3 speed automatic corolla should be avoided? - Page 3 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 10-28-2008, 07:04 PM   #21
Registered Member
 
Join Date: Oct 2007
Posts: 298
Country: United States
Quote:
Originally Posted by RoadWarrior View Post
I think that's why a lot of DOHC motors have gearing that has them at 3500-4000rpm at 60, no low end torque.
That's not really the issue. Contrary to popular belief, the cause of poor low end torque is low engine displacement for the weight of the vehicle, not the DOHC valvetrain. For instance, a B18C5 is considered 'torqueless' in an Integra Type-R. But if you put that same 1.8 liter motor into a 2000 pound CRX, it suddenly becomes MUCH more torquey. Of course, there are other reasons why automakers go with a short fifth gear. First of all, most people don't like a car that can't accelerate in fifth gear. To MANY, it is a sign that the car is just plain 'weak'. Also, if the top gear is really tall, then, unless the automaker is willing to build a six speed, you end up with a transmission with gears 1-4 that are overly tall and widely spaced for everyday driving.
__________________

StorminMatt is offline   Reply With Quote
Old 10-28-2008, 07:46 PM   #22
Registered Member
 
Phase_22's Avatar
 
Join Date: Oct 2007
Posts: 6
Country: United States
Lightbulb 4 valve misconceptions

Quote:
Originally Posted by bowtieguy View Post
i talked to a guy that has a 3 speed prizm, and he said he REALLY wishes he had another gear!
Word
Quote:
Originally Posted by RoadWarrior View Post
DOHC motors.
For an engine with 2 camshafts, yes, there is a reduction in available output of torque
Quote:
Originally Posted by RoadWarrior View Post
I think that's why a lot of DOHC motors have gearing that has them at 3500-4000rpm at 60, no low end torque.
In theory, the 4 valve combustion chamber lends itself to high rpm gains and a lack of low rpm drivability. However, recent production 4 valve combustion chamber designs for cars & trucks do not utilize (unlike motocycle--sportbikes) 4 valve combustion chamber benefits. I think the general prevalence/preference of the 4 valve combustion chamber equipped engine is Noise Vibration Harshness (NVH).
__________________

__________________
Phase_22 is offline   Reply With Quote
Old 10-28-2008, 08:02 PM   #23
Registered Member
 
Join Date: Oct 2007
Posts: 298
Country: United States
Quote:
Originally Posted by Phase_22 View Post
For an engine with 2 camshafts, yes, there is a reduction in available output of torque
Is THAT why a Pontiac Iron Duke has SO much more torque than a Honda K24 or a Nissan QR25DE?
StorminMatt is offline   Reply With Quote
Old 10-28-2008, 08:07 PM   #24
Site Team / Moderator
 
Jay2TheRescue's Avatar
 
Join Date: Sep 2008
Location: Northern Virginia
Posts: 4,657
Country: United States
Location: Northern Virginia
Quote:
Originally Posted by StorminMatt View Post
Is THAT why a Pontiac Iron Duke has SO much more torque than a Honda K24 or a Nissan QR25DE?
I had that engine in my AMC Spirit paired up with a Pontiac 4 speed manual and that car got ~800 miles on a tank of gas.
__________________






Jay2TheRescue is offline   Reply With Quote
Old 10-29-2008, 08:10 AM   #25
Registered Member
 
Join Date: Nov 2007
Posts: 1,111
Country: United States
Send a message via AIM to dkjones96
Quote:
Originally Posted by StorminMatt View Post
Is THAT why a Pontiac Iron Duke has SO much more torque than a Honda K24 or a Nissan QR25DE?
Wow, yeah, that's a fair comparison. An engine from the 80s compared with an engine with new technology.

How about comparing the Nissan VQ35 engine with the Pontiac 3.6L engine.

Nissan 3.5L DOHC 24-valve makes 258 ftlbs at 4400 and 270 HP at 6000 Altima is rated at 19/26 FWD with CVT and weighs 3400 lbs

Pontiac 3.6L OHV 12-valve makes 251ftlbs at 3200 and 252 HP at 6300 G6 is rated at 17/26 FWD with 4-speed auto and weighs 3300 lbs

They aren't far off from each other. The -2 MPG in the Pontiac can be easily attributed to the 4-speed vs CVT. The Pontiac has 7 less ftlbs of torque but makes it where someone can actually use it without having to rev the engine up. A lot like the G8(my fav!).

My personal favorite:
Pontiac 3.6L OHV 12-valve makes 248 ftlbs at 2100 and 256 HP at 6300 G8 is rated at 17/25 RWD with 5-speed auto and weighs 3885 lbs

Lets see your DOHC engine make peak(or any) torque that low. That 3.6L G8 engine has a 4200 rpm powerband (the Altima's is 1600 rpm). That's HUGE! Plus, it only gets -2 city and -1 highway and weighs about 500 pounds more than the Altima.

The only reason I didn't use it in the comparison is because the G6 is more apples to apples as far as cars are concerned.
__________________
- Kyle
dkjones96 is offline   Reply With Quote
Old 10-30-2008, 12:02 AM   #26
Registered Member
 
Join Date: Oct 2007
Posts: 298
Country: United States
Quote:
Originally Posted by dkjones96 View Post
How about comparing the Nissan VQ35 engine with the Pontiac 3.6L engine.

Nissan 3.5L DOHC 24-valve makes 258 ftlbs at 4400 and 270 HP at 6000 Altima is rated at 19/26 FWD with CVT and weighs 3400 lbs

Pontiac 3.6L OHV 12-valve makes 251ftlbs at 3200 and 252 HP at 6300 G6 is rated at 17/26 FWD with 4-speed auto and weighs 3300 lbs

They aren't far off from each other. The -2 MPG in the Pontiac can be easily attributed to the 4-speed vs CVT. The Pontiac has 7 less ftlbs of torque but makes it where someone can actually use it without having to rev the engine up. A lot like the G8(my fav!).

My personal favorite:
Pontiac 3.6L OHV 12-valve makes 248 ftlbs at 2100 and 256 HP at 6300 G8 is rated at 17/25 RWD with 5-speed auto and weighs 3885 lbs

Lets see your DOHC engine make peak(or any) torque that low. That 3.6L G8 engine has a 4200 rpm powerband (the Altima's is 1600 rpm). That's HUGE! Plus, it only gets -2 city and -1 highway and weighs about 500 pounds more than the Altima.

The only reason I didn't use it in the comparison is because the G6 is more apples to apples as far as cars are concerned.
A couple of things to keep in mind here. First of all, the RPM at which peak torque occurs says NOTHING about what is happening above or below that point. Just because one engine produces 248ft-lb at 2100RPM, and another produces 258ft-lb at 4400RPM, this does not mean that the engine with the higher torque at the higher RPM is producing LESS than 248ft-lb torque at 2100RPM. It could even be producing MORE torque. After all, torque curves tend to be pretty constant on engines these days. So unless you actually see a dyno curve of BOTH motors, you just can't say for sure.

Secondly, I know I may be nitpicking somewhat. But you are comparing a 3.5l motor with a 3.6l motor. This may not seem like alot, and it isn't. But torque is VERY heavily tied into engine displacement. In fact, you will find that most engines produce a peak torque (in ft-lb) that numerically is within plus or minus 20% of the cubic inch displacement (consider a few examles for yourself). So a displacement difference of 100cc (assuming that this is truly the difference in displacement of the motors) will, all other factors being equal, give the larger engine a 6ft-lb advantage. Something to consider.
StorminMatt is offline   Reply With Quote
Old 10-30-2008, 02:08 AM   #27
Member
 
Join Date: Dec 2006
Posts: 59
Country: United States
Hi swng, that two-speed Toyota transmission was probably the 'Toyoglide'. I owned a 1978 Civic with a similar two-speed and it was OK round town but at speeds more than 50mph it really became a buzz-box.
markweatherill is offline   Reply With Quote
Old 10-30-2008, 08:33 AM   #28
Registered Member
 
Join Date: Jun 2008
Posts: 60
Country: United States
Do Not Buy That Car, They Are Hsit

Quote:
Originally Posted by civic94 View Post
im looking into the classifieds, and a 93+ corolla with the 3 speed auto (Base) are about 2,000 bucks, but should they be avioded just because it only has 3 forward gears?


isnt the engine buzzing at 3000 rpm at 60mph?
Your going to have to weight this reply heavily as it comes from a former owner of one. I sold the piece of crap a few months ago for $975, dead tranny.

We were the original owner of this 1994 3-speed automatic Corrola base model. Very poor drivetrains,underpowered and overworked. Its wanted a fourth gear so bady it screamed out of the engine bay to 'please shift me!" but there was nothing there. There was a different engine and tranny in the other model for that year that had more torque and more horsepower and got better mileage because it could relax the engine at highway speeds.

The model you are looking at is horribly unreliable and breakdown prone. The kind of crap that you'd expect from a 70's era USA car maker. Shocks were totally gone at 80k miles, Alternator, starter, constant leaks, ate oil, transmission fried at 130k. Buzzes and rattles throughout the interior. The car was maintained on the maintenance schedule and it literaly shakes itself apart.

DO NOT BUY THIS PIECE OF CRAP !!!
SCoupe is offline   Reply With Quote
Old 10-30-2008, 09:55 AM   #29
Registered Member
 
goofy1's Avatar
 
Join Date: May 2008
Posts: 169
Country: United States
Blackhawk is a 3 speed auto. but it's a 97 tercel. but i have a scanguage. it's revving between 3000-3400 between 55-65mph. But i've notice i get super mpg's at 35-45 mph. on a flat road doing 45 i was getting 49.4 mpg. but driving 45 on the highway here is way too dangerest. plus KY gives a tickets for doing more then 8 mph below the posted speed limit.
__________________
"But Doc, we dont' have enough road to get it up to 88 miles per hour"
goofy1 is offline   Reply With Quote
Old 10-30-2008, 11:04 AM   #30
Site Team / Moderator
 
Jay2TheRescue's Avatar
 
Join Date: Sep 2008
Location: Northern Virginia
Posts: 4,657
Country: United States
Location: Northern Virginia
Sounds like that gearing is ideal for city driving...

-Jay
__________________

__________________






Jay2TheRescue is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Arco gas - mileage poor jbum General Fuel Topics 9 07-07-2013 12:25 PM
Fuelly Android App - eehokie Fuelly Web Support and Community News 2 07-14-2010 09:59 PM
91 CRX DX 5 Speed Head Gasket Confusion UfoTofU General Maintenance and Repair 2 04-26-2008 11:09 AM
MID Install SVOboy Experiments, Modifications and DIY 33 06-04-2007 11:27 AM
New member, old hand kitcar Aerodynamics 30 05-19-2007 06:37 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 09:15 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.