Question about intakes and down pipes.

[jtlctr]

First off, I’m considering a HVI just for a little extra sound. I understand that, without tuning, any aftermarket intake will disrupt MAF readings at least a little bit and The ECU will adjust fuel trims to compensate. Has anyone observed their fuel trims with any of the intakes available? And what is generally considered a safe range?

My second question is about installing a downpipe. Is it safe to install one without throwing off the factory tune much, catted or catless Also, is there any improvement in turbo lag with the aftermarket downpipe?

realize that any mod will not be fully realized until it’s tuned for and I do plan on tuning eventually (looking at you, Jester!) once I get over the financial hit of buying the car itself.

sorry for the barrage of questions. Any input would be appreciated!

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[Shankmeyster]

Intakes will be compensated by the ECU, although I'd suggest doing an ECU relearn after install. It has been said that anything under 10% +/- on long term and short term trims is fine.
A DP will most likely require a tune since the cat won't be the same as the factory one and will throw off what the ECU sees on the back end.

 

[Pekingduck]

First off, I’m considering a HVI just for a little extra sound. I understand that, without tuning, any aftermarket intake will disrupt MAF readings at least a little bit and The ECU will adjust fuel trims to compensate. Has anyone observed their fuel trims with any of the intakes available? And what is generally considered a safe range?

My second question is about installing a downpipe. Is it safe to install one without throwing off the factory tune much, catted or catless Also, is there any improvement in turbo lag with the aftermarket downpipe?

realize that any mod will not be fully realized until it’s tuned for and I do plan on tuning eventually (looking at you, Jester!) once I get over the financial hit of buying the car itself.

sorry for the barrage of questions. Any input would be appreciated!

Both will be fine. But the only thing for catless downpipe it throw a check engine light. I really like the catless downpipe for better spool, better top end, and it add noise.

 

[Jester04]

Not necessarily true. Aftermarket tuners have to scale the MAF sensors due to the larger tube size or position of the sensor. The ECU will attempt to adapt the best it can, but will not be optimal. Will it hurt the car? No. But likely will run a bit more rich or lean than needed. Fuel trims will not be perfect. A tuner can get it almost perfect by altering the MAF calibration as compared to the commanded AF ratio and measured AF ratio.

@Jester04 can probably explain it better since it’s been a while for me.

Correct you want your fuel trims as close as possible to 0 with a +-5% usually. But everything on the intake side has ti be calibrated through the MAF.

 

[Jester04]

Thanks! A lot of people think the ECU can compensate, but it doesn’t have as tight of tolerance for fuel trims as a properly scaled MAF will once tuned. If you want your car running optimally, get tuned for that intake.

Yes the ecu will compensate but ideally you want it programmed correctly like you stated. It is the best way to get the car running correctly with no hiccups.

 

[johnny.silva7]

I recently added a PRL HVI, TSP DP, and PRL front pipe without a tune. Car doesn't throw any codes. It has a nice little idle and punchier throttle (& cool sound) at mid-range.

I did an oil change prior and took a sample to Blackstone. I have a couple track days coming up plan to do another oil sample afterwards.

 

[jtlctr]

I appreciate the input, everyone. Thank you! I’m thinking I’ll probably hold off on this stuff for now and add parts when I’m ready to shell out the $ for a proper tune.

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