Drivetrain Operation Final Drive (OFD)
Peace Keeper
Joined: Dec 2006
Posts: 2,747
Likes: 1
From: Defiance, Ohio
Um, if I remember right, and I know Eric will correct me. Helix sells/sold straight cut gears with lower ratios. Cosmic Purple had them in his car for a while...no offense, but you need to chill. Go out for a drive, come back, drink a beer, and relax. Then, post some more...
Peace Keeper
Joined: Dec 2006
Posts: 2,747
Likes: 1
From: Defiance, Ohio
3rd Gear
Joined: Oct 2007
Posts: 218
Likes: 0
From: Annapolis, Maryland
LOL thanks for the chill tip.
Yeah that's just a lowered final drive gear. I have a 2006 which from what I have heard already has a lower final drive than the 2004ish cars (???). I would like to get into some power upgrades and that's why I thought about straight cut gears (easier to change, stronger, etc.) Am I right in this logic or is the stock transmission good for some high power racing?
By the way I was looking to the future thinking of getting a 2006 (or younger) MCS to strip out and tune up for a full blown track car. I may not do much to the one I have now since I have to drive it every day. Any thoughts?
Yeah that's just a lowered final drive gear. I have a 2006 which from what I have heard already has a lower final drive than the 2004ish cars (???). I would like to get into some power upgrades and that's why I thought about straight cut gears (easier to change, stronger, etc.) Am I right in this logic or is the stock transmission good for some high power racing?
By the way I was looking to the future thinking of getting a 2006 (or younger) MCS to strip out and tune up for a full blown track car. I may not do much to the one I have now since I have to drive it every day. Any thoughts?
I don't think straight cut gears are easier to change Calaway16. For race applications(assortment of ratios) you'll find more selection usually.
As for strength-all else being equal-aren't helical gears stronger because of their longer base and load spreading? Side loading(poor thrust washers) and that extra gear face mating surfaces are power sappers. The synchro hubs and dog teeth are the same for helical and SC synchro boxes. I'm all for a dog box though! Gone are the wear points for a synchro box(dog teeth, outer synchro hubs, cones and baulk rings).
Jeremy
Are straight cut gear sets made from a higher grade steel? It would make sense to me!
As for strength-all else being equal-aren't helical gears stronger because of their longer base and load spreading? Side loading(poor thrust washers) and that extra gear face mating surfaces are power sappers. The synchro hubs and dog teeth are the same for helical and SC synchro boxes. I'm all for a dog box though! Gone are the wear points for a synchro box(dog teeth, outer synchro hubs, cones and baulk rings).
Jeremy
Are straight cut gear sets made from a higher grade steel? It would make sense to me!
3rd Gear
Joined: Oct 2007
Posts: 218
Likes: 0
From: Annapolis, Maryland
I'm not really sure honestly. I've just heard that straight cut are easier to change because of some reason... lol this is why i would like a dog box: http://www.youtube.com/watch?v=asFwD...eature=related
It sounds cool. Oh; that's where I saw the bit about straight cut being stronger: one of the comments. I'll look it up a bit tonight and report on my findings.
It sounds cool. Oh; that's where I saw the bit about straight cut being stronger: one of the comments. I'll look it up a bit tonight and report on my findings.
Peace Keeper
Joined: Dec 2006
Posts: 2,747
Likes: 1
From: Defiance, Ohio
All I can say is talk to Jan
Nice video...check out this one
http://www.youtube.com/watch?v=dmJH84FnQa8
Nice video...check out this one
http://www.youtube.com/watch?v=dmJH84FnQa8
this is too strange... i just got all pi$$ed off over something that happened two years ago. but seeing how i had no knowledge as to when; does that mean time was irrelevant? whole tree in the woods thing really . i need a beer .
6th Gear
Joined: Jul 2004
Posts: 2,664
Likes: 1
From: Orlando, FL
First, remember that there are several different terms being thrown around here. Straight cut gears are exactly that, straight cut. Dog engagement is simply how the gear selector engages the next gear. The term 'dog' refers to several large teeth that slide into holes onto the next gear over. You can have a syncro'd gearbox with dog engagement and you can have a syncro'd gearbox with straight cut or helical cut gears.
I assume when you mean "change" you mean change gears. In normal shifting, straight cut gears probably don't help. They might even increase wear and tear on the tranny as the gears are clattering about. Helical gears can slip a little which acts as a cushion to other components. The upgrade kit for the MINI is (to my knowledge) not a full straight cut set but just a straight cut final drive gear.
Straight cut gears are usually stronger than helical gears and they transmit nearly all power to the next gear which is why they are used in racecars. They are loud. Helical gears slip a little so they aren't noisy but they also have a lot more friction which reduces their efficiency to transmit power.
Dog engagement is the preferred method that racers use to shift faster. The 'dogs' are very strong and can withstand being slammed into the next gear as long as the rpm is somewhat matched. If it's perfectly matched, the shift is effortless and amazingly quick. This is why they don't need to clutch. The harder you slam it into the next gear, the easier the dogs engage. Also, a lot of gearboxes that have dog engagement are not syncro'd which requires you to either shift without the clutch or double clutch all your shifts. Think dump trucks or semi's.
I honestly don't know what the MINI uses for gear engagement. Nor do I even know what the other types of engagement are. My experience is limited to Formula SAE where we use a Honda bike motor that has all gears on a single shaft and dog engagement so we can shift without a clutch. It definitely adds wear by doing this but our car is a purpose built racecar so we don't have a problem doing it. Cars have a layshaft in there and I don't know how that gets thrown into the mix.
Straight cut gears are usually stronger than helical gears and they transmit nearly all power to the next gear which is why they are used in racecars. They are loud. Helical gears slip a little so they aren't noisy but they also have a lot more friction which reduces their efficiency to transmit power.
Dog engagement is the preferred method that racers use to shift faster. The 'dogs' are very strong and can withstand being slammed into the next gear as long as the rpm is somewhat matched. If it's perfectly matched, the shift is effortless and amazingly quick. This is why they don't need to clutch. The harder you slam it into the next gear, the easier the dogs engage. Also, a lot of gearboxes that have dog engagement are not syncro'd which requires you to either shift without the clutch or double clutch all your shifts. Think dump trucks or semi's.
I honestly don't know what the MINI uses for gear engagement. Nor do I even know what the other types of engagement are. My experience is limited to Formula SAE where we use a Honda bike motor that has all gears on a single shaft and dog engagement so we can shift without a clutch. It definitely adds wear by doing this but our car is a purpose built racecar so we don't have a problem doing it. Cars have a layshaft in there and I don't know how that gets thrown into the mix.
Kapps I didn't know you could get a synchronized dog box. I thought the clutch/throttle was used as the synchro for that trans set-up.
FYI: 1st photo is of a simple 4 speed straight cut synchro trans for a Mini.
2nd photo is of a simple 4 speed dog engagement trans for a Mini.
And don't bike boxes have layshafts too? Where do you place the laygear then to house the various ratios to engage the mainshaft gears?
Our MINIs have twin layshafts/laygears to shorten the overall legnth of our gearbox correct? It's a neat way of stuffing the 6 speed drivetrain into front wheel drive car! Old Minis had to place the gearbox beneath the motor in a space saving effort and only managed to fit 4 forward gears.
BTW all cars have a straight cut 1st gears/1st on laygear. This is to accomodate reverse gear selection in a non crash effort.
Back on topic: Has anybody stripped and swapped over a rebuilt 2005+ gearset into a 2002-2004 trans before? Any pics of gearboxes? I've seen a few guys here do diff swaps and such but I've not seen and internal work.........yet, which is a good thing I suppose.
Jeremy
FYI: 1st photo is of a simple 4 speed straight cut synchro trans for a Mini.
2nd photo is of a simple 4 speed dog engagement trans for a Mini.
And don't bike boxes have layshafts too? Where do you place the laygear then to house the various ratios to engage the mainshaft gears?
Our MINIs have twin layshafts/laygears to shorten the overall legnth of our gearbox correct? It's a neat way of stuffing the 6 speed drivetrain into front wheel drive car! Old Minis had to place the gearbox beneath the motor in a space saving effort and only managed to fit 4 forward gears.
BTW all cars have a straight cut 1st gears/1st on laygear. This is to accomodate reverse gear selection in a non crash effort.
Back on topic: Has anybody stripped and swapped over a rebuilt 2005+ gearset into a 2002-2004 trans before? Any pics of gearboxes? I've seen a few guys here do diff swaps and such but I've not seen and internal work.........yet, which is a good thing I suppose.
Jeremy
4th Gear
Joined: Nov 2006
Posts: 499
Likes: 0
From: Baton Rouge, LA
http://video.google.com/videoplay?do...arch&plindex=0
Watch that first...
Now onto the tech:
Two methods of engagement: Dog and synchro. Both formats have dog "teeth" that actually engage a selected gear, but the difference is in how the gear is brought up to speed (from which the transmission monikers are taken). In a "dogbox," a solid collet connects with the spinning output shaft and is immediately engaged. In a synchrobox, the engagement is done with a somewhat tapered collet...a much more gradual and less harsh process. Neither format requires double de-clutching or double clutching. It is fully possible to have a dogbox with helical gears, or a synchrobox with straight cut gears, or any other combination.
It is not possible to have a synchro'ed dog engagement...it's one or the other. BOTH formats have dog teeth on the portion opposite the collect though. Just wanted to clear up the use of these terms.
Straight cut gears are usually regarded as "stronger" because they take the force of the impact over the face of a tooth at once, as opposed to helical cut gears which are a gradual engagement. You do not, do not want straight cut gears beyond 3rd or so in a street car...as shown in the video one of you guys posted, you NEED to wear earplugs less you go deaf from the noise they make. You can actually hear the straight cut reverse gear in our car...makes the RC car noise.
- Matt
Watch that first...
Now onto the tech:
Two methods of engagement: Dog and synchro. Both formats have dog "teeth" that actually engage a selected gear, but the difference is in how the gear is brought up to speed (from which the transmission monikers are taken). In a "dogbox," a solid collet connects with the spinning output shaft and is immediately engaged. In a synchrobox, the engagement is done with a somewhat tapered collet...a much more gradual and less harsh process. Neither format requires double de-clutching or double clutching. It is fully possible to have a dogbox with helical gears, or a synchrobox with straight cut gears, or any other combination.
It is not possible to have a synchro'ed dog engagement...it's one or the other. BOTH formats have dog teeth on the portion opposite the collect though. Just wanted to clear up the use of these terms.
Straight cut gears are usually regarded as "stronger" because they take the force of the impact over the face of a tooth at once, as opposed to helical cut gears which are a gradual engagement. You do not, do not want straight cut gears beyond 3rd or so in a street car...as shown in the video one of you guys posted, you NEED to wear earplugs less you go deaf from the noise they make. You can actually hear the straight cut reverse gear in our car...makes the RC car noise.
- Matt
3rd Gear
Joined: Oct 2007
Posts: 218
Likes: 0
From: Annapolis, Maryland
Sorry I was unclear. I meant "change" as in swap out gears for different ratios. Once again I didn't have time to do any research last night and I won't be back for a couple days (going to the track... oh yeah!).
http://video.google.com/videoplay?do...arch&plindex=0
Watch that first...
Now onto the tech:
Two methods of engagement: Dog and synchro. Both formats have dog "teeth" that actually engage a selected gear, but the difference is in how the gear is brought up to speed (from which the transmission monikers are taken). In a "dogbox," a solid collet connects with the spinning output shaft and is immediately engaged. In a synchrobox, the engagement is done with a somewhat tapered collet...a much more gradual and less harsh process. Neither format requires double de-clutching or double clutching. It is fully possible to have a dogbox with helical gears, or a synchrobox with straight cut gears, or any other combination.
It is not possible to have a synchro'ed dog engagement...it's one or the other. BOTH formats have dog teeth on the portion opposite the collect though. Just wanted to clear up the use of these terms.
Straight cut gears are usually regarded as "stronger" because they take the force of the impact over the face of a tooth at once, as opposed to helical cut gears which are a gradual engagement. You do not, do not want straight cut gears beyond 3rd or so in a street car...as shown in the video one of you guys posted, you NEED to wear earplugs less you go deaf from the noise they make. You can actually hear the straight cut reverse gear in our car...makes the RC car noise.
- Matt
Watch that first...
Now onto the tech:
Two methods of engagement: Dog and synchro. Both formats have dog "teeth" that actually engage a selected gear, but the difference is in how the gear is brought up to speed (from which the transmission monikers are taken). In a "dogbox," a solid collet connects with the spinning output shaft and is immediately engaged. In a synchrobox, the engagement is done with a somewhat tapered collet...a much more gradual and less harsh process. Neither format requires double de-clutching or double clutching. It is fully possible to have a dogbox with helical gears, or a synchrobox with straight cut gears, or any other combination.
It is not possible to have a synchro'ed dog engagement...it's one or the other. BOTH formats have dog teeth on the portion opposite the collect though. Just wanted to clear up the use of these terms.
Straight cut gears are usually regarded as "stronger" because they take the force of the impact over the face of a tooth at once, as opposed to helical cut gears which are a gradual engagement. You do not, do not want straight cut gears beyond 3rd or so in a street car...as shown in the video one of you guys posted, you NEED to wear earplugs less you go deaf from the noise they make. You can actually hear the straight cut reverse gear in our car...makes the RC car noise.
- Matt
Remember reverse is heard easily because you're actually hearing 4 gears engage(1st/reverse and reverse/synchro hub) to complete the reversing of the mainshaft/3rd motion with in turn drives the pinion and crown wheel.
Jeremy
2nd Gear
Joined: Feb 2008
Posts: 100
Likes: 0
might be better off looking at trans adaptors and new axle shafts. or the Uk diesel mini trans? I know that on the VW side the guys with high powered tubro vr6 will switch over to the diesel trans. Seams like the Diesel mini trans be something to look into as a swap or for parts?
6th Gear
Joined: Aug 2002
Posts: 2,253
Likes: 0
From: NY NY
i stand by what i said, which was exactly about showing respect for other's experience and that some things are better left to the expert.
Would you suggest in geberal that, hey give it a go, mess with your brakes, struts tie bars, soup up you engine and test it out on a freeway entrance? What about endangering the public when your non-specialist, first time welded tie bar breaks and your car rolls over? Calaway, are you so sure of yourself that you would dig into the ECU or the ABS? where do you draw the line?
Would you suggest in geberal that, hey give it a go, mess with your brakes, struts tie bars, soup up you engine and test it out on a freeway entrance? What about endangering the public when your non-specialist, first time welded tie bar breaks and your car rolls over? Calaway, are you so sure of yourself that you would dig into the ECU or the ABS? where do you draw the line?
2nd Gear
Joined: Feb 2008
Posts: 100
Likes: 0
and every expert started somewhere at a level way less then expert.
By your account a person should only do things they are experts on and all other things in life they should pay an "expert" for. did you pay a typing expert to type your response. Did you pay an expert to turn your computer on?
and every expert started somewhere at a level way less then expert.
By your account a person should only do things they are experts on and all other things in life they should pay an "expert" for. did you pay a typing expert to type your response. Did you pay an expert to turn your computer on?
By your account a person should only do things they are experts on and all other things in life they should pay an "expert" for. did you pay a typing expert to type your response. Did you pay an expert to turn your computer on?
Looks like you are going to have a hard time making friends around here.
Think of NAM like surfing. Paddle out at your home break and do what you want. Paddle out in Hawaii and you better sit inside and give respect to those that have been their for years. Start slow, earn some respect and then have fun.
Just a little friendly advice.
Longboard
i stand by what i said, which was exactly about showing respect for other's experience and that some things are better left to the expert.
Would you suggest in geberal that, hey give it a go, mess with your brakes, struts tie bars, soup up you engine and test it out on a freeway entrance? What about endangering the public when your non-specialist, first time welded tie bar breaks and your car rolls over? Calaway, are you so sure of yourself that you would dig into the ECU or the ABS? where do you draw the line?
Would you suggest in geberal that, hey give it a go, mess with your brakes, struts tie bars, soup up you engine and test it out on a freeway entrance? What about endangering the public when your non-specialist, first time welded tie bar breaks and your car rolls over? Calaway, are you so sure of yourself that you would dig into the ECU or the ABS? where do you draw the line?
nice to see you posting again!!!
2nd Gear
Joined: Feb 2008
Posts: 100
Likes: 0
Charger,
Looks like you are going to have a hard time making friends around here.
Think of NAM like surfing. Paddle out at your home break and do what you want. Paddle out in Hawaii and you better sit inside and give respect to those that have been their for years. Start slow, earn some respect and then have fun.
Just a little friendly advice.
Longboard
Looks like you are going to have a hard time making friends around here.
Think of NAM like surfing. Paddle out at your home break and do what you want. Paddle out in Hawaii and you better sit inside and give respect to those that have been their for years. Start slow, earn some respect and then have fun.
Just a little friendly advice.
Longboard
This is a chat board open to people of all skills and knowledge levels. I stand by what I said. Nobody is born an expert and everybody must learn.
6th Gear
Joined: Aug 2002
Posts: 2,253
Likes: 0
From: NY NY
i did use the word "some"
on the other hand, there are some skills that I won't attempt because i respect the inherent abilities required: I stay away from circuit board trouble shooting, for example. doesn't mean you should, but i suggest you take your time becoming an expert on non-critical work before trying X-ray quality structural welding. Oh, and keep your car out of my area until your suspension welds are expert
on the other hand, there are some skills that I won't attempt because i respect the inherent abilities required: I stay away from circuit board trouble shooting, for example. doesn't mean you should, but i suggest you take your time becoming an expert on non-critical work before trying X-ray quality structural welding. Oh, and keep your car out of my area until your suspension welds are expert
Since I have been surfing for 25 years all over the world and taught countless people to surf I think I can qualify as an expert
. I also do surfboard restoration as a hobby . Look in my pics and you can see all the boards in my garage.I agree this is an open board. I am just giving you a little piece of advice. The choice to listen is yours.
Longboard (get it?)
Coordinator :: Low Country MINIs
iTrader: (3)
Joined: Apr 2004
Posts: 1,874
Likes: 0
From: charleston, SC
Charger,
The first time i saw you post charger i thought the exact thing...you were comparing our cars to harleys? hahah ....Let the big dogs do their things and you can read things and beleive what you want...like longboard said the guys who have been here for years our respect and sit back and learn....ok im done sorry jus thad to vent
Jack
The first time i saw you post charger i thought the exact thing...you were comparing our cars to harleys? hahah
....Let the big dogs do their things and you can read things and beleive what you want...like longboard said the guys who have been here for years our respect and sit back and learn....ok im done sorry jus thad to ventJack
3rd Gear
Joined: Oct 2007
Posts: 218
Likes: 0
From: Annapolis, Maryland
i did use the word "some"
on the other hand, there are some skills that I won't attempt because i respect the inherent abilities required: I stay away from circuit board trouble shooting, for example. doesn't mean you should, but i suggest you take your time becoming an expert on non-critical work before trying X-ray quality structural welding. Oh, and keep your car out of my area until your suspension welds are expert
on the other hand, there are some skills that I won't attempt because i respect the inherent abilities required: I stay away from circuit board trouble shooting, for example. doesn't mean you should, but i suggest you take your time becoming an expert on non-critical work before trying X-ray quality structural welding. Oh, and keep your car out of my area until your suspension welds are expert
I lack confidence enough in many things to try them, but sometimes my determination and stupidity exceeds my concern lol; but I would never let my stupidity endanger members of the public; I think that goes for all of us here....
Last edited by Calaway16; Feb 22, 2008 at 11:32 AM.
if a guy wants to try something on his own ...let him . if you feel he's being direspectful to another member then let them comment . i've been a long time away from this stuff but recently did the bottom end . i was cautious and got all the necessary specs etc. if i screwed the pooch oh well it's my car . if not cudos to me . alot of forward thinking would be held back by your attitude jim .