power loss need help from someone!

[Loochy88]

Re: power loss need help from someone!

maybe i missed it: are you throwing any codes?? (is your SES light on?)

[camaroz87]

Re: power loss need help from someone!

nope no codes at all!

[Ace]

Re: power loss need help from someone!

I just popped a coil at 68K miles and the check engine flashed a few times then went off even tho the car was still missin on to cylinders. But sure enough it still saved the code when i read it with the code reader.

[Ace]

Re: power loss need help from someone!

Does your car sound like a lawn mower?

[slow6]

Re: power loss need help from someone!

I just popped a coil at 68K miles and the check engine flashed a few times then went off even tho the car was still missin on to cylinders. But sure enough it still saved the code when i read it with the code reader.

The misfire will flash the SES light. I've had hella misfires in the past, the SES light flashing would come and go. sounds normal

Does your car sound like a lawn mower?

you're right but,
thats not a fair comparison.. a lawn mower is a 2-stroke engine ;)

The way you can tell its misfireing is (the SES flashing). But when you misfire it is violent and kinda shakes the car a little. You can feel it and hear it. It feels like you loose power for less than a second everytime (and it misfires ALOT)

[kuttman]

Re: power loss need help from someone!

we need a certan amount of back presure for it to work right the computer will try to copinsate for the change and it cant

[Ace]

Re: power loss need help from someone!

most lawn mowers i ever used was a 4 stroke.

[Ace]

Re: power loss need help from someone!

The truth - exhaust gas velocity

Here's the real deal about choosing an exhaust that is too big. I'm not a physicist, my understanding of fluid dynamics is very limited.... but here's my understanding.

Exhaust gases moving out of your exhaust can be used to pull other exhaust gases out of your cylinders. This is why headers are sized and the tubes matched the way they are. This effect is called scavenging. The faster the gases move, the more you benefit from scavenging.

The larger the tubing, the slower the gases move, the less scavenging occurs. (but, more ultimate flow with less restriction is possible)

The smaller the tubing, the faster the flow. (but obviously, the resistance can quickly overcome the benefit of scavenging if you start reducing your tubing size... a drinking straw simply can't flow enough for a motor)

Notice I didn't say anything about backpressure. Backpressure is just a measure of the restriction in the system. It can be caused by bends, narrow tubing, badly flowing mufflers, etc. Backpressure will be present in any system - but the less that is there the better. A large diameter system with a restrictive muffler (and therefore a high backpressure) will not gain any velocity. So now you will have to worst of both worlds - reduced scavenging and a restriction to free flow at higher rpms.

Some people claim to lose low end power when strapping on a big bore exhaust. This may be true, but it's because of a decrease in the scavenging effect, not because you don;t have enough backpressure.

[camaroz87]

Re: power loss need help from someone!

then how do exhaust help us i def lost low end power by adding the 3" magnaflow but i need low end power i dont wanna floor it just to get ahead on the highway its bad enuff gas prices are ridiculous....today i was going up a hill and i literally had to floor it..im just gunna sell my car its too much

[Ace]

Re: power loss need help from someone!

Well with the power loss your explaining it definetly isnt a exhaust problem. I would bet $100 dollars its a coil. How many miles did u have on the coils?