View Full Version : M6 @280hp with boltons NA w/13.9 A/F!!!


camaro4me
05-14-2007, 01:18 PM
Ok, I had my car dynoed last week after i got my nitrous setup in. We went to do a pass na to get a baseline, and the motor started detonating really bad around 4800 and wouldnt pull past 5200. It only made 280 hp and A/F was at 13.9. of course we stopped. I just recieved my 39lbs injectors and I have a mail order tune on the way from EFIlive to get a good base line. What else could be causing this though?? One very reliable source told me that my fuel pump could be on its way out the door. if anyone can think of anything else, i am all ears. Thanks

camaro4me
05-14-2007, 01:19 PM
btw, the only boltons are lid, flowmaster, ported throttle body and descreened maf. The guys at Efilive told me they thought it was because i have a descreened maf, but since i am running a dry shot, i thought i had to descreen it.

TwistedSS
05-14-2007, 01:28 PM
You don't have to descreen your MAF to run a dry shot.

edcmat-l1
05-14-2007, 01:41 PM
Check to make sure the hot wires in the maf arent dirty. Thats the most likely cause.

smokin2001formula
05-14-2007, 01:44 PM
Descreening a maf might give you a 1/2 hp boost on a dyno. It is there to keep shit out of your engine. I would definetely put it pack in or get a new maf with a screen. By the way the bigger ones like the 85mm from slp are useless as well and can cause the car to run lean.

camaro4me
05-14-2007, 01:50 PM
i didnt take it off for hp, but to keep the dry shot from freezing the screen. that is what I heard all over the boards. do you think the fuel pump is dying??

smokin2001formula
05-14-2007, 02:00 PM
It could very well be the fuel pump. Never had one go out on me though. Gonna upgrade mine with turbo kit going on soon. Hopefully someone will chime in that has had a pump go out on them before and what the characteristics were like. Maybe also try a search about fuel pumps failing or just broken. That might help some. Sorry I couldn't help you out more.

LostCauseZ06
05-14-2007, 03:36 PM
usually when fuel pumps go they go... as in bye bye no car turny onny/vroom vroom...


you sure the car was entering WOT?? almost seems like you werent getting full WOT and it was keeping your fueling in lean cruise lol


you got the dyno chart?

camaro4me
05-14-2007, 07:41 PM
i dont have the dyno chart, but might be able to get it. I am for sure though that it is getting to wot.

camaro4me
05-15-2007, 01:38 PM
bump for some more responses

Asmodeus
05-15-2007, 04:55 PM
get a stock MAF on there.

massls1guy
05-15-2007, 05:14 PM
changing the fuel filter might be a good idea as well

3.4camaro
05-16-2007, 10:30 PM
yeah check out that fuel filter and put some seafoam in the tank. if you don't know what seafoam is go look in the "general maintenance and repairs" section.

And the screen is not there to act as a filter. It is there to staighten out the air running across the hot-wire in the MAF. This is needed on truck MAFs with side-intake, but not our straight tube intake.

The air filter keeps shit out of the engine, cuz, you know, its a filter. :)

FU_I_AM_UltraZ
05-23-2007, 10:17 AM
Descreening a maf might give you a 1/2 hp boost on a dyno. It is there to keep shit out of your engine. I would definetely put it pack in or get a new maf with a screen. By the way the bigger ones like the 85mm from slp are useless as well and can cause the car to run lean.


If you have an airfilter under the air lid, you should have to worry about large debris going into the motor. i descreened mine and haven't had a problem for 25k miles so far and started to port a spare. i don't trust aftermarket MAF. I had a problem with a granatelli one and won't ever bujy their crap again or recommend anyone else either

FU_I_AM_UltraZ
05-23-2007, 10:21 AM
Ok, I had my car dynoed last week after i got my nitrous setup in. We went to do a pass na to get a baseline, and the motor started detonating really bad around 4800 and wouldnt pull past 5200. It only made 280 hp and A/F was at 13.9. of course we stopped. I just recieved my 39lbs injectors and I have a mail order tune on the way from EFIlive to get a good base line. What else could be causing this though?? One very reliable source told me that my fuel pump could be on its way out the door. if anyone can think of anything else, i am all ears. Thanks

when was the last time you changed the fuel filter? ever use that Sea Foam stuff? to clean your intake and valves up a little. you might have some gunk robbing you. from your bolt-ons, you should have at least 310rwhp depending on if you have a A4 or M6

Tuner@Straightline
05-23-2007, 09:01 PM
I'll have to check on my laptop at home, but I believe that your year F-body doesn't enter power enrichment til 5500rpm. So above that RPM it's not adding any fuel, just going off what the MAF is reading. As far as descreening, when tuned properly, it doesn't matter, aftermarket, stock, descreened, they'll all work. I've seen SLP MAF's nearly dead on, and I've seen stock ones off by as much as 12% in some places, and vice versa. I don't think it's the fuel pump, the either work or not, but it'd be a good idea to check the fuel filter.

camaro4me
05-23-2007, 10:03 PM
i am going to change the fuel filter, but i already changed back to a stock screened maf, and it didnt make any difference. I just got an pcm in from efilive and will be installing that tomorrow as well as my cobra 39lbs injectors

Justin00SS
05-23-2007, 10:06 PM
Descreening a maf might give you a 1/2 hp boost on a dyno. It is there to keep shit out of your engine. I would definetely put it pack in or get a new maf with a screen. By the way the bigger ones like the 85mm from slp are useless as well and can cause the car to run lean.

Wrong.

If something it small enough to get passed your AIR filter. Then the screen in the maf won't stop it. :judge:

Its to straighten out the airflow.

5_02ls1
05-23-2007, 11:28 PM
Descreening a maf might give you a 1/2 hp boost on a dyno. It is there to keep shit out of your engine. I would definetely put it pack in or get a new maf with a screen. By the way the bigger ones like the 85mm from slp are useless as well and can cause the car to run lean.
:stupid:

That screen is there to straighten airflow so the meter can read properly :search:

On an fbody its worthless but on a truck with the elbow in front of the meyter it has a purpose..
Oh yeah the air filter is what keeps shit out of your engine...
Most dry kits recomend descreening due to the screen fressing

+1 on cleaning the MAF....also put a fuel press gauge on it that will tell you the state of the pump....

Bader-X
05-24-2007, 06:07 AM
1998 Z28

lost 32 hp after my engine rebuild and fixing a non working spark coil and after taking it to a different shop it was 4 burnt wires (were touching the headers for few hours at the rebuilders shop while idling) and 1 bent spark plug end (bad installation) and I got back those 32 rwhp after that at least and before changing the spark plugs and wires it was 13.5 afr then it went down to about 13.0 afr oh and there was one of the two knock sensors dead changed that too :)

second guess was when I bought the car it was a as fast as most V6 cars and hesetating alot was a bad fuel pump and wiring for it.

erikthegoalie
05-25-2007, 10:07 PM
Descreening a maf might give you a 1/2 hp boost on a dyno. It is there to keep shit out of your engine. I would definetely put it pack in or get a new maf with a screen. By the way the bigger ones like the 85mm from slp are useless as well and can cause the car to run lean.


:huh:

The filter keeps shit out of your engine...the screen straightens airflow to improve readings...I have a descreened maf, no problems....

98Z28CobraKiller
05-28-2007, 10:03 AM
I'll have to check on my laptop at home, but I believe that your year F-body doesn't enter power enrichment til 5500rpm. So above that RPM it's not adding any fuel, just going off what the MAF is reading. As far as descreening, when tuned properly, it doesn't matter, aftermarket, stock, descreened, they'll all work. I've seen SLP MAF's nearly dead on, and I've seen stock ones off by as much as 12% in some places, and vice versa. I don't think it's the fuel pump, the either work or not, but it'd be a good idea to check the fuel filter.


PE entry is determined by tps %.

BLK02WS6
05-28-2007, 01:10 PM
PE entry is determined by tps %.

X2 - the RPM and MAP settings are overrides, not what determines PE entry.

sloganish
05-28-2007, 02:29 PM
:huh:

The filter keeps shit out of your engine...the screen straightens airflow to improve readings...I have a descreened maf, no problems....


x2, i dont have a descreened maf however, purley because theres no reason to do it in my eyes, id rather have my airflow readings be straightened out before reaching the maf wire than have a 1/2 horse on the dyno :drive: