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View Full Version : Comparisons of Turbo motor Vs. N/A motor info!


nitrorocket
06-30-2006, 01:06 PM
I though I would list my experience with my turbo engine compared to my previous motor, pro’s and con’s. I figured some might take this info as good knowledge for there own future projects. It is info you don’t see first hand anywhere and stuff a lot of people don’t realize.

Old motor:

- 427” Tall deck dart block SBC
-4” stroke
-6.125” rods
-Solid roller .690 lift cam, 265 @.050
-10.5:1 compression
-18 degree Dart heads with 2.15/1.625” valves
-1.7:1 shaft rockers
-1.625” valve springs with 750 lb. open pressure!
-Custom single plane “053” Nascar intake
-Accel Gen 7 fuel injection & 83 lb./hr injectors
-Approx. 650 hp at 7000 rpm.

This motor costs approximately $20,000 to duplicate. It was built to be a “Street” driver motor. The engine was driven a about 3000 total miles over the few years I had it along with a few drag strip passes. It sounded wicked and had gobs of power for a N/A motor. The fuel injection was a nice feature for startup drivability and consistency, but added huge cost to the engine.

Positives of the motor were the sound; it sounded awesome, had a real nice rumble and had about a 1000 rpm idle. The motor would start right up at the turn of the key at any temp, never had to touch the gas. The motor was also a simple standard SBC based motor that was very easy to work on.

Negatives were the cost, $20k is way too much money for a motor that is not for racing and gets street driven. Motors wear out, and to wear out a $20K engine by cruising back and forth to a car show did not make sense! The motor got very poor mileage. I was getting right about 10 mpg if I drove nice, if I went on beat runs, I could burn a half tank within 10 miles. The motor was also very high maintenance. Most people do not realize until you own one how much this can limit you and cost. I had to replace the valve springs, rocker bearings, and lifters every 1500 miles! At $900 in parts alone, this was not fun.

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New turbo motor:

-347” Aluminum block LS1
-Stock crank
-6.125” rods
-Hydraulic Roller .581 lift, 224 @ .050
-8:1 Compression
-Factory heads with porting
-Dual valve springs
-Stock intake
-Stock computer
-Makes about 1000 hp at 6000 rpm

Turbo setup:

-Twin 61 mm GT35 Ball bearing turbos
-1.75” stainless headers
-Twin Racegate Wastegates
-1 50mm Blow off valve
-1500 CFM air/air intercooler

I have half into this motor over what my 427 cost. This motor is actually a real “street” motor. I can drive cross-country back and forth until I run out of gas money! It idles at 800 rpm, can go on a cruise without attracting Police officers, and is quiet. I have driven the motor about 1500 miles along with a dyno pull and strip pass so far with good results.

Positives of the motor are the mileage. The setup is getting about 15-city mpg and should get about 20-mpg highway if I drive nice. The motor is quiet enough to finally hear my radio and talk with my family! Being that the moor is basically just a ls1 with turbos on it, it runs drives, starts, and does everything a regular ls1 does. That is REAL nice, I don’t have to worry about maintenance and getting stranded over some rare expensive race part failure. The power is more then a street car EVER needs.

Negatives are the complexity of the setup. On top of the simple little LS1, is a lot of plumbing. There are lines all over for oiling, cooling, and exhaust that were not easy to rout cleanly. The other negative is that I had to design and build the entire setup myself instead of buy parts off the shelf. This added a lot of time to the build. I had one turbo failure from a faulty turbo that resulted in the purchase of the two ball bearing turbos, that failure will not happen again. This may sound weird but another negative is the power. If you are not careful it can get out of hand real fast. With each ¼” of throttle pedal travel equaling about 100 hp, if you go over a bump in the road or slide in your seat and wiggle the gas pedal…. The tires will spin.


Conclusion…. Forced induction, whether it be turbo’s or a supercharger, is the BEST way to make reliable power. You can never have a motor with all the benefits without it. It is also much cheaper then a big horsepower N/A motor. That was a factor that made me go the F.I. route.

customcam
06-30-2006, 06:18 PM
thast so cool good write up
lets us now what were in for if we choose to go that way :thumbsup:
big hp man!

EFI
06-30-2006, 06:26 PM
Thanks for the info. I'm leaning towards a twin turbo set up for my car, and your write up has pushed me even further in that direction. I like the idea of something that I can drive, yet pushes me back in my seat when I get after it.

syborg tt
07-02-2006, 09:31 AM
I also agree with you about turbo being the way to go. And your choice of a LS_ motor is the way to go. Even a regular small block TT is awesome choice and parts are even cheaper and more plentiful.

ps - don't ever build a tt v6 as everything is custom i mean everything.