Gibson has come out with this dyno chart, which you oughta all check out:

http://www.gibsonperformance.com/index.asp?p=exhperf

It covers various years and engines of Chevy, Dodge, Ford, Jeep, Nissan, and Toyota. I've never seen such a chart for a given catback system, and its very informative. Hp and torque increase claims of manufacturers for their products are always very suspect. However, the hugh differences in the range of hp and torque increases for various engines with the same muffler, and the fact that some of the shown increases are very low, indicate to me that the chart's no BS and can be trusted.

The chart includes the 3.0 and 4.0 Ranger engines.

 

id like to see the charts to see what it does over the whole curve

 

wow 7hp and 2ft.lbs of torque for a 400 dollar exhaust, how depressing... i suddenly had a change of heart for gibson

 

12hp/17tq seems like reasonable numbers for the 4.0

 

99-01 4.0 ranger? Do they group the OHV and SOHC together? Are the gains the same on both. I suspect it to be just the OHV for some reason don't ask me why.

 

isn't the sport trac (2001) 4.0 the same used in 01+ ranger 4.0s (SOHC)? if so, 17/30 isn't too bad..

 

i dont know, 30 lb ft torque gain seems highly unlikely...there is nothing else there, gas engine wise, that produces those gains...and i dont think the stock exhaust is that restrivtive. im probaly wrong but 30 is a lot for just a cat back...

also if u look a 2002 exploder with the 4.0 produced a 19 torque gain which is close to what the rangers run...

id also like to see the actual chart to see how it effects the power curves. actually anything but a big displacement engine or diesel shows poor gains for the price...maybe its just me but it doesnt seem worth it...

 

But along with the "Gains" you get a nicer sound...which is a big plus.

 

oh ya, nicer sound...the reason most people buy an exhaust...

 

Dont sound right. I have looked at flow charts, gibson's systems are usually the worst.

 

here's a leak: i'm now an official Gibson dealer

details coming soon

 

If you want real performance just run straight pipe from the cat back, I dont see these numbers as being quite accurate.

 

No offence to anyone who has it, but my buddy and i both had gibson and they sounded like ****, it sounded more like a import car with a fart can on it, then it did a truck, get a magnaflow it sounds deeper

 

Ah yes, exhaust wars. Very refreshing as this has NEVER been discussed on here before...

I do like that chart, John. The most detailed one I seen also.

I have a FlowMaster dumped at the rear axle. Before that I had a Dynomax but I smacked it up too much. The FlowMaster can survive me scraping it around offroad better, and it sounds nice. Not a partisan though -- just need something that works really, and hope for gains.

 

ha, real performance?

And Borla is even deeper

 

I call bs.. they say 99-01 gained the same? that was 2 different engines!!!!

 

I had a Gibson SS on my 01, I loved the look and sound.
I didn't notice any increase though in pulling...

 

I can't say I noticed any gains since it was the previous owner that put it on, but my truck seems to have quite a bit of power. Enough to get me a speeding ticket on wednesday atleast...