Wheres the best place to get them? How much should they run$$$?
3.90 gears
- Thread starter 03DarkShadow
- Start date
Damn boy you got too much money(lol). Good times at the track, but with those trap speeds you should be around 11.8-11.6. I bet you caught hell with traction. I ordered some nittos for this weekend. I hope they get here in time. I got the 315's and hoping for mid-low 12's. I hope you are going to let your let your wife take it down the 1320(lol). Ive never seen a woman so in to mustangs. I love it. See yall there.
Silver 03 Cobra
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- Joined
- Mar 8, 2002
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- 2,054
03, I have Moser 3.90's bought from www.holcombmotorsports.com for $180. I went from FRPP 4.10's to the 3.90's. That seemed to be about the best price with the places I checked. They were in stock. They are also located in NC and I usually get stuff the next day. They are great to deal with and wil not BS. If you give any special shipping instructions such as express shipping or having things drop shipped from the manufacturer they are can always be counted on to get it to you. Their prices have also gotten a lot better over the past year especially since they got more into the modular side of the business. If you don't have them and we can get up a group to race I'll let you try mine out.
JMD, if you spin off the line your trap speeds are generally higher than when you get slicks and hook. I was trapping 96 mph on F1's. I have a friend that is a hard core 10.5 class racer. He has his own shop and Dynojet. I was telling him when I got my ET's I'd be trapping close to 100. He said he bet I lost speed. He was right. I dropped to 95 but knocked close to 5 tenths off my ET. I was happy with that. I have gotten a little better and I trap 97 mph now. But, you're right about the ET, with 03's mods he should run 11's easily especially with some ET's.
JMD, if you spin off the line your trap speeds are generally higher than when you get slicks and hook. I was trapping 96 mph on F1's. I have a friend that is a hard core 10.5 class racer. He has his own shop and Dynojet. I was telling him when I got my ET's I'd be trapping close to 100. He said he bet I lost speed. He was right. I dropped to 95 but knocked close to 5 tenths off my ET. I was happy with that. I have gotten a little better and I trap 97 mph now. But, you're right about the ET, with 03's mods he should run 11's easily especially with some ET's.
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Thanks for the info Silver03. You bet i caught hell w/ traction. No more go fast goodies are going on the car until the rear is built to hook up! I tried getting her to run it Sunday but she wouldnt. If we go Saturday she said she wanted to take it down the track. I bet when she does, ill never get to take it again. lol
Just got my Pro 5.0 3.90 gears for my 97 Cobra at partshopper.com (stangnet). $179 + $22 shipping.
I currently have 4.30s in. Wow, great acceleration until you get to 105+. Just way too much gear for me though. @80mph in 5th I'm at 3200rpms!!!!!! I know you guys have 03 Cobras, but regardless, with the extra power you have, I would never go above 3.90s with the 03 cobra:
#1 - gas mileage will be effected. Your 6th gear is .62 compared to my 97 cobra tranny overdrive gear - .67, not that great of a difference w/ your extra gear.
#2 - it just makes a lot more sense to obtain real power instead of swapping gears in your cars. Espcially considering how little it costs to obtain great power gains. I've heard catback exhausts give you ~25+hp! I hate all of you
I think if you are going to change your gears, going to 3.73 from 3.55 is a waste. 3.55-3.90 is a good jump.
To figure out the exact rpm, do the following
1. Find out the rpm you are at in 6th gear at a speed (70mph,80mph, etc)
2. 3.90 (new gear)/3.55 (current gear) = 1.0985 = 9.85% increase in RPM
3. Then take that percentage and multiply it by the RPM you currently are at w/3.55s at a certain speed. So let's say you are at 2100rpms @65mph in 6th -> 2100*.0985 = 206.85 (rpm increase)
4. Now take your rpm and add the rpm increase from step 3 ->
2100+206.85 = 2306.85rpms w/3.90s.
Cheers,
Dean
I currently have 4.30s in. Wow, great acceleration until you get to 105+. Just way too much gear for me though. @80mph in 5th I'm at 3200rpms!!!!!! I know you guys have 03 Cobras, but regardless, with the extra power you have, I would never go above 3.90s with the 03 cobra:
#1 - gas mileage will be effected. Your 6th gear is .62 compared to my 97 cobra tranny overdrive gear - .67, not that great of a difference w/ your extra gear.
#2 - it just makes a lot more sense to obtain real power instead of swapping gears in your cars. Espcially considering how little it costs to obtain great power gains. I've heard catback exhausts give you ~25+hp! I hate all of you
I think if you are going to change your gears, going to 3.73 from 3.55 is a waste. 3.55-3.90 is a good jump.
To figure out the exact rpm, do the following
1. Find out the rpm you are at in 6th gear at a speed (70mph,80mph, etc)
2. 3.90 (new gear)/3.55 (current gear) = 1.0985 = 9.85% increase in RPM
3. Then take that percentage and multiply it by the RPM you currently are at w/3.55s at a certain speed. So let's say you are at 2100rpms @65mph in 6th -> 2100*.0985 = 206.85 (rpm increase)
4. Now take your rpm and add the rpm increase from step 3 ->
2100+206.85 = 2306.85rpms w/3.90s.
Cheers,
Dean
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Nice work hantzis, I drove in a fully modded except for l/t 03 Friday w/ 480hp/530tq and he had 4:10's and it was perfect. I'm alittle undecided I like to drive on the highway so 3:90 don't seem to high. :beer:
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