So I am doing some research on the exhausts available for the 98 version of the blazer....

Ideas...

Straight duals...
Straight single....
High flow cat with muffler...
Cherry bomb...
flowmasters...

Now I know everyone wants loud/beastly sound...
But which one would give the best performance.. I was reading about back pressure and that if you go with straight dual pipes your performance will lessen...

I am just looking for some input, as I want my blazer louder... and performing better... but I will not through straights on it if it will perform like a dog...

 

I have a Flowmaster 4 series single pipe exhaust which sounds good, its throaty but not quite obnoxious

 

But does it cause poor performance? I know I could google the crap out of this, but dyno/lab results can disagree with personal experience...

 

actually i had no performance drop , had a small gain though but it really wasn't noticable, it just sounds really good imo

 

'Personal experience' (butt dyno) is no substitute for actual dyno results. It's like the old saying, "Who are you going to believe, me or your lying eyes?"
The problem is trying to find dyno results for these engines. They are just not performance oriented and people don't want to spend money for using dynos.

 

Being an engineering student, we are told to "assume" and then when we graduate we still assume, and throw in a factor of safety to cover our a$$e$.... Now We also learn that this factor of safety is due to the idea that nothing is "ideal" whereas the dyno is an idealized situation, without the same load that is on your vehicle.. granted there are chasis dynos,

but if both you and I buy a bolt, same bolt down to spec, say with a yield strength of like 60k psi... And we stress them to 45k psi, and mine breaks... its because things are similar and the strength of the steel is an idealized property...

I am ranting out my butt, but I would rather listen to 25 guys who have tried 10 different ways to make power and know one that works, rather than the people behind performance parts, because we all know that during dyno testing for these parts they are idealized situations and sometimes use different components to get "their idealized results"

 

The only time you will loose power and make your truck feel like a "dog" as you explain it is if you go with too large of an exhaust pipe so your truck looses its exhaust velocity. Not backpressure in reality you dont want ANY backpressure. You could go dual straight pipes if you wanted. But I would suggest 2" Pipe no larger than 2.25 honestly. Everyone is so mislead with the whole backpressure thing. Your motor doesent want its used exhaust gases still in the combustion chamber, and when you have backpressure it makes the engine work harded to push out the exhaust as compared to a good flowing exhaust with high velocity that makes use of your power.

 

back pressure helps with low end torque.. but a goodhigh flowing exhaust helps with top end performance.. now WLORTEN i put a 40 series flowmaster on with a high flow cat and took out the smaller cat before the main cat, i never made any pipe larger than it was i just opened up the exhaust stream better. i honestly notice a differnece than when it was stock. my friend has a stock 01 blazer and i smoke him every time. So i guess it had to do something.

 

I was looking at doing the same thing (removing the pre-cat) for the same reasons you have stated however, I was just worried about the O2 sensors being thrown off in doing so. You havent had any problems with the sensors I am assuming?....

Thanks!

 

All backpressure does is make your engine work harder and you loose power. Backpressure in anyway shape and form is not what you want nor is it at all any good. The reason why it feels like your looseing power is because of the air/fuel ratio is being leaned out and needs to be richened and then problems solved. Nowadays most are done computerized.