Mfactory Final Drive Ring and Pinion

[Dave-ROR]

Originally Posted by JoeBoxer

$750 seems really high for a ring and pinion to me compared to other platforms where i've looked at them.

We don't know the MAP/street price yet though.. unless MFactory uses the same price for MAP as MSRP...

[xjohnx]

Originally Posted by Dave-ROR

Definitely DIY-able. It's more involved than many DIYs but it's not that hard.

Install prices, like the other poster mentioned, should be around $300.

An old ITR Expo sponsor sells MFactory so I did get some info from him:
-FDs are forged from SAE8620 steel and should be good for at least 300whp. MSRP $749.95. Ratios 4.5 and 4.7 as already stated.
-Other Ratios are possible, but a close gear set may come first (6MT only)
-Helical LSD is forged from SAE 4320 steel, rated for 1,000whp. MSRP $684.95
-Meta-Plate LSD is also SAE4320, but rated for 500whp. Available in 1.0, 1.0/1.5 and 2.0. Adj for pre-load and lock up. MSRP $899.95.

Sounds great. Very tempting. I always wanted to go with the 4.929 FD in my ITR but that install was quite a bit more involved, if i recall.

[Dave-ROR]

Originally Posted by xjohnx

Sounds great. Very tempting. I always wanted to go with the 4.929 FD in my ITR but that install was quite a bit more involved, if i recall.

Bah, we did that install so many times... we installed Trey's while drunk at NOPI one year. By drunk I mean started drinking at 6:30AM, could barely stand by 10AM, started the install at 10:30, finished around 2...

There was a time that Craig, Matt and myself could have done that install blindfolded...

[xjohnx]

Originally Posted by Dave-ROR

Bah, we did that install so many times... we installed Trey's while drunk at NOPI one year. By drunk I mean started drinking at 6:30AM, could barely stand by 10AM, started the install at 10:30, finished around 2...

There was a time that Craig, Matt and myself could have done that install blindfolded...

Wow, and i thought i was nuts having Yack and Will install Toda Spec-B's in my ITR while in the parking lot of the innkeeper the night before a track weekend at VIR.

I think i've been one upped.

[Dave-ROR]

Originally Posted by xjohnx

Wow, and i thought i was nuts having Yack and Will install Toda Spec-B's in my ITR while in the parking lot of the innkeeper the night before a track weekend at VIR.

I think i've been one upped.

If Jack was sober, that would be nuts

I should be seeing Will next month, stopping by Nick T's shop for some drinking and Will is (last I knew) planning to come out.

Jack never shows up to anything besides Expo these days.

Oops off topic sorry guys lol

[ill86]

Originally Posted by serialk11r

Changing the diff could be thought of as a small change for the dollar spent at any rate since you're not increasing power, and you're not making the gear ratios closer :P The only place where you gain acceleration is 1st gear, outside first gear it's not much improvement overall since you have more power available at some speeds, less at others.

I've changed r/p in several of my personal cars and trucks (and sprockets on bikes).
I could easily appreciate the mechanical gain in all gears. Let alone your decreasing the load on the motor.

decreased load can also improve fuel efficiency

And yes, I'm aware that it doesn't add power but it has certainly decreased lap times on track. YMMV.

I'm fully aware of the pros and cons here.

Peace.

[JoeBoxer]

I used to have a Dodge Ram with a 5.7 and 4.56 gears were a very common upgrade on them, it didn't even really hurt the already poor gas mileage. I think a ring and pinion set should be about $400 though i guess with those platforms though there are a lot more sales to be had.

[ill86]

Originally Posted by JoeBoxer

I used to have a Dodge Ram with a 5.7 and 4.56 gears were a very common upgrade on them, it didn't even really hurt the already poor gas mileage. I think a ring and pinion set should be about $400 though i guess with those platforms though there are a lot more sales to be had.

The 86 is still new. I believe this is why the pricing is higher. I have typically paid $350-550 for r/p sets.

Please note however, the first ones out of Japan (auto factory) are $1200+.. So, $750 doesn't seem that bad.

Cusco has some available now as well. With and w/o lsd pricing.

[carbonBLUE]

It would be awesome with a 5.11 gear in an AT. It would close the gear ratio difference between AT and MT, coupled with faster shift times!


Maybe ECUtek has a solution for tuning the transmission?

[serialk11r]

Originally Posted by ill86

In my opinion decreased load can also improve fuel efficiency.

Well, your opinion is the opposite of the truth :P

[JoeBoxer]

Originally Posted by serialk11r

Well, your opinion is the opposite of the truth :P

Not neccessarily, you would think a lower gear ratio would always provide worse mpg but if you do primarily city driving i think the opposite would be the case. If you are on the freeway 60% of the time or more then yes mpg would most likely suffer.

[serialk11r]

Originally Posted by JoeBoxer

Not neccessarily, you would think a lower gear ratio would always provide worse mpg but if you do primarily city driving i think the opposite would be the case. If you are on the freeway 60% of the time or more then yes mpg would most likely suffer.

If your eco-driving is very refined then sure you could get better gas mileage since you essentially have more gear ratio choices for the same speed range but otherwise it's a toss up. Most people I think would lose fuel economy because they'd be more inclined to press less hard on the gas to compensate for the increased acceleration off the line (higher load is more efficient up to ~80-90%, shorter gears make you spend less time at higher load since you have more power available), and because they will likely not adjust their shifting enough to take advantage of the higher gears being accessible at lower speeds.

The only time a shorter gear is possibly more efficient than a longer gear due to decreased load is if you're rolling in 5th/6th gear off throttle at idle, because the load on the engine is too high for efficient combustion. For small engines hypermilers observe that rolling in 4th gear at idle gives the best fuel economy. Above ~1200-1500 rpm, increased load is higher efficiency for all practical purposes (usually you need 2000rpm before maximum load stops seeing a large efficiency drop).

[JoeBoxer]

Honestly most people willing to change out the ring and pinion probably aren't worried that much about mpg's though, you have a valid point but if you are worried about gas mileage you probably wouldn't be in this thread unless you wanted the higher ratio's.

[xjohnx]

Originally Posted by ill86

How can my factual accounts of my personal activities be construed as opinion and false?

Originally Posted by ill86

In my opinion decreased load can also improve fuel efficiency.

This could have something to do with it being construed as opinion.