3,90, 4.10, 4.33 - really that much difference?
#26
I'm a boost creep...
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Originally posted by dag
No, these are not hard to find, you call mazdatrix and they send them.
No, these are not hard to find, you call mazdatrix and they send them.
I don't find $400 (slightly more with tax and shipping) to be a whole hell of a lot for a nice performance upgrade
Dude, this takes less than a day if you're even remotely competent.
People always tend to think that if their turbocharged car isn't as fast as they would like it then they can either just up the boost or swap to a larger turbo but it isn't that simple.
Flame away if you so choose.
Originally posted by sillbeer
Me personally I would jump all over a 4.30 gear.
Me personally I would jump all over a 4.30 gear.
#27
don't spend 400 bucks on 4.30 spend the 400 on 4.60 gears.
if you have 2 300 rwhp cars and they are running in a straight line the guy with the lower gears is going to win ever time in a drag race. A guy around here in Northern VA races 3rd gens and he runs 4.60 in all of his street cars and also his drag car that hit 9 seconds.
if you have 2 300 rwhp cars and they are running in a straight line the guy with the lower gears is going to win ever time in a drag race. A guy around here in Northern VA races 3rd gens and he runs 4.60 in all of his street cars and also his drag car that hit 9 seconds.
#28
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Actually NZ I've found that it isn't always that simple. You start throwing huge turbos and more boost at your car then you'll have a car that: A. Isn't fun to drive around on the street. and B. will get it's *** handed to it by a crx on a canyon road or a very tight road course.
-David Guy
-David Guy
#29
Originally posted by dag
Actually NZ I've found that it isn't always that simple. You start throwing huge turbos and more boost at your car then you'll have a car that: A. Isn't fun to drive around on the street. and B. will get it's *** handed to it by a crx on a canyon road or a very tight road course.
-David Guy
Actually NZ I've found that it isn't always that simple. You start throwing huge turbos and more boost at your car then you'll have a car that: A. Isn't fun to drive around on the street. and B. will get it's *** handed to it by a crx on a canyon road or a very tight road course.
-David Guy
#30
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It doesn't decrease handling, however it will tweak your powerband to a point that it becomes unwieldy. Just look at Mani and his Supra, he steps down to a smaller turbo, putting down ~450 horses and steps up to a higher final drive whenever he road races. I use this example mainly due to the fact that most high horsepower supras tend to have a horrible dyno plot/torque area and very high peak numbers, I am not comparing an rx7 to a supra.
-David Guy
-David Guy
#33
Werd. Its not always helpful for traction limited cars. But your car will be trying to accelerate faster. But once you get going, you better watch out.
See I personally don't like setting a car up for drag racing. Wide soft-sidewall tires, heavy flywheels, and soft suspension setups are not things that make cars fun to drive. Its hard as hell to launch a Carrera GT, but do you think Porsche cares that the car could get better 60' times?
See I personally don't like setting a car up for drag racing. Wide soft-sidewall tires, heavy flywheels, and soft suspension setups are not things that make cars fun to drive. Its hard as hell to launch a Carrera GT, but do you think Porsche cares that the car could get better 60' times?
#34
kill it with BOOMSTICK!
The difference between a 4.10 and a 4.30 would actually be very noticable, being that with that setup, a stock s5 N/A could probably give a s5 TII a run for its money in 0-60 times. Just for all you kids, thats a 40 HP handicap that is overcome by sheer gearing ratios, that and the N/A powerband is longer then the TII's, so that would give a slight advantage.
Personally, I would want a 4.30 in my rear end for around town and racing, but a 4.10 or 3.90 for highway (or the occasional "testing" of the local radar speed boxes)
Personally, I would want a 4.30 in my rear end for around town and racing, but a 4.10 or 3.90 for highway (or the occasional "testing" of the local radar speed boxes)
#35
Originally posted by Terrh
I don't see how (once your car makes power) gearing can change 1/4 mile times at all...
if my car makes enough power to be able to not get traction at all in 1st (and 2nd on demand), how is MORE torque to the ground going to help me?
I don't see how (once your car makes power) gearing can change 1/4 mile times at all...
if my car makes enough power to be able to not get traction at all in 1st (and 2nd on demand), how is MORE torque to the ground going to help me?
#37
i'll blow YOUR valve off
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dude the main problem with all this is you just spin your gears that much worse. You have to be a master of hte launch before you even THINK about that. I've lost to 200 HP hondas with a 400 RWHP car because of that before.
#38
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There's so much misinformation here it's sad...
My GTUs gets 25-31mpg (varies on which type of gas I put in) freeway driving at 80mph (4k rpm), this is definatly not far off from my 4.1 '87 sport (26-29), at 80mph. As far as acceleration, my GTUs accelerates dead even with the 4.1's, the only gear I ever can pull on anyone is 3rd, and even that has it's limits. The difference is NOT noticable at all. I've driven in countless different FC's with all sorts of gearing, and the only real noticable difference was going from 3.9 to 4.3, or similar.
My GTUs gets 25-31mpg (varies on which type of gas I put in) freeway driving at 80mph (4k rpm), this is definatly not far off from my 4.1 '87 sport (26-29), at 80mph. As far as acceleration, my GTUs accelerates dead even with the 4.1's, the only gear I ever can pull on anyone is 3rd, and even that has it's limits. The difference is NOT noticable at all. I've driven in countless different FC's with all sorts of gearing, and the only real noticable difference was going from 3.9 to 4.3, or similar.
#39
Is that thing Turbo?
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Well I have to say I deffinetly notice the 390 to 410 difference in 3rd gear. This seems so wierd that some people have a hard time understanding it. If you are goin all out drag and don't care about gas mileage or top speed (Only a concern for those of you whose cars hit there top speed at redline) then get the smallest(largest Number) gears you can find. Many dage muscle cars use from 5.0 and up. I thing sonicrat and NZ convertible have this topic coverd tho
#40
I'm awesome!
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Originally posted by dag
I'm sorry NZ, but you're wrong and this is why:
No, these are not hard to find, you call mazdatrix and they send them.
Ok, I don't find $400 (slightly more with tax and shipping) to be a whole hell of a lot for a nice performance upgrade
Dude, this takes less than a day if you're even remotely competent.
Um, ~350 rpm difference at cruise in the 80 mph range isn't a whole hell of a lot more fuel consumption, believe me, I know. And noise? Please. Again ~350 rpm is minor.
This is going to be a constant 5% multiplier to your power, if you up your power guess what? You'll still have a 5% increase, it's not static.
I think I've laid it all out, and to me thiss is a very significant modification. People always tend to think that if their turbocharged car isn't as fast as they would like it then they can either just up the boost or swap to a larger turbo but it isn't that simple. Look at dyno queens compared to roadrace beasts, dyno queens have one goal, make a shitton of power and have bragging rights, do they need ninja gear ratios? No. Do to they require correct sizing on wheels/tires? No. Do they need to be as light weight as possible? No. Do they even need suspension modifictions? No.
I guess my point is that many of these modifications are dismissed far too quickly due to the fact that our cars can make power very easily, and many members tend not to realize that you must take the whole picture into account, as well as a very very tight wallet which kills any sort of significant driveline modification. for example you see a fair amount of interest in creating a 9000+ rpm redline on roadrace cars, however how many peoplehave asked about running diff coolers for their rides? Not a whole hell of a lot.
This ends my (hopefully) informative little rant. Flame away if you so choose.
-David Guy
I'm sorry NZ, but you're wrong and this is why:
No, these are not hard to find, you call mazdatrix and they send them.
Ok, I don't find $400 (slightly more with tax and shipping) to be a whole hell of a lot for a nice performance upgrade
Dude, this takes less than a day if you're even remotely competent.
Um, ~350 rpm difference at cruise in the 80 mph range isn't a whole hell of a lot more fuel consumption, believe me, I know. And noise? Please. Again ~350 rpm is minor.
This is going to be a constant 5% multiplier to your power, if you up your power guess what? You'll still have a 5% increase, it's not static.
I think I've laid it all out, and to me thiss is a very significant modification. People always tend to think that if their turbocharged car isn't as fast as they would like it then they can either just up the boost or swap to a larger turbo but it isn't that simple. Look at dyno queens compared to roadrace beasts, dyno queens have one goal, make a shitton of power and have bragging rights, do they need ninja gear ratios? No. Do to they require correct sizing on wheels/tires? No. Do they need to be as light weight as possible? No. Do they even need suspension modifictions? No.
I guess my point is that many of these modifications are dismissed far too quickly due to the fact that our cars can make power very easily, and many members tend not to realize that you must take the whole picture into account, as well as a very very tight wallet which kills any sort of significant driveline modification. for example you see a fair amount of interest in creating a 9000+ rpm redline on roadrace cars, however how many peoplehave asked about running diff coolers for their rides? Not a whole hell of a lot.
This ends my (hopefully) informative little rant. Flame away if you so choose.
-David Guy
#41
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For the record, taller gears will give a turbo motor more load which will help spool.
Taller ratios would let the turbo do the work by using torque for a longer period of time.
Taller ratios would let the turbo do the work by using torque for a longer period of time.
#43
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Originally posted by $150FC
For the record, taller gears will give a turbo motor more load which will help spool.
Taller ratios would let the turbo do the work by using torque for a longer period of time.
For the record, taller gears will give a turbo motor more load which will help spool.
Taller ratios would let the turbo do the work by using torque for a longer period of time.
-David Guy
#44
I'm a boost creep...
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Originally posted by dag
Actually NZ I've found that it isn't always that simple. You start throwing huge turbos and more boost at your car then you'll have a car that: A. Isn't fun to drive around on the street. and B. will get it's *** handed to it by a crx on a canyon road or a very tight road course.
Actually NZ I've found that it isn't always that simple. You start throwing huge turbos and more boost at your car then you'll have a car that: A. Isn't fun to drive around on the street. and B. will get it's *** handed to it by a crx on a canyon road or a very tight road course.
And simply increasing the boost with your existing turbo will have absolutely zero negative effect on drivability or turbo lag. Quite the opposite in fact.
#45
Originally posted by powrdby13B
I've lost to 200 HP hondas with a 400 RWHP car because of that before.
I've lost to 200 HP hondas with a 400 RWHP car because of that before.
-Joe
#46
OK, next project...
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I am going from 3.9 to 4.3 in my vert this week. I'll let everyone know what my butt thinks about it when I get it done.
BTW, it has always been my understanding, and the formula posted bears this out, that the torque produced at the flywheel gets multiplied through the gears, so not only does the 4.3 provide more actual torque to the ground, it helps the most in the lower gears where the ratio is the shortest, and low end/ low speed torque is what the rotary needs the most help with.
I'm planning on staying NA and 5-10% means alot to me.
BTW, it has always been my understanding, and the formula posted bears this out, that the torque produced at the flywheel gets multiplied through the gears, so not only does the 4.3 provide more actual torque to the ground, it helps the most in the lower gears where the ratio is the shortest, and low end/ low speed torque is what the rotary needs the most help with.
I'm planning on staying NA and 5-10% means alot to me.
#48
"For the record, taller gears will give a turbo motor more load which will help spool.
Taller ratios would let the turbo do the work by using torque for a longer period of time."
150FC wins with this comment. Lower gears are always better for racing. You just have to come to a point where you figure out if your car is a daily driver/highway long distance runner or a street/weekend racer.
You can't have the best of both worlds. If you want to best of both worlds buy a Jap street bike
Taller ratios would let the turbo do the work by using torque for a longer period of time."
150FC wins with this comment. Lower gears are always better for racing. You just have to come to a point where you figure out if your car is a daily driver/highway long distance runner or a street/weekend racer.
You can't have the best of both worlds. If you want to best of both worlds buy a Jap street bike
#49
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What About Tire Size?
Nobody mentions putting smaller tires on the back, ie. going from 205/60 15's to 205 50 15's. That shortens the wheel diameter by like 1". Isn't that pretty much the same effect as putting in lower rear gears?
200 ft-lb at engine * 3.475 = 695 ft-lb at the driveshaft
695 ft-lb *4.1 = 2849.5 ft-lb at the half-shafts
or
695 ft-lb *4.3 = 2988.5 ft-lb at the half-shafts
139 ft-lb gain at the wheel by switching from 4.1 to 4.3 rear gears.
Force at tire contact patch:
Torque = Force * Distance
Force = Torque / Distance
2849.5 / 1.029 = 2849.5 lbs of force with 205 60 15 wheels
2849.5 / 0.9625 = 2960.5 lbs of force with 195 50 15 wheels
163 lbs of force change
Go here for more info on power and gear ratios:
http://www.allpar.com/eek/hp-vs-torque.html
Dave
Dave
200 ft-lb at engine * 3.475 = 695 ft-lb at the driveshaft
695 ft-lb *4.1 = 2849.5 ft-lb at the half-shafts
or
695 ft-lb *4.3 = 2988.5 ft-lb at the half-shafts
139 ft-lb gain at the wheel by switching from 4.1 to 4.3 rear gears.
Force at tire contact patch:
Torque = Force * Distance
Force = Torque / Distance
2849.5 / 1.029 = 2849.5 lbs of force with 205 60 15 wheels
2849.5 / 0.9625 = 2960.5 lbs of force with 195 50 15 wheels
163 lbs of force change
Go here for more info on power and gear ratios:
http://www.allpar.com/eek/hp-vs-torque.html
Dave
Dave