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Topic: 3.73 gears? (Read 3469 times) previous topic - next topic

3.73 gears?

Reply #15
Quote from: Haystack;333682
For the track, you want to be at the top of forth when you cross the line, regardless of tranny. That way you are getting all of the power to the ground that you have gearing for.

... I should have said 1:1, not forth.


Yeah, and looking at the chart, this is about 127mph with 3.73's. Still though, there is also a slight problem with such simple statements if utilizing 1st is actually a waste of time for any of a few reasons.
1988 Thunderbird Sport

3.73 gears?

Reply #16
Quote from: Seek;333681


*edit 2*
I had severe traction issues with stock TC 225 tires when my auto transmission would shift into 2nd (1.55) with 3.55 rearend gearing (5.5x total) with the transmission's hard shifts, on completely dry pavement with semi-performance street tires. While it moved well in the seat-of-pants feel in 2nd and 3rd, I ended up moving down to 3.08's which are right in the middle of 2.73's and 3.55's in terms of gearing gains and lost no time to 70mph since I wasn't having to let off the gas for the 1-2 shift. It still breaks them loose if I'm on anything but perfect pavement but safety was a major concern and I didn't want to go with wider tires. It gets quite bad when every time you go into 2nd, the car fishtails and you have to let off the gas. It's easy to go overboard for a specific setup. People should keep such things in mind also - it's best to keep the power where it's usable than to just spin the tires. 1st gear in most vehicles can already get them spinning so why waste all that power that 1st is there to give you?


So you have this problem too. I still have 3.73s. First is quite useless with a large amount of throttle from a stop unless I'm at the track. Squiggly black marks are not fun every time I want to accelerate quickly from a stop. The car will spin the tires on a OD-2 down shift at 70 mph which is kinda scary...
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

3.73 gears?

Reply #17
Quote from: thunderjet302;333696
The car will spin the tires on a OD-2 down shift at 70 mph which is kinda scary...


Do you really downshift to 2nd at 70mph?  That just doesnt sound like a good idea.:wtf:
Mike

3.73 gears?

Reply #18
Quote from: mcb82gt;333712
Do you really downshift to 2nd at 70mph?  That just doesnt sound like a good idea.:wtf:


Quote from: thunderjet302

TSI AOD with 2800 PI converter


Not sure most transmissions will go down to 2 at 70mph with 3.73's in the rear but it's certainly possible at higher rpm's.
1988 Thunderbird Sport

3.73 gears?

Reply #19
It kicks down to 2nd for a split second then back up to 3rd. It's supposed to do that with the valve body mods. The way the trans is built it ain't going to hurt it. I just scares the  out of me when it does it:hick:. It won't go down to 2nd above 70 mph. With the non lock up converter I'm turning 2800 rpm at 70 mph.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

3.73 gears?

Reply #20
I have 4.10's in my 88 Sport with AOD transmission..... wish I put in 4.30's

 I leave it in D driving around town and only use the overdrive for highway driving... my off road and 2 chamber flowmasters sure sound good.. :burnout:

3.73 gears?

Reply #21
Quote from: no911forme;333736
I have 4.10's in my 88 Sport with AOD transmission..... wish I put in 4.30's


Autos are different since their 1st gear is nowhere near the ratio of the I4 T5. 2.4 1st first mated up to 4.1 rear = 9.84x advantage with gearing. 1st gear in most manuals is much higher and the I4's 1st is 3.97 - multiplied by a rearend ratio of 3.55, this is still much more advantage and rpm ramp up rates at 14.09 over your 9.84. You have much more time in 1st, plus autos can (the stock aod can be pretty sloppy though) handle a quick 1-2 shift much better than a person with a manual.

For a track or city driven vehicle, 4.3's would be fine with the AOD and run the quarter well behind a mild engine, with traction.
1988 Thunderbird Sport

3.73 gears?

Reply #22
Quote from: thunderjet302;333721
It kicks down to 2nd for a split second then back up to 3rd. It's supposed to do that with the valve body mods. The way the trans is built it ain't going to hurt it. I just scares the  out of me when it does it:hick:. It won't go down to 2nd above 70 mph. With the non lock up converter I'm turning 2800 rpm at 70 mph.


Sorry, my bad.  I thought we were talking about a T5. :hick:
Mike

3.73 gears?

Reply #23
Peak power(or just after peak) in direct drive(4th) is where you want to cross through the traps...regardless of 1st gear.  It doesn't matter if you shift to second gear 6ft out or at the 60ft mark, you're still making that shift, you're not losing any time.

I would much rather have that super short 1st gear.  It's easier to drive on the street with less clutch slippage required, you can creep around parking lots at super slow speeds without clutching it every other second, and it makes it easier to get out of the hole with more consistency.

With my old standard T5(3.35 1st), I cut extremely consistent 60' times, with the T5Z(2.95 1st) it was much slower out of the hole launching the same way...I accidentally slipped the hell out of it on the last run and it was slighly quicker than my best 60' with the old standard T5.

I vote for gears!

Good luck,
Don
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

3.73 gears?

Reply #24
I thought if your running a car with boost,you would want a higher rear gear numerically lower!!! Some turbo apps i seen like 3.08-3.55 max gear ratio. Helps boost pull longer and harder instead of banging gears like a mofookie?????????
1987 T-bird SportCoupe,302,5spd,8.8,3.27s,pbr brakes,spindles,2003 rear,18inch 06 gt rims!!!!:evilgrin:
2006 Gt Mustang,3v,5spd,8.8,3.55s,GT500rims.
1990 T-bird LX,3.8,aod,loaded,stock!!
1999 Trailblazer(wifes rig)

3.73 gears?

Reply #25
I'll say it again. For a daily driver, I personally won't go any lower than 3.55 gears with a 3.97 first gear T5. ITS PERSONAL CHOICE. If you don't mind shifting into second 15 feet out of the hole, go for it. Just seems useless to me.
Given the choice between a good quality cam that will increased my horsepower and torque across THE ENTIRE RPM BAND, or gears that will only get me off the line A LITTLE better, I'll go with the cam.
Not knowing how to install a cam is a poor excuse. LEARN. I'ts a 2.3 Ford, it ain't that hard.
88 TC 5speed, 168000+ miles, stock 2.3T long block, ported RFE6 exhaust, Evergreen T3 running 15#'s.
Up next: FMIC, fresh air intake, ported intakes, ported big valve head.

3.73 gears?

Reply #26
How about this, which do you think will be faster? Which will accelerate the car quicker, 1/4 mile or not? The stock, or 3:73 or higher gears? The HP will remain the same, but it increases basically the leverage the engine has on the rear end. That will make it faster. Might not be much, but it would. The only real change I see to this, is if you blow the tires off with the better gear. A way under geared first ratio will feel better and let you enjoy the boost longer, but will be slower from second on, where the engine will still easily hit boost, but will be in those gear longer.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com