300maximilien wrote:I'm not picking on ya Tom, but is this fair to say...
2 1st Gen LH manifolds - $??
2 Magnaflow Spun Hi-Flow Converters $100 each?
1 Flowmonster X-pipe $40
2 Thrush Welded Mufflers $40 each?
2 4" resonated exhaust tips $30 each
That's $350 in parts not including mani's and labor...
Also this is a great explanation on back pressure. I am no expert, but everything I read points to the same conclusion. Unless you are getting more fuel in there is not much gain to reduced back pressure. And with modern engines unless you can alter the fuel program you can actually reduce power.
Every naturally aspirated 4 stroke gasoline or methanol engine will run it's best with no back pressure. Any automotive engineer or racing engine builder will confirm that.Of course this info is only as good as it's source. And could only be 100% if before and after DYNOs are done at each power adder step.
The problem is, virtually all carburetors and fuel injection systems were designed for engines that are muffled and have some back pressure. The result is many times when back pressure is reduced or eliminated the fuel curve is disturbed and the engines often loose low end torque because of the mismatched lean fuel curve. A simple jet change many times wont correct this. It requires a completely new fuel curve that is beyond most people's capability. This results in many people believing some back pressure is necessary,
There are no mufflers or back pressure on professional racing cars like F-1, NASCAR or NHRA.
A small amount of back pressure does not hurt performance much and it is impossible to dampen the exhaust noise without a little restriction (back pressure) so any street car will have some back pressure.
I won't say what I spent on the parts, but you are partially accurate.
As far as back pressure, all my years of experience tells me that street cars need some back pressure to run optimally.
My system has back pressure....anything in the system (ie: catalytic converters, bends, mufflers) create back pressure.
I will say this....the two best mods I have ever done to my car are the high stall torque converter, and the 1G exhaust manifolds, without question.