Gear ratios are worthless. Any good solutions? - Page 3 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 02-14-2012, 10:46 AM   #41
Junior Member
 
Join Date: Mar 2011
Location: Ballina Australia
Posts: 86
Total Cats: 2
Default

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.
spaztikcamel is offline   Reply With Quote
Old 02-14-2012, 12:01 PM   #42
I'm Miserable!
 
Join Date: Dec 2011
Posts: 346
Total Cats: -223
Default

Quote:
Originally Posted by Dem768 View Post
Mine aren't off for my setup- I used the Flyin Miata calculator. He might have different tires though.
ohh ok gotcha what tires you running?
Boost Joose is offline   Reply With Quote
Old 02-14-2012, 12:17 PM   #43
Senior Member
Thread Starter
iTrader: (7)
 
Join Date: Sep 2009
Location: Royal Oak Michigan
Posts: 756
Total Cats: 67
Default

Quote:
Originally Posted by Boost Joose View Post
ohh ok gotcha what tires you running?
225/45/16

Quote:
Originally Posted by spaztikcamel View Post
changing from 4.3 to 3.63 makes the car feel a lot slower.
just ask me how i know
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.
miatauser123 is offline   Reply With Quote
Old 02-14-2012, 07:44 PM   #44
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,895
Total Cats: 109
Default

Quote:
Originally Posted by Dem768 View Post
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.
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.
miata2fast is offline   Reply With Quote
Old 02-14-2012, 07:47 PM   #45
Junior Member
 
Join Date: Mar 2011
Location: Ballina Australia
Posts: 86
Total Cats: 2
Default

Quote:
Originally Posted by Dem768 View Post
225/45/16



Well the facts are facts. It shouldn't feel slower and it definitely wont be slower.
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.
spaztikcamel is offline   Reply With Quote
Old 02-14-2012, 07:50 PM   #46
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

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.
JasonC SBB is offline   Reply With Quote
Old 02-14-2012, 08:00 PM   #47
Senior Member
Thread Starter
iTrader: (7)
 
Join Date: Sep 2009
Location: Royal Oak Michigan
Posts: 756
Total Cats: 67
Default

Quote:
Originally Posted by spaztikcamel View Post
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.
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.
miatauser123 is offline   Reply With Quote
Old 02-15-2012, 07:29 AM   #48
I'm Miserable!
 
Join Date: Dec 2011
Posts: 346
Total Cats: -223
Default

Quote:
Originally Posted by spaztikcamel View Post
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.
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
Boost Joose is offline   Reply With Quote
Old 02-15-2012, 07:48 AM   #49
Junior Member
 
Join Date: Mar 2011
Location: Ballina Australia
Posts: 86
Total Cats: 2
Default

Quote:
Originally Posted by Boost Joose View Post
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
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.
Quote:
Originally Posted by Boost Joose View Post
Moar load=Moar spool
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.
spaztikcamel is offline   Reply With Quote
Old 02-15-2012, 08:13 AM   #50
I'm Miserable!
 
Join Date: Dec 2011
Posts: 346
Total Cats: -223
Default

Quote:
Originally Posted by spaztikcamel View Post
6psi.
Here's your problem.
Boost Joose is offline   Reply With Quote
Old 02-15-2012, 08:20 AM   #51
Junior Member
 
Join Date: Mar 2011
Location: Ballina Australia
Posts: 86
Total Cats: 2
Default

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
spaztikcamel is offline   Reply With Quote
Old 02-15-2012, 12:50 PM   #52
Senior Member
Thread Starter
iTrader: (7)
 
Join Date: Sep 2009
Location: Royal Oak Michigan
Posts: 756
Total Cats: 67
Default

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.

miatauser123 is offline   Reply With Quote
Old 02-15-2012, 03:49 PM   #53
Elite Member
iTrader: (2)
 
Mobius's Avatar
 
Join Date: May 2008
Location: Portland, Oregon
Posts: 3,178
Total Cats: 266
Default

Then maybe you need to hop onto Corky's "is anybody interested in a T5 conversion kit" thread on m.net.
Mobius is offline   Reply With Quote
Old 02-15-2012, 03:59 PM   #54
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,363
Total Cats: 1,323
Default

If 3.636s aren't enough, you should consider a Ford 8.8 swap and 3.27s or 3.08s or 2.73s.
Savington is offline   Reply With Quote
Old 02-15-2012, 04:07 PM   #55
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,185
Total Cats: 2,582
Default

So basically after all this discussion, you end up on post #2 by yours truly
18psi is offline   Reply With Quote
Old 02-15-2012, 04:21 PM   #56
Senior Member
Thread Starter
iTrader: (7)
 
Join Date: Sep 2009
Location: Royal Oak Michigan
Posts: 756
Total Cats: 67
Default

Quote:
Originally Posted by 18psi View Post
So basically after all this discussion, you end up on post #2 by yours truly
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?
miatauser123 is offline   Reply With Quote
Old 02-15-2012, 06:05 PM   #57
90R
Junior Member
iTrader: (4)
 
Join Date: Jul 2010
Posts: 278
Total Cats: 0
Default

Quote:
Originally Posted by Dem768 View Post
Are there gear set's available that space things out a little better? Under 2k?
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.
90R is offline   Reply With Quote
Old 02-15-2012, 06:08 PM   #58
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Quote:
Originally Posted by Savington View Post
If 3.636s aren't enough, you should consider a Ford 8.8 swap and 3.27s or 3.08s or 2.73s.
Or FM's CTS-V diff plan.
JasonC SBB is offline   Reply With Quote
Old 02-15-2012, 06:28 PM   #59
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,185
Total Cats: 2,582
Default

Quote:
Originally Posted by Dem768 View Post
Are there gear set's available that space things out a little better? Under 2k?
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
18psi is offline   Reply With Quote
Old 02-15-2012, 06:43 PM   #60
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,363
Total Cats: 1,323
Default

Quote:
Originally Posted by JasonC SBB View Post
Or FM's CTS-V diff plan.
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.
Savington is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 Yesterday 10:04 PM
My solution for Oiltemp and Oilpressure input into Megasuirt (MS3) Zaphod MEGAsquirt 41 01-24-2016 01:25 PM
WTB MP62 (Hotside) (NB2) Rick02R WTB 3 01-03-2016 08:18 PM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 06:01 AM.