So I got the car dynoed....

[StangLou]

When you start getting into the 14's with A/F after prolonged racing hard driving or just a long cruise on the highway you will start putting holes in pistons.

If I was s/c and running a 14+ a/f then I would worry, but an NA engine isnt going to experience those kind of problems. Before anything that major happened there would be major detonation going on and the spark knocking would be obvious. My car was tuned to where it would spark knock, then backed down 2-4 degrees, I cant remember which one. A/f was a constant 14.5-14.7 and I never heard a ping. Car ran
That freaking tb/plenum combo made me pig rich, around 12.3. I think thats the main reason I didnt see but like 3hp increase peak. After some tuning it was the same hp increase, but I picked up a bit more torque, and a/f leveled out at 13.5. We were crunched for time, so we werent able to fully push the car like I wanted.
Like I said, Im no a/f expert, but I trust my tuner and know what my car was at and is at now. I asked them since a lot of guys on here were like "man, your car is going to blow." I was told to only worry if my a/f went above 15 on an n/a car. Once your s/c you start to worry about mid 12's to 13's. The car saw MANY a high mile cruises, dragstrip duty, and hard street use.
Im all about edumacation though . So if someone wants to go into the a/f aspect with me Im all ears!
Not trying to hijack the thread, my appologies

 

[BlueJoker]

quick update:

I know, I know, i said I'd post the before and afters today (12-13-04) however theres a 'small' storm headed out this way tomorrow (charlie), so the shop called me and I've got to reschedule the apt. I STILL plan to post the graphs and get you alls input. Thanks again to all who replied!

 

[98SteedaStang]

I put down 213hp and 260tq. It feels fast. Try getting a tune the LTs and exhaust will change your A/F. I've heard that LTs will make you run Rich with a capital "R". Dont worry about the headers. Us auto guys dont have much choice. the Hookers look nice but I hate how only their mid-pipe will work. Never looked at Kooks, any good?

 

[Dr. Wu 2000]

I think a custom tune will really help. When I had my GT, it was an auto with all the normal bolt-on's minus long tubes and i put down 251/280. I had JDM Eng. do my custom tune with a Superchip. I think with an auto a custom tune is a must.

 

[007]

Another low-dyno auto here. Actually I feel a little better seeing that everyone else is experiencing the same thing. Drivetrain loss sucks. My next mod = Tremec TKO.

 

[forpit2000gt]

Get a custom tune for your setup and you will probably see the numbers come up another 10 to 15 hp and tq. For your mods, that is going to be realistic numbers.

 

[stangman]

So you think the brand of headers I chose has something to do with my a/f?

just curious

every LT header will make you run rich. the reason why is, the o2 sensor is moved farther back. a o2 sensor needs to be at a certain temp. to work properly, with moving it back, it takes longer to get to operating temp. On occasion i'll get a SES light from it, but that's only if i'd made a few short trips & the sensor didn't have time to heat up.

as far as brand of headers you bought, the macs put out of the best numbers the quality of the coating (HTS) is what most have a beef with. the HTS tends to rust, but where you live in FL you wont see that as easily & if it bothers you that bad, get the ceramic coated ones they make now Don't listen to half the people that say all mac stuff is crap, because half of them are saying it because they heard it from other people, not from their experience not saying mac is the nicest stuff you can get, because it's not the nicest, but it's not as bad as everyone makes it out to be

 

[vidmaster]

Someone on modular depot contacted SLP to find out if their LT's work on AUto GT's and they do, so that's another option for quality LTs.

 

[Mach142]

Hey BlueJoker - sounds like we have a similar problem. I had just had the oxygen sensor bung installed and did a quick connect of the Innovate LM-1 A/F meter. I took the Mach for a ride to let it warm up. During the ride the LM-1 was giving me a 14.6-14.7 reading during normal driving - right where it should be. When I was able to open her up, the A/F seemed to be a litttle erratic and dropped very low around 5K. I played back the run on my PC and found that it jumped around between 11.5 and 12 at lower RPMs and then dropped to 9.5 at 5K. That sounds ugly to me! I am not sure where to start. Mods are minimal - Magnaflow catback, K&N filter and a Predator tune. Unless I get some help from this forum, I may start by going back to a stock tune to see what happens then. At this point in time, I am just sort of lost for the cause. I am not sure if I would get any help from the dealer.

 

[BlueJoker]

Mach142
Hey BlueJoker - sounds like we have a similar problem. I had just had the oxygen sensor bung installed and did a quick connect of the Innovate LM-1 A/F meter. I took the Mach for a ride to let it warm up. During the ride the LM-1 was giving me a 14.6-14.7 reading during normal driving - right where it should be. When I was able to open her up, the A/F seemed to be a litttle erratic and dropped very low around 5K. I played back the run on my PC and found that it jumped around between 11.5 and 12 at lower RPMs and then dropped to 9.5 at 5K. That sounds ugly to me! I am not sure where to start. Mods are minimal - Magnaflow catback, K&N filter and a Predator tune. Unless I get some help from this forum, I may start by going back to a stock tune to see what happens then. At this point in time, I am just sort of lost for the cause. I am not sure if I would get any help from the dealer

.

Ill let you know if i find anything out when i go to back to the shop, my best answer for your problem though would get a speed shop to dyno tune your car and upload the settings to the predator, then just tweek it however you want. hope that helps a little.

 

[Mach142]

The downard spike in the ratio does not seem normal and I would like to figure out why it spiked rather than to do a patch in tuning. Besides, I am not sure that the adjustment range in the Predator will correct for such a major spike. I will look forward to hear what the shop tells you.

 

[JayC]

mac long tubes....man what a shame. Pinching pennies in the wrong department bro.

This is some great information...........please PM Mustang92 (Bill Putnam) and tell him what a big mistake he made going with the wrong headers.




1999 - 2003 2V Naturally Aspirated 1/4 ET:
1 . Steve Drier (Houston Performance) - 11.24 @ 118.00 ( 1995 GT AUTO - SVO HEADS/INTAKE, STROKED )
2 . KenB - 11.33 @ 119.95 ( 2000 GT 5 SPD )
3 . starkie - 11.84 @ 113.12 ( 2001 GT 5 SPD )
4 . madmike - 11.92 @ 112.75 ( 2000 GT 5 SPD )
5 . Bill Putnam - 11.97 @ 113.20 ( 2000 GT 5 SPD ) << cheap MAC longtubes


Jay

 

[BlueJoker]

Sorry no graphs but....

Here are the results from the dyno tune

240rwhp
274rwtq

I asked again what the 'spikyness' of the af could be, but got the same 'not to sure' answer. The car is now running about 13.1-13.4 af and is still spikey
all across the rev range. idles about the same and fills a bit stronger on the ol but o meter, however the roads are really wet so i havent had a chance to open her up.

btw it was about 480 chip=250 2hours tuning=200

i was also quoted for a complete kenne bell install (9lbintercooled) + gear swap (back to 3.27) of about 7k, this seem ok? or am i gonna save a bunch somewere else?

 

[Craig Mack]

i was also quoted for a complete kenne bell install (9lbintercooled) + gear swap (back to 3.27) of about 7k, this seem ok? or am i gonna save a bunch somewere else?

$7000? Tell him to suck your balls. Kenne Bells such a rip off.

I was close to buying a used (mint) condition Vortech V1 supercharger kit, complete with 93mm maf, injectors, all the hardware, etc for $1250 for my COBRA. The guy (96 cobra) made 420rwhp @8psi with only exhaust. I know, its a totally different ballgame power wise on a Cobra, but you see my point. (value wise)

Do not waste $7000 on that BS. Centrifugel blowers like Vortech, Paxton, etc. won't give you the "instant" power that roots/twin screw blowers give, but they can be had MUCH cheaper,give better peak HP gains, are more efficient, and will still make your car haul MAJOR @ss. If you look you could easily find a used Centrifugel Supercharger kit for your car in MINT condition, and have it installed, making more HP for a fraction of the price.

And as far as swapping back in the 3.27's, even with a supercharger thats a bad move. I wouldn't go any longer than 3.55's, 3.73s optimum IMO.

Just my .02, good luck.