I have a small dilemma that maybe you guys can help with. I need a tranny for my lsvtec. I used to have a gsr tranny that took a crap, so i put an LS just to drive around. The car feels very sluggish with this tranny. I know everyone raves about the 4.7 ITR trannys, but this is not practical for me because i drive about 20 miles on the hwy 4 days a week and from what i hear ill be at 5000+ rpm at 80MPH in 5th gear. So, i wanted to know if i should go with a jdm b16 LSD tranny or a GSR tranny with a 4.785fd and no LSD. Both will put me at about ~4400 rpm @ 80 MPH in 5th gear ( i can live with that).

GSR with 4.785 FD should have a decent 5th gear so will the b16 tranny. But which of these two will have better accelaration in the lower gears? Will the lsd make a big difference in drag racing/driving on the street?

Please give me your opinions.
GSR tranny with 4.785FD or
JDM b16 tranny with LSD


thanks in advance.

 

jdm b16 is better

 

those would be some pretty evenly matched tranny's.

the gsr tranny would ''accelerate'' faster, even though gearing is longer.
3rd gear:
gsr= 1.36 * 4.78= 6.500(absolute gear ratio)
b16= 1.45 * 4.4 = 6.38

4rd
gsr= 1.03 * 4.78= 4.92
b16= 1.10 * 4.4 = 4.84

at 80 of 5th both trannys are going to be around 4200-4300 with the gsr tranny needing some more rpms to get to 80mph

But the b16 has lsd..mmm

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SUPERNATURAL &raquo;</TD></TR><TR><TD CLASS="quote">jdm b16 is better</TD></TR></TABLE>

i really respect your opinion, what made you say the b16 lsd will be a better choice?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mmuller &raquo;</TD></TR><TR><TD CLASS="quote">those would be some pretty evenly matched tranny's.

the gsr tranny would ''accelerate'' faster, even though gearing is longer.
3rd gear:
gsr= 1.36 * 4.78= 6.500(absolute gear ratio)
b16= 1.45 * 4.4 = 6.38

4rd
gsr= 1.03 * 4.78= 4.92
b16= 1.10 * 4.4 = 4.84

at 80 of 5th both trannys are going to be around 4200-4300 with the gsr tranny needing some more rpms to get to 80mph

But the b16 has lsd..mmm</TD></TR></TABLE>

so according to your absolute gear ratio formula

1st gear
gsr= 15.45
b16=14.21

2nd gear
gsr=9.10
b16=9.26

hmmmmm. Looks like the gsr with the 4.7fd will accelarate quicker in every gear. Thanks for that formula.

 

i own an itr tranny w/ an ats 4.9 fd and at 5th gear 80 mph it was at 4,900-5,000 rpm's.

i've also driven a b16 and w/ it's 4.4 fd at 80 mph in fifth gear it's at 4,300-4,400 rpm's

that's how i test out what fd is in the tranny.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mmuller &raquo;</TD></TR><TR><TD CLASS="quote">But the b16 has lsd..mmm</TD></TR></TABLE>


i agree lsd is a nice add in. i have a ctr tranny and love it.

 

Bump, I am curious about this myself!

 

any more opnions?

 

felix, if you have the rpms, and the power band to support the 4.7 fd then i would suggest you get it! but if you want to keep the revs down, use a fith gear from a hydro ls transmission. that will keep you well under 4K rpms @ 80 mph on the highway!

 

i was running a 4.78 b16 1-4 w/ gsr fifth and that was a nice tranny. for less of a hassle you could slap a 4.78 in a gsr. yes it will be close proximity with b16 4.40 gearing and you would probably be hard pressed to find big differences in drag racing performance. i honestly think lsd makes a lot more difference in track racing with corners. lsd is nice to have though either way.