Hi Rob,
Great articles and photos, thanks so much ,
I have a 1994 BMW 318is. It gets great gas mileage and would love to get even better mileage . The rear end (3rd) member locked up when I first got the car, so I found a deal on a 325 axles and rear end , put it in never changed any gears do you know if the 325 is different than the 318is both were manual transmissions. Should I leave well enough alone ?
Thanks,
FAN
Hello Fan and thank you!
I found this excellent website that lists a LOT of BMW gear ratios, perhaps all of them: http://www.bokchoys.com/differential/GearRatios.htm
It seems that you now have a less-aggressive final drive ratio of 3.15 vs. 3.45. So if you like your mileage and the acceleration is adequate, I would leave it alone and congratulate yourself on a fuel saving modification.
I wouldn't suggest trying anything numerically lower than 3.15 such as the 2.93, even if you can find it. My concern would be inadequate acceleration with the 4-cylinder engine. This would mean using higher revs and consuming more gas, effectively negating your intended result. Also, it may mean using a higher gear for cruising at certain speeds and poor acceleration in 5th gear. If you know anyone that has done it, be sure to write back and share!
___________
Have a question about cars you would like answered? Performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
Showing posts with label Ask Rob About Cars. Show all posts
Showing posts with label Ask Rob About Cars. Show all posts
Sunday, August 8, 2010
Toyota FJ Opinion? Ask Rob About Cars
Brandon from Brandon, FL writes:
I am always in the market for a new ride I like the Accord. But I really enjoy a Crossover-SUV with the higher up feeling. But there are none that are in my price range so for the past year I've been stuck. But with my warranty now up I am back to searching for a good weekend deal in the paper. What do you think of the Toyota FJ Cruiser, black on black with dual exhaust? It has a good sporty look to it. I also am not really worried about gas I don't drive much at all. My current ride gets about 16/21 mpg city/highway.
Brandon,
The Toyota FJ is a nice beefy, ride. Toyota reliability and distinctive, retro styling are nice touches. In fact, my sister really wants one! It definitely has off-road intentions so that part might be wasted in your neck of the woods. There is nothing wrong with that if gas consumption isn't a concern.
I suggest two things though. If you tend have rear seat passengers or cargo, try climbing in and out and see what you think in terms of access. Second, take the car into a crowded parking lot and park it between cars and back it up a few times. See if the visibility is acceptable for the daily driving you'll be doing. Good luck in your search!
___________
Have a question about cars you would like answered? Performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
I am always in the market for a new ride I like the Accord. But I really enjoy a Crossover-SUV with the higher up feeling. But there are none that are in my price range so for the past year I've been stuck. But with my warranty now up I am back to searching for a good weekend deal in the paper. What do you think of the Toyota FJ Cruiser, black on black with dual exhaust? It has a good sporty look to it. I also am not really worried about gas I don't drive much at all. My current ride gets about 16/21 mpg city/highway.
Brandon,
The Toyota FJ is a nice beefy, ride. Toyota reliability and distinctive, retro styling are nice touches. In fact, my sister really wants one! It definitely has off-road intentions so that part might be wasted in your neck of the woods. There is nothing wrong with that if gas consumption isn't a concern.
I suggest two things though. If you tend have rear seat passengers or cargo, try climbing in and out and see what you think in terms of access. Second, take the car into a crowded parking lot and park it between cars and back it up a few times. See if the visibility is acceptable for the daily driving you'll be doing. Good luck in your search!
___________
Have a question about cars you would like answered? Performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
Sunday, February 7, 2010
Porsche Panamera - why is it so quick?
Three letters in the March 2010 Car & Driver question the 3.3 second 0-60mph time of the Porsche Panamera Turbo that was tested the December 2009 issue. That makes it potentially quicker than many cars with much more power and less weight including the McLaren F1, Ferrari Enzo and Porsche's own GT-2. Weighing 4409lbs with 500hp, on paper it shouldn't beat any of them. There are three reasons it's so quick.
All-wheel drive, the dual clutch transmission and gearing that is probably more aggressive than any performance car in history make it accelerate quicker than much more powerful and lighter cars. The Panamera Twin Turbo is in 3rd THIRD! gear by the time it hits 60mph. Many extreme cars like the Bugatti Veyron, Chevrolet Corvette ZR-1 and others go over 60mph in 1st gear. Check out the Bugatti Veyron road test with the top 10 quickest cars they have tested.
The all-wheel drive ensures no slippage unlike the others where power delivery has to be managed with available traction. I eluded to this challenge in my 60-130mph article. A 1.2 second 0-30mph time is extraordinary, on par with the AWD Veyron and GT-R. I would guess this translates to a 1.6 second 60ft at the dragstrip given the previously mentioned gearing.
The horsepower deficit is apparent in the trap speed in the 119mph range vs. the 125-130mph or higher times of the other cars. With excellent track preparation, technique and usually drag radial tires, a few have been able to match the launch of the Panamera and therefore run a much quicker quarter mile. Modern-day street car drag racing legends such as "Ranger" and "Furman" are examples of Corvette and Viper drivers who have done this.
Finally the 7-speed dual-clutch transmission means nearly uninterrupted power delivery. As one clutch disengages, the next engages with a speed and consistency that can't be humanly repeated. With 5 non-overdrive gears, it's fierce.
There is no other-worldly driving skill excuse or strongly suspect fudging of power levels in any gear with the Porsche Panamera Twin Turbo, unlike the Nissan GT-R. The car doesn't defy physics but it's transmission sure tries to make it seem so. Just wait when the new 911 Twin Turbo is tested.
The 2010 Porsche 911 Twin Turbo assuming the gearing is the same as the Panamera is that it will accelerate even quicker since it's about 800lbs lighter than the Panamera. So besides still not matching the GT-R's "factory" 'Ring time, it still won't accelerate to 130mph 1.6 seconds quicker than production models nor accelerate from 120 to 130mph in .9 seconds either in production form.
A great link for various automotive calculators courtesy of Wallace Racing. There are several for 60ft translations and various speed indicators.
__________
Have a question about cars you would like answered? Want to know about performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
More About: drag racing · performance · Car and Driver · racing · GM · Ferrari · Corvette · Nissan · Porsche · Panamera · Dodge · Veyron · Chevrolet · Viper · cars · Lamborghini · Ask Rob About Cars
All-wheel drive, the dual clutch transmission and gearing that is probably more aggressive than any performance car in history make it accelerate quicker than much more powerful and lighter cars. The Panamera Twin Turbo is in 3rd THIRD! gear by the time it hits 60mph. Many extreme cars like the Bugatti Veyron, Chevrolet Corvette ZR-1 and others go over 60mph in 1st gear. Check out the Bugatti Veyron road test with the top 10 quickest cars they have tested.
The all-wheel drive ensures no slippage unlike the others where power delivery has to be managed with available traction. I eluded to this challenge in my 60-130mph article. A 1.2 second 0-30mph time is extraordinary, on par with the AWD Veyron and GT-R. I would guess this translates to a 1.6 second 60ft at the dragstrip given the previously mentioned gearing.
The horsepower deficit is apparent in the trap speed in the 119mph range vs. the 125-130mph or higher times of the other cars. With excellent track preparation, technique and usually drag radial tires, a few have been able to match the launch of the Panamera and therefore run a much quicker quarter mile. Modern-day street car drag racing legends such as "Ranger" and "Furman" are examples of Corvette and Viper drivers who have done this.
Finally the 7-speed dual-clutch transmission means nearly uninterrupted power delivery. As one clutch disengages, the next engages with a speed and consistency that can't be humanly repeated. With 5 non-overdrive gears, it's fierce.
There is no other-worldly driving skill excuse or strongly suspect fudging of power levels in any gear with the Porsche Panamera Twin Turbo, unlike the Nissan GT-R. The car doesn't defy physics but it's transmission sure tries to make it seem so. Just wait when the new 911 Twin Turbo is tested.
The 2010 Porsche 911 Twin Turbo assuming the gearing is the same as the Panamera is that it will accelerate even quicker since it's about 800lbs lighter than the Panamera. So besides still not matching the GT-R's "factory" 'Ring time, it still won't accelerate to 130mph 1.6 seconds quicker than production models nor accelerate from 120 to 130mph in .9 seconds either in production form.
A great link for various automotive calculators courtesy of Wallace Racing. There are several for 60ft translations and various speed indicators.
__________
Have a question about cars you would like answered? Want to know about performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
More About: drag racing · performance · Car and Driver · racing · GM · Ferrari · Corvette · Nissan · Porsche · Panamera · Dodge · Veyron · Chevrolet · Viper · cars · Lamborghini · Ask Rob About Cars
Sunday, January 17, 2010
Silicon Valley Auto International Auto Show 2010 slideshow of customs and modified cars
As mentioned in my previous article here, one of the highlights of the show was the South Hall with numerous custom and modified cars, low riders, trucks, etc. There was even some live entertainment and dancing.
__________
Have a question about cars you would like answered? Want to know about performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
__________
Have a question about cars you would like answered? Want to know about performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
Silicon Valley International Auto Show 2010 slideshow commentary
Observations made while photographing the cars and making comparisons. Easily done while being so accessible and in close proximity to each other. Click here for the review of the show.
Click here for the slideshow of the South Hall featuring custom and modified cars
_________________
Have a question about cars you would like answered? Want to know about performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: askrobaboutcars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
Tuesday, January 5, 2010
Buying Tips for Performance Chips
Chips, handheld tuners, engine control units; they are all used to change the power output of an engine and the shifting of automated (automatic and automated manual) transmissions. The problem is how to choose based on their claims. Based on a friends 997 Porsche Twin Turbo shopping experience, there are certain things to be aware of and questions to ask if you're new to modding your car and there are no clear choices.
It's easy enough to buy on owners recommendations and write-ups in the forums. Not everyone is of the mindset for maximum horsepower though. Some don't even want to void their warranty. Go figure. Sometimes ownership of the car determines your choice. Not so with an LS1 Fbody (Camaro/Trans-Am). There are a ton of choices written up here.
The biggest controversy is horsepower claims. Where do the numbers come from and how are they measured? Keep in mind the biggest horsepower gain isn't always the best choice for your application.
Factors to consider are numerous. Will quality be affected? If supercharged or turbocharged, will the sparking life be shortened? Will there be an octane sensitivity other than a simple race gas tune? Is dyno tuning allowed for more exact and correct tuning or is a "canned" tune all that is available? Perhaps both are possible. Sometimes other vehicle electronic controls are tapped to control the level of the tune from stock to tuned to race gas. For example of this is using the cruise control button to select the tune. Sometimes, you just don't have a choice and have to go with what's available.
Are the horsepower claims taken directly from flywheel or from the dynometer? If taken from the flywheel, the implication is that the engine was removed and tested under controlled conditions. A time consuming and expensive process but more accurate.
If taken from the dynometer, and quoted as an estimated flywheel increase, what percentage loss are they calculating? Keeping in mind there are minor variations in production tolerances for horsepower ratings. One engineering team said 2% is allowable for their line of performance engines. An engine can also make more power when running cool vs. at normal operating temperature vs. running hot or "heat soaked". Taking all this into consideration, claims AND your results can vary wildly.
Was the car modified with intake and exhaust changes that show a greater horsepower enhancement than bone stock? Was 91 octane gas used vs. 93 octane? California is stuck with lousy 91 octane gas and therefore the goofballs at C.A.R.B. (California Air Research Board) dictate the octane auto manufacturers must comply with, among other restrictions. But other parts of the country have 93 octane available at the pump and there is and that allows for a little more power if tuned for it.
It's possible your emissions may be affected negatively. But that is why the "stock" tunes remain accessible. The performance aspect of the tune may not comply with emission requirements. But many times, the car will get better mileage.
As far as warranty concerns, some say their modified tune doesn't leave a trace when the car comes in for warranty work. Some manufacturers may claim otherwise. Well known BMW tuner Dinan matches the manufacturers' warranty and has a relationship with BMW. If your fellow owners have history, and there are a lot of established ones, enjoy that extra kick in the back and head snap with those shifts!
__________
Have a question about cars you would like answered? Want to know about performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
It's easy enough to buy on owners recommendations and write-ups in the forums. Not everyone is of the mindset for maximum horsepower though. Some don't even want to void their warranty. Go figure. Sometimes ownership of the car determines your choice. Not so with an LS1 Fbody (Camaro/Trans-Am). There are a ton of choices written up here.
The biggest controversy is horsepower claims. Where do the numbers come from and how are they measured? Keep in mind the biggest horsepower gain isn't always the best choice for your application.
Factors to consider are numerous. Will quality be affected? If supercharged or turbocharged, will the sparking life be shortened? Will there be an octane sensitivity other than a simple race gas tune? Is dyno tuning allowed for more exact and correct tuning or is a "canned" tune all that is available? Perhaps both are possible. Sometimes other vehicle electronic controls are tapped to control the level of the tune from stock to tuned to race gas. For example of this is using the cruise control button to select the tune. Sometimes, you just don't have a choice and have to go with what's available.
Are the horsepower claims taken directly from flywheel or from the dynometer? If taken from the flywheel, the implication is that the engine was removed and tested under controlled conditions. A time consuming and expensive process but more accurate.
If taken from the dynometer, and quoted as an estimated flywheel increase, what percentage loss are they calculating? Keeping in mind there are minor variations in production tolerances for horsepower ratings. One engineering team said 2% is allowable for their line of performance engines. An engine can also make more power when running cool vs. at normal operating temperature vs. running hot or "heat soaked". Taking all this into consideration, claims AND your results can vary wildly.
Was the car modified with intake and exhaust changes that show a greater horsepower enhancement than bone stock? Was 91 octane gas used vs. 93 octane? California is stuck with lousy 91 octane gas and therefore the goofballs at C.A.R.B. (California Air Research Board) dictate the octane auto manufacturers must comply with, among other restrictions. But other parts of the country have 93 octane available at the pump and there is and that allows for a little more power if tuned for it.
It's possible your emissions may be affected negatively. But that is why the "stock" tunes remain accessible. The performance aspect of the tune may not comply with emission requirements. But many times, the car will get better mileage.
As far as warranty concerns, some say their modified tune doesn't leave a trace when the car comes in for warranty work. Some manufacturers may claim otherwise. Well known BMW tuner Dinan matches the manufacturers' warranty and has a relationship with BMW. If your fellow owners have history, and there are a lot of established ones, enjoy that extra kick in the back and head snap with those shifts!
__________
Have a question about cars you would like answered? Want to know about performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!
Subscribe to:
Posts (Atom)