6spd conversion?
10-17-2005, 04:20 PM
#61
Rennlist Member
you agree with the first statement, but have a problem with the second?
So, again, you loose 5th gear, and get this .5 (i rounded, its more like 1.37x)version of 1st gear, but make no mistake, the rest of the gears are not effected. 2nd doesnt act like 1st gear, IT IS the new 1st gear. 3rd is now 2nd, 4th is now 3rd and 5th is now 4th and you then dont have a 5th. see how this works? you are getting caught up in the gear names not the numerical ratios. trust me, your car doesnt know if a 8:1 over all ratio for 2nd is called 1st, 2nd or 3rd. its a final gear ratio. Also, the main point is that for our cars and many like ours, the spacing doesnt change as they are pretty close from 1st to 5th. close ratio gear boxes are different, and for 1984 928S boxes with the 2.2:1 , this radical rear end change hurts in a big way if you need to get in to the "new" 4th, due to the old 5th being 50% lower (or 2:1 change)
so, in summary, 0-100 is only effected by the .5 of 1st gear added and 5th removed. the rest of the gears are exactly like 1st through the old 3rd. (assuming a 0-120mph range of operation) to be more clear, 0-20mph or something is improved by the 2.73/3.73 or about 40% advantage in the new 1st, but all other gears would be identical , meaning from 20mph to 118mph, all the ratios used would be the same. this helps launch, but not much else. (which is a huge deal in drag racing)
mk
So, again, you loose 5th gear, and get this .5 (i rounded, its more like 1.37x)version of 1st gear, but make no mistake, the rest of the gears are not effected. 2nd doesnt act like 1st gear, IT IS the new 1st gear. 3rd is now 2nd, 4th is now 3rd and 5th is now 4th and you then dont have a 5th. see how this works? you are getting caught up in the gear names not the numerical ratios. trust me, your car doesnt know if a 8:1 over all ratio for 2nd is called 1st, 2nd or 3rd. its a final gear ratio. Also, the main point is that for our cars and many like ours, the spacing doesnt change as they are pretty close from 1st to 5th. close ratio gear boxes are different, and for 1984 928S boxes with the 2.2:1 , this radical rear end change hurts in a big way if you need to get in to the "new" 4th, due to the old 5th being 50% lower (or 2:1 change)
so, in summary, 0-100 is only effected by the .5 of 1st gear added and 5th removed. the rest of the gears are exactly like 1st through the old 3rd. (assuming a 0-120mph range of operation) to be more clear, 0-20mph or something is improved by the 2.73/3.73 or about 40% advantage in the new 1st, but all other gears would be identical , meaning from 20mph to 118mph, all the ratios used would be the same. this helps launch, but not much else. (which is a huge deal in drag racing)
mk
Originally Posted by m21sniper
"So, as i said, you now have a .5 of 1st gear, then your 2-5th all become exactly the same as 1st through 4th. (and you loose 5th)"
Precisely.
"so, not really very much is changed, except in drag racing, you could have a much better launch, but everything after that would be identical."
Well a lot is changed, 2d now acts as 1st did, and 3d is as 2d was, etc.
So at any speed up to about 100mph you're going to get much harder acceleration gear for gear(ie 2d in the 3.73 car vs 2d in the 2.73 car). It doesn't just work for first, but for all the gears.
Of course all that wonderful acceleration comes at the cost of a lot of top end, but drag racers dont really care about that sort of thing.
Getting to redline in top gear by the end of the 1/4 is all that matters.
Precisely.
"so, not really very much is changed, except in drag racing, you could have a much better launch, but everything after that would be identical."
Well a lot is changed, 2d now acts as 1st did, and 3d is as 2d was, etc.
So at any speed up to about 100mph you're going to get much harder acceleration gear for gear(ie 2d in the 3.73 car vs 2d in the 2.73 car). It doesn't just work for first, but for all the gears.
Of course all that wonderful acceleration comes at the cost of a lot of top end, but drag racers dont really care about that sort of thing.
Getting to redline in top gear by the end of the 1/4 is all that matters.
10-17-2005, 04:42 PM
#62
Originally Posted by mark kibort
you agree with the first statement, but have a problem with the second?
So, again, you loose 5th gear, and get this .5 (i rounded, its more like 1.37x)version of 1st gear, but make no mistake, the rest of the gears are not effected. 2nd doesnt act like 1st gear, IT IS the new 1st gear. 3rd is now 2nd, 4th is now 3rd and 5th is now 4th and you then dont have a 5th. see how this works? you are getting caught up in the gear names not the numerical ratios. trust me, your car doesnt know if a 8:1 over all ratio for 2nd is called 1st, 2nd or 3rd. its a final gear ratio. Also, the main point is that for our cars and many like ours, the spacing doesnt change as they are pretty close from 1st to 5th. close ratio gear boxes are different, and for 1984 928S boxes with the 2.2:1 , this radical rear end change hurts in a big way if you need to get in to the "new" 4th, due to the old 5th being 50% lower (or 2:1 change)
so, in summary, 0-100 is only effected by the .5 of 1st gear added and 5th removed. the rest of the gears are exactly like 1st through the old 3rd. (assuming a 0-120mph range of operation) to be more clear, 0-20mph or something is improved by the 2.73/3.73 or about 40% advantage in the new 1st, but all other gears would be identical , meaning from 20mph to 118mph, all the ratios used would be the same. this helps launch, but not much else. (which is a huge deal in drag racing)
mk
So, again, you loose 5th gear, and get this .5 (i rounded, its more like 1.37x)version of 1st gear, but make no mistake, the rest of the gears are not effected. 2nd doesnt act like 1st gear, IT IS the new 1st gear. 3rd is now 2nd, 4th is now 3rd and 5th is now 4th and you then dont have a 5th. see how this works? you are getting caught up in the gear names not the numerical ratios. trust me, your car doesnt know if a 8:1 over all ratio for 2nd is called 1st, 2nd or 3rd. its a final gear ratio. Also, the main point is that for our cars and many like ours, the spacing doesnt change as they are pretty close from 1st to 5th. close ratio gear boxes are different, and for 1984 928S boxes with the 2.2:1 , this radical rear end change hurts in a big way if you need to get in to the "new" 4th, due to the old 5th being 50% lower (or 2:1 change)
so, in summary, 0-100 is only effected by the .5 of 1st gear added and 5th removed. the rest of the gears are exactly like 1st through the old 3rd. (assuming a 0-120mph range of operation) to be more clear, 0-20mph or something is improved by the 2.73/3.73 or about 40% advantage in the new 1st, but all other gears would be identical , meaning from 20mph to 118mph, all the ratios used would be the same. this helps launch, but not much else. (which is a huge deal in drag racing)
mk
You are a very hard man to agree with mark...cause i'm never really sure what you're saying....LOL.
The only thing im even disagreeing with is, 'it helps launch but not much else'.
It helps the average acceleration through the whole run because the final drive is a full 1 point lower, and because you don't 'leave' part of your useful engine power unused at the end of the run.
10-17-2005, 10:48 PM
#63
Burning Brakes
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on the street and on street tires, i think if you raced to any distance beyond what could be reached in 1st gear on the 3.73, the 2.73 would win. i don't think you're gonna get off the line that much better with a 3.73 and shifting from ".5" gear to first is gonna light em up and waste more time than just skipping that shift with a 2.73 first gear.
10-18-2005, 01:14 PM
#64
Rennlist Member
Finally, someone gets it!!! thats the answer for almost all the discussions we have had about gearing. Dont know what is so confusing about the concepts. (i guess its kind of like the hp torque discussion) its simple, but complicated at the same time!)
MK
MK
Originally Posted by jyoon
on the street and on street tires, i think if you raced to any distance beyond what could be reached in 1st gear on the 3.73, the 2.73 would win. i don't think you're gonna get off the line that much better with a 3.73 and shifting from ".5" gear to first is gonna light em up and waste more time than just skipping that shift with a 2.73 first gear.
10-18-2005, 01:27 PM
#65
Originally Posted by jyoon
on the street and on street tires, i think if you raced to any distance beyond what could be reached in 1st gear on the 3.73, the 2.73 would win. i don't think you're gonna get off the line that much better with a 3.73 and shifting from ".5" gear to first is gonna light em up and waste more time than just skipping that shift with a 2.73 first gear.
Rest assured that the typical muscle car running ladder bar suspension and running cheater slicks will greatly benefit from a gearing change, and no, it will not all be wasted in tire smoke.
One trip to the drag strip and a chat with all the guys running sub 13 seconds will confirm the usefulness of a gearing change. It's one thing to say, 'i dont think x will work', it's quite another to go to the strip and see X work in car after car week after week.
Last edited by m21sniper; 10-18-2005 at 02:03 PM.
10-18-2005, 02:29 PM
#66
Burning Brakes
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there comes a point where the gearing is too low and it's no longer useful. if you shift too much, it wastes time and doesn't help. take for example a viper. assume it can hit 60 mph in first gear. then you get a viper and gear it down so low it hits 60 in 6th gear. then we race them to 60. i'd bet about anything i own, the one that starts in 1st and hits 60 in first will beat the one shifting through all 6 gears.
10-18-2005, 02:44 PM
#67
Originally Posted by jyoon
there comes a point where the gearing is too low and it's no longer useful. if you shift too much, it wastes time and doesn't help. take for example a viper. assume it can hit 60 mph in first gear. then you get a viper and gear it down so low it hits 60 in 6th gear. then we race them to 60. i'd bet about anything i own, the one that starts in 1st and hits 60 in first will beat the one shifting through all 6 gears.
In drag racing circles the A/T turns the tables on the manual, and the faster your car is, the greater the advantadge the A/T offers.
10-18-2005, 02:44 PM
#68
Drifting
ideally you would tune the transmission to be somewhere between peak horsepower and redline in top gear at your desired top speed, 1st gear would be towhere you could just barely chirp the tires with full throttle off the line. The rest of the gears would be spaced at an interval to keep you in the best powerband.
10-18-2005, 03:27 PM
#69
Rennlist Member
again, someone else that understands almost perfectly!
however, there are some areas of wheel spin and launch that the drag guys understand that are a little out of my relm of understanding. if you watch the 300mph passes, there is a lot of wheel spin and its by design. However, you get the main point.
MK
however, there are some areas of wheel spin and launch that the drag guys understand that are a little out of my relm of understanding. if you watch the 300mph passes, there is a lot of wheel spin and its by design. However, you get the main point.
MK
Originally Posted by patrat
ideally you would tune the transmission to be somewhere between peak horsepower and redline in top gear at your desired top speed, 1st gear would be towhere you could just barely chirp the tires with full throttle off the line. The rest of the gears would be spaced at an interval to keep you in the best powerband.
10-18-2005, 03:40 PM
#70
Rennlist Member
its not that hard to understand. Just look at the resultant ratios of the 3.09 vs the 2.2 discussion. (very close to the the 3.73 vs 2.73 change we are talking about)
S4 1st through 5th TOTAL RESULTANT Ratio to the wheels.
8.9
5.9
4.24
3.2
2.2
agreed?
S4 with a change of rear end to 3.09
RESULTANT RATIOS to the wheels:
12.4 (.5 1st as i call it)
8.3 new 1st
5.9 new 2nd
4.5 new 3rd
3.09 new 4th
you Actually get a S4 with a very low 1st and all the gears up to 4th pretty close to the same. you then loose 5th. not much has changed except 1st and all the other usable gears up to redline in 4th are left in tact.
as far as drag racing, you would hit the new 3rd, which is close to the old 3rd and wind out to 118mph same as before, and having the same rates of acceleration along the way (except 1st )
Is this not clear now???
Let me know
MK
see what happed?????? is it clear??
1st is changed now much lower by 40%
NOTE this is also the basis for my GTS 3.09 discussion as that change just creates an S4 gear box, sans 5th gear as well.
GT with 3.09 makes:
11.6 (new 1st)
7.76 (taller than S4 1st)
5.53 (same as S4 2nd)
4.17 (same as S4 3rd)
3.09. same as S4 4th)
Look at an S4 gearing above. you get a 7% lower 1-2 combination average then 3rd, and 4th remain the same. both topping out at near 3.09 :1. (3.2:1 for the S4)
its all about the ratios, and their closeness, not about the name designators
S4 1st through 5th TOTAL RESULTANT Ratio to the wheels.
8.9
5.9
4.24
3.2
2.2
agreed?
S4 with a change of rear end to 3.09
RESULTANT RATIOS to the wheels:
12.4 (.5 1st as i call it)
8.3 new 1st
5.9 new 2nd
4.5 new 3rd
3.09 new 4th
you Actually get a S4 with a very low 1st and all the gears up to 4th pretty close to the same. you then loose 5th. not much has changed except 1st and all the other usable gears up to redline in 4th are left in tact.
as far as drag racing, you would hit the new 3rd, which is close to the old 3rd and wind out to 118mph same as before, and having the same rates of acceleration along the way (except 1st )
Is this not clear now???
Let me know
MK
see what happed?????? is it clear??
1st is changed now much lower by 40%
NOTE this is also the basis for my GTS 3.09 discussion as that change just creates an S4 gear box, sans 5th gear as well.
GT with 3.09 makes:
11.6 (new 1st)
7.76 (taller than S4 1st)
5.53 (same as S4 2nd)
4.17 (same as S4 3rd)
3.09. same as S4 4th)
Look at an S4 gearing above. you get a 7% lower 1-2 combination average then 3rd, and 4th remain the same. both topping out at near 3.09 :1. (3.2:1 for the S4)
its all about the ratios, and their closeness, not about the name designators
Originally Posted by m21sniper
LOL, that's what i said.
You are a very hard man to agree with mark...cause i'm never really sure what you're saying....LOL.
The only thing im even disagreeing with is, 'it helps launch but not much else'.
It helps the average acceleration through the whole run because the final drive is a full 1 point lower, and because you don't 'leave' part of your useful engine power unused at the end of the run.
You are a very hard man to agree with mark...cause i'm never really sure what you're saying....LOL.
The only thing im even disagreeing with is, 'it helps launch but not much else'.
It helps the average acceleration through the whole run because the final drive is a full 1 point lower, and because you don't 'leave' part of your useful engine power unused at the end of the run.
10-18-2005, 03:44 PM
#71
Rennlist Member
good points. also, keep in mind that since you are not changing the spacing of gears a 6 speed viper would be 4 gears that would be 1st,and then 2 gears you would use to 60mph. for the bulk of the 0-60 pass, the gearing would be the same, however you would have 4 gears to get out of from 0-5mph,5-10, 10-20mph and then you would get into the 2 gears used to reach 60mph. (exageration , but you get the point)
mk
mk
Originally Posted by jyoon
there comes a point where the gearing is too low and it's no longer useful. if you shift too much, it wastes time and doesn't help. take for example a viper. assume it can hit 60 mph in first gear. then you get a viper and gear it down so low it hits 60 in 6th gear. then we race them to 60. i'd bet about anything i own, the one that starts in 1st and hits 60 in first will beat the one shifting through all 6 gears.
10-18-2005, 04:25 PM
#72
Road Warrior
Rennlist Member
Rennlist Member
fwiw, IMO the way to get better starts on the AT cars is to simply raise the stall on the torque converter... on my 85S w/AT, I noticed a HUGE performance gain off the line by simply shifting the stall from the 1600rpm factory setting to about 2150rpm.... puts the car in the power band as it's starting to engage (like reving more on a manual), and whoosh!! rapid starts, flawless shifting and the factory gearing seems quite fine after that....
pretty inexpensive too - only about $275 to change the shims, course it's a PITA to R&R it, but if you're doing trans work anyway.... kinda like adding a lower gear, w/out all the fuss and no top end loss either...
pretty inexpensive too - only about $275 to change the shims, course it's a PITA to R&R it, but if you're doing trans work anyway.... kinda like adding a lower gear, w/out all the fuss and no top end loss either...
10-19-2005, 04:33 PM
#73
"its not that hard to understand. Just look at the resultant ratios of the 3.09 vs the 2.2 discussion. (very close to the the 3.73 vs 2.73 change we are talking about)"
Not comparable. The gearing of the transaxles ends up making the effective ratios almost the same in the 928 with the 2.73 rears, as you've pointed out numerous times.
What we're discussing here is KEEPING the gear set of the 2.20 transaxle and ONLY changing the ring and pinion.
Two totally different things.
"S4 1st through 5th TOTAL RESULTANT Ratio to the wheels.
8.9
5.9
4.24
3.2
2.2
agreed?"
With 3.09(using your adjusted gear ratio numbers):
12.4 1st, approx +30% increase in torque multiplication vs S4 box
8.3 2d, approx +30% vs s4
5.9 3d, approx +20% vs s4
4.5 4th approx +20% vs s4
3.09 5th, approx + approx 30% vs s4
Clearly the S4 box with 3.09 gears installed has a huge advantadge in acceleration for drag racing purposes.
"you Actually get a S4 with a very low 1st and all the gears up to 4th pretty close to the same."
Not even close, as i just showed above.
"you then loose 5th. not much has changed except 1st and all the other usable gears up to redline in 4th are left in tact."
Everything has changed.
"as far as drag racing, you would hit the new 3rd, which is close to the old 3rd and wind out to 118mph same as before, and having the same rates of acceleration along the way (except 1st )"
There's simply NO WAY an S4 with 30% more gearing in 3d will pull to the same speed as a stock s4(our 3d gear is now EXACTLY the same ratio as 2d gear was before- 5.9:1). Whatever the old top speed was in second will now be the new top speed in 3d, though of course we'll ge there MUCH faster).
"Is this not clear now???"
What's clear is that you either don't understand what is going on when ONLY the ring and pinion is changed, or that you're again miscommunicating your point.
"see what happed?????? is it clear??
1st is changed now much lower by 40%"
ALL the gears are now much lower.
"its all about the ratios, and their closeness, not about the name designators"
W R O N G.
It's about the total package.
Not comparable. The gearing of the transaxles ends up making the effective ratios almost the same in the 928 with the 2.73 rears, as you've pointed out numerous times.
What we're discussing here is KEEPING the gear set of the 2.20 transaxle and ONLY changing the ring and pinion.
Two totally different things.
"S4 1st through 5th TOTAL RESULTANT Ratio to the wheels.
8.9
5.9
4.24
3.2
2.2
agreed?"
With 3.09(using your adjusted gear ratio numbers):
12.4 1st, approx +30% increase in torque multiplication vs S4 box
8.3 2d, approx +30% vs s4
5.9 3d, approx +20% vs s4
4.5 4th approx +20% vs s4
3.09 5th, approx + approx 30% vs s4
Clearly the S4 box with 3.09 gears installed has a huge advantadge in acceleration for drag racing purposes.
"you Actually get a S4 with a very low 1st and all the gears up to 4th pretty close to the same."
Not even close, as i just showed above.
"you then loose 5th. not much has changed except 1st and all the other usable gears up to redline in 4th are left in tact."
Everything has changed.
"as far as drag racing, you would hit the new 3rd, which is close to the old 3rd and wind out to 118mph same as before, and having the same rates of acceleration along the way (except 1st )"
There's simply NO WAY an S4 with 30% more gearing in 3d will pull to the same speed as a stock s4(our 3d gear is now EXACTLY the same ratio as 2d gear was before- 5.9:1). Whatever the old top speed was in second will now be the new top speed in 3d, though of course we'll ge there MUCH faster).
"Is this not clear now???"
What's clear is that you either don't understand what is going on when ONLY the ring and pinion is changed, or that you're again miscommunicating your point.
"see what happed?????? is it clear??
1st is changed now much lower by 40%"
ALL the gears are now much lower.
"its all about the ratios, and their closeness, not about the name designators"
W R O N G.
It's about the total package.
10-19-2005, 05:32 PM
#74
Rennlist Member
Its very clear you are misuderstanding the concepts or me, or both!
Lets try one more time, but briefly.
1. we are talking about changing the ring an pinion only. S4 gear box with a 2.2 stock ring and pinion vs a 3.09 change and even a reference to a GTS gear box with a 3.09. with the S4, i have made it clear that the ONLY changes are the ring an pinion, proof by the resultant ratios. (e.g. "example" 8.9:1 S4 first gear with a change of a 3.09:1 ring and pinon yeilds a new 1st gear of 12.5:1. MATH: 1.40% x 8.9 = 12.5:1 )
2. PLEASE look at the data above one more time. I clearly lay out the gear ratios. YOU CLEARLY are comparing the numerical designators and this is incorrect and misleading. look at the resultant ratios.
3.
Lets try one more time, but briefly.
1. we are talking about changing the ring an pinion only. S4 gear box with a 2.2 stock ring and pinion vs a 3.09 change and even a reference to a GTS gear box with a 3.09. with the S4, i have made it clear that the ONLY changes are the ring an pinion, proof by the resultant ratios. (e.g. "example" 8.9:1 S4 first gear with a change of a 3.09:1 ring and pinon yeilds a new 1st gear of 12.5:1. MATH: 1.40% x 8.9 = 12.5:1 )
2. PLEASE look at the data above one more time. I clearly lay out the gear ratios. YOU CLEARLY are comparing the numerical designators and this is incorrect and misleading. look at the resultant ratios.
3.
Originally Posted by m21sniper
"its not that hard to understand. Just look at the resultant ratios of the 3.09 vs the 2.2 discussion. (very close to the the 3.73 vs 2.73 change we are talking about)"
Ill insert some comments below. you are fighting this, why??
MK
Not comparable. The gearing of the transaxles ends up making the effective ratios almost the same in the 928 with the 2.73 rears, as you've pointed out numerous times.
What we're discussing here is KEEPING the gear set of the 2.20 transaxle and ONLY changing the ring and pinion.
Two totally different things.
"S4 1st through 5th TOTAL RESULTANT Ratio to the wheels.
8.9
5.9
4.24
3.2
2.2
agreed?"
With 3.09(using your adjusted gear ratio numbers):
12.4 1st, approx +30% increase in torque multiplication vs S4 box
>>>>>>>>>>>>>>>>>>no, 40% increase
8.3 2d, approx +30% vs s4
>>>>>>>>>>>>>>>>> actually .93 of 1st in a stock S4 set up
5.9 3d, approx +20% vs s4
>>>>>>>>>>>>>>>>>>>actually the same as a 2nd in an S4
4.5 4th approx +20% vs s4
>>>>>>>>>>>>>>>>>>>04% vs 3rd gear on a stock S4
3.09 5th, approx + approx 30% vs s4
>>>>>>>>>>>>>>>>>>>>.96 of the stock s4 4th gear
>>>>>>>>>>>>>you are getting way to caught up in the gear ratios "names" (i.e. 1st , 2nd, 3rd, etc) that DOESNT matter. Think about it, if you got all the the gears down to fit into a 60mph range, you still would have 2 gears, .7 apart that would take you from 20 to 40 and then 40 to 60mph, just like 1st and 2nd. however, 3 more gears would be below that buring rubber.
You ahave to look at the entire system here, you are focused on just one component (the gear "names") its all about the ratios. YOU DO NOT gain in all gears, this was the point of the laborious gear ratio thread!!!! gearing doesnt make HP. it only makes more efficient use of the hp over the operational range.
trust me. I teach this on a daily basis at work and use it in racing analysis as well. Its some thing i truely understand. Sorry, if im not making it clear enough for you .
Clearly the S4 box with 3.09 gears installed has a huge advantadge in acceleration for drag racing purposes.
>>>>>>>>no, only in 1st gear, which could be a big factorfor launch. but every gear after the "new and improved 3.09 :1 1st gear" would not be effected ,as reported above.
"you Actually get a S4 with a very low 1st and all the gears up to 4th pretty close to the same."
Not even close, as i just showed above.
>>>>>>>>>>>>>>>>>>>you showed nothing, other than you are hung up with the ratio names, not the actual mechanical reductions
"you then loose 5th. not much has changed except 1st and all the other usable gears up to redline in 4th are left in tact."
Everything has changed.
>>>>>>>>>>>>>>>>>>>NO NO NO.only 1st gear has changed, the other ratios are close to the same, but you loose 5th gear and 4th will have a greater spacing with an S4 box vs a GTS with equal spacing all along. BUT we are talking about 0-120mph, so 1-4th gear with the new box with 3.09 and 1-3rd with the stock S4 box. this is the best description. Now, look at the actual ratios of both. one uses 4 gears with this lower 1st we talk about, the other uses 3 gears. those 3 gears are almost identical to the 4 gears used in the 3.09 change.
"as far as drag racing, you would hit the new 3rd, which is close to the old 3rd and wind out to 118mph same as before, and having the same rates of acceleration along the way (except 1st )"
There's simply NO WAY an S4 with 30% more gearing in 3d will pull to the same speed as a stock s4(our 3d gear is now EXACTLY the same ratio as 2d gear was before- 5.9:1). Whatever the old top speed was in second will now be the new top speed in 3d, though of course we'll ge there MUCH faster).
>>>>>>>>>>>>>>>>>>>.you are missing the key point. the ratios are the same. remember, im callng the gear the "new 3rd" . the new third and the old third would have the same 4.5:1 ratio., as would 2nd and 1st.
this is why you would have only a 1st gear change with the big advantage out of the hole, but the other gears and better said, ratios would be near identical and have the same accelerative forces.
"Is this not clear now???"
What's clear is that you either don't understand what is going on when ONLY the ring and pinion is changed, or that you're again miscommunicating your point.
>>>>>>>>>>>>>>>>>>>>>>this is clear. do you understand now, because i certainly do, but i still must be missing the mark with you if you dont agree now!
"see what happed?????? is it clear??
1st is changed now much lower by 40%"
ALL the gears are now much lower.
"its all about the ratios, and their closeness, not about the name designators"
W R O N G.
>>>>>>thats a bold statement with little or nothing to back it up
It's about the total package.
>>>>>>>yes, it its, but look at the ratios and get back to me
>>>>>>you cant look at the ratios gear for gear, because that is not what is happening to the car at the speeds through the drag race. the engine through the gears applies torque to the wheels (ie HP) over its operational range. the engine doesnt change, it doesnt know what gear its it, nor does the wheels, what is known is the ratio that the wheels get their torque through. if the ratio is the same, regardless of the gear designator, the car will accelerate the same. In a drag race, the 3.09 has a 40% advantage (actually less based on redline and lower torque in the curve) in 1st, to a 71% slower speed than a stock S4. after that, both cars at any speed will have the same ratios and acceleration rates. sure, if the 3.09 car can keep traction, it will have a sizable lead after 39mph. however, after both cars reach 39mph, they will both have the exact same gear ratios to 118mph. (just that the 3.09 car ran trough an extra gear out of the shoot!) Get it now????
let me know!!
Mk
Ill insert some comments below. you are fighting this, why??
MK
Not comparable. The gearing of the transaxles ends up making the effective ratios almost the same in the 928 with the 2.73 rears, as you've pointed out numerous times.
What we're discussing here is KEEPING the gear set of the 2.20 transaxle and ONLY changing the ring and pinion.
Two totally different things.
"S4 1st through 5th TOTAL RESULTANT Ratio to the wheels.
8.9
5.9
4.24
3.2
2.2
agreed?"
With 3.09(using your adjusted gear ratio numbers):
12.4 1st, approx +30% increase in torque multiplication vs S4 box
>>>>>>>>>>>>>>>>>>no, 40% increase
8.3 2d, approx +30% vs s4
>>>>>>>>>>>>>>>>> actually .93 of 1st in a stock S4 set up
5.9 3d, approx +20% vs s4
>>>>>>>>>>>>>>>>>>>actually the same as a 2nd in an S4
4.5 4th approx +20% vs s4
>>>>>>>>>>>>>>>>>>>04% vs 3rd gear on a stock S4
3.09 5th, approx + approx 30% vs s4
>>>>>>>>>>>>>>>>>>>>.96 of the stock s4 4th gear
>>>>>>>>>>>>>you are getting way to caught up in the gear ratios "names" (i.e. 1st , 2nd, 3rd, etc) that DOESNT matter. Think about it, if you got all the the gears down to fit into a 60mph range, you still would have 2 gears, .7 apart that would take you from 20 to 40 and then 40 to 60mph, just like 1st and 2nd. however, 3 more gears would be below that buring rubber.
You ahave to look at the entire system here, you are focused on just one component (the gear "names") its all about the ratios. YOU DO NOT gain in all gears, this was the point of the laborious gear ratio thread!!!! gearing doesnt make HP. it only makes more efficient use of the hp over the operational range.
trust me. I teach this on a daily basis at work and use it in racing analysis as well. Its some thing i truely understand. Sorry, if im not making it clear enough for you .
Clearly the S4 box with 3.09 gears installed has a huge advantadge in acceleration for drag racing purposes.
>>>>>>>>no, only in 1st gear, which could be a big factorfor launch. but every gear after the "new and improved 3.09 :1 1st gear" would not be effected ,as reported above.
"you Actually get a S4 with a very low 1st and all the gears up to 4th pretty close to the same."
Not even close, as i just showed above.
>>>>>>>>>>>>>>>>>>>you showed nothing, other than you are hung up with the ratio names, not the actual mechanical reductions
"you then loose 5th. not much has changed except 1st and all the other usable gears up to redline in 4th are left in tact."
Everything has changed.
>>>>>>>>>>>>>>>>>>>NO NO NO.only 1st gear has changed, the other ratios are close to the same, but you loose 5th gear and 4th will have a greater spacing with an S4 box vs a GTS with equal spacing all along. BUT we are talking about 0-120mph, so 1-4th gear with the new box with 3.09 and 1-3rd with the stock S4 box. this is the best description. Now, look at the actual ratios of both. one uses 4 gears with this lower 1st we talk about, the other uses 3 gears. those 3 gears are almost identical to the 4 gears used in the 3.09 change.
"as far as drag racing, you would hit the new 3rd, which is close to the old 3rd and wind out to 118mph same as before, and having the same rates of acceleration along the way (except 1st )"
There's simply NO WAY an S4 with 30% more gearing in 3d will pull to the same speed as a stock s4(our 3d gear is now EXACTLY the same ratio as 2d gear was before- 5.9:1). Whatever the old top speed was in second will now be the new top speed in 3d, though of course we'll ge there MUCH faster).
>>>>>>>>>>>>>>>>>>>.you are missing the key point. the ratios are the same. remember, im callng the gear the "new 3rd" . the new third and the old third would have the same 4.5:1 ratio., as would 2nd and 1st.
this is why you would have only a 1st gear change with the big advantage out of the hole, but the other gears and better said, ratios would be near identical and have the same accelerative forces.
"Is this not clear now???"
What's clear is that you either don't understand what is going on when ONLY the ring and pinion is changed, or that you're again miscommunicating your point.
>>>>>>>>>>>>>>>>>>>>>>this is clear. do you understand now, because i certainly do, but i still must be missing the mark with you if you dont agree now!
"see what happed?????? is it clear??
1st is changed now much lower by 40%"
ALL the gears are now much lower.
"its all about the ratios, and their closeness, not about the name designators"
W R O N G.
>>>>>>thats a bold statement with little or nothing to back it up
It's about the total package.
>>>>>>>yes, it its, but look at the ratios and get back to me
>>>>>>you cant look at the ratios gear for gear, because that is not what is happening to the car at the speeds through the drag race. the engine through the gears applies torque to the wheels (ie HP) over its operational range. the engine doesnt change, it doesnt know what gear its it, nor does the wheels, what is known is the ratio that the wheels get their torque through. if the ratio is the same, regardless of the gear designator, the car will accelerate the same. In a drag race, the 3.09 has a 40% advantage (actually less based on redline and lower torque in the curve) in 1st, to a 71% slower speed than a stock S4. after that, both cars at any speed will have the same ratios and acceleration rates. sure, if the 3.09 car can keep traction, it will have a sizable lead after 39mph. however, after both cars reach 39mph, they will both have the exact same gear ratios to 118mph. (just that the 3.09 car ran trough an extra gear out of the shoot!) Get it now????
let me know!!
Mk
10-19-2005, 06:12 PM
#75
No, im not misunderstanding what's at play here at all.
Look at the two trannies, first a stock S4, then an S4 with a 3.08 rear:
S4 w/2.20 ring and pinion:
8.9
5.9
4.24
3.2
2.2
S4 w/3.08 ring and pinion:
12.4 1st
8.3 2d
5.9 3d
4.5 4th
3.09 5th
(again using your figures for both units).
What is eminently clear about the two above sets of gear ratios is that the s4 trans w/3.08 ring and pinion offers much greater torque multiplication in ALL gears.
Gear for gear, the S4 with the 3.08 ring and pinion WILL accelerate faster to 100mph than the one with the 2.20 will, and by a very wide margin.
This is the reasoning behind NASCAR teams installing as low as a 4.88 ring and pinion set for short ovals, and as high as 2.56 ring and pinion set for the superspeedways.
One gets you blinding acceleration, but at relatively low top speeds, the other gets you massive top end at the cost of acceleration(note that it takes a 'nextel' cup car a full 2.5 mile lap at talladega to get back up to speed).
If you change your ring and pinion to a lower ratio, all other things being equal(including traction), the car with the lower ring and pinion WILL accelerate faster in ALL gears.
Look at the two trannies, first a stock S4, then an S4 with a 3.08 rear:
S4 w/2.20 ring and pinion:
8.9
5.9
4.24
3.2
2.2
S4 w/3.08 ring and pinion:
12.4 1st
8.3 2d
5.9 3d
4.5 4th
3.09 5th
(again using your figures for both units).
What is eminently clear about the two above sets of gear ratios is that the s4 trans w/3.08 ring and pinion offers much greater torque multiplication in ALL gears.
Gear for gear, the S4 with the 3.08 ring and pinion WILL accelerate faster to 100mph than the one with the 2.20 will, and by a very wide margin.
This is the reasoning behind NASCAR teams installing as low as a 4.88 ring and pinion set for short ovals, and as high as 2.56 ring and pinion set for the superspeedways.
One gets you blinding acceleration, but at relatively low top speeds, the other gets you massive top end at the cost of acceleration(note that it takes a 'nextel' cup car a full 2.5 mile lap at talladega to get back up to speed).
If you change your ring and pinion to a lower ratio, all other things being equal(including traction), the car with the lower ring and pinion WILL accelerate faster in ALL gears.