FE Power Forums
FE Power Forums => Non-FE Discussion Forum => Topic started by: FElony on March 04, 2018, 02:01:37 PM
-
Anyone have an A<-->B comparison in ET going from a close ratio C6 to a wide ratio? No other changes.
-
There are variables like the weight of the vehicle and horsepower. A heavy car will benefit more from the wide ratio. A light quick car could possible do better with the close ratio.
-
In a word, no I can't tell you an ET difference with just the trans mod. I changed a few other things in my combo at the same time the wide ratio kit was put in. Mine was done at the advise of my trans guy. He said the planetary had 6 gears and was done for a strength upgrade. My Mustang had a normally aspirated 454 and ran around 11 flat at the time.
At first I hated it because of the pretty large "drop-off" when I shifted into high. At the time I was running 4.11 gears.
When I put the blower on it made a different problem. It made first gear pretty useless but second and third were ok.
I eventually put 3.70 gears in. With the increase in power of the blower, the very high third gear just made it go faster and first and second gear just right.
I guess I'm say'n if you don't have a bunch of power, you might like the lower first and second gear...but will hate the drop into third. If you're running a bunch of gear on a higher powered drag racing car, you might find first too low. If you're running pretty good power in a mostly street car like mine...you might just like installing "highway gears" and use the torque of the motor to haul ass.
Long winded way to say exactly what the above post said. It's all in the combo.
-
No A-B testing here either, but I can tell you that going to low ratio gearset was a negative in my street/strip car. It made 1st gear useless and compounded that with bigger rpm drops between gears. It was a lose-lose situation. My opinion is that the low ratio gearset is only good for low powered and/or heavy cars, or true strip cars with traction that can use the extra gearing at launch.
paulie
-
OK, thanks for the replies. My curiosity comes from the many people who have gone wide ratio in the Top Loader because of the large mid-range of the 428 (and larger). The car in question is an intermediate that currently has 3.50's with 275's out back. Not sure at this point whether to leave it sedate or turn up the wick a bit. Sounds like wide gears go down the list a bunch.
-
A manual transmission equipped car is more sensitive to gear ratio. An automatic is inherently more forgiving due to the slip of the torque converter, even with a stock torque converter.
I would use a wide ratio C6 in a medium to heavy weight car with higher gears, like 3.00-3.50, and a moderate hp engine, or a smaller cid engine.
JMO,
paulie
-
Jerico usually recommends about 3.00 first gear in a drag car.
I use a 2.78 box and a 4.57 in my Starliner. 2 tons of fun on the street!
Ron.
-
A manual transmission equipped car is more sensitive to gear ratio. An automatic is inherently more forgiving due to the slip of the torque converter, even with a stock torque converter.
I would use a wide ratio C6 in a medium to heavy weight car with higher gears, like 3.00-3.50, and a moderate hp engine, or a smaller cid engine.
JMO,
paulie
Yes. A mildly cammed CobraJet with race headers and 3.50's at 3800 lbs. Hence my initial curiosity to see an A/B.
-
I think it might be a good idea in that application. I think it'd be worth a few hundred extra bucks.
JMO,
paulie
-
Seems like there is a 6-pinion planetary option by going wide. May be overkill for this car, but could help a more masculine build.
-
I have run simulations for ratio changes using a C4 - I didn't see enough to justify the cost. 6 pinion planetary is good insurance if you are beating on it. However, we've been racing C4s for many years in the 450~500 HP power range and I can remember replacing one (1) stock three pinion unit.
-
I'm with Paulie ... wide ratio C-6 would be great in a hard working Tow Vehicle , or maybe a real heavy cruiser that you didn't want to gear vendor or OD it , you could couple the big first gear ratio with a 2.75 gear and it would still take off good at the light and cruise good down the highway short of adding another gear with a GV or just going 4 sp auto
-
OK, thanks for the replies. My curiosity comes from the many people who have gone wide ratio in the Top Loader because of the large mid-range of the 428 (and larger). The car in question is an intermediate that currently has 3.50's with 275's out back. Not sure at this point whether to leave it sedate or turn up the wick a bit. Sounds like wide gears go down the list a bunch.
The difference between a wide and close toploader is huge when dealing with first gear. The close ratio was better used for road racing because first gear is so long(just about the same as 2nd gear in a wide box) and you can use it on the track. They did use it in drag racing, but they used 5.13 gears in the back. No body uses that much gear anymore(because you can get a transmission with a deep first gear). Thus you can control your trap RPM better.
I tried a close ratio ONCE in my pickup many years back. I broke my wide rato box and a friend loaned me his close. UGH, that was shorted lived. Even with 4.56 gears it was horrible getting started from a light and 1st gear would get you to speed without having to shift into 2nd. The supposed "close ratio gearing is better" argument is bull pucky in my opinion.
-
Following this thread closely. Currently starting a 428 stroked to 463 build for my 64 Galaxie, a 3.50 gear in the diff with a c6. I am wondering if wide ratio kit would be worth the effort. The mill will be a hydro roller mild build cruiser with TFS heads. Any thoughts will be appreciated.
Thanks Joe Menard
-
The weird thing is, if somebody has a wide ratio toploader and a 3.25 rear gear, nobody complains about it. If somebody has close ratio toploader and 3.89 rear gear they act like it takes an act of Heaven to get the car moving, but both scenarios have the exact same overall first gear ratio. Why is that?
paulie
-
The weird thing is, if somebody has a wide ratio toploader and a 3.25 rear gear, nobody complains about it. If somebody has close ratio toploader and 3.89 rear gear they act like it takes an act of Heaven to get the car moving, but both scenarios have the exact same overall first gear ratio. Why is that?
paulie
Could it be that the lower trans gearing makes the pinion climb up on the ring gear harder than the higher trans gear, which might raise the front end more, appearing to have more acceleration?
-
More likely is that the guy who runs a 3.89 gear expects the car to accelerate off the light - the 3.25 guy knows its gonna be something of a puppy. Perceived expectation...
-
Second gear, third gear don't feel as quick in the close ratio transmission because of the rear gears don't pull as hard with the 3.25 as the 3.89. It is the final where the loss of acceleration changes regardless of what the initial equals. Joe-JDC
-
Overall gear ratios.
Wide ratio with 3.25:
9.04/6.27/4.42/3.25
Close ratio with 3.89:
9.02/6.57/5.02/3.89
Rpms after shift with 6000 rpm shift.
Wide ratio with 3.25:
1st-2nd - 4165 rpm (53 mph) *with 27" tire
2nd-3rd - 4228 rpm (77 mph)
3rd04th - 4412 rpm (109 mph)
Close ratio with 3.89:
1st-2nd - 4371 rpm (53 mph)
2nd-3rd - 4580 rpm (73 mph)
3rd-4th - 4651 rpm (96 mph)
So your rpms at the shifts are going to be higher with the close ratio for more power (depending on the engine combination). And your speeds will be lower. So less air drag. I think the close ratio will accelerate harder on the shifts, and accelerate the same on the launch.
Feel free to check my math. I'm in a hurry.
JMO,
paulie
-
If you change rear gearing and change transmissions, yes the gearing works out. But leave the rear alone and change transmissions. That is when it all goes sideways. That is when it feels like it won't get out of its own way.
2.78 x 3.25 = 9.03 (6.27 sec gear)
2.32 x 3.25 = 7.54 (gets close to sec gear of wide ratio)
Even with my 4.56 gears in my truck it was a horrible feeling taking off. Was not as quick....unless you can slip the clutch and hold the RPM up. I would suppose with a lightweight, 3200# car it would not be so significant a loss?
-
Honestly for a street car, most of you guys are a bunch of pussycats. How do you think guys back in the late 60's or early to mid 70's drove around? There were L78 Chevelles with 3.55 rear gears, for instance. Do you think they just couldn't do it? It takes a good clutch foot to get an old musclecar out of the hole, but they could do it. It's not like we're magically smarter than those guys. You had to balance throttle and clutch and wheel spin. While I've never had an L78 Chevelle , I've had 3.00 geared and 2.75 geared '69 Cougars with 2bbl 351W's and 3 speed sticks. I think the first gear ratio on the 3 speed toploader is 2.99:1 so not a lot of overall ratio. I could drive normally or fry the tires off. I never had to replace a clutch in tens of thousands of miles of driving. There was no problem. I feel like our perspective has changed to the point where we expect everything to be sooooo easy.
JMO,
paulie
-
.Close ratio box with 3.70 gear would wipe a Sof Loc clutch out in a weekend
-
.Close ratio box with 3.70 gear would wipe a Sof Loc clutch out in a weekend
I street raced a 428CJ (Fairlane) Cobra and a 429CJ Spoiler in the 80's, both with 2.32 first and 3.50 gears. Both had clutches that were already in there when I bought the cars. I pounded them hard. No failures. Maybe it's today's clutches that are garbage. When I see the move away from B&B Long to those phaggy diaphragm (GM-style) clutches, I know the end of the world is not far away. Gimme three fingers, baby.
-
I think it might have something to do with a 25 year old left knee versus a worn out 62 year old knee , that the doctors tell me the joint needs to be replaced in the knee and the nut behind the wheel could use some work also .
-
Honestly for a street car, most of you guys are a bunch of pussycats. How do you think guys back in the late 60's or early to mid 70's drove around? There were L78 Chevelles with 3.55 rear gears, for instance. Do you think they just couldn't do it? It takes a good clutch foot to get an old musclecar out of the hole, but they could do it. It's not like we're magically smarter than those guys. You had to balance throttle and clutch and wheel spin. While I've never had an L78 Chevelle , I've had 3.00 geared and 2.75 geared '69 Cougars with 2bbl 351W's and 3 speed sticks. I think the first gear ratio on the 3 speed toploader is 2.99:1 so not a lot of overall ratio. I could drive normally or fry the tires off. I never had to replace a clutch in tens of thousands of miles of driving. There was no problem. I feel like our perspective has changed to the point where we expect everything to be sooooo easy.
JMO,
paulie
Easy has NOTHING to do with it. My ONLY point was the 2.32 is not an optimal first gear for performance driving, aka: drag racing. If you want to road race, then fine, it gives you longgg legs in first gear which is great. For drag racing, it makes it hard to be consistent. Yes, back 40 yrs ago that was all there was. 3200# clutches, skinny bias play tires and peg legs. Yup, it took talent to get them to get moving. That has nothing to do with the conversation I'm having.
In drag racing, it is all about the combination of clutch, tire and traction. They all have to work together and picking the most consistent one to slip. Something HAS to slip. With todays technology with clutches, sticky tires and the infinite possibilities of gear ratios there is no need to work with something difficult. You mention changing rear gears to match the starting line ratio. Fine, but you also gain a TON of finish line RPM which is not always doable.
Like I said, only the fact I went from a wide ratio to a close ratio, my starting line ratio went away and I didn't care for it. It means my clutch(I run a 25 yr old Centerforce DF) has to slip more and I didn't like its manners for a 4100# truck.
My Nash is 3.25 first gear. Do you think I could get away with a 2.32 toploader and have the car run the same? Maybe, if I wanted to replace the clutch every few passes. That ain't happening. I get 2-3 yrs out of it currently. Easier? Ya, I guess. Cheaper? Definitely.
-
I imagine driving a 302 Z28 with a 2.20 1st gear and 3.73 rear gears would have been maybe the most difficult situation back in the old days. A Boss 302 with close ratio top loader and 3.50 gears would have been easier, in my opinion. I think the Boss 302's came with close or wide ratio, almost randomly.
JMO,
paulie
-
I am not a close ratio fan in toploaders, unless maybe in small block road racers, but that is theory only, I don't do that LOL
I did run my Mustang from Vegas to Anaheim and out to Huntington Beach with a 2.32/3.70 rear/12 inch clutch/28 inch tall tire/433 FE with a P-sonic and a 250@.050 108 LSA solid Isky. It made it, but notice what I did about a year after that run (489/5 speed/4.11 gears LOL)
However, all the guys with wide ratio sets in a C-6 seem disappointed. It's hard to compare a clutch and solid drive to the gearing with a fluid drive because pre-stall, the torque converter adds torque multiplication
So drag racing, I would expect a wide ratio C-6 might do OK using standard SLR calcs assuming the ratio spread from 1-2 and 2-3 isn't wonky as a result of the deep first
However, on the street, my hunch is that the combination of the converter multiplication and the low gearset makes the low gear looser (lower) and the step from 1-2 more pronounced and in that case, therefore the wide ratio C-6 isn't as happy as a wide ratio Toploader.
Trying to make sense of it, but I haven't found a single car friend who dislikes a wide ratio Toploader and at the same time haven't found a single car friend thrilled with a low gear C-6. Thoughts from the slush box guys?
-
Well said, Ross. Big difference between autos and sticks when it comes to gear ratios. That's why I said the manual is much more sensitive in that regard.
I didn't like my wide ratio C6. In fact, sometimes I think less gear ratio can sometimes make an auto work better. I think it can make the converter work better by putting a higher load on it.
I like to tweak all you super low gear ratio manual tranny guys, but I get that it makes a difference. It is funny though. 30-40 years ago, it was all close ratio this and close ratio that. Now, it's all more ratio this and more ratio that. I think catch phrases are just catch phrases and it's the specifics that matter. I'll stand by my assertion that the close ratio toploader with 3.89 gears will pull harder in all gears than the wide ratio with 3.25's. What bugs me is that as soon as someone hears "close ratio toploader" they've already made up their mind that it's going to be a slug.
JMO,
paulie
-
It will be a "slug" if you keep the same rear gears(apples to apples). That is the problem and you have to take that into account. You can tweak me all you want, but I know what works. There is nothing wrong with a close ratio, but not for use in drag racing "today". Not 45 yrs ago, today. With today's technology.
You can run 3.25 gears with a wide ratio and get on the highway and cruise at much lower rpm. Try that with 3.89/4.11's and let me know how you like it. Yes, it might accelerate the same, but that is why everyone bitches about not having OD on the highway. My truck has 4.56 gears and 29" tires and the 428 runs 3500 rpm on the highway. Luckily I don't plan long trips with it, but I run the highway whenever the need arises. It runs in the sweet spot and all I have to do it lean into the throttle and it runs away from traffic.
I agree, automatics seem to work better with less first gear. Let the converter do the work. Might build a bit of heat, but the cooler takes care of that.
-
I am not a close ratio fan in toploaders, unless maybe in small block road racers, but that is theory only, I don't do that LOL
I did run my Mustang from Vegas to Anaheim and out to Huntington Beach with a 2.32/3.70 rear/12 inch clutch/28 inch tall tire/433 FE with a P-sonic and a 250@.050 108 LSA solid Isky. It made it, but notice what I did about a year after that run (489/5 speed/4.11 gears LOL)
However, all the guys with wide ratio sets in a C-6 seem disappointed. It's hard to compare a clutch and solid drive to the gearing with a fluid drive because pre-stall, the torque converter adds torque multiplication
So drag racing, I would expect a wide ratio C-6 might do OK using standard SLR calcs assuming the ratio spread from 1-2 and 2-3 isn't wonky as a result of the deep first
However, on the street, my hunch is that the combination of the converter multiplication and the low gearset makes the low gear looser (lower) and the step from 1-2 more pronounced and in that case, therefore the wide ratio C-6 isn't as happy as a wide ratio Toploader.
Trying to make sense of it, but I haven't found a single car friend who dislikes a wide ratio Toploader and at the same time haven't found a single car friend thrilled with a low gear C-6. Thoughts from the slush box guys?
Like I said before it took me a while to find a place where the wide ratio kit shines. My car has 33" tall tires and 3.70 gears. With my blown deal I really have loads of torque at 3000 rpm up through redline. The high gear drop off in rpm works great in my application now as it drops right into a torque "sweet-spot".
Didn't care for the low gear kit when I was N/A.
-
It will be a "slug" if you keep the same rear gears(apples to apples). That is the problem and you have to take that into account. You can tweak me all you want, but I know what works. There is nothing wrong with a close ratio, but not for use in drag racing "today". Not 45 yrs ago, today. With today's technology.
You can run 3.25 gears with a wide ratio and get on the highway and cruise at much lower rpm. Try that with 3.89/4.11's and let me know how you like it. Yes, it might accelerate the same, but that is why everyone bitches about not having OD on the highway. My truck has 4.56 gears and 29" tires and the 428 runs 3500 rpm on the highway. Luckily I don't plan long trips with it, but I run the highway whenever the need arises. It runs in the sweet spot and all I have to do it lean into the throttle and it runs away from traffic.
I agree, automatics seem to work better with less first gear. Let the converter do the work. Might build a bit of heat, but the cooler takes care of that.
I never made a comparison between two cars with the same rear gear and a wide and close ratio tranny. My car has 4.11's and it's horrible driving on the highway. I can do the math and see that 3.25's with a wide ratio is better on the highway. I'm not sure what point you're trying to make.
paulie
paulie
-
You kept saying how a close ratio works out better, but you change the numbers in the rest of the equation(ie=rearend) to get it. That is not an equal comparison if you are comparing just the transmission first gears(which is what the post was about). Granted, it was about C6 gears but the toploader was mentioned and the whole conversation went sideways. Which again is not apples to apples.
That was my point. Your comparison is not legitimate to what was asked.
-
Somebody else brought up wide and close ratio toploaders. My comparison is legitimate because there is no reason why you have to run the same rear gear with two different transmissions. That wouldn't make any sense.
JMO,
paulie
-
In a word, perception. :)
KS
-
In a word, perception. :)
KS
Barry mentioned that, too. Fair enough.
paulie
-
.Close ratio box with 3.70 gear would wipe a Sof Loc clutch out in a weekend
I street raced a 428CJ (Fairlane) Cobra and a 429CJ Spoiler in the 80's, both with 2.32 first and 3.50 gears. Both had clutches that were already in there when I bought the cars. I pounded them hard. No failures. Maybe it's today's clutches that are garbage. When I see the move away from B&B Long to those phaggy diaphragm (GM-style) clutches, I know the end of the world is not far away. Gimme three fingers, baby.
When I ordered my '64 Custom/427, I had a choice of a 3.50 or a 4.11. I got a 4.11 and then sourced a 3.50 for daily drive-around and long trips. But the 3.50 was hard on the clutch. (I'd replaced the T-10 with a big in-'n'-out Top-Loader. Doing so meant replacing the disc and that meant going to truck parts for such as the disc and the fork and the TOB.)
Several months later I pulled one face off the disc. Checking told me that it was fairly common with the 3.50 gear. So it's nothing new!
KS
-
I have used C6s in my Fairmont, with both the stock ratios, and later, with the Ford Motorsport "Low drag low gear" setup. I ran the car for several years with the 2.72 1rst gear and 4.56s in the rearend, and I did like the lower gearing. Bear in mind that I only drive the Fairmont at the dragstrip, and with slicks, it always hooks well.My thinking with my car was that I didn`t want to rev the stock 428 internals much over 6000 RPM, so that ruled out as much rearend gear as I would have like for strong acceleration, the lower 1rst gear helped the launches, and the 428 had enough torque to not mind the bigger drops on the gear changes.
As for the close vs wide Toploader, I vote wide ratio all the way. I had 4.30 gears in my 70 428 CJ 4 speed Mach 1, with 28" tall Goodyear slicks, even dumping the clutch over 5000 RPM, the car felt weak thru 1rst gear. For 1 race, a buddy lent me his big spline, 2.78 1rst gear "crashbox" Toploader from his old Modified Production Pinto. We did not have 60 foot times back in those days, but the improved launch was amazing, unfortunately, the main shaft broke on the 2-3 shift, so I never did get to make a full pass with the wide ratio, but in talking to other Ford stick racers at that race, they expected a 2 to 2 1/2 tenth immprovement in the 1/4 mile numbers. Even at only 3100 lbs, my 428 or 427 FE powered Fairmont used a 3.19 1rst gear and 4.56 gears, and did not seemed over geared, with the 331 SB Ford, I also use a 3.19 low gear and 5.13 rear gears, and may switch to 5.38s. Having owned several Toploader equipped street cars, both close & wide ratio, I can not think of any situation where I would chose a close ratio version. (I don`t road race!). The main reason the FOX 5.0L Mustangs were so stong running with moderst HP was that the T5s had a 3.35 low gear. A FOX Mustang with that 3.35 1rst gear, and only 3.08 rear, has more starting line ratio than my 70 Mach 1 had with a close ratio Toploader and 4.30s! Years ago, I drove my buddy 66 7 Liter Galaxie, with 3.00 gears and a close ratio Toploader, and it was an absolute turd for acceleration off the line. So was another buddys 70 Boss 302 with a close ratio and 3.50s. Sorry Paulie, this isn`t just numbers on a calculator, but real world driving experiances. Back in the days of crappy skinny street tires, the close ratios tall 1rst gear may have been OK, but I don`t race on F70 14s anymore.
-
... Even at only 3100 lbs, my 428 or 427 FE powered Fairmont used a 3.19 1rst gear and 4.56 gears, and did not seemed over geared, with the 331 SB Ford, I also use a 3.19 low gear and 5.13 rear gears, and may switch to 5.38s.
Several years ago I did an "interview" with the owner of an E/Stock 390 Fairlane that was running at a Div 7 meet here in AZ. I posted this on the old forum. He was running 5.29's out back and a 3.29 in the Jerico. He said that first was only to 60-foot the car, and that was the best combo thus far for him. I don't recall his shift point.
-
Sorry Paulie, this isn`t just numbers on a calculator, but real world driving experiances. Back in the days of crappy skinny street tires, the close ratios tall 1rst gear may have been OK, but I don`t race on F70 14s anymore.
Me too, Rory. That I have used stock and wide ratio C6's. I already said that I think in a strip situation with lots of traction it would be different. Maybe you missed that.
paulie
-
... Even at only 3100 lbs, my 428 or 427 FE powered Fairmont used a 3.19 1rst gear and 4.56 gears, and did not seemed over geared, with the 331 SB Ford, I also use a 3.19 low gear and 5.13 rear gears, and may switch to 5.38s.
Several years ago I did an "interview" with the owner of an E/Stock 390 Fairlane that was running at a Div 7 meet here in AZ. I posted this on the old forum. He was running 5.29's out back and a 3.29 in the Jerico. He said that first was only to 60-foot the car, and that was the best combo thus far for him. I don't recall his shift point.
Probably talking to Andy Kimball, right? Beige 66 Fairlane 390.
-
Probably talking to Andy Kimball, right? Beige 66 Fairlane 390.
Yes, I believe that was his name. You could run it through the archives in Anthony's forum, in theory. The pics are going to be gone, of course. I have them on another hard drive.
Edit: That would have been in the "Gallery" subforum.
-
I like to tweak all you super low gear ratio manual tranny guys, but I get that it makes a difference. It is funny though. 30-40 years ago, it was all close ratio this and close ratio that. Now, it's all more ratio this and more ratio that. I think catch phrases are just catch phrases and it's the specifics that matter. I'll stand by my assertion that the close ratio toploader with 3.89 gears will pull harder in all gears than the wide ratio with 3.25's. What bugs me is that as soon as someone hears "close ratio toploader" they've already made up their mind that it's going to be a slug.
JMO,
paulie
Well, a 4.56-4.88 car won't be a slug with a 2.32, it'll accelerate just like a 3.80 geared wide ratio....
Except that at the speed the 4.56 car is at 6500 rpm the 3.80 geared car will only be turning 5500 rpm :)
As far as your example though, you aren't incorrect, 1st is a wash, 2nd and 3rd should pull harder with your close ratio, 3.89 combo, but if the car can pull 5700 rpm with a 26 inch tall tire, it's doing 115 mph, it's doing that at 4800 with the 3.25.
Even at 75 mph, there is a 600+ rpm difference driving down the highway
Wide ratio toploaders are not a must-do, but they are way more versatile in an engine with a relatively flat torque curve, but there is a point of no return, take a TKO with a 3.27 1st, it's nearly impossible to gear for both 1st and 5th in that combo. 2.87/.64 however is a nice big block street combo
-
The newest MT-82 and the new 10R80 have 4.24 and 4.69 first gears, respectively. With the Performance 3.73 gearset, that gives starting line ratios of 15.815 and 17.494. Underrated 460hp. Howzcum our steep first gears are useless, but them new cars ain't? 2018 Mustang weighs same as 1969 FE Torino.
-
How come really fast drag cars sometimes use a two speed tranny with a 1.82 first gear?
-
So since, I saw an 8 second car with a 1.82:1 first gear and a 1.00:1 second gear, I think that's what you need in any situation.
JMO,
paulie
-
The newest MT-82 and the new 10R80 have 4.24 and 4.69 first gears, respectively. With the Performance 3.73 gearset, that gives starting line ratios of 15.815 and 17.494. Underrated 460hp. Howzcum our steep first gears are useless, but them new cars ain't? 2018 Mustang weighs same as 1969 FE Torino.
So, I'd have to dig into all the parts of those cars, but overall
Drag racing - although not specifically built for drag racing, the engines pull 7500 rpm, so if the gears are steep, you don't have to pull the next one immediately, if you do, it's a 10 speed and has lots of intermediate shifts done by solenoid actuation not valve body, so happens pretty quick, and last, there is nothing loose about a modern converter. My hunch is the converter has a very low stall speed and they make it up with gear
Street driving - lots of gears that shift a lot LOL, same tight converter and separate intake and exhaust cams that allow changing of the valve events significantly for load and RPM so you can have an engine tuned for a WAY tall top gear while still letting it rev for a short gear
My wife drives a Cherokee with an 8 or 10 speed, I forget, and it's pretty slick. My daughter bought a new Wrangler (Jeep type Jeep) One year newer, same engine, 5 speed AT, it's a pig compared to the Cherokee. 30+ highway vs 19 highway, 24 mpg in town vs 16, and it'll eat it's junch in a drag race. If that Jeep dropped to 3 gears, it'd be even worse
How come really fast drag cars sometimes use a two speed tranny with a 1.82 first gear?
Purpose built, loose converter, light car, lots of RPM, and very unique applications. You won't see many big bodied girls hanging the hoops with Powerglides
But I see you answered yourself :) I am not saying an always or never, but as a rule of thumb, the right ratios are right. I just don't see a lot of right with the narrow boxes in big block applications. AT, different story, but if you had more gears to choose, I'd likely change my mind because you could shift quickly and leave her screaming
-
As always a fair and measured response, Ross. It all depends on the particulars. I would say that in some instances I would rather have a close ratio toploader than a wide. I think If I optimized my Cougar it would have a 4.22 or 4.30 rear gear. It has 4.11's now and tops out at about 135 mph, but it does about 124 or so in the quarter. So a lower rear gear would help. With a 4.22 or 4.30 rear gear I think I would rather have a close ratio toploader. This car uses sticky street tires, but not slicks. I think I would be faster with the close ratio box.
That said, a wide ratio box will work good in a wider range of circumstances. A narrow ratio box will work good in a narrower range of circumstances. No doubt.
JMO,
paulie
edit: that is if I had a toploader, not a C6.
-
How come really fast drag cars sometimes use a two speed tranny with a 1.82 first gear?
Really light cars with big horse power and the lack of gear keeps the tires from spinning. I know lots of dragsters that start in 2nd many times. If not, they leave in 1st and have the noid shift it in like .2 seconds. Again, keeps traction issues at bay.
Again, with a converter it is not an issue. Most have a very loose converter anyway and heat is not an issue with a car that only runs for 8 seconds at a time.
-
How come really fast drag cars sometimes use a two speed tranny with a 1.82 first gear?
In my case, its all about the transmission's ability to take the power. I'm confident that an ATI Powerglide backed by a Gear Vendors O/D can take anything I can throw at it. I used a C-4 up to about 950 HP, but at the 950 HP level I had to have it gone through every year to make sure it would live. The C-4 seems pretty bulletproof at 750-800 HP, but over 900, not so much. And as far as I know there isn't a streetable trans with more gears out there that can take 1000+ HP, outside of a Lenco. I've seen the power capacity claims from some of those overdrive transmissions but I don't believe them, based on others experience I've read about online.
Here's another consideration - traction at the drag strip. When I had the supercharged engine in my Mach 1, I was using a pretty small tire to fit the factory wheelwells. Even with the 1.82 first in the Powerglide, I could not get the car to hook on the 10" Mickey Thompson slicks until I went all the way down to a 3.50 rear gear. Just too much power at the wheels with a deeper gear, blew the tires off every time with 4.11s and 3.89s. The picture of my Mach 1 in my signature was taken leaving the line at Cordova with 3.50 gears and the Powerglide.
And one other thing - I tried the "gear splitting" technique with the Gear Vendors overdrive on that car, and found absolutely no difference in ET. So, first gear would have been an overall ratio of 6.37, first O/D was 4.97, second gear was 3.50, and second O/D was 2.73. Of course I never got into second O/D on the track, trap speed was over 150 MPH in second gear. But despite the fact that I had three gears on the track instead of two, there was no change in performance. The converter compensated for the lack of the third gear, when just running two speeds.
This discussion drives home the point that the whole car and its use has to be a consideration. The calculus is completely different for a 425 lb-ft, 550 HP small block street car, where an 8 or 10 speed transmission might be available, and might actually live.
-
I am with you Jay, the best tranny is one that doesn't blow up...and if you have the rpm range and power to only shift once, that's the way to go.
-
... the best tranny is one that doesn't blow
I'm quite sure Justin Trudy would not agree.
Anyway, watching videos of current cars I see lots of 8-second V8's going through 4 gears. I hear some mention 700r4's. Traction is key, yes. Years ago I asked Stan Weiss to figure, using a car that liked 4.11's in the traps, what would happen if an AOD was used with 6.20 gears, since 4th would be about the same trap ratio. He said it would be worth at least a tenth, maybe more.
I gotta think that racing a 2-speed automatic is one of life's most boring experiences. I also gotta think that shifting a 5-speed stick geared in the 7's was one the exact opposite. Gotta find middle ground.
-
Dude, 8 second passes are far from boring, no matter how many times you have to shift.
-
Jay, it all depends on the car and setup. The quickest car I ever made a pass in , wasa buddys full tube chassis Super Gas 84 Thunderbird, low like a Pro Stocker of the day, in the late 80s. It had a 460 Ford based engine with a Powerglide, and it was a very boring car to drive. My best in the TBird was a 9.40 @ 146 MPH, and although it set you back in the seat pretty good, it just felt not very exciting, as it just kinda squited straight down the track, no more than an inch or 2 under the front tires,and like a few other 9 second Powerglide tube chassis cars that I have driven, once you put the Glide in high gear, not much going on. With a stock chassis, small tire car, you would probably have a bit more driving to do, so that would keep it intersting. By the way, the guy with the TBird made a couple of passes in my Fairmont the same day, even though it had the C6 at the time, and was only running mid 10s, he thought between the big wheelstands and having to shift it himself TWICE, it was a blast to drive. I have never driven a rear engine dragster (doubt I could ever find one I could fit into!), but talking to a few buddys that have tried them, they were fast but very dull to drive.
-
https://www.youtube.com/watch?v=cCFd2l_DPTo
The feel, the sound, the smell, is more important to me than actual ET.
https://www.youtube.com/watch?v=TrKJsP99pcQ
Although a Chev-fest back then, I can't help but wonder what the small Ford would be like in this form with today's heads and intake.
-
As usual, I'm feeling I have too many irons in the fire.