Getting 3.90s next week.

[USMCracing]

I'm getting a set of 3.90s next week. After alot of thinking and trying to decide which is the best gear to go with 3.90, 4.10, or 4.30. I don't want to buy part twice so since I'm going being going with a super charger later this year I decided that the 3.90s would be the better of the three. Does anyone here run them with or without a SC? What kind gas mileage are getting on the highway cruiser around 80/85mph?

Next MOD will be control arms. \

:beer:

 

[SNK BITN]

3.90's? Are you gonna be pushing 500+ rwhp or something?

 

[USMCracing]

No I'm shooting for 500+rwhp, I've heard that with 4.10s and a super charger you spin really bad. If you know something I don't please share it with me. I can still change my mind. Thanks

 

[USMCracing]

I'm thinking of going with the KB charger and they make lots of Tq. so traction will harder to get with the 4.10 or 4.30 gears and I do allot of highway driving.

 

[hantzis]

Originally posted by USMCracing
I'm thinking of going with the KB charger and they make lots of Tq. so traction will harder to get with the 4.10 or 4.30 gears and I do allot of highway driving.

Exactly. I'm N/A. I went from 3.73s to 4.30s back down to 3.90s. WIth our .67OD ratio (unlike new mustangs .62OD), in 5th at 80mph I was at 3150rpms (WAY TOO HIGH IMO). Gas mileage absolutely sucked. With 3.90s (Pro 5.0), @80mph in 5th I'm now at 2900rpms. Much nicer for highway trips.

I get around 240miles per tank now.

If you are concerned about running high rpms and getting crappy mileage, I think you will be very pleased with 3.90s.

The one bad part about 3.90s is that the gears are a real pain to install. I heard getting the pattern "right" is not easy. Took my mechanic ~6 hours to install. A lot of people complain about a 5th gear whine, so make sure to get that pattern set perfect.

Good luck,
Dean

 

[cobrachic]

I have 4:10's in my car, but haven't really run the car since the s/c was installed. I have a Vortech and the last dyno numbers (before my tune today) was 426 rwhp. I am taking it to the strip tomorrow, so I'll have to let you know how I like it.

 

[USMCracing]

Cool, Good luck at the track Cobrachic.

 

[SNK BITN]

Okay, it was me that didnt know you were gonna go with a KB. I've driven a Vortech 98 Cobra with 4.30's and that was fun, he went to 4.10's and tamed that beast down a great deal. Good luck to ya.

 

[hantzis]

USMRacing, how do you like the gears?????

Dean

 

[USMCracing]

I didn't get them, I changed my mind. And the gears were used and the mechanic at All Mustang told me its harder to set up used gears. So I decided not to get them and now my wife is pissed off about me getting the gears. I was going to have a set of 4.10s put in at All Mustang tomorrow but the wife canceled those plans. So who knows when I'm going to beable to get gears now. I decided not to go with the KB now too, ATI Pro charger is the brand I'm thinking about now. But the charger isn't going to happen for some time. Why can't I have a cool wife that understands the need to make your car faster. any time I mention the words Cobra, gears, Super Charger, or anything Cobra/car related she gets mad and the fighting begins. She says that I'm almost 27 and still actting like I was at 17. Is it just my wife that is like this or is there car friendly wives out there?

 

[hantzis]

Originally posted by USMCracing
I didn't get them, I changed my mind. And the gears were used and the mechanic at All Mustang told me its harder to set up used gears. So I decided not to get them and now my wife is pissed off about me getting the gears. I was going to have a set of 4.10s put in at All Mustang tomorrow but the wife canceled those plans. So who knows when I'm going to beable to get gears now. I decided not to go with the KB now too, ATI Pro charger is the brand I'm thinking about now. But the charger isn't going to happen for some time. Why can't I have a cool wife that understands the need to make your car faster. any time I mention the words Cobra, gears, Super Charger, or anything Cobra/car related she gets mad and the fighting begins. She says that I'm almost 27 and still actting like I was at 17. Is it just my wife that is like this or is there car friendly wives out there?

BS. If my girlfriend complained about me spending money on my car, I would put her in her place. But she doesn't. She is very cool about it and encourages me to spend money on my car because it makes me happy. Why does your wife have such a problem with this? Does she feel you should spend the $$ on her instead? If it is your $$, I say do whatever you want with it. It is your $$, not hers.

And about modifying cars being a teenage thing. That is also total BS. Your performance vehicle and modifying your performance vehicle is a hobby. I know 60 year old men who modify their performance cars. It is part of our American culture and for many of us, it is part of our "American Dream".

Your wife makes me mad. I feel bad for you.

Dean

 

[USMCracing]

I hear you but I do love my wife so I'm not going to PUT HER IN HER PLACE. We have a baby on the way so I kind of see her side but its not liek we are hurting for money here. I just sold my Land Cruiser so I have enough money to buy the gears and super charger now and have a few grand left over. She makes more then I do so I don't understand why $500 for gears bothers her so much. We have been together for along time, started dating in High School spring of 1995 and I had a 91 LX 5.0 then and I've had a few other stang since then. I'm sure we'll fight about this again when I get home and all weekend. Later

 

[hantzis]

Originally posted by USMCracing
I hear you but I do love my wife so I'm not going to PUT HER IN HER PLACE. We have a baby on the way so I kind of see her side but its not liek we are hurting for money here. I just sold my Land Cruiser so I have enough money to buy the gears and super charger now and have a few grand left over. She makes more then I do so I don't understand why $500 for gears bothers her so much. We have been together for along time, started dating in High School spring of 1995 and I had a 91 LX 5.0 then and I've had a few other stang since then. I'm sure we'll fight about this again when I get home and all weekend. Later

I hear ya. "Putting her in her place" has a lot of physical conotations to it, but all I meant is that I would speak my mind and tell her something along the lines of, "Sorry, you have no say in this matter." My girlfriend makes more $$ than I also. I'm surprised she has such a problem with you doing this. Anyways, good luck. I hope your supercharged dream comes true

Dean