MKIIT - E153 Tranny - Gearing options and their affects

[JekylandHyde]

I've been learning a bit about trannies and gearing, and I am still by far a newb, but I wanted to share some of the things that I have been looking at in the hopes that others might benefit from the research and math presented.

I'm just playing around with looking at the different gear options we have and different options for final drives. For this comparison, I looked at three gear sets and three final drives that are available for the E153.

The sets looked at are:
Stock MR2T set up, the Solara gear set and the Phoenix Power gear set.

Although I have no intention of ever dropping the huge $$$ (over $3K) for the PP gears, one of the board vendors on MR2OC.com is currently selling a few of the Phoenix Power final drives ... so there are options out there for us.

First, let's look at the affect of the combinations of gear sets and final drives on the top speed attainable in each gear.
I used Hyde for the purposes of plugging in the math, so a redline of 8500 rpms was used along with a 25.73" tall rear tire.



Next, let's look at each gear sets affect on acceleration.
For doing these calculations, I used one of the most comprehensive acceleration calculators that I could find. Although I do not put any weight in to specific numbers found, I am confident in the relationship between the numbers. For example: I do not think the math accurately portrays a real 1/4-mile potential, but does reflect which gear combination "should be" quicker & faster.

Again, I used Hyde's stats (weight, torque, tires, etc) for the calculations.



Comments & critique are welcome.

[JekylandHyde]

This speed per gear chart is made using a 93T stock-sized 225/50/15 tire @ the OEM redline of 6250 rpms:

[tHa kNiGHt FaLL]

I Like The Solara Set w/ Solara Final Drive...

[MR2Jedi]

Whats your opinion Doc? it's all Greek to me...I guess the PP gives the best time?

[JekylandHyde]

The "best" option, like in most cases, depends on your goals.

Right now, for me personally, I am trying to reduce the number of shifts I am doing regardless of the type of racing that I am participating in. That being said, I am mostly interested in top speeds per gear.

I'm considering the stock tranny with the Solara final drive.

As you can see in the first chart, I would be able to go over 50 mph in 1st gear
Right now I am doing 47 mph in 1st and it has been killer autocrossing,
but I do sit at the rev limiter for a while ... so more mph would be helpful in 1st.

The same goes for 2nd and 3rd on the hillclimbs.

In drag racing, I am trapping at 130 mph and with the Solara final driver I would be at 132 mph at the top of 3rd so I could completely eliminate a shift in a drag race.

The question is, are the benefits of the lost shifts greater than the acceleration that is lost?

[MR2Jedi]

47 in 1st??? Damn!!! and 132 at the top of 3rd! holy moly ! How many RPMs is that? I can't even imagine...
So do you think you're gonna modify the tranny ?

[JekylandHyde]

I redline at 8500 rpms.

I have not decided if we are modding the tranny or not.
I actually have two 93 LSD trannies, so we just might have to play with one of them.