Need info on Gears
05-04-2006, 12:14 AM
#1
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Need info on Gears
I know a lot of 4.6 owners swap out the factory gears as one of the first mods, but I do not hear a lot of this going on with the IRS Cobra's. What are the benefits/negative to changing out the gears in your diff. I've read that gas mileage goes to crap, but is your car more responsive? Is it worth doing if it's a daily driver mostly used for crusing? I have to admit I am a little lost when it comes to gearing, and messing with the Diff. If you go with shorter gearing when you are in over drive wont the RPM's run higher?
05-04-2006, 04:16 PM
#2
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RE: Need info on Gears
https://mustangforums.com/m_1321939/tm.htm
Read that thread....
My post from it.. and its applicable to any stang, IRS or not. Only thing is with the IRS you have even more wheel hop.. just something you have to get used to.
Read that thread....
My post from it.. and its applicable to any stang, IRS or not. Only thing is with the IRS you have even more wheel hop.. just something you have to get used to.
I have a 97 cobra, basicaly the same motor as yours just different setup on the heads. The way our cars make torque at low RPMS is by shutting of one intake valve per cylander until 3250rpm. When you hit 3250rpm it opens.. its basicaly like a butterfly valve... like I said they do that for torque purposes.. however, your torque curve, much like mine, is funky as all hell. Its almost a flat line till nearly 4k.. then it curves up in a hurry.. but try to launch at 4 grand with out slicks and an upgrded clutch/flywheel and some suspension work and see how that goes.
N/A Cobras NEED STEEPER GEARS to make up for the disadvantage of low end torque. There is no question there. Its a fact. Why are the Mach's quicker with the same motor setup? 3.55's is the main reason. Gears make a much larger difference on our cars then on 2v or 5.0 stangs. I went 4.10's and I have the older tranny (t-45). I run 3k at 80mph. With the newer tranny which you should have in the 01, you will be even lower then that. My times suck *** (2.4 60') due to track/street tires/no suspension work with the gears... I just could not hook to save my life. Since the last time I went to the track I changed my clutch and I should have my dr's on this week.. will make a world of difference... hopeing to cut off .4 on my 60' and hopefully pull mid 13's in the next week or 2 when I make it back to the strip.
N/A Cobras NEED STEEPER GEARS to make up for the disadvantage of low end torque. There is no question there. Its a fact. Why are the Mach's quicker with the same motor setup? 3.55's is the main reason. Gears make a much larger difference on our cars then on 2v or 5.0 stangs. I went 4.10's and I have the older tranny (t-45). I run 3k at 80mph. With the newer tranny which you should have in the 01, you will be even lower then that. My times suck *** (2.4 60') due to track/street tires/no suspension work with the gears... I just could not hook to save my life. Since the last time I went to the track I changed my clutch and I should have my dr's on this week.. will make a world of difference... hopeing to cut off .4 on my 60' and hopefully pull mid 13's in the next week or 2 when I make it back to the strip.
05-05-2006, 12:16 AM
#4
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RE: Need info on Gears
HAV, thanks for the info that thread was pretty informative, and funny as well (lol). I am the second owner of my 01 Cobra, I picked it up from a local Ford Dealer. You said somthing in the thread that I found interesting.
" I went 4.10's and I have the older tranny (t-45). I run 3k at 80mph. With the newer tranny which you should have in the 01, you will be even lower then that. "
I drive about 30 miles hwy each day. When I am cruising at 80MPH the RPM's are sitting right at about 2700, could it be possible that the gears were swaped out already by the previous owner, what would be the eaisest way to confirm this. I have test driven quiet few Cobras in my quest to finally own one. This one seemed unusually quicker off the line then others I have tested and I have suspected that the orginal owner swaped out the gears. Also what are the stock gears for the 01's I know 03/04's were more aggresive. Thanks again for you help. And everyone else who relied with info. appreciate it.
" I went 4.10's and I have the older tranny (t-45). I run 3k at 80mph. With the newer tranny which you should have in the 01, you will be even lower then that. "
I drive about 30 miles hwy each day. When I am cruising at 80MPH the RPM's are sitting right at about 2700, could it be possible that the gears were swaped out already by the previous owner, what would be the eaisest way to confirm this. I have test driven quiet few Cobras in my quest to finally own one. This one seemed unusually quicker off the line then others I have tested and I have suspected that the orginal owner swaped out the gears. Also what are the stock gears for the 01's I know 03/04's were more aggresive. Thanks again for you help. And everyone else who relied with info. appreciate it.
05-05-2006, 10:55 AM
#5
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RE: Need info on Gears
I'm having 4.10s' put in on the 16th.. I was told by my tech that Cobras have no torque and they need the gear to get moving.. Once moving they have no problem because the motors like to rev high.. He strongly recommended 4.10s to really wake the car up.. However, I don't use my Cobra as a daily driver.. Its a once to twice a week driver..
I plan on breaking out the car today and going for a drive.. I have stock gears and will let you know what my RPM is @ 80 MPH..
I plan on breaking out the car today and going for a drive.. I have stock gears and will let you know what my RPM is @ 80 MPH..
05-05-2006, 11:36 AM
#6
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RE: Need info on Gears
ORIGINAL: Mt Twigbert
I'm having 4.10s' put in on the 16th.. I was told by my tech that Cobras have no torque and they need the gear to get moving.. Once moving they have no problem because the motors like to rev high.. He strongly recommended 4.10s to really wake the car up.. However, I don't use my Cobra as a daily driver.. Its a once to twice a week driver..
I plan on breaking out the car today and going for a drive.. I have stock gears and will let you know what my RPM is @ 80 MPH..
I'm having 4.10s' put in on the 16th.. I was told by my tech that Cobras have no torque and they need the gear to get moving.. Once moving they have no problem because the motors like to rev high.. He strongly recommended 4.10s to really wake the car up.. However, I don't use my Cobra as a daily driver.. Its a once to twice a week driver..
I plan on breaking out the car today and going for a drive.. I have stock gears and will let you know what my RPM is @ 80 MPH..
And if you want to figure out what gears you have there is an easy test.. jack the car up, put a piece of tape on the drive shaft, and turn the rear wheels a full turn. count how many times the drive shaft turns and that's your ratio. if it turns 3 1/4 times? 3.27's. 3 1/2? 3.55's slightly past 4? 4.10's. Definatly check before you buy anything.. I have seen more then one story on this forum where someone had t heir gears replaced only to find out that they either put the exact same ones in.. or like someone back in january, they got 3.73's agains all our advice.. and found out afterwards they had 4.10's already and had lowerd the ratio... I dont think that guy ever came back on... lol.
05-05-2006, 03:47 PM
#7
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RE: Need info on Gears
ORIGINAL: CobraDriv3r
I drive about 30 miles hwy each day. When I am cruising at 80MPH the RPM's are sitting right at about 2700, could it be possible that the gears were swaped out already by the previous owner, what would be the eaisest way to confirm this.
I drive about 30 miles hwy each day. When I am cruising at 80MPH the RPM's are sitting right at about 2700, could it be possible that the gears were swaped out already by the previous owner, what would be the eaisest way to confirm this.
05-06-2006, 02:10 AM
#8
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RE: Need info on Gears
HAV/TWIG Thanks for the info. I will be jacking the car up Tomorrow and checking. I'll keep you all posted. To be honest I kinda Like the fact that the car makes its torque and HP higher in the REV Range. I used to have a Acura GSR back in 98 Drove it till the wheels fell off. Young and Dumb guys!!! LOL, but I had to rev the **** out of it to get any fun going and I have to admit it was kinda cool when that VTEC kicked in so high in the REV range. But man I love this Cobra to Death. Muscle cars are the ****.
05-07-2006, 07:45 PM
#9
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RE: Need info on Gears
ORIGINAL: yellowcobra
i have heard to leave the gears because i believe they are 3.73s(with the 03-04cobra). I would recommend a shifter though, but probably not gears.
i have heard to leave the gears because i believe they are 3.73s(with the 03-04cobra). I would recommend a shifter though, but probably not gears.
05-08-2006, 05:11 AM
#10
Join Date: May 2006
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Posts: 31
RE: Need info on Gears
I have 4.10's with a T56 six speed. I'm tachin' 2900 @ 80MPH. About 2400 @ 65MPH. I have Nitto 315/35Rx17 DR's on the rear (10 1/2" wheel, 1/2" spacer and rolled fender wells) with full coil overs. I took her out and raced her Friday night at Street Grudges. She burns down the track like a house of fire! I still spin those beefy DR's..........about 30 feet in 1st, 10 feet in second and I bark 3rd. When I launch her REALLY hard and the tires had a good warm up burnout, she'll wheelie about 6" off of the ground.
Throttle response with these gears is AWESOME! It's a head snapper 1st - 4th when cruising and you punch the gas really quick. My wife complains she'll wake up with black eyes!
I also have a Dynotech aluminum drive shaft that is BEEFY, so it handles the torque well.
I bought the car set up already, so I don't know if you need the shaft upgrade w/ stronger U-joints or not.
She came with an Accufab throttle body, K&N intake, 40# injectors, full length headers, 3" exhaust into Borla mufflers with a 2 1/2" exit, T56 six speed tranny, short shifter, Dynotech aluminum drive shaft, 4.10 gears, fully adjustable coil overs all the way around, front camber plates, quad clutch adjuster, King Cobra clutch, urethane bushings, some aftermarket beefy *** undercarriage bracing and the Nitto 315 DR's on 10 1/2" wheels.
She's VERY stiff driving. Great for cornering (NO body roll) and drag racing, but she'll make your kidneys bleed on long drives. I don't soften the suspension because she sits so low I don't want to rub my tires.
She's been whining and crying lately, so I'm going to give in and give her what she's begging for - a Zex 100 wet shot (with proper tuning so she doesn't blow)! That should put me around 420 to the wheels - I'll let you know after a Dyno session.
As for changing to 4.10 gears - I WOULD! That way if you ever plan to build your car out, your already one step closer.
Here's some links to pics of my Cobra..........................
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR
Throttle response with these gears is AWESOME! It's a head snapper 1st - 4th when cruising and you punch the gas really quick. My wife complains she'll wake up with black eyes!
I also have a Dynotech aluminum drive shaft that is BEEFY, so it handles the torque well.
I bought the car set up already, so I don't know if you need the shaft upgrade w/ stronger U-joints or not.
She came with an Accufab throttle body, K&N intake, 40# injectors, full length headers, 3" exhaust into Borla mufflers with a 2 1/2" exit, T56 six speed tranny, short shifter, Dynotech aluminum drive shaft, 4.10 gears, fully adjustable coil overs all the way around, front camber plates, quad clutch adjuster, King Cobra clutch, urethane bushings, some aftermarket beefy *** undercarriage bracing and the Nitto 315 DR's on 10 1/2" wheels.
She's VERY stiff driving. Great for cornering (NO body roll) and drag racing, but she'll make your kidneys bleed on long drives. I don't soften the suspension because she sits so low I don't want to rub my tires.
She's been whining and crying lately, so I'm going to give in and give her what she's begging for - a Zex 100 wet shot (with proper tuning so she doesn't blow)! That should put me around 420 to the wheels - I'll let you know after a Dyno session.
As for changing to 4.10 gears - I WOULD! That way if you ever plan to build your car out, your already one step closer.
Here's some links to pics of my Cobra..........................
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR
http://www.ratemysrt4.com/mediapic.p...member=05.5ACR