GT40P heads, Cobra intake, full exhaust, C&L MAF- only 196.70 RWHP on DYNO!!!!!- HELP

Lxpony

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Ok, so brought (what I thought was going to be a beast) to the dyno this morning - dynojet- and got a big surprise! MY CAR HAS NO BALLS- I thought for sure my car would have more balls then this-

The intial reaction by the guys there was that the car was running way lean- I was the only non- blown car there so I was the leanest but because I was N/A- I went home and reviwed some info and confirmed that a N/A "chemically perfect" stoicometric ratio is 14.7:1. Well - all the blown guys were around 11:1 and there I was leaner then Mary Kate Olsen! based on what I see from the A/F ratio off my slip I am right at around 14.7:1 so where is my power?

so I took photos of 2 plugs- #1 and #5 and they look fine to me- they have about 500 miles on them- please take a look at plugs and time sheet....

I dont think that I am lean- I have 24# with matched C&L tube, stock FPR and 190 LPH pump- I guess my car stock put out about 170 at the rear wheels (pathetic as hell).

my only purpose of the dyno was to baseline prior to my vortech next month but now I an thinking I should go with the S trim and not the SC since I am about 50 HP behind where I thought I should be-

the Gt40p heads are bone stock as is the intake- shorty headers and C&L 76mm are the only real engine mods...... but I swear I thought some guys with the same combo where making close to 300 rwhp??? Do I suck? should I put a brick on the gas and drive it over a cliff?

The dyno slip are the same but with and without flash on my camera


PLEASE HELP!











 
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SmockDoiley

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Yes, that is the ideal calculated perfect A/F ratio, but it doesnt work in real life. And can actually be bad if running bad gas, pulling something, hauling ass up a hill and so on. For a nerd mobile it may be good, but we hot rodders need to tune for hot rodding which means you need to bring that A/F down to around the 13/1 area. Also, what is your timing set at? Running a little richer not only allows for more gas but allows for more timing which means more power. You could see a huge spike in power if you bump up the pressure and raise the timing if your set low right now. Also, get a leak down test on the motor to make sure its healthy. All the parts in the world will do no good if the motor is crap. As for your mods, the dyno is showing about 230 at the flywheel which if all you have is gt40p stock heads, CAI and headers, this may not be too bad. Do you have a full exhaust or just the headers? Your car really needs exhaust and an intake to really take advantage of heads or a supercharger. Dont be too disappointed.
 

Grn92LX

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Idealy you want a 13:1 a/f for a n/a car, but the low-mid range can be a little leaner. Fix your issues before installing a supercharger. Do you have a FP gauge? If so, what is FP doing at wot, is it dropping or steady @ 39psi? In your case, an afpr could help, try 45psi and see what happens. Are you running the right spark plugs for the P heads? Bad fuel filter?? Check the basics man, clean your maf wires. Maybe try disconnecting ther battery overnight to fully clear the KAM, then put it back on and go for a drive and wot blasts. Maybe the eec can adapt your fuel curves.
 

Lxpony

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my timing is set to 10 degrees (stock)- so bumping timing up would afffect FP?

If getting a AFPR is the answer that I would be happy but I thought that if I bumped up FP by 3-6 PSI then the compter, via the O2 sensors, would detect this and lean me back down to the stock FP? Is this not correct?

I have a high flow H-pipe with 2 cats, shorty unequal headers, and flows.. for exhaust
 

Grn92LX

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Yes, sometimes that is the case and the eec will adapt out the FP changes by changing the injector pulsewidth. In your case, I dont think it will do that as your way off in your a/f. Timing has nothing to do with FP. Try running 14-16* timing. Are you using a cobra/explorer manifold? Assuming you have P heads and a cobra manifold with the typical bolt ons, with a good tune you should have around 250rwhp..
 

Lxpony

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I do have an electric FP gauge- it was steady at just under 40 PSI at WOT which is what is supposed to be I know.... maybe I will go with an AFPR to start-

I am running plugs that per Autozone's computer are meant for those heads- Motorcraft platnums, fuel filter has approx 2k miles on it- fuel pump is 1 month old and about 200 miles on it- 190 LPH unit
 

battyice

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The computer can change the injector's pulse width, but can't really change your fuel rail pressure. Many people find extra hp by installing/tweaking an afpr; and even if it is not the source of your problem, it will be a neccessity down the road if you want to do more modifications.

Also, have you checked your car to see if it is throwing any codes? That would be worth a shot IMHO; you need to make sure your O2 sensors and whatever else are functioning correctly.
 

SmockDoiley

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Thats why you ditch the stoich and go to a richer A/F around 13/1. You'll be much safer and make more power. As for your mods, you are low if you have a cobra intake and full exhaust. But again, bump up the timing and FP. Timing has nothing to do with FP. Trust me if your timing and fuel pressure is stock, youll be amazed how much power youll make if you adjust those.
 

Lxpony

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ok then a AFPR is the next purchase- no check engine lights but I realize that doesn't mean it is not throwing codes- I will have my mechanic buddy plug into the socket by the driver side rear strut tower to double checkI will wait for the SC until I get my AF back under or close to 13

o2 senors are new- have about 3k miles on them
 

Ranchero5.0

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You need a decent fuel pressure regulator. The fuel pressure adjustment acts like a power valve in a carb. If it's too low the car won't pull very well, and if it's too high the car loads up during a pull. The puter runs set tables during WOT and doesn't care about the o2 readings, but will lean itself out during non WOT situations.

When I bought my '93 the fuel pressure was set at 38psi without a vacuum source and they were using the FMU to raise the fuel pressure. I had no 'power valve' function and the car fell on it's face and went lean before boosting. Now I run it at 45psi with vacuum and the fuel runs about 40psi at cruise speeds and the A/F is happy.

Jamie
 

nito88stang

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TIMING add more timing, if your car ends up liking 16* of timing then thats 6* of timing you need. Thats like 20 hp left on the table if not more. Play with the timing, and just listen for pinging.
 

hllon4whls

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I am with these other guys. You just need to tune the power out of your car. When I first ran my car, I ran 12.50's. With a little tweaking, it went 11.96. With a better carb, locked out dist and some more tuning, 11:60's.

Remember, the trick is in the TUNE!
 

kystang1889

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also if you are running 24# injectors what size mass air to you have if you have the stock mass air that is hurting you too, you need a mass air cal. for the bigger injectors also what cam are you running, you need a nice size cam to really open up those heads
 

Schlodes

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Stock cam isn't that bad and would work well with a 1.7 rocker. Bump the timing like everyone else is suggesting it will make a good difference. Does the car have the stock clutch fan? Ditch it. How about accessories? Smog pump still on? I know its only like 2 HP to spin it, but, every little bit helps. I've never had luck with platinum plugs really... maybe try a Ford Motorcraft stock heat range plug got the P heads, gapped at stock specs??? What throttle body do you have. With good heads and intake the stock T body could be a bottle neck. :shrug:

Is it an AOD or 5 speed. [didnt read thorugh reply..]
 

gt90stang

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First off is your TPS adjusted correctly and is it actually going into OL or WOT operation. In WOT operation the PCM uses tables to determine the AFR from trim values learned while driving. In my datalogs with Tweecer RT the AFR is pretty close to what is in the tables. For the stock PCM the tables are shooting for 12 to 12.5:1 at OL or WOT conditions and this is what my datalogs have shown. I have leaned mine to 13 to 13.5:1 and notice a definite improvement in performance.

If you vehicle isn't getting into OL or WOT then it would normally run at Stoich in closed loop operation.

Something is out of cal. in your setup and unless you can datalog what is going on your just shooting in the dark. I use Tweecer RT and a WB02 to tune.

Good Luck, Don
 

89MustangGX

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I just skimmed through some of the replies, but I wanted to reply when I saw the dyno chart. I've seen really spikey curves like that before, and I think it usually indicates an ignition problem.

I didn't see anyone else mention it, so maybe I'm not even close...???
 

Lxpony

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guys, in an attempt to fatten up the A/F I put my 19# C&L tube back into the mass air meter and the car is running as well as it did with the correctly calibrated tube. so atleast I fattened up the A/F a little bit with that correct?
 
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