matrix performance upgrade article

[notslow65]

http://www.diynetwork.com/diy/ab_par...081603,00.html

Has this been posted already????

after someone has professionally taken an XR and done the SRI, axleback muffler and even piggy back ECU upgrade they only reaped 6HP???????!!!!!!!!

I'd imagine this is a more realistic view on all these bolton upgrades unlike the advertisers boasting 12 +HP with just a muffler swap!!!!

[Locomotion]

There was a 6hp increase in PEAK power. But if you click on figure I, it looks more like there was a 20hp increase right before 4k rpm--assuming that the blue line represents stock hp/torque and the yellow line represents the hp/torque after the mods. The midrange power increase is much more impressive than the peak power increase.

[joemaniaci]

Yeh, I kind of wish they rated horsepower as an average, instead of peak. Whats the point of peak when youre only achieving it for 1/10 of a second. they should just take the horsepower rating at every 500 rpms, add them together and then divide by however many increments of 500 you had. Whats the point of making 200 hp at 6000 rpms if youre making less than 100 hp from 4000 or below, just an example.

[notslow65]

Originally Posted by Locomotion

There was a 6hp increase in PEAK power. But if you click on figure I, it looks more like there was a 20hp increase right before 4k rpm--assuming that the blue line represents stock hp/torque and the yellow line represents the hp/torque after the mods. The midrange power increase is much more impressive than the peak power increase.

I noticed the increase in the mid rpm range but the dyno graph is very vague. Odd how that "test" never boasted about the "improvements" in the mid rpm level.

In the "drag race" world hopefully your shiftpoints dont drop too low. If someone maintains and stays in the higher rpms they take less time to recover. This is why people should be shifting aproximately 10% past the peak HP so that the engine stays in the sweet spot.

Peak HP is very important since this is what keeps you accelerating. The torque is what gets you going. More HP means higher MPH numbers on a timeslip at the track.

I guess there is a significant gain to keep the car accelerating in the 4000+rpm range. 6 HP gain at the peak sounds more like the limitation of the cylinder head and cam profile.