4.6 in a 5-speed SC

MaddMartigan said:
FWIW, I have a 347 stroker in my 1993 Thunderbird LX. The car weighs 3975 with me in it. With the crappy JBA Cat4ward headers that I have it has only run a 13.3@98. Those numbers usually befuddle ALL of the calculators out there.

Someone pointed out above that the 92 Crown Vic used the 3.8/5.0 bellhousing. This is helpful info if someone is bent on the conversion.

As for your car, I come up with an ideal 1/4 run of 13.9@98mph, or 13.3@102mph. This means that your car is falling on it's face up top for some reason. It launches hard, but then can't keep up with itself. Maybe lack of fuel?

Anyway, if I use your mph for HP calculation I get 275rwhp, and if I use your ET I get 300rwhp. If it makes 300rwhp, then 390fwhp would be believeable. I'm betting you have some more performance in there just begging to get out.
 
XR7 Dave said:
Someone pointed out above that the 92 Crown Vic used the 3.8/5.0 bellhousing. This is helpful info if someone is bent on the conversion.

As for your car, I come up with an ideal 1/4 run of 13.9@98mph, or 13.3@102mph. This means that your car is falling on it's face up top for some reason. It launches hard, but then can't keep up with itself. Maybe lack of fuel?

Anyway, if I use your mph for HP calculation I get 275rwhp, and if I use your ET I get 300rwhp. If it makes 300rwhp, then 390fwhp would be believeable. I'm betting you have some more performance in there just begging to get out.

I almost positive that the headers are killing me. They have a 2" collector and 1 1/2" primaries with 14ga. steel so they are really lacking in flow. I am working on getting a set of long tubes to fit.
 
XR7 Dave said:
Ya, I got a little carried away with the responses, but I think it is important to understand that I'm not bashing the 4.6 either. There are reasons that I think the 3.8 offers plenty of performance for the car it came in and I hate to see people dump endless amounts of time and effort into a car only to get discouraged when things don't work out the way they had envisioned.

FWIW I am more baffled by how MTNCAT run 13.3's with so little HP than how MTNCAT is by baffled by the 250-260rwhp that we get from stock SC's. It just doesn't compute. According to my math a 257rwhp car that runs 13.3 @ 102 should weigh in at 3350 with driver. Is your car really that light? :confused: I know that a fully dressed SC weighs in at 3950-4150 with driver.

If case anyone doubts my math, Connie Baker made 261rwhp on Saturday at the dyno, which with her measured 3875 race weight, ran 13.90 on Sunday. According to my math that equates to 259rwhp. My math is darn close.

Either these 4.6 motors don't subscribe to the same math/physics as the rest of us or MTNCAT's car made closer to 300rwhp than it did 250rwhp. :)

Dave, The 1MTNCAT weighs in at 3760 with me in the car. I go about 170 myself. I have weighed the car at various tracks and its always within about 25 lbs one way or the other of those numbers. A whole flock of us weighed our rides at Richmond FFW this past June. The V8 cars all weighed less than the SC's. Mike Siska car was right at 3970 If I remember correctly. BUt it also has a cage, the intercooler, all the Allen stuff on it plus Mike is Heavier than I am so that all comes into play. My car is not a stripped street version, it has everything on and in the car that it came with and thats how I run it. I bought this car new in 1996 for My Birthday and have had it ever since so I know there is nothing different about it. It was on the track the first time at 900 Miles and has been there ever since.

As far as the HP numbers and such, It was dynoed at Amazon racing last year in August and Tuned by Jerry W. It was tuned on a Mustang Dyno. It is a factory stock 96 shortblock with the PI heads and PI cam coversion only so its basically a Factory PI with just a slight increase in Compression due to the Head swap. It does have the Bullitt intake and TB on it as well and a 90 MM Maf. It has only underdrives, FP regulator, JBA SHorty Headers, 4.10 gears, and a converter in the 4R70W with the J-mod. Exhaust is still the 2 -1-2 design but diameters have been changed to 2 1/2-3"-2 1/2" pipe. Thats the story on the car as it is. Suspension is stock except for the airbags in the springs, and a set of custom Subframe bars underneath that weight about 20 lbs each that I used to help stiffen the car. Larger fuel pump and the Nitrous power adder when I choose to use it are the only other mods. The car has run 13.5's on 245-60-15 BF Goodrich TA Street tires on many occasions and pulls 1.8's to low 1.9's 60 ft on those. It 60's at 1.61-1.7's on the juice.

As far as the power equation, I cant answer that, it has always defied the calculator. I do believe that the calculator does not justify an Overhead cam motor though. You figure less valve train losses at Higher RPM so that may account for some, but who knows. I know I don't! I just take them as they come. I'm hoping I can get some headwork, cams, long tubes, etc etc done over the winter and see how she does on the motor and the juice next year. I suppose time will tell.

Thats about the best Information I can give you. Play with the calculator and see if you can gain anymore insight. If you can please let me know, I'd be interested too LOL!!

later guys/gals
 
1MTNCAT said:
Thats about the best Information I can give you. Play with the calculator and see if you can gain anymore insight. If you can please let me know, I'd be interested too LOL!!

later guys/gals

I think I will tune in on this one since I have a V8. I personally believe that it is less expensive to mod a SC to a higher HP number than a 4.6L.

I agree that the 3.8L is a higher maintenance engine than the 4.6L/ 5.4L. Heck all I did to my mod motor engine this year was to replace the oil and clean it a few times.

I saw Mikes car back when it was known as Broken bird. He was one of the pioneers for the bullet intake and I know for a fact that he spent some money on the tune.

I think the secrete to the fast V8's is the transmission. Years of research have allowed them to get the highest level of efficacy possible. Ranging from the original J-Mod to the latest and greatest state of the art Darrin and DirtyDog transmission with 3+ plate TQ's these machines are efficient. Combined with a computerized Tune at the optimal shift points it will be hard to shift as well with a 5-speed as one of the automatics can.

Just my 2 cents...

DSC01351.jpg
 
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1MTNCAT said:
Dave, The 1MTNCAT weighs in at 3760 with me in the car.

It was tuned on a Mustang Dyno.

The car has run 13.5's.

As far as the power equation, I cant answer that, it has always defied the calculator.

Play with the calculator and see if you can gain anymore insight. If you can please let me know, I'd be interested too LOL!!

Ok, a little more info goes a long way. ;) Most Mustang Dyno's read about 10% lower than the Dyno Jet that my calculations are factored around.

So we take 256 x 1.10 = 281 Dyno Jet rwhp (which btw is 1 rwhp/cubic inch, not too shabby at all).

Then using 13.3 ET along with 3760 race weight and I come up with 287rwhp (13.5 comes out to 275rwhp for you running on an "off" day). Your car and my calculator get along just fine. :)
 
1MTNCAT said:
Since I sort of got drug into this I'll just say this. I have no problems with the Super Coupes or the Community as a whole as some V8 folks have but let me assure you that the car (My Car 1MTNCAT) did do 13's with Typical bolt- ons with the FACTORY STOCK 4.6 NON-PI engine and not once but several times. If there is any doubt there is video out there and Mike Siska, was there with his bird when it did it. Not only that, Jerry W of SCT was also present at the time. All in all that day the car made 21 passes morning and afternoon, all on the motor. Best of 13.89-worst of 14.07, so much for the 4.6 theory! Here's the real kicker, it had 116K miles on it when it did it!

The current PI set up, FACTORY STOCK Shortblock with Stock Untouched PI heads and PI cams, has gone a best of 13.3 @ 102.2 at the MN12 Nationals in North Carolina last September.

The arguements may remain but those are facts. With the only power adder being a ZEX nitrous system, the FACTORY STOCK shortblock has gone low-low 12's @ 109 MPH. BTW the STOCK 116 K motor went 12.89 @ 105 MPH before I swapped in the PI Version.

On the Dyno at Amazon racing Last August 2004, Jerry W of SCT tuned the car, it showed 257HP @ 317 TQ at the wheels on the motor, and 347HP @ 503 TQ at the wheels on the juice.

I Just wanted to relay the facts as they are. Next year I hope to Have the heads ported and polished and possibly aftermarket cams to see what it will do on the same set-up.

I've run at Hagerstown with Coy Miller on Occasion. If you don't believe me speak with him. He's seen it on more than one occasion a year or so ago.

Just wanted to pass this along.

Good luck in your modding!!!! :)

I wasn't trying to say anything about the motor being stock. The sentence reads "STOCK MN12 with a 4.6 PI" therefore making it not a stock MN12. Damon got what I was saying anyway... it was just the way the sentence was worded. And I would be glad to have my ~~~ handed to me by Connie. :D Lighten up a bit here guys.
 
Dirk SC said:
I wasn't trying to say anything about the motor being stock. The sentence reads "STOCK MN12 with a 4.6 PI" therefore making it not a stock MN12. Damon got what I was saying anyway... it was just the way the sentence was worded. And I would be glad to have my ~~~ handed to me by Connie. :D Lighten up a bit here guys.

:) I am lightened up and have been from the beginning of my posts here. Just being informative and relaying the correct information. The Sentence should have read "STOCK MN12 with a FACTORY STOCK NON-PI 4.6L", Therefore making it what it was, a stock MN12. It is not a factory stock MN12 with a PI engine in it, I agree. However, this PI engine is still Stock itself just to set the record straight.

Just trying to clarify the statements so everyone understands.
 
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