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Discussion Starter #1 (Edited)
97 cobra with:
dr gas x-pipe o/r
borla catback
steeda pulleys
k&n

thats about it for power mods.

pull 1: 286.4rwhp and 275.9rwtq
pull 2: 286.7rwhp and 274rwtq.

what do you guys think? i was only expecting about 275rwhp.
 

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I think your numbers look pretty good. At the time, I had similar mods to you (except I had the C&L) and I put out 292/278 SAE.

Good luck,
Brian
 

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Good results!! Would you mind replying with your numbers in 100 rpm increments from 4000 to your max rpm for one of the pulls? I'm looking for some numbers for comparison. Is you x-pipe catted or an o/r?

TIA
 

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Discussion Starter #4
Blown46Cobra said:
Good results!! Would you mind replying with your numbers in 100 rpm increments from 4000 to your max rpm for one of the pulls? I'm looking for some numbers for comparison. Is you x-pipe catted or an o/r?

TIA
i will get the graph scanned and have it posted tonight or tomorrow. the x pipe is an o/r pipe.
 

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That's good #'s for those mods. Congrats.
 

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Discussion Starter #7
heres my graph. the dyno guy said its running pretty rich. i should be able to squeeze a few more horses out of it with a tune, but not until i get headers and a powerpipe of some sort and a MAF.



 

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That thing is running WAY too rich up top! The ideal A/F ratio for a N/A Cobra setup is 12.8-13.0. Lean it out and you will pick up some power. ;)
 

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Definetely too rich. That's pig rich and then some. I start at about 12.5:1, then lean out to 13.4 by the time I reach redline. Make sure the guy has a reliable (wideband) a/f sensor before accepting those numbers as being true. Rotate your MAF to the 9 o'clock position if you want to lean it out some. I wonder if your O2's are still good. If one or two of those are shot, the symptoms can include running rich and really crappy mileage. How is your mileage? Are you running colder than stock plugs?
 

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Rotating the MAF is not going to change the a/f ratio. The a/f ration is determined by the o2 sensors during closed loop driving. Those tables are then used for WOT. I agree his numbers are rich but very "stock" according to Ford (for 96-98 Cobra). In the 99+ cars they leaned the mixture up significantly (WOT). If you want to lean it up, get a tune/chip.

Thanks,

Chris Yates
96 Cobra
 

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Chris Yates said:
Rotating the MAF is not going to change the a/f ratio. The a/f ration is determined by the o2 sensors during closed loop driving. Those tables are then used for WOT. I agree his numbers are rich but very "stock" according to Ford (for 96-98 Cobra). In the 99+ cars they leaned the mixture up significantly (WOT). If you want to lean it up, get a tune/chip.

Thanks,

Chris Yates
96 Cobra
Then why did my a/f change, and why was there a 16rwhp difference between having my Maf turned straight up, and at the 3 o'clock position?
 

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I'm guessing you did that change on the dyno as a before an after, right? If that's the case the EEC hasn't noted the change (takes place during closed loop driving). There's a whole host of other possibilities which I'll get into if the above isn't the testing method you used.

Thanks,

Chris Yates
96 Cobra
 

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Yeah, I tried 3 different positions during the runs. When I switched it to the straight up position, they drove the car on the dyno for 4 minutes or so to help it relearn a bit. I'm sure it wasnt enough time though. While the peak power was alot lower, my torque curve was much smoother with the meter straight up. With it at 3 o'clock, I had a bit of a dip in torque in the 3-4k range, but in the 4000-6500 range, power was 15-20 rwhp higher all the way up. One thing I wanted to add was, I had my maf in the straight up position for months, and I had a perpetual stalling problem. I rotated the Maf, and my stalling problems were cured, as well as feeling a sotp improvement in power. The dyno showed my butt dyno was working. After months of having my maf straight up, why didnt my computer ever figure things out? I don't believe the test results on the dyno were just because the eec didnt have enough time. The computer had months to learn the straight up position, and it never did. Tell me why rotating the maf to the 9 o'clock position cures 9 out of 10 rich conditions with CAI applications?
 

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32V,

Couple different things here. First is the stalling. Most often this is caused by the pressure wave that bounces back towards the MAF when the throttle slams shut. Some of the after-market MAF will cause the stall under these conditions. I'm surprised you have the problem with the ProM because it's usually the C&L that stalls. Rotating the MAF changes the location of the sensor and can change the way the wave hits the MAF. Now, on to the dyno... ; ) Unless you practice extreme consistency on the dyno you will see variations from one run to the next. For example, during the local SVTOA dyno day last week time and time again we saw cars make more power each run with number peaking on or around the third or fourth pull. Why? Because the oil/coolant/engine/diff/tranny/etc are warming up. Who's to say the first pull was when the coolant temp was 185 and the next when it was 205? The best way to get meaningful numbers would be to make several pulls with the MAF in each configuration with cool down time between all the runs. And no, 4 minutes on the dyno is not enough for the EEC to compensate for a lean or rich condition. The bottom line is the MAF simply reads the amount of air entering the engine. The EEC through the o2 sensors will adjust fuel accordingly. Might you see a/f reading vary from time to time, probably. Over the long haul though the EEC will tweak the tables to find what Ford thinks is the perfect a/f ratio.

Thanks,

Chris Yates
96 Cobra
 

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Discussion Starter #16
32VHEMIJR said:
Definetely too rich. That's pig rich and then some. I start at about 12.5:1, then lean out to 13.4 by the time I reach redline. Make sure the guy has a reliable (wideband) a/f sensor before accepting those numbers as being true. Rotate your MAF to the 9 o'clock position if you want to lean it out some. I wonder if your O2's are still good. If one or two of those are shot, the symptoms can include running rich and really crappy mileage. How is your mileage? Are you running colder than stock plugs?
my gas mileage is fine. its about ~20mpg with my 4.10s. i'm using NGK TR-55 gapped at .054".
 

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I agree with what your saying about the wave hitting the maf. Makes sense. As far as the numbers going up with each run, this hasnt always been the case with me. I've had sessions where the numbers get lower with each run. As far as ther coolant temp, I hit 318 with the engine fan on, so most likely it was a little too hot for power production, but who knows. FYI, first run was with the maf at 2 o'clock. This is the position I had it in for months (not 3 o'clock). At this run I hit 311. Straight up, 298, 3 o'clock, 314. My 318 number was the uncorrected actual hp for that last run.
 

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Those are nice numbers Stangin. :cool: I'm curious, if you had a catted X instead of the O/R X, how much less hp do you think there would be? I'm working on the same setup with the exception of catted vs. O/R. You mentioned you'll probably get a powerpipe as well. Do you think you'd be able to keep your strut tower brace on?

Nice Numbers :joy:
 

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missouri,

With your list of mods you'll probably be around 280rhwp. Most stock 97 Cobras are good for 255-262rwhp stock. You'll get 8 or 9 with pulleys and 10-12 for the H pipe.

Chris Yates
96 Cobra
 
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