550's slower than before?

[AWDDSMCRAZY]

Guys Im having a problem. I cant figure out why my car wont pull as hard as it did with the stock injectors. I've been replacing/upgrading parts trying to get it running and tuned right.

I have MAFT in blow thru, Walboro 190, boost @ stock, 550's, SAFCII, datalogger

Ive been trying to get this under control for the last month and Im going crazy and it's getting expensive. I used a boost leak tester and looked for leaks. Couldnt find any @ 30psi. When I had the 440's the car pulled much harder than it does with the 550's but there was knock on the datalogger. I have the MAFT set at -20 to compensate for the 550's but my karman is still hitting 1600 at 12psi. During this there is no knock. The injector duty cycle went down to 70 percent with the 550s instead of the 90's it was before.

Even with the -20 on the maft in order to get my trims lean enough to 100 I need to go another 15 percent leaner on the afc. Anything more than 12 psi and I get crazy knock.

Any help would be appreciated. Thx in advance

 

[Cool Mr Steve]

If you could post a log, it would be very helpful. Also, make sure to update your profile when you get a chance. I know you have a quick run down of your parts in your post, but it's always nice to be able to pull up your profile and have a look. If you don't update your profile by the time you post your log, let us know if your car is a 1g or 2g.

 

[AWDDSMCRAZY]

I'll post a log when I get home. I have both 12psi and one at 17psi. BTW updated the profile and its a 1g.

Thx

 

[94Jettameowpsst]

Well without any type of chip or antyhign compensating for the deadtime on the injectors, leaning it out will raise your timing. Im assuming thats why you are getting knock but then again you could just try turning up the boost and adding a bunch of fuel and see where your timings at after that. I got mine to run on 650s @ 23 psi by just retarding the cas a good bit but even then i was knockin up top due to 26+deg ta.

 

[AWDDSMCRAZY]

Heres the log. I couldnt post it in a gallery so I did on another forum I belong to. Heres the link info and or direct link

You must be logged in to view this image or video.

http://www.allthingsmoto.com/photopost/data/500/login.JPG

 

[GVR4592]

You need to be at WOT for an accurate datalog, those numbers are useless. The MAFT is not neccesary for your setup. I would go back to a stock maf, tuning will be much easier. If you are going to keep it then set it for the stock injectors and use the SAFC for the injector compensation and fine tuning.

 

[AWDDSMCRAZY]

?? That was WOT, both gears. Ill try setting the MAFT back to stock and adjusting from there. I'm not removing the MAF just for the sake that I'm on an upgrading process. The only reason I dont have a 20g on there yet is because I would like to get fuel and timing under control before I blow something up.

Thx

 

[blcknspo0ln]

your TPS shows that you are not at WOT. they should be at 100% most of the log..

 

[AWDDSMCRAZY]

I'll try readjusting again to see 100 percent all the time. I had it at the floor the whole time. Maybe I have a bad TPS. Before I adjusted it, it was always at 80% or so. Ill post another log after I can get 100 percent.

 

[blcknspo0ln]

adjust your TPS as per VFAQ instructions. then (if you have a logger or SAFC) and look at your percentages at WOT when the car is off.