TRUE OF FALSE Power Loss After Intake and Exhaust Setup

Zoren 370 · 12-18-2014, 09:52 PM

Quote:

Originally Posted by jwick

Same boat before I went turbo

You guys do know you need to reset the ECU after the mods and maybe perform the idle relearn

Yo pass it left homie

Yup I had all my mods at 2k miles and I'm at 27k miles now the engine is like getting better and better without a tune.

The only time I would possibly go and have a tune once I swap out my manifold with motordyne. That to Im still thinking if I'll do...as the car runs perfect!

I can roll one up for you bud!

Jordo! · 12-18-2014, 10:43 PM

It depends.

A DIY intake (home hack job), in which the tubes may move around, will cause lots of air turbulence and the MAF's will not get stable readings, usually resulting in power loss.

A poorly designed intake with a different diameter than OEM or bends just before or after the MAF can cause a related set of problems due to misreads, stable or not.

To the best of my knowledge, none of the non-DIY/non-ebay intakes cause this to the point of significant problems; where they might cause some misreads (e.g., reading lean -- not generally resulting in power loss, BTW), a tune will correct.

The only other thing I can think of is the M370 IM, which tends to move peak torque down a bit, resulting in a low end bump at the cost of a tiny bit of top end. Also can be mitigated with tuning.

For exhaust, short of overly large diameter piping, really any mod that improves flow will gain power on this motor. Some header designs favor mid to top end gains over low end. The issue is more complex than merely accounting for "backpressure" (e.g., valve timing and lift comes into play), but overly large diameters (say, over 3") could slow exhaust pulses enough at low speed for some loss, although it might pick up power approaching redline.

Pretty much any cat back and ANY replacing or removing of the cats (CEL's from secondary O2's notwithstanding -- again fixed with a tune) will result in more power.

In short, other than a custom, but inexpertly made, or random "generic" part, most bolt-on's result in gains, not losses. Whether a quality part or not, a tune is always advisable -- not necessarily required for safety, but advised for optimal performance.

Read T · 12-18-2014, 11:14 PM

I've heard that turbocharging increases back pressure and decreases horsepower. That's why the C7 is faster than the Focus ST.

jwick · 12-18-2014, 11:31 PM

Quote:

Originally Posted by Read T

I've heard that turbocharging increases back pressure and decreases horsepower. That's why the C7 is faster than the Focus ST.

Zoren 370 · 12-18-2014, 11:49 PM

Quote:

Originally Posted by Read T

I've heard that turbocharging increases back pressure and decreases horsepower. That's why the C7 is faster than the Focus ST.

What the Fart back pressure is that? Thats really funny!

edub370 · 12-19-2014, 09:16 AM

there should be no physical way to lose power with intakes and exhaust. its commons sense and dyno proven. who the hell told u this stuff?

Bshields22 · 12-19-2014, 11:26 AM

Hey guys! Thanks for all the help! I'll let you know my findings!

Cheers!

12-18-2014, 10:43 PM	#17 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 418	It depends. A DIY intake (home hack job), in which the tubes may move around, will cause lots of air turbulence and the MAF's will not get stable readings, usually resulting in power loss. A poorly designed intake with a different diameter than OEM or bends just before or after the MAF can cause a related set of problems due to misreads, stable or not. To the best of my knowledge, none of the non-DIY/non-ebay intakes cause this to the point of significant problems; where they might cause some misreads (e.g., reading lean -- not generally resulting in power loss, BTW), a tune will correct. The only other thing I can think of is the M370 IM, which tends to move peak torque down a bit, resulting in a low end bump at the cost of a tiny bit of top end. Also can be mitigated with tuning. For exhaust, short of overly large diameter piping, really any mod that improves flow will gain power on this motor. Some header designs favor mid to top end gains over low end. The issue is more complex than merely accounting for "backpressure" (e.g., valve timing and lift comes into play), but overly large diameters (say, over 3") could slow exhaust pulses enough at low speed for some loss, although it might pick up power approaching redline. Pretty much any cat back and ANY replacing or removing of the cats (CEL's from secondary O2's notwithstanding -- again fixed with a tune) will result in more power. In short, other than a custom, but inexpertly made, or random "generic" part, most bolt-on's result in gains, not losses. Whether a quality part or not, a tune is always advisable -- not necessarily required for safety, but advised for optimal performance. Zoren 370 and Zbrah like this. __________________ Enjoy it. Destroy it.

12-18-2014, 11:14 PM	#18 (permalink)
Read T A True Z Fanatic Join Date: May 2012 Location: Raleigh, NC Posts: 1,046 Drives: 11 Nissan 370z BC 6M Rep Power: 18	I've heard that turbocharging increases back pressure and decreases horsepower. That's why the C7 is faster than the Focus ST. jwick and DEpointfive0 like this. __________________ 2011 Nissan 370z Black Cherry Sport Pkg - Daily Driver, , 1960 Morgan +4 fun car, 1986 BMW 325ES, 1998 M3 and 1996 Spec Miata - Race Cars SUPPORT TEAM WINSOME RACING - WRL, CHUMP, LEMONS

12-19-2014, 09:16 AM	#21 (permalink)
edub370 A True Z Fanatic Join Date: May 2011 Location: KCMO Posts: 3,458 Drives: 09 370z S/T 6MT Rep Power: 20	there should be no physical way to lose power with intakes and exhaust. its commons sense and dyno proven. who the hell told u this stuff? __________________ 09 370Z ST 6MT//Injen CAI//Greddy CBE//TP//TSW's//Swifts//Stillen lip//Whiteline sways 326whp/268tq

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12-19-2014, 11:26 AM	#22 (permalink)
Bshields22 Enthusiast Member Join Date: Nov 2012 Location: Anaheim, CA Posts: 422 Drives: 2012 Black 370Z-R Rep Power: 698	Hey guys! Thanks for all the help! I'll let you know my findings! Cheers!