i recieved a new motor for oil consumption and have had test pipes on since the motor had about 1 mile on it. Basically I drove home and put all mods in sig back on... Motor now has about 7,000 miles on it and feels stonger then ever. My co-workers who are mechanics like me (marine mechanics) say that im killing that new motor because there designed to have backpressure and are factory tuned for it. And that running test pipes from birth will kill it real quick...

Are they saying the truth? Im no car motor expert but I still believe that exhaust is AFTER the fact and has nothing to do with the motor.

Just want some more opinions..

Thanks guys

 

Having a slightly rich or slightly lean motor due to testpipes is going to kill it?

Just nod your head and walk away.

 

With that logic, wedge a potato in your exhaust tips and tape it shut.... create some back pressure!

 

Actually running to lean can burn up a motor real quick.

 

yes running an engine 15:1AFR WOT for a few minutes will burn it up, however the difference test pipes are making is more like .1-.2afr variation. Test pipes will not hurt your engine. And that whole 'backpressure closes valves and the engine needs it' bull **** is exactly that....bull ****. Why would every car designed to get maximum power run open exhaust (or atleast a straight pipe) ?

 

No doubt, but I highly doubt running test pipes would cause a car to run soooo lean, it would get damaged.

 

Also....Infiniti of Tampa has told me that if they catch you with test pipes on your G35 they will void your warranty. They believe that test pipes cause excessive oil consumption. My friend with a 06 G has to remove his test pipes every time he gets service at the dealer. They will install high-flow cats for you though...

Now how could not running cats cause excessive oil consumption???

 

Just a BS answer, how many Gs and Zs burn oil with 100% stock motors?

 

+1

 

The exhaust mods will alter the torque and horsepower curve. Better or worse I cannot tell without a before and after dyno.

 

The test pipes have been on my car since conception and my car hasn't randomly exploded yet, lol.

 

Have you ever took it into the dealer with them on?

 

I did with my TT z32 several times and they didnt say sheet about them.

 

if your just cruising around town in your Z, i dont think the test pipes are much of an issue.

if you race your car alot, then you might look into gettin it tuned better for the test pipes. not saying theyre the problem, but running to rich or lean is.

a few weeks ago i sucked an exhaust valve in my 555ci chevy motor because it was too lean and we didnt catch it in time.

 

Test pipes won't cause any harm on the engine. I will go as far as saying that I don't see how test pipes even alter your fueling. They have nothing to do with it. I know, everybody on this site is convinced that having test pipes changes your AFR but that makes absolutely no sense. The ECU has no feedback to recognize the change in configuration so how can AFR change? Air is always metered so air cannot sneak in while ECU is not looking What does make sense is improved VE during valve overlap. Especially on an NA car, valves overlap during exhaust phase to promote better gas evacuation and improved VE on the intake side. This can falsely alter your AFR readings and register as leaner AFR due to extra air caught in the wash from the intake valve. That makes sense to me. To the OP, I think you can sleep soundly and not worry about the test pipes.

Dealers do all sorts of crazy things to prevent people from making their life difficult. When cars come in broken, they have to blame something or someone, so they will blame your test pipes. The techs, half the time, don't understand the issues so they come up with crazy explanations how dirty air filters cause lean AFRs. Right. It doesn't have to make sense and they certainly will not listen to you. They're not experts in car tech, they are just trained to handle common issues. BTW, there's no such thing as voiding the warranty. They can deny your claim if the change you made can be linked to the cause of the problem. I'd like to see how test pipes caused someone's window motor to stop working ...if you had such an issue.

Engines do not need back pressure, ever. I don't know how this myth was created. What engines do need is a well flowing exhaust. Properly matched tubing is key which promotes good gas evacuation. Having back pressure is never good.

 

+ 1,000,000 internets

It has been said time and time again -- backpressure = unnecessary and bad.

 

i personally fall into the group of people that say "break it in how its going to be ran" if your car is NA and you plan to do FI its really best to do while the motor is breaking in so it breaks in with FI, you break your car in with test pipes on it and its going to like to run with them even better because it broke in running that a/f and that backpressure, ect... like the other guy said, just smile and nod

 

you guys are somewhat correct about the back pressure deal. engines do not need packpressure to make horse power, but unless your dealing with 600hp, you do need packpressure to make torque. torque is the driving force in being quick, not fast, but quick. if you wanna go 200mph, build 3" duals. if you wanna get some where, figure out what size is right for your app. and no one needs to call me a liar unless you have worked in the exhaust business longer than me!

 

people are very unclear about backpressure. you need to create backpressure and need to release it the same amount it's created, essentially, equalling zero backpressure. i think the myth of 'needing' backpressure came about because a lot of people with 5" fart cannon's weren't building enough backpressure to utilize them. basically no, you don't need backpressure at any HP levels.

 

Then goto Lokey