Well went to a dyno today......

[Johnny Langton]

I'm just saying that the people have told me that the dynojet would read about 10 or so hp higher than the mustang dyno. Thats all i'm saying.

But my main concern is why a completely stock other than cat back 97 grand marques made that close to a modded mustang. i really fail to believe that the pi intake, exaust, and filter would only give 10hp. Exspecially since people rave on and on about how the pi intake will give you 15 rwhp more by itself. Thats all i'm saying.

You're still looking at it all wrong.
Was your torque converter locked during the pulls?
Was the CV's torque converter locked during the pulls?
What was the air fuel on the CV?
The PI intake does indeed yield 15-20 rwhp. Your engine is drowning in fuel,so it's not gonna make power until that stops.
JL

yes both the converters locked. They had problems getting mine to lock the first run threw but the second it locked. The GMarques' torque converter locked also. I don't remember the GM's a/f ratio. I'll ask next time i see him, probably friday.

So my problem is the factory tune then? even if i got with the npi intake will that still be a problem or will it fix it slightly? So getting a good tune would fix this problem all together.

You know this for a fact? Was somebody connected to the EEC and commanding a locked converter? If not-there's no way that your converter was locked.
JL

 

[voidfinger]

I'm just saying that the people have told me that the dynojet would read about 10 or so hp higher than the mustang dyno. Thats all i'm saying.

But my main concern is why a completely stock other than cat back 97 grand marques made that close to a modded mustang. i really fail to believe that the pi intake, exaust, and filter would only give 10hp. Exspecially since people rave on and on about how the pi intake will give you 15 rwhp more by itself. Thats all i'm saying.

You're still looking at it all wrong.
Was your torque converter locked during the pulls?
Was the CV's torque converter locked during the pulls?
What was the air fuel on the CV?
The PI intake does indeed yield 15-20 rwhp. Your engine is drowning in fuel,so it's not gonna make power until that stops.
JL

yes both the converters locked. They had problems getting mine to lock the first run threw but the second it locked. The GMarques' torque converter locked also. I don't remember the GM's a/f ratio. I'll ask next time i see him, probably friday.

So my problem is the factory tune then? even if i got with the npi intake will that still be a problem or will it fix it slightly? So getting a good tune would fix this problem all together.

You know this for a fact? Was somebody connected to the EEC and commanding a locked converter? If not-there's no way that your converter was locked.
JL

Hmmm, they were telling me that after blah blah blah rpm the converter will lock up in this gear... the didn't say anything about hooking it up. It didn't jump out of gear when they started making the pull or nothing so i guessed it was locked.... at least that is what they told both of us.... I might have got shitted lol for my low low hp sakes i hope so hahaha

But seriously i didn't know they hooked it up to the computer and forced the converter lock up.

 

[Johnny Langton]

Hmmm, they were telling me that after blah blah blah rpm the converter will lock up in this gear... the didn't say anything about hooking it up. It didn't jump out of gear when they started making the pull or nothing so i guessed it was locked.... at least that is what they told both of us.... I might have got shitted lol for my low low hp sakes i hope so hahaha

But seriously i didn't know they hooked it up to the computer and forced the converter lock up.

The TCC is locked via a solenoid that's controlled by the EEC. '98 GT's do not lock the TCC at WOT in stock programming, and there's not any particular RPM that the EEC commands lockup-its based on vehicle speed and load. What's your EEC catchcode? I'll do a bit of checking to see more details on the OEM calibration.
JL

 

[voidfinger]

exactly what is the catch code?? Its not that big of a deal really. I'm pretty close to haveing a 4th gear anyway lol.

 

[Jrgunn5150]

I had the Xcal and they leaned it quite a bit, the initial pull was like 188, the second was 205, the third, my transmission broke in half :lame:

 

[jfor441]

I went to a dyno day and they used a dyno dynamics dyno. Very similar to a Mustand dyno. I put 177 hp and 230 tq to the wheels.

 

[QwanSanchez]

I put down 190whp and 264 wtq completely stock in my 96 GT

 

[Johnny Langton]

exactly what is the catch code?? Its not that big of a deal really. I'm pretty close to haveing a 4th gear anyway lol.

The 4 digit computer code.
I'll assume it's an XTA2-that's what alot of them were.
It does lock the converter at WOT in 3rd gear,but only after several timers have expired. So basically...your TCC wasn't locked during that pull. Since you'll be above the "fluid coupling" state of the torque converter(approx 2400 rpms with the stock converter) during a dyno pull-there's minimal losses,but there are still losses due to the driveline not being solidly locked.
2-3% on average,but that's still 2-3%.
Now as for the air fuel....

The table above is the base fuel table for your car. What this table shows is lambda. Lambda is the stoich point of the air fuel ratio in an internal combustion engine. For all practical purposes-it's a 14.64:1 ratio of air to fuel. The table show the percent of lambda that's commanded for the intersection of load and RPM that you're looking for. Most N/A modulars never see 100% load,so the typical max load is around 85-90%. We'll use 90% since there's a column for that already,and it'll be easier to follow.
So,at 4000rpms and 90% load-the EEC is commanding 12.12:1 air fuel(14.64 x .828=12.12). That's all fine and dandy until the catalyst temperature control steps in(emmisions control to protect the cats from overheating). This is setup in this particular calibration at a calculation of 89% of commanded lambda,which in this case is 10.78:1(our commanded lambda of 12.12 x .89=10.78). the catalyst temp control kicks in during dyno pulls because the load is high, rpms are low to start the pull, and the cataylst protection strategy calculates the temperature of the catalysts based on the engine's running conditions. When the catalysts reach 1550 degrees farenheit, the catalyst temp protection strategy takes over commanded lambda and that's why you have an 11:1 air/fuel at 4000rpms, 10.69:1 at 5000 rpms,and 10.28:1 air fuel at 6000 rpms when cat temp control takes over.
This is why it's imperative to have a good tune for the car to get the most power out of it. Tuning strategies also vary from model to model, so the CV that was on the dyno may not have had such an aggressive cat temp control as your car does. That's just one possibility as to why it made close to the same power your car did.
Any questions?
JL

 

[voidfinger]

I had the Xcal and they leaned it quite a bit, the initial pull was like 188, the second was 205, the third, my transmission broke in half :lame:

How did that happen ?>????

 

[voidfinger]

I put down 190whp and 264 wtq completely stock in my 96 GT

Dyno Jet numbers huh ?

 

[voidfinger]

exactly what is the catch code?? Its not that big of a deal really. I'm pretty close to haveing a 4th gear anyway lol.

The 4 digit computer code.
I'll assume it's an XTA2-that's what alot of them were.
It does lock the converter at WOT in 3rd gear,but only after several timers have expired. So basically...your TCC wasn't locked during that pull. Since you'll be above the "fluid coupling" state of the torque converter(approx 2400 rpms with the stock converter) during a dyno pull-there's minimal losses,but there are still losses due to the driveline not being solidly locked.
2-3% on average,but that's still 2-3%.
Now as for the air fuel....

The table above is the base fuel table for your car. What this table shows is lambda. Lambda is the stoich point of the air fuel ratio in an internal combustion engine. For all practical purposes-it's a 14.64:1 ratio of air to fuel. The table show the percent of lambda that's commanded for the intersection of load and RPM that you're looking for. Most N/A modulars never see 100% load,so the typical max load is around 85-90%. We'll use 90% since there's a column for that already,and it'll be easier to follow.
So,at 4000rpms and 90% load-the EEC is commanding 12.12:1 air fuel(14.64 x .828=12.12). That's all fine and dandy until the catalyst temperature control steps in(emmisions control to protect the cats from overheating). This is setup in this particular calibration at a calculation of 89% of commanded lambda,which in this case is 10.78:1(our commanded lambda of 12.12 x .89=10.78). the catalyst temp control kicks in during dyno pulls because the load is high, rpms are low to start the pull, and the cataylst protection strategy calculates the temperature of the catalysts based on the engine's running conditions. When the catalysts reach 1550 degrees farenheit, the catalyst temp protection strategy takes over commanded lambda and that's why you have an 11:1 air/fuel at 4000rpms, 10.69:1 at 5000 rpms,and 10.28:1 air fuel at 6000 rpms when cat temp control takes over.
This is why it's imperative to have a good tune for the car to get the most power out of it. Tuning strategies also vary from model to model, so the CV that was on the dyno may not have had such an aggressive cat temp control as your car does. That's just one possibility as to why it made close to the same power your car did.
Any questions?
JL

Yes, what if i don't have cats ?

at 5k the car was at 11.9 and then nose dives to 11.4 at 5500, they stopped it after that. Is that about right? thanks Mr. Langton.

 

[Johnny Langton]

Yes, what if i don't have cats ?

at 5k the car was at 11.9 and then nose dives to 11.4 at 5500, they stopped it after that. Is that about right? thanks Mr. Langton.

The EEC doesn't know that you don't have cats.....it's still doing it's job in trying to protect them from overtemp.
JL

 

[voidfinger]

If you don't mind me asking, how would a tuner turn that "off" . It sounds like something embedded in the pcm. Thanks, and sorry for all the questions. When i comes to tuning ... give me a Really long screwdriver and a holley any day lol.

 

[Johnny Langton]

If you don't mind me asking, how would a tuner turn that "off" . It sounds like something embedded in the pcm. Thanks, and sorry for all the questions. When i comes to tuning ... give me a Really long screwdriver and a holley any day lol.

It's really easy-if you know what you're doing. People pay alot of money for tuning software and training on how to use it,so I'm not gonna give up much detail on it.....But if you're looking for a good tuner-I can make some recommendations on who actually know what they're doing.
JL

 

[voidfinger]

anyone in the charlotte, NC area. I've already got an idea of whole i would like to tune it since on the sct newsletter he got the premier sct tuner... they came down and trained him on how to use it and licenced him or something. , but he is the one that did the dynoing... ya know.

 

[justinschmidt1]

I didnt really feel any gain from the pi intake untill it was tuned.

 

[voidfinger]

cool, gotcha. I'm just wondering now if i should put my pi heads cams and intake on the car or should just take the pi off and sell the kit.... or should i use it..... I don't know.

I think i'm just going to do the pi head swap and do the t45 swap with some 4.10's and slowly save up for the cobra motor... hmmm

 

[Jrgunn5150]

The fools who this fool paid 350 to to put 4.10's in the rear end used the factory shims, which meant there was way to much backlash. Vibrations ran up the driveshaft and shattered the case. Three times before I figured it out...

 

[voidfinger]

wow did they make it right though???

 

[Steven]

cobra swap isnt that big of a deal.. a good running 5 speed PI GT with gears gives a 96-98 cobra run for its money