Performance loss with Full APEX-i exhaust

[turboblack2door]

i had a greddy sp2 cat back on my spyder before i put the downpipe back APEX-i N1 on my car and i think i lost power. Anyone notice power loss with this exhaust

 

[talonalex92]

Hm, maybe if its a smaller size pipe?

 

[talonalex92]

I dont know the sizes but thats the only thing I can think that would make you actually, loose power.

 

[nfernotalon]

Is this on the assdyno?

 

[turboblack2door]

the apexi has bigger diameter pipe and yes it was on the ass dyno

 

[ILLiCliPSE]

you probably lost a little torque since the piping is bigger, which is why it probably feels slow on the but dyno, yet you probably netted some unnoticable horsepower.

 

[turboblack2door]

do you think it'll be faster over all even though i lost torque?

 

[gsxtasy]

I doubt it, maybe if you were at the limits of your other exhuast, which i doubt. If it is, it probably won't be very noticeable.

 

[deflator]

do you think it'll be faster over all even though i lost torque?

Unless you went with a 4" exhaust, probably. With the larger piping, you're moving where your exhaust is most efficient into higher RPMs. Does it feel slower even at WOT?

 

[turboblack2door]

yea it doesnt' spin the tires as much anymore

 

[dsmsucks]

Wow thats REAL odd. When I did the exhaust on my car it made a BIG difference.

 

[99gst_racer]

I don't know of a single ass dyno that is calibrated tight enough to pick up a couple HP difference.
And swapping between different cat-backs probably won't net a large enough gain to be noticed on the butt-dyno either.

If you can actually feel a difference in HP, then it probably wasn't due to swapping cat-backs.

 

[turboblack2door]

it wasn't just the cat back. With the greddy sp2 i had the stock downpipe and cat. With the APEX-i it's the downpipe back with no cat

 

[1gDSM4g63]

do you think it'll be faster over all even though i lost torque?

Switching from Greddy and Apexi is not going to make a noticeable difference. It all depends how good of a driver you are when it comes to the little things like that. But if you're coming from stock exhaust yes it would a difference.

it wasn't just the cat back. With the greddy sp2 i had the stock downpipe and cat. With the APEX-i it's the downpipe back with no cat

If you install the Apexi without the cat that would make a huge difference. With no cat it causes less restriction and higher flow which will have the biggest gain at high rpms.

 

[PieEyedPiper]

The N1 necks down to >2.25" in some spots. What is the most narrow passage in the Greddy exhaust?

You might consider bolting up your old catback in place of your new one for further testing.

Though, as mentioned already, the ass dyno isn't the best method.

 

[turboblack2door]

i know the ass dyno isn't the best method but the greddy is a 2 1/2in all the way through. with the stock downpipe

 

[rich3389]

Just because the car is now "spinning tires" less doesn't mean its from the exhaust change.
It can be many things, air temp, water temp, road surface, even the quality of the gas in your car, the car can be pulling the timing only every once in a while.

 

[DSMopar]

The N1 necks down to 2.25" in some spots. What is the most narrow passage in the Greddy exhaust?

You might consider bolting up your old catback in place of your new one for further testing.

Though, as mentioned already, the ass dyno isn't the best method.

Yep, I can vouch for that, you didn't say if it were a 'GT' spec, but if it's an N1... there are some small sections.

If I paid good money for mine i'd be pissed, but I didn't... so

You don't even want to see the N1 DP, it's depressing.... I'll be making a thread on that one....

This is for a 1g AWD but i'm assuming the 2g is similar