80-Series Flowmaster enough back pressure?

Minh · Post by **Minh** » Wed Sep 03, 2003 3:20 pm

I'm entertaining the possibility of having dual side pipes while still having that deep flowmaster rumble

The 80-series Flowmaster #42583 has a 2.5 inch input with dual 2.5 ouput where one is at the back and the other is at the front next to the input.
http://www.pro-max.com/FM80series.htm

Does 80 Flowmaster Series have enough back pressure for a 2 liter engine? I don't want to burn up the engine. Suggestion would help if you got any...

Thanks...

Dave · Post by **Dave** » Wed Sep 03, 2003 7:59 pm

Minh,

Back in the good old highschool days I used to run an L20B in my 510 with 2.5 inch exhaust leading to nothing but a $15 cherry bomb from NAPA. Later I upgraded to a Supertrapp that I ran with no plates or end cap. One guy told me I was risking burning up the exhaust valves. Something about sucking up cold air after the engine was shut off. Sounded like an urban myth to me. I ran this setup for 3 years without a hint of a problem.

If someone out there has actually burned up their Datsun engine running an exhaust system with too little back pressure, I'd love to hear about it. Unless someone has some solid proof otherwise, my opinion is that your only risk is losing some low end torque.

That said, I'll brace myself for the onslaught of responses for people with burned up Datsun engines in the back shed....

Dave

Minh · Post by **Minh** » Thu Sep 04, 2003 2:02 pm

Well... Dave does have point.

Since it is better to err on the side of caution. I guess I better stick with the single front inlet, dual back outlet 40 series...

Besides the 80 sereis is almsot twice price of the 40 series.