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Philosophy of Gearing

Posted by dunhamr1 
dunhamr1
Ryan Dunham
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Re: Philosophy of Gearing
June 29, 2017 07:44AM
Quote
Robert Culbertson
Ryan,
Double check the number of teeth and the ratios. The ratio in 5th is also controlled by the input shaft gear and cluster/counter gear tooth counts. So swapping just 5th might not actually be the change you're looking for. For instance, using the 0.80 5th with a 3.35 1st drops the OD closer to 0.9...

As far as gearing, the 4.88 is still a bit too high, but it's way better than the stock 4.1 that was in the car originally. Switching to a 5.29 would drop the top speed, and up the accel.
I see the point is using 1-4 and a longer final drive, but you'll be stuck in each gear longer and loosing time vs using 1-5 and a shorter final drive.

LOL at 4.88 being too high. More rally!! Assuming I can get the Camaro V8 t5 box and the supra 4.3 diff in the Merkur, it'll have a theoretical top speed of 140 at 6k rpm in 5th, so that's not too good. Keeping the stock T9 and putting the 4.3 diff in it would yield lower top speed but I'd not want to go crashing around on a T9.

If it's apart anyway, would it be too crazy to swap the cluster/counter gear too? This is all theoretical at the moment, long ways away from trying to swap things around.
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Robert Culbertson
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Re: Philosophy of Gearing
June 29, 2017 09:18AM
Mounting up a Camaro T5 to a ford bellhousing is going to take some work, as the bolt pattern on the trans is different, and the input shaft is a different length, and the input shaft is a different spline count. You might be able to swap all the gears over to a Ford case and change out the input shaft.

What about the ferd T5 with a .74 or .78 OD?
Is the T9 really that weak? I know they don't have the best gearing from the factory.

The 4.3 rear gearing is nice. We just swapped that back into the ecoboost merkur from a 3.9. The 3.9 was used in a pinch as that was all we had laying around. It also eased the abuse to the tires caused by Dave's right foot. Now they have no mercy smiling smiley



Edited 1 time(s). Last edit at 06/29/2017 09:19AM by Robert Culbertson.
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dunhamr1
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Re: Philosophy of Gearing
June 29, 2017 10:35AM
Quote
Robert Culbertson
Mounting up a Camaro T5 to a ford bellhousing is going to take some work, as the bolt pattern on the trans is different, and the input shaft is a different length, and the input shaft is a different spline count. You might be able to swap all the gears over to a Ford case and change out the input shaft.

What about the ferd T5 with a .74 or .78 OD?
Is the T9 really that weak? I know they don't have the best gearing from the factory.

The 4.3 rear gearing is nice. We just swapped that back into the ecoboost merkur from a 3.9. The 3.9 was used in a pinch as that was all we had laying around. It also eased the abuse to the tires caused by Dave's right foot. Now they have no mercy smiling smiley

I suppose I'd need something like this (see link) but that's almost more than I paid for the trans itself!! I'd just run a Chevy clutch and make something work for the flywheel.

http://www.jegs.com/i/McLeod/673/8607/10002/-1?CAWELAID=1710534893&CAGPSPN=pla&CAAGID=44693592161&CATCI=pla-176559534071&CATARGETID=230006180039219045&cadevice=c&gclid=CjwKEAjwytLKBRCX547gve7EsE4SJAD3IZV6XI0zwwMGA9is0gpsfV5UhDX4yIG04Ib_XS_5ijy97xoCqIvw_wcB

I don't think the T9 is particularly weak but there not rated for much abuse. In a street car and on JVL's admonishment, keeping the fluid level high enough should make it last. Ratios would be the motivation for changing the trans, not necessarily the worry that it'll asplode.

I'm still looking for an LSD center section to slap onto the 4.3 ring and pinion I've got sitting in the garage, and looking forward to trying to get that in there eventually, mine will be a street car/ occasional rallyx for a bit. Trying to assemble radios and dashes and heaters and such right now.

Haha no mercy! What tires have you guys been running lately?
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Robert Culbertson
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Re: Philosophy of Gearing
June 29, 2017 12:49PM
Quote
dunhamr1
Haha no mercy! What tires have you guys been running lately?

We tried the Hoosiers and they worked fine. Then we switched to the new new compound Dmacks with bigger tread blocks in the 215 size.
The Volvo ran the same set at Oly and Idaho. Podiumed both days at Oly (1st/2nd) and took overall 2wd light at Idaho. At Idaho we were one tire fryer for 3-4 stages and you couldn't even tell. The old tires wouldn't make it through 3 stages.
Dave ran the new Dmacks on the rear for both days at Idaho, and he never rotated them. They're not even down to 50%. He ran the Hoosiers at RMR and had to rotate and add 2-fresh tires. But different rocks and road conditions between RMR and Idaho.



Edited 2 time(s). Last edit at 06/29/2017 12:50PM by Robert Culbertson.
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MarkHille
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Re: Philosophy of Gearing
June 30, 2017 06:50AM
Quote
dunhamr1
Quote
Robert Culbertson
Ryan,
Double check the number of teeth and the ratios. The ratio in 5th is also controlled by the input shaft gear and cluster/counter gear tooth counts. So swapping just 5th might not actually be the change you're looking for. For instance, using the 0.80 5th with a 3.35 1st drops the OD closer to 0.9...

As far as gearing, the 4.88 is still a bit too high, but it's way better than the stock 4.1 that was in the car originally. Switching to a 5.29 would drop the top speed, and up the accel.
I see the point is using 1-4 and a longer final drive, but you'll be stuck in each gear longer and loosing time vs using 1-5 and a shorter final drive.

LOL at 4.88 being too high. More rally!! Assuming I can get the Camaro V8 t5 box and the supra 4.3 diff in the Merkur, it'll have a theoretical top speed of 140 at 6k rpm in 5th, so that's not too good. Keeping the stock T9 and putting the 4.3 diff in it would yield lower top speed but I'd not want to go crashing around on a T9.

If it's apart anyway, would it be too crazy to swap the cluster/counter gear too? This is all theoretical at the moment, long ways away from trying to swap things around.


http://www.thegearbox.org/catalog/item/3819132/3532263.htm It looks like some years the cluster may be swappable but I would be weary doing things not many people have done before. Not even the 4 cylinder ford t5 and the 8 cylinder ford t5 transmissions are a direct swap. The pilot bearings are a different size the spline count is different. It is really hard to beat the 2.95 ratio. Add the .80 5th and you basically have the same gearing as a Subaru 6 speed minus the 6th gear. With a 4.3 it goes pretty good. Prices keep on going up because that is more than I paid for sure. Can you still do it for under $1000 dollars including a new clutch? Possibly. Probably not when you throw in the supra diff kit and the driveshaft unless you are really lucky and come across parts for super cheap.
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john vanlandingham
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Re: Philosophy of Gearing
June 30, 2017 01:38PM
Quote
dunhamr1
Quote
Robert Culbertson
Ryan,
Double check the number of teeth and the ratios. The ratio in 5th is also controlled by the input shaft gear and cluster/counter gear tooth counts. So swapping just 5th might not actually be the change you're looking for. For instance, using the 0.80 5th with a 3.35 1st drops the OD closer to 0.9...

As far as gearing, the 4.88 is still a bit too high, but it's way better than the stock 4.1 that was in the car originally. Switching to a 5.29 would drop the top speed, and up the accel.
I see the point is using 1-4 and a longer final drive, but you'll be stuck in each gear longer and loosing time vs using 1-5 and a shorter final drive.

LOL at 4.88 being too high.

3.08 is high..
4.88 is low..or short..

On a turbo car with a 2.95 first 4.88 is TOO low.. into the realm of 2 car length 1st..Greateye rolling smiley
On a n.a car that will rev happily to 7000 4.88 can fake it, but all thru history a typical overall top gear ratio is around 5:1....
It may be done with a 1;1 top and a 5.1 final, or it may be done with a 4.25 and a 1.15 top doesn't matter..

Then we can factor in the on average much faster roads here and diddle things a little taller maybe but just gotta bear in mind: turbo vs non-turbo...
All the precedent you need is long well established, you don't need "advice" from guys who can't even reflexively get "high" and "low" right.



John Vanlandingham
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john vanlandingham
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Re: Philosophy of Gearing
June 30, 2017 01:41PM
Quote
MarkHille
Quote
dunhamr1
Quote
Robert Culbertson
Ryan,
Double check the number of teeth and the ratios. The ratio in 5th is also controlled by the input shaft gear and cluster/counter gear tooth counts. So swapping just 5th might not actually be the change you're looking for. For instance, using the 0.80 5th with a 3.35 1st drops the OD closer to 0.9...

As far as gearing, the 4.88 is still a bit too high, but it's way better than the stock 4.1 that was in the car originally. Switching to a 5.29 would drop the top speed, and up the accel.
I see the point is using 1-4 and a longer final drive, but you'll be stuck in each gear longer and loosing time vs using 1-5 and a shorter final drive.

LOL at 4.88 being too high. More rally!! Assuming I can get the Camaro V8 t5 box and the supra 4.3 diff in the Merkur, it'll have a theoretical top speed of 140 at 6k rpm in 5th, so that's not too good. Keeping the stock T9 and putting the 4.3 diff in it would yield lower top speed but I'd not want to go crashing around on a T9.

If it's apart anyway, would it be too crazy to swap the cluster/counter gear too? This is all theoretical at the moment, long ways away from trying to swap things around.


http://www.thegearbox.org/catalog/item/3819132/3532263.htm It looks like some years the cluster may be swappable but I would be weary doing things not many people have done before. Not even the 4 cylinder ford t5 and the 8 cylinder ford t5 transmissions are a direct swap. The pilot bearings are a different size the spline count is different. It is really hard to beat the 2.95 ratio. Add the .80 5th and you basically have the same gearing as a Subaru 6 speed minus the 6th gear. With a 4.3 it goes pretty good. Prices keep on going up because that is more than I paid for sure. Can you still do it for under $1000 dollars including a new clutch? Possibly. Probably not when you throw in the supra diff kit and the driveshaft unless you are really lucky and come across parts for super cheap.

I'd use Misterbitchy Evo as the yardstick since they are slightly closer to the T5 (1st thru 4th) AND they kick and stomp Sub-a-rats into lifeless twitching puddles of poo worldwide, maybe the slight difference helps. They also use a 4.37 final drive making the comparison nice.



John Vanlandingham
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Robert Culbertson
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Re: Philosophy of Gearing
June 30, 2017 01:53PM
Quote
john vanlandingham
Quote
dunhamr1
Quote
Robert Culbertson
Ryan,
Double check the number of teeth and the ratios. The ratio in 5th is also controlled by the input shaft gear and cluster/counter gear tooth counts. So swapping just 5th might not actually be the change you're looking for. For instance, using the 0.80 5th with a 3.35 1st drops the OD closer to 0.9...

As far as gearing, the 4.88 is still a bit too high, but it's way better than the stock 4.1 that was in the car originally. Switching to a 5.29 would drop the top speed, and up the accel.
I see the point is using 1-4 and a longer final drive, but you'll be stuck in each gear longer and loosing time vs using 1-5 and a shorter final drive.

LOL at 4.88 being too high.

3.08 is high..
4.88 is low..or short..

On a turbo car with a 2.95 first 4.88 is TOO low.. into the realm of 2 car length 1st..Greateye rolling smiley
On a n.a car that will rev happily to 7000 4.88 can fake it, but all thru history a typical overall top gear ratio is around 5:1....
It may be done with a 1;1 top and a 5.1 final, or it may be done with a 4.25 and a 1.15 top doesn't matter..

Then we can factor in the on average much faster roads here and diddle things a little taller maybe but just gotta bear in mind: turbo vs non-turbo...
All the precedent you need is long well established, you don't need "advice" from guys who can't even reflexively get "high" and "low" right.

I was talking NA there John. We still feel that the 4.88 is too HIGH geared, and we should have gone 5.38 in the diff, which is LOWER. Even at OTR and Oly we were never close to the rev limiter with the .80 5th and 4.88. That's with the 16v motor that makes a good deal more power and torque than the old 8v.

I know that dave doesn't even use 1st with the ecoboost powah and a 4.3 r&p, so he could go LOWER still (like a 4.56) and have more torque in the 3/4/5 gears with a slightly lower r&p.

Turbo car, the common 4.3 or 4.56 would be nice. I'd go at least 4.3 or 4.56 and a .80 5th for stage, but that's just me.
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Robert Culbertson
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Re: Philosophy of Gearing
June 30, 2017 02:02PM
Quote
john vanlandingham

On a turbo car with a 2.95 first 4.88 is TOO low.. into the realm of 2 car length 1st..Greateye rolling smiley
On a n.a car that will rev happily to 7000 4.88 can fake it, but all thru history a typical overall top gear ratio is around 5:1....
It may be done with a 1;1 top and a 5.1 final, or it may be done with a 4.25 and a 1.15 top doesn't matter..

You bring up a good point here John. The top end gearing is usually around 5:1 for NA.
But if you aim for that in 4th (like a 4.88), you're just caring around an extra gear for weight and a not ideal 1-2 gap. Yes the high 5th is nice for cruising, but we almost never used it on transits as the 8v motor didn't have enough torque to pull it unless it was completely flat.

If you aim for using 5th (.8 or .74) and a lower r&p, you get smaller gaps between the gears, and more torque to the tires in all gears. You still have the non-ideal 1-2 gap, but you can choose to launch in 2nd if it's a level or downhill start. Then use 1st for the uphill starts, cruising the service park, or loading the car onto a trailer.
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p0inT92
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Re: Philosophy of Gearing
July 01, 2017 09:01AM
Doesnt seem like Ryan´s question really got answered, so.
Iam not a expert, but of what i read the gearing in a racebox is suppose to keep you in the powerband, so lets say if you redline at 7k, and you "powerband" start around 5k, you just gear your car not to fall under 5k when up-shifting, makes sense to me and seems pretty simple.
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dunhamr1
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Re: Philosophy of Gearing
July 11, 2017 08:06AM
Quote
p0inT92
Doesnt seem like Ryan´s question really got answered, so.
Iam not a expert, but of what i read the gearing in a racebox is suppose to keep you in the powerband, so lets say if you redline at 7k, and you "powerband" start around 5k, you just gear your car not to fall under 5k when up-shifting, makes sense to me and seems pretty simple.

In a sense it was answered, but like most things, the answer is "It depends."

I think in most cases (unless you have stupid money to spend) you're limited by the gearboxes that were produced for that application (you're lucky if you can use a T5, lots of options there), as well as the final drive (though you can always change it, ala JVLs Supra diff mount).

I think the answer so far is:

No need for crazy top speed in rally (thus the goal of a lower final drive).
Balancing the final drive with a usable space between gears 2-5(6 for 6 speed), 1st gear not TOO high or TOO low (car/driver/clutch dependent).
Specific numbers will depend on engine/application (power/torque bands vs RPM)

Edit: Revised statement about gears.



Edited 1 time(s). Last edit at 07/11/2017 01:23PM by dunhamr1.
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john vanlandingham
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Re: Philosophy of Gearing
July 12, 2017 01:41PM
Quote
dunhamr1
Quote
p0inT92
Doesnt seem like Ryan´s question really got answered, so.
Iam not a expert, but of what i read the gearing in a racebox is suppose to keep you in the powerband, so lets say if you redline at 7k, and you "powerband" start around 5k, you just gear your car not to fall under 5k when up-shifting, makes sense to me and seems pretty simple.

In a sense it was answered, but like most things, the answer is "It depends."

I think in most cases (unless you have stupid money to spend) you're limited by the gearboxes that were produced for that application (you're lucky if you can use a T5, lots of options there), as well as the final drive (though you can always change it, ala JVLs Supra diff mount).

I think the answer so far is:

No need for crazy top speed in rally (thus the goal of a lower final drive).
Balancing the final drive with a usable space between gears 2-5(6 for 6 speed), 1st gear not TOO high or TOO low (car/driver/clutch dependent).
Specific numbers will depend on engine/application (power/torque bands vs RPM)

Edit: Revised statement about gears.

Yes, exactly..It depends..
Depends on if one actually wants to rally a car with a real live box or fap endlessly about some ideal that is, in the end, unattainably expensive, or rare.....

Depends on how much and how wide the torque the motor makes is delivered<---------THIS being the no 1 overarching factor..

Depends on one's approach to the learning of driving skills vs just playing at rallys when they happen..

(the major thing I like about the Xratty 2,3 turbo or Volvo 2,3 turbo combined with a 2.95 gearset T5 AND retaining the otherwise dumb 0.73 5th gear is the ability to get the 1t thru 4th ratios for fun, and quite usable with the BROAD power deliver, have hard 3rd and 4th gear accelleration, BUT a nice calm cruise in 5th --less revs than a stock street car for a given mph---for those either long transits or and this is the KEY thing...to let you drive long distances comfortably in search of safe places to PRACTICE....
Now as far as I know, nobody thinks practice is something they need and consequently, nobody seems to be making any efforts to do it....so evidently I suffer from a misapprehension about the absolute critical need of practicing, and hence the utility of having a car that can rip 1st thru 4th and then cruise at 70mph all day at relaxed revs...)

It all depends.

Depends on if your approach to results is self-improvement primarily, or purchase, or in some notorious cases, spending a lot of other peoples money because you're a 27 year old who while never having driven a whole rally is convinced that you have the evisdently god-given knowledge to know what is needed..

From personal experience and 30 years of watching Merikun and Canajian rally, I think the mostly ignored self-improvement part is whats needed and that means practice, and LOTS of it..

hence: turbo 2,3 making broad and nice torque.....4,3 or 4,37 final, 2.95 gearset with 0.73 top is just about perfect (as references to Misterbitchy Evo 3 and onward attests)

Normal aspirated different story... but still depends..



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Robert Culbertson
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Re: Philosophy of Gearing
July 12, 2017 02:17PM
Hey now, I'm 29!
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Not Trolling
Keith Morison
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Re: Philosophy of Gearing
July 12, 2017 02:28PM
Quote
john vanlandingham
From personal experience and 30 years of watching Merikun and Canajian rally, I think the mostly ignored self-improvement part is whats needed and that means practice, and LOTS of it.
But driving around in fifth to find a deserted - but not properly closed - road to practice doing what you think is right doesn't really help much does it?
Sanctioned test days where you can take a variety of known good drivers in the car with you combined with rally schools that give you sound fundamentals to practice with later (usually for about the cost of one or two rally weekends, and MUCH more seat time) are a big part of what is missing - from my 15 years of watching, and being involved in the sport.
One constant I've found is that people who go to schools with the intent to learn, almost always come out instantly faster and safer on stages. On the other hand, people who go out and practise the same 'bad habits' rarely get better, and quickly become harder to teach different approaches to.

None of which has anything to do with gearing ratios... which I think everyone knows are one of the first things you want to optimize in a car to make it work really, really well - if your class allows it. (Good suspenders MIGHT be the first thing... imho)
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Robert Culbertson
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Re: Philosophy of Gearing
July 12, 2017 03:02PM
Quote
Not Trolling
... which I think everyone knows are one of the first things you want to optimize in a car to make it work really, really well - if your class allows it. (Good suspenders MIGHT be the first thing... imho)

Tires, suspension, and schooling/learning proper car control and lines. Not particularly in that order, but all 3 are very important.... probably more so than gearing.
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