement. I'm using one of the Ebay front mount air to air's along with a Snow water/meth kit. The air to air seems to be working well. My air temps not going above ambient where as before, they still would even, with the Snow kit. I'm very happy with it. Here's a link to a post i put up with my final pics in it. I haven't attached a link to them in my sig yet. I've read the Vortech aftercoolers work well. I would guess you should be good with that. I wouldn't be too worried about breaking the T-56, but if your still on a 10-bolt rear, then i'd be worried.

Ken R.

 

10 bolt LOL. That was out a long time ago. I've got a 12 bolt, denny's DS with HD yoke, Mcloed street twin & Spohn TA but the tranny itself hasn't been upgraded at all. It's the weakest point of the driveline.