spaztikcamel

changing from 4.3 to 3.63 makes the car feel a lot slower.
just ask me how i know

sure you get to spend longer in each gear but to even get to the same speed as the shorter gearing it takes longer than it did before as there is more load on the engine.

I would go the 3.9 if given the choice again. but im currently at 170whp so I might change my mind when i add in some more boost once I can cure my misfire.

Boost Joose

ohh ok gotcha what tires you running?

miatauser123

iTrader: (7)

225/45/16

Well the facts are facts. It shouldn't feel slower and it definitely wont be slower. The only time I ever feel like it's fast is whatever gear I start in, because I get to experience the entire gear. Then it's shift..shift..shift.

miata2fast

iTrader: (2)

I think he is talking about how slow it accelerates.

The ideal gear ratio is really dependent on how much power to weight ratio you have. It is silly for a 350 hp car to have the same ratio as a car with 150 hp.

Too many people here are installing super tall gear ratios because guys with high horsepower cars are influencing them to do so. You know how dog *** slow my car would be if I had a 3.63? It would suck.

spaztikcamel

With higher gearing youll be transfering less torque to the road as compared to before.
i.e. for the car to go from 5krpm to 6krpm it will take longer than it did before as there is more load.

so while you spend less time changing gears and will almost definantly be quicker over a set distance I highly doubt it will feel quicker.

but if it does and thats the way you go, awesome.

JasonC SBB

There is an optimum set of gearing based on power/wt, power/drag, and how quickly the driver shifts.

Ratios too close wastes time shifting, as the OP found out.

The ratios need to be more widely spaced with more power. (You effectively get wider spacing with a taller rear gear, see my earlier post)

The ratios need to get closer as you get higher in speed (higher gears). That's why the RPM drop with each upshift reduces as you accelerate. The reason for this is it takes more time to wind out each gear, the higher the speed is, and keeping RPM near the peak power point is more important than not wasting time upshifting.

miatauser123

iTrader: (7)

Put it this way. The only time my car feels fast is whatever gear I start in. Because after that I end up shifting every 2 seconds.

Example: Starting in third at 4200RPM and rolling all the way out until 7500 feels like a power house. Then I shift from 3-4 and only increase 20 MPH then shift again... and again. It's worthless.

And more load than I have is a GOOD thing. I'm not trying to participate in tugging contests. That means it's actually moving the damn car.

Boost Joose

Moar load=Moar spool

It's not about quickness here, its about throwing you back in the seat and keeping you there. I bet his car is quicker than your car with the 3.63 gears

spaztikcamel

I would agree his car is quicker after checking his build thread there is no doubt he has enough power to pull off the gearing.
yeah but its like 100 rpm difference

I still feel op with think it feels slower while it may not necessarily be slower.

I agree if feels fastest in the gear you take off from because you get to feel the full sensation but try taking off in a higher gear next time than normal and youll understand that it feels less agressive (slower imo) than the normal gear you take off in.

In the end I probably notice it too much as I am on 5sp with far less hp with a seemingly incurable misfire preventing me from upping boost from 6psi.

Boost Joose

Here's your problem.

spaztikcamel

was running 15 on the td04 but now got a new turbo and misfire (not at the same time) before I got the chance to turn up the boost on the new turbo.

still it went from feeling slow to feeling slower

miatauser123

iTrader: (7)

Facts that end this story:

1. My car needed more gear with the 5 Speed and a 4.30
2. The 6 Speed with a 3.636 is still slightly shorter than the 5 speed with the 4.30.
3. The End.

Mobius

iTrader: (2)

Then maybe you need to hop onto Corky's "is anybody interested in a T5 conversion kit" thread on m.net.

Savington

iTrader: (31)

If 3.636s aren't enough, you should consider a Ford 8.8 swap and 3.27s or 3.08s or 2.73s.

18psi

iTrader: (76)

So basically after all this discussion, you end up on post #2 by yours truly

miatauser123

iTrader: (7)

Yeap. I figured the 3.6 would be my only realistic solution/bandaid.

Are there gear set's available that space things out a little better? Under 2k?

90R

iTrader: (4)

all the aftermarket gear sets for the 5 speed make the gearing more close ratio.
You could use a B series truck trans (or some such) with a Miata bell housing.

JasonC SBB

Or FM's CTS-V diff plan.

18psi

iTrader: (76)

For under 2k, I'd probably look into what these guys are suggesting with the domestic rear end and some ultra low 3.xx to high 2.xx

Savington

iTrader: (31)

I've never understood why people use the CTS-V diffs. Even the CTS-V guys swap to Ford 8.8 units for strength. They have a TON of available gear ratios, they are plentiful and silly cheap, and they are more than strong enough for the application.