V8 Intake = Loss of Torque?

[zielritter]

All-
As some of you know, I had a custom intake on my previous 2012 V6. After purchasing a V8 a couple weeks back I built something similar out of 3.5" piping for the 4.6l (pic attached). I fashioned it after other intakes I've seen people use for the Tau.

Driving around the past week I couldn't help but notice two things:

1) With the custom intake, the engine feels like it's lugging often at low RPMs. One can feel and hear the engine act as if it's struggling breath- almost like a dieseling sound when going up an incline in a higher gear. I checked several times and there are absolutely not vacuum leaks in my system.

2) Slight hesitation, following by a period of what I perceived as sluggish acceleration compared to stock. This was the first thing that jumped out at me when I pulled out of my cul-de-sac after installing it.

Now, before you say something about it, I did reset the ECU after installing the intake to compensate for any confusion it may be experiencing with the sudden change in airflow (although the merits of this are dubious).

Anyways, tonight I went back to the OEM set up (sans two resonators), and voila- much less delay off the line (sprint booster was set at red for both intakes) and a more linear "feel" of acceleration.

Thoughts:
The Lambda V6 is a rev monster to begin with, especially in the 12-14 guise. The lofty peak HP and torque numbers to begin with may have partially disguised the loss of torque that accompanied installing a custom intake.

The 4.6l V8 on the other hand makes its peak torque at a much lower 3500 rpms. Therefore, eliminating the magnetic flap along with the rest of the stock system caused a much more pronounced loss of low end torque.

Am I still getting a decent gain up top with a less restrictive custom intake? Perhaps, but with a torquey V8 is the accompanying loss of low end worth it for a daily driver? Right now, I'm not sure it is. I'm thinking, maybe, with the dyamic intake profiles that come with a V8 that uses CVVT, this engine needs a well engineered intake like OEM that allows it suck air through a small straw and then two small straws as it opens up.

Your thoughts? Any others experienced what I'm talking about? Disclaimer that IANAE and could just be talking out my ass here.

 

[2011 Genesis 4.6]

just my first thought here but you could have been pulling HOT HOT air in because of your filter location the hot exhaust is right there.
Could that have caused you a loss of low end torque, I suspect so.
I hope others chime up on this but I doubt a straight through high flow intake is causing any loss of torque just by being what it is.

 

[zielritter]

just my first thought here but you could have been pulling HOT HOT air in because of your filter location the hot exhaust is right there.
Could that have caused you a loss of low end torque, I suspect so.
I hope others chime up on this but I doubt a straight through high flow intake is causing any loss of torque just by being what it is.

I thought about that too, but I was experiencing the sensation of a loss of torque even before engine temperatures were really high. Like I mentioned, I went back to stock after driving earlier with the intake and noticed a marked difference in responsiveness.

 

[scottdk]

I put my flap back in my car too. Felt low on low end grunt. Seems to have remedied the issue with the flapper back in.

 

[Tailwalker]

I have noticed this as well with my intake, but only when I am putting around trying to keep the MPG up. When I do get on it, there is an ever so slight hesitation akin to stock, then she's all there....very much so in 'manual' mode. This is from a stop, rolling stop, and just all out.

 

[zielritter]

I have noticed this as well with my intake, but only when I am putting around trying to keep the MPG up. When I do get on it, there is an ever so slight hesitation akin to stock, then she's all there....very much so in 'manual' mode. This is from a stop, rolling stop, and just all out.

Yeah, i guess we need a dyno or at least a back to back acceleration test. Sounds like a job for me one weekend while the wife is working.

I definitely feel the lag is higher and power down from a stop with the intake. I don't really know how to remedy that aside from dropped down to 3" piping, which I think would strangle this engine up top. Damn engineers must've actually known what they were doing.

 

[2011 Genesis 4.6]

even with exhaust work done you feel it? my intake is stock other then removed flapper and resonators. I don't feel it but that sounds like what you have going on zielritter

 

[zielritter]

even with exhaust work done you feel it? my intake is stock other then removed flapper and resonators. I don't feel it but that sounds like what you have going on zielritter

Yep, even with the exhaust. I actually never drove it with the intake and stock exhaust. I took it straight from the dealer to the exhaust shop and had them switch out the cat-backs. I'm usually pretty objective when it comes to mods too. I'm not one to throw on an intake and say "wow, I can feel the extra power". This time though I definitely felt something was off.

Does anyone happen to know the tube diameter on the R2C? Did they do a dyno?

 

[Tailwalker]

For the record, mine is 4". I have a primary cat back as well. Outside of the slight hesitation on light acceleration, I think the car is indeed quicker under WOT. I will see if I can get a video

 

[consilius]

Just wanted to chime-in.

I used to feel that lack of power on the low-end torque but after installing the Dynomax VT in my vehicle and I feel a lot less of that. Maybe about 40% less than before.

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[Youseethefight]

No heat shield, you may have heat soak.

 

[Aquineas]

Might be relevant..
R-Spec dyno with an intake
R-Spec dyno with no intake
Another R-spec with no intake

 

[dmitriylm]

Might be relevant..
R-Spec dyno with an intake
R-Spec dyno with no intake
Another R-spec with no intake

The trick with dynos is that they are basically incomparable. Notice how the first dyno with the Abel Racing intake got 354whp while Edmunds got 364whp on a stock car. The Abel Racing intake claims 15whp gain so their baseline dyno was 339whp compared to 364whp for Edmunds. I wish the Abel Racing video wasn't of such poor quality so that we can look at the dyno graph and look at the difference between stock and intake. If the torque readings don't drop in the lower RPM's then we can safely assume low end torque isn't impacted.

 

[MIKES3]

Other than the flapper I dont think these intakes are restrictive at all.

 

[Aquineas]

The trick with dynos is that they are basically incomparable. Notice how the first dyno with the Abel Racing intake got 354whp while Edmunds got 364whp on a stock car. The Abel Racing intake claims 15whp gain so their baseline dyno was 339whp compared to 364whp for Edmunds. I wish the Abel Racing video wasn't of such poor quality so that we can look at the dyno graph and look at the difference between stock and intake. If the torque readings don't drop in the lower RPM's then we can safely assume low end torque isn't impacted.

I hear you and I realize that there are different dyno types and there are lots of variables, even down to temperature and humidity. But there are two dynos which show the Genesis with HP in the mid-360s, and one outlier. I guess I would have preferred that the one outlier would have performed a before and after dyno to show the changes their mod does.

 

[zielritter]

^^
It's dubious when you claim "15hp increase", but you don't show the before dyno.

 

[dmitriylm]

^^
It's dubious when you claim "15hp increase", but you don't show the before dyno.

You can see clearer dynos from Abel Racing here:

http://www.genesisowners.com/hyundai-genesis-forum/showthread.php?t=8919

The stock 5.0 put down 328/313 which is 36whp less than Edmunds stock dyno but this can be chalked up to any number of factors and the operator can manipulate the output as well. It looks like Abel used a Dynojet which tend to read high when compared to a Mustang or some other dyno types so the low readings are strange.

 

[Aquineas]

You can see clearer dynos from Abel Racing here:

http://www.genesisowners.com/hyundai-genesis-forum/showthread.php?t=8919

The stock 5.0 put down 328/313 which is 36whp less than Edmunds stock dyno but this can be chalked up to any number of factors and the operator can manipulate the output as well. It looks like Abel used a Dynojet which tend to read high when compared to a Mustang or some other dyno types so the low readings are strange.

Yep, they seem low, lower than the other two dynos I re-posted from Youtube.

 

[Tailwalker]

Forgot to add my dyno results for you. Runs were performed with ESC enabled, which may impact the numbers a bit. First run was with stock intake, second with k&n drop in, and third with full intake.


I should mention that this is for the 4.6, not 5.0...so different tranny and displacement, but given the intake design is the same you would think the results would be parallel.

 

[zielritter]

Forgot to add my dyno results for you. Runs were performed with ESC enabled, which may impact the numbers a bit. First run was with stock intake, second with k&n drop in, and third with full intake.
View attachment 5538

I should mention that this is for the 4.6, not 5.0...so different tranny and displacement, but given the intake design is the same you would think the results would be parallel.

Thanks! Good to see there was a healthy increase in torque and power from at least 4k on and not just the 500rpms right before the redline. Do the plotted points indicate the largest difference between the values as opposed to the maxes listed at the top? I'm a bit of a noob when it comes to dyno charts.