Looking for 2nd gen 4.6 Rear Diff

[Newbie]

Hi there,

Does anybody have a source for a second gen 4.6 rear end? I know they used to make them, but have not for some time now. Anybody using one to clutter their garage???

I know all the fast guys use the 5.12 but I'd like to try going DOWN from my current 4.88.

Steve

[RP Performance]

Originally posted by Newbie@Nov 24 2005, 06:29 AM
Hi there,

Does anybody have a source for a second gen 4.6 rear end? I know they used to make them, but have not for some time now. Anybody using one to clutter their garage???

I know all the fast guys use the 5.12 but I'd like to try going DOWN from my current 4.88.

Steve

66555



Not sure if the 4.6 is still available but you should be able to get a 4.44 still.

[Andy Bettencourt]

Call Mike at ISC Racing, I think he had one done for Kip that may still be sitting around...

iscracing.net

AB

[Newbie]

ISC has ONE, and it may be the last one around. He thinks it will cost $2500. Sounds a little steep for an experiment, what do you think?

I was hoping there would be some laying around in storage somewhere.

Steve

[Andy Bettencourt]

The only reason I would go down from a 4.88 would be to develop a dedicated enduro car...or to develop a car as a ONE track pony.

Otherwise, you are giving up speed.

AB

[hare_ITC]

Originally posted by Andy Bettencourt@Nov 25 2005, 01:10 PM
The only reason I would go down from a 4.88 would be to develop a dedicated enduro car...or to develop a car as a ONE track pony.

Otherwise, you are giving up speed.

AB

66645



Agreed, even then I would opt for the cheaper 4.44 than can be found in miata's at your local junk yard. :D

[C. Ludwig]

Originally posted by hare_ITC@Dec 8 2005, 11:39 AM
Agreed, even then I would opt for the cheaper 4.44 than can be found in miata's at your local junk yard. :D

67584



Miatas came with a 4.10 or 4.30. And many of the 4.30 gears were in the smaller diff that won't work in an RX-7.

[benspeed]

I've got the 4.6 in my car (Kip's old car). My last Mazda had the 5:12 and it's definetly faster. If I wasn't moving into stock cars I'd buy a 5:12 and have my buds at Flatout pop it in.

Cheers,

[Newbie]

Does that mean you're selling the RX-7 to another person who may have a 5.12 put in and is looking to get rid of the obsolete 4.6??? :rolleyes:

[benspeed]

I wish I had a buyer! Too many friggin 2nd gens over on the classifieds section. I might just keep the sled and have my SPO stock car too! That way I can show up at key races to aggrevate my old ITS buds.

I might consider a swap for a good 5:12...


Cheers,


PS - Andy, you gotta put some good contraversial stuff up so we have some entertainment in the off-season here - the site's a little quiet!

[jcmotorsports]

Hey Ben
Now you have the idea!!! It'll be fun to have another former ITS driver to show up with to annoy the regulars :happy204:
Just Kidding Guys :P

John Costello

P.S. He's right there are too many for sale!!!! I need more garage space and the red and white rocket takes up too much space!!!!!!

[Chris Wire]

Originally posted by benspeed@Dec 9 2005, 10:55 AM
I've got the 4.6 in my car (Kip's old car). My last Mazda had the 5:12 and it's definetly faster. If I wasn't moving into stock cars I'd buy a 5:12 and have my buds at Flatout pop it in.

Cheers,

67727


Mike used the 4.6 in Kip's old car specifically at Sebring and possibly at other tracks. I don't think he used it at Daytona. The idea was eliminate the need for 5th gear, and with the 4.6 and a 225/50-15 tire, he was able to do that.

While I don't think that the 4.6 is a better all-around gear than the 5.12, it may be better at specific tracks.

[JeffYoung]

A 5.12? Wow. What kind of RPM do you guys pull?

[Eagle7]

Originally posted by JeffYoung@Dec 9 2005, 09:44 PM
A 5.12? Wow. What kind of RPM do you guys pull?

67783

Up to 9K. Not much power over 8K though. Not much torque anywhere.
With 225/45-15 tires 8K in 4th gear is 107 MPH. 5th gear speed depends on which transmission you've got.

[benspeed]

Originally posted by Chris Wire@Dec 9 2005, 10:54 PM
Mike used the 4.6 in Kip's old car specifically at Sebring and possibly at other tracks. I don't think he used it at Daytona. The idea was eliminate the need for 5th gear, and with the 4.6 and a 225/50-15 tire, he was able to do that.

While I don't think that the 4.6 is a better all-around gear than the 5.12, it may be better at specific tracks.

67770



You are correct sir! I never have to pull 5th in this car, but at the short tracks like LRP or NHIS I'm at a disadvantage.

A 5:12 with the GTU fifth gear is the setup to have. Even at the fast tracks like the Glen or Pocono it's faster. You do row the gears alot though and I also think that the high rev 2nd to 3rd shift must be done with a moments hesitation to let the tranny catch up or you can blow your trans easy (done it twice).

[Eagle7]

Originally posted by benspeed@Dec 12 2005, 10:32 AM
You are correct sir! I never have to pull 5th in this car, but at the short tracks like LRP or NHIS I'm at a disadvantage.

A 5:12 with the GTU fifth gear is the setup to have. Even at the fast tracks like the Glen or Pocono it's faster. You do row the gears alot though and I also think that the high rev 2nd to 3rd shift must be done with a moments hesitation to let the tranny catch up or you can blow your trans easy (done it twice).

67953

With the 5.12 do you have corners that are clearly 2nd gear? Since I got mine this past season, I've been learning all new shift points, and although there a few corners that are quite tempting, I'm currently thinking they're all faster with 3rd gear.

[ddewhurst]

Steve, which track's do you want to use the 4.6 ?

[Newbie]

Blackhawk and Road America, mostly Blackhawk

[benspeed]

Originally posted by Eagle7@Dec 12 2005, 05:35 PM
With the 5.12 do you have corners that are clearly 2nd gear? Since I got mine this past season, I've been learning all new shift points, and although there a few corners that are quite tempting, I'm currently thinking they're all faster with 3rd gear.

67996


There are only two corners that I do in second with either the 5:12 or the 4.6 - devils elbow at Pocono and turn three going up the hill at NHIS. These are very low speed corners and must be done in second or you get pulled big time. It puts a whipping on your tranny. The fraction of a second you hesitate before jamming it in third will help prolong your trans. I had a bad habbit of shoving it in third and just ignoring the grind. An expensive habbit until I started being very gentle and precise with my shifting.

[ddewhurst]

Steve, let's stick with Blackhawk Farm for talking. Using your 4.88 what gear do you use through T3 & going to 4 & on the front straight & the straight before T7.

What times do you turn at the Farm with your 4.88 & whatever size tires ?

[Newbie]

Dave,

I run out of 3rd gear in turn 3 and need to shift 3/4 of the way through..as you know, the rear is pretty loaded and I'd rather not unload it. I have been, but it does not seem right. Plus, I have to make another shift for 3B or whatever the sharp right hander is. I'm also out of my power band at the end going into turn 7 and into turn 1. I run 225/45/15's.

My times at BFR have dropped every time I've been there. My fast lap was 1:23.4, and I'm not getting everything out of the car. Quite frankly, I'm slow in the corners. Once I get to carry more speed through the corner, I'll be way out of gear. The 5.12 makes it a 4th and 5th gear track. I figure I'm better off keeping it 3rd and 4th with higher rev's. Not conventional thinking, but what the heck!

The car is up on a rack right now. Once I get it straight, I'll be able to corner balance and set it up even better. More seat time plus a better set up will lead to more speed. That plus the new exhaust, down to minimum weight and a few other goodies I will be adding should help get around. Oh yeah, I'll be adding a bitchin' new paint job too!

Merry Christmas and Happy Holidays.

Steve

[ddewhurst]

The 4.44 came on the 87/88 Mazda 4x4 pickup on the front axle.

The 4.625 and the 4.778 come on the Kia Sportage 4x4 on the front axle.

Check with Mazda Comp for fit to the 2nd gen pumkin.

Happy Holiday