What is the best mod for quick 1/4 mile times?

[ckolony]

Just wondering what you guys think

[fred 4 pt 3]

Go 3.27 for a 5 speed and 3.55 for 94/95 auto, 3.73 for the 89/93 auto. You better build the whole driveline for a stage 2 motor.

[Blown95SC]

Fred: How come you recommend the 3.73's for the 89/93 and not the 94/95's? Just wondering because I have a 95 Auto and I'm about to purchase gears for it.

Adam

[Joe Santillo]

That's the way to get the most power. If you do only 1 mod, do a complete system. I ran a 14.9 with exhaust as my only mod.

If you do gears on a 95 auto, go with the motorsport 3.73 pumpkin. That way you get a 'posi', less weight(not much) and the gears. You will be able to fry the tires though. A stock 95 sc barely chirps the tires stock.

Joe 95 sc auto 14.6@94mph

[fred 4 pt 3]

Well the later ones with the wide ratio gearset will be a little bit low in first gear with a 3.73 - my opinion. I want as much mph out of first as I can in a wide ratio setup because the step to second is so far. Hence the idea of the later birds with 3.55. Now, I could be screwed up here, since I'm thinking the wide ratio box started the same time as the later model blower/plenum and maybe it was the '93 model.

[Joe Santillo]

Unless you change cam and heads, the 1-2 shift on a 94-95 results in very little power drop. Looking at my dyno sheet, I drop from 201 rwhp to 180 rwhp following the shift.

Fred, your engine makes increasing power with rpm. The late SC has such a weak cam that the power is less than 0.5 dB down at 3500 rpm. I bet your motor is down 1.2 dB at 3500 rpm compared to peak power. (I thought you would like the dB thing).

First gear is not that short for me. Remember, you are making a crap-load more power than the rest of us. (almost 3dB more) If you drag race, go with the 3.73's. Even if you don't, why bother with 3.55's. That's only a 7% change from the factory 3.31's.(What's that in dB?) Not worth the money... Do the exhaust for better power/mileage/sound/head-gasket-life.

Dr. Joe (not really a Dr. but I certainly deserve the title more than Russ :-)

[NYC Russ]

Much more deserving, eh? For use of the highly technical term "a crap-load more power"?

Anyway, to get back to the original question asked, you are all wrong. The mod that will give you the most bang for the buck is far and away, NOS. Of course, if you do the exhaust and gears with it, you get more performance than just NOS alone, but I can get any SC to run (at least one) 13 sec pass on NOS.

And as for gears, according to Joe's theory, even 3.73s aren't worth it as they are "only" 11% greater than the 3.31s. Following that logic, one would take a pass on the 4.30s (13%) and head straight for the 4.56s (a whopping 18%). Clearly, all of us have been buying the wrong gears :P

[Stryford]

what does the stock '94 SC w/AOD have, as far as gears?

[Hot Rod Joe]

A bomb exploded behind the SC will also send it to a quick 1/4...

You know where I was going. Nitrous is great if you are in to that sort of thing but DO THE EXHAUST FIRST!

The 94-95 SC with the 4R70W automatic had either 3.27 or 3.31 gears depending on who you talk to. There was no gear option in 94-95.

Joe

[NYC Russ]

Show me where he says "reliable" mods... And I'm confident a 50shot on a stock exhaust (and stock SC pulley) will work just fine, assuming at least 93 octane. If it weren't a full weekend project to change my head gaskets, I'd strap on a 125shot just to prove my point that almost any car can take one run of mega-juice :)

Of course, once you factor in reliability, I'd have to go with the gears... Dunno if they actually make the car quicker than exhaust but I think they are the least likely thing to cause problems later :)

[sctomb]

Fred, the transmission changeover occurend in the '93 model year. 89-92 have the AOD, and 93 AODE and 94-94 4R70W. I believe. I may be a little off, but I think this is the way it is.

Tom

[95SCBird]

AODE and 94-94 4R70W
I have a 95 sc with AOD. What does the 4r70w mean. Does is come stock in all 93 -95. What gears are in it and what is a good upgrade?

Thanks

[Andy 94Sc]

If you have a '95 I know you do not have an AOD. '94 and '95 SC's have the 4R70W. From what I understand 4R70 is sort of an industry wide generic term for a 4 speed automatic, the W indicates Wide ratio gearset. The wide ratio gearset is the majority of the difference between this trans and the AODE. I am not sure of the gear ratios, but 1st gear is deeper than the AODE, and I think overdrive may be a little different also.

If you really want to convince yourself you do not have an AOD look for two things. 1. is there a T.V. cable, or third cable attached to your throttle body? I bet you have an opening in the bracket with no cable there. 2. Do you have an Overdrive lockout switch on the side of the shifter? This is only on Electronic transmission cars, the AOD is not electronically controlled.

[CrazyWilly]

I agree with Fred on the gears for the '94/'95's I was calculating the RPM with 3.73's for my '94, and I thought they would be a little high (RPM wise)for my car.

[Joey16know it all]

something tells me that a 75 shot would out do all of those

[cary Jackson]

It's gotta breathe in and out. (mostly out!) Spray, gears, pulleys, tranny kit, don't matter if theres noplace for the exhaust to go. Exhaust system hands down!

[sabbySC]

I learned the hard, way, while nitrous will do the most it can't be used without exhaust first so say exhaust

[Pablo94SC]

I have 3.27's in my 94 auto according to the tag on the differential housing. Not 3.31. I agree with Dr. Fred, the 3.55's are definitely the way to go to get the most outta the 4R70W...especially in 1st and 2nd.

4 = 4 gears R = rearwheel drive 70 = factory numbering W = wide ratio gear set

AOD
1 – 2.40
2 – 1.47
3 – 1.00
4 – 0.67

4R70W
1 – 2.84
2 – 1.55
3 – 1.00
4 – 0.70

Of course this thread is long since dead... but I thought I'd bring it back to life.

Paul

[Jimmy 2Coupes]

The axle tag on my 94 automatic says 3.31. I installed 3.55's, a trac-lok differential and it was a huge improvement. I would say 3.55's or 3.73's in a 94/5 automatic SC is matter of preference and IMHO 3.55's are close to perfect.


http://sc.communities.msn.com/tn/33/90/ThunderbirdRow/2/5.jpg

[V6Sprout]

i vote for gears!