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  • Fox 5.0 Mustang Tech

rearend gear help, adding more power.

  • Thread starter Thread starter Foxfan88
  • Start date Start date Sep 1, 2007

Foxfan88

My Grandpa has great wood.
Sep 13, 2004
2,487
4
0
Miami, Ok
Sep 1, 2007
#1
  • Sep 1, 2007
  • #1
i run 3.90s right now. before i added my SC it ran good. i put some suspension parts on the car and i got it hooking pretty nice on the street. i could be at 3k in first gear and punch it and it would hook and go. NOW with the SC i can barely be rolling first and gun it and FRY the tires all the way though first and second. i have to feather 2nd for a while and then it will finally hook up.

my rearend is also getting the 1 wheel peel thing going on when i just rev up and dump the clutch, doing a burnout it will get both and spinning them from a roll it will get them both b/c the car will get sideways.

i am planning on a powerpipe, tweecer rt, bigger crank pulley and a blower cam. hope to make 8-10 psi with it and when i get it all tuned in REAL good, i hope for it to make 380-400 RWHP

my 3.90s right now seem like too much. it gets up and goes but it tops out 4th gear real fast and i have nothing left to do. and first and second are useless. even with people in the car and a full tank of gas i can still fry the hell out of the tires pretty good.

i am thinking getting a higher gear in the rearend. get the rearend rebuilt/freshend up and it would give me a good chance to get my speedo fixed and reading accuratly. they dont make speedo gears for 3.90s

i was thinking of going with 3.55s but i am worried it will kill SOTP feel of the car before i add the extra boost and the tune. i know the car will probably get from pt A to pt B faster since it wouldnt want to spin the tires quite as easy but it might feel underpowered.

just seeing if you guys think it will be a wise choice going to 3.55s.will make it a better driving car around town, better highway rpms. and if i make the power i hope for i am not going to need a 3.90 gear to get moving. and wont have to shift as soon as i hit the gas

ive asking this gear question before i had my SC and decided to wait and see how the car acted with the SC on it, and it feels like too much gear.

i know i am probably making this out to be too big of a deal. i dont think the gear will make too much difference but i just need some opinions.

plus i was thinking, with my z spec t5, with the 2.95 first and higher OD ratio it would make for a more useable first gear on the street and pretty good highway cruising rpms.
 

Bad92GT

The 5 Minute Plan Man
Jun 10, 2004
492
0
0
SC
Sep 1, 2007
#2
  • Sep 1, 2007
  • #2
i'd go to 3.55s man.. 3.73s at the most. guy running a turbo notchback has 3.73s with slicks.. he drives it ever day. I guess it depends on your preference though
 

90_Red_LX

Member
Sep 29, 2003
668
5
19
Asheboro, NC
Sep 1, 2007
#3
  • Sep 1, 2007
  • #3
I'd go no lower than 3.55s. Heck I might would consider 3.27s.
 

cenok is family

15 Year Member
Jun 25, 2003
1,409
69
79
Norman, Ok
Sep 1, 2007
#4
  • Sep 1, 2007
  • #4
blah 3.27's are weak! i had them in my coupe. didn't have a blower, but it's a dogg of a gear. go with 3.55's.
 

squeak93

15 Year Member
Jun 2, 2005
2,260
362
164
Joplin, Missouri
Sep 1, 2007
#5
  • Sep 1, 2007
  • #5
You have a few options. 1. Keep ur current gears, rebuild the trac loc and get taller slicks ( u need slicks/drag radials no matter what)
2 get 355's for fuel mileage or get 373 for performance.

3 take the blower off and sell it to me
 

Boss91GT-SC

Member
Jul 13, 2007
27
2
19
Hope Mills NC
Sep 1, 2007
#6
  • Sep 1, 2007
  • #6
I have 3:73's and first is worthless all I do is smoke the tires. I'll probably drop to 3:55's and get some slicks. I think you would be happy with the 3:55's
 
L

lang williams

New Member
Jun 11, 2003
567
0
0
cleveland, oh
Sep 1, 2007
#7
  • Sep 1, 2007
  • #7
option 4) swap me your 390's for a spare set of 355's i have in the garage. lol. i have 456's in the car right now but it was a strip car before i got it an i plan on drivin it on the street 99% of the time.
 

408gt91

Member
Apr 29, 2007
114
0
16
N.H.
Sep 1, 2007
#8
  • Sep 1, 2007
  • #8
go with 3:55's i had 3:73s with a 306 and had the same tire smoking fun through 1st and 2nd.
now ive got a 408 with 3:73s and 4 gears of crazyness.lol
 

squeak93

15 Year Member
Jun 2, 2005
2,260
362
164
Joplin, Missouri
Sep 1, 2007
#9
  • Sep 1, 2007
  • #9
All u need is tires of the right size. 3.73's are the perfect gear. FoxFan u know of Tony's orange capri that runs 11's??? It has 3.73 and traps 120+ (dont remember exactly) but it had just 26 inch slicks at the time. Now I pretty sure his 351 would rev higher but I think u will be dissapointed with 3.55's.
 
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