Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
Turbo is the way to go. Only problem is that the factory assembly units are too small for any major power. The units are the size of a mans fist (so to speak) while a custom larger unit will give the oomph to go on Boost. Factory units are small with a dump gate so that people will not blow up the engine. A engine will blow before a Turbo quits without a waste gate to dump the exhaust gas.
Generally 5 lbs of boost is considered the max on a factory street car while a custom unit can function at 15 lbs of boost in the street. As a retired mechanic I built one and still have it in my VW bug that puts out 200HP.
Only problem is installing one in a smog controlled vehicle. Only solution would be to have a older car that is smog exempt and install a after mkt unit by a Turbo Pro. The power and expense is well worth it in the long run as long as you keep the car for a few yrs.
Good luck... Steve
Not sure where you're coming from. There are factory 2.0 turbocharged motors out there putting out as much as 290HP and 2.5L setups at up to 315 HP. That's plenty. As for your 5 pounds of boost assertion... just off the top of my head the minimum amount of boost put out by a factory turbo setup is 9 pounds in the BMW straight-six twin-turbo. The WRX puts out 13 pounds, the STi 15 pounds, the Mitsubishi 2.0 is factory-set at 19 pounds and the high-end GM ecotec is tuned for 20 pounds.
Some of you are forgetting what drives a Turbo to BOOST. It is the exhaust gas that turns the impeller whether it be a small 4 cyl...6 cyl...V8 or a 18 wheel Diesel. They can all have close to the same Boost number but give power to a different weight car/truck...thus my statement of a min of 5 lbs of boost.
Turbos are mated to a specific size of engine as the Turbo Model size will vary depending on the brand and performance needed. I personally have a Rajay B25 for my small engine but changed the housing to get a boost at lower RPM to match my engine needs and performance.
Your example of twin Turbos on a straight 6 are the same as Porsche Turbo running two small units over say one large unit. Same comparison would be the usage of muli carbs on a V8 instead of one 4bbl.
We can go back and forth all day long...no need too...every setup is different and the results will vary.
Had a friend with a Turbo VW dragster that pulled 30 lbs of boost at the light on the strip. His engine was a larger unit then my small engine rail. My engine being smaller gave me good boost numbers but not the power to the rear wheels is what we are all looking for.
Repeating myself...boost numbers may be high...what about the power to the wheels.
Are we going to be talking factory assembly setups or custom Turbo applications.
Don't think the Factories built assembly line Turbo cars for the drag strip.
As I stated in a previous post...a engine will BLOW before a Turbo quits without a waste gate.
The only time I've really seen 5psi-6psi max boost levels has been on aftermarket turbo's applied to factory high compression motors (lots of Hondas).
With higher compression engine, the boost is generally kept low. A high pressure turbo will usually go with a low compression engine (as Steve alluded to earlier). Most Hondas, for example, start with high compression and are high revvers. The combination demands lower boost but higher revving nature makes up for the power.
Even RDX that you mentioned as having 14 psi, runs that boost only upto 4500 rpm, and then it is dropped to about 8 psi by the time it gets to 6500 rpm.
Get a VW TDI turbo diesel. Either a Jetta, Golf, or Passat. There isn't a better car for climbing hills than a TDI. It will not only climb any hill in high gear, but it will get 40+mpg doing it. No better bang for the buck, barr none.
Some of you are forgetting what drives a Turbo to BOOST. It is the exhaust gas that turns the impeller whether it be a small 4 cyl...6 cyl...V8 or a 18 wheel Diesel. They can all have close to the same Boost number but give power to a different weight car/truck...thus my statement of a min of 5 lbs of boost.
Turbos are mated to a specific size of engine as the Turbo Model size will vary depending on the brand and performance needed. I personally have a Rajay B25 for my small engine but changed the housing to get a boost at lower RPM to match my engine needs and performance.
Your example of twin Turbos on a straight 6 are the same as Porsche Turbo running two small units over say one large unit. Same comparison would be the usage of muli carbs on a V8 instead of one 4bbl.
We can go back and forth all day long...no need too...every setup is different and the results will vary.
Had a friend with a Turbo VW dragster that pulled 30 lbs of boost at the light on the strip. His engine was a larger unit then my small engine rail. My engine being smaller gave me good boost numbers but not the power to the rear wheels is what we are all looking for.
Repeating myself...boost numbers may be high...what about the power to the wheels.
Are we going to be talking factory assembly setups or custom Turbo applications.
Don't think the Factories built assembly line Turbo cars for the drag strip.
As I stated in a previous post...a engine will BLOW before a Turbo quits without a waste gate.
Ah, I don't think anybody is forgetting what drives a turbo to boost. As for "are we going to be talking factory assembly setups or custom turbo applications..." well, to be honest, I can't really tell what you're talking about in this post. But you said in an earlier post that factory settings for turbo boost are 5 pounds max, which is just flat wrong. Factory setups are pushing anywhere from 9 to 20psi.
Also, something else I saw upstream is that turbos are generally for low-compression setups. Well, direct injection is starting to this. The improved atomization of direct injection means it takes less fuel to sufficiently cool the combustion chamber to prevent pre-ignition. As a result we're seeing cars with compression ratios as high as 9.5 to 1 with boost of up to 16psi.
This is part of the reason why we are seeing a resurgence in turbocharged engines. One reason turbocharged engines historically achieve lower gas mileage, even on the highway when the turbo is basically sleeping,, is the lower compression ratio. Now that compression ratios on turbocharged cars are moving upward, it's becoming easier to make decent power and still meet fuel efficiency and emissions requirements. BMW is ditching its V10 for a turbocharged V8. GM is ditching its 2.2 for a 1.4L turbocharged unit. A lot of Ford V8s will probably be replaced with a 3.5L twin-turbo V6.
People are not aware of what I referred too the 5 lbs of boost as being with a waste gate.
Anyone with any Turbo Knowledge would understand my meaning.
Buy the book "Turbochargers" by Hugh Macinnes and open your eyes.
I did and still do not know it all.
Steve
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
