Z feels slower after plenum spacer?
 

I installed my motordyne 5/16 plenum spacer the other day and so far ive noticed these things...

- Smoother idle and very quiet now.

- The RPM's seem to raise alot quicker, im able to get to 6k alot faster now.

- The car doesnt sound as "mean" in lower RPM's its not as deep sounding as it was around 2500rpm's (which kinda sucks)

- Now the big one. I dunno if its the lack of the deep roar but the car feels less tourqey, by that I mean I feel I have to push it harder to really feel it and get sucked into my seat, it used to be very meh around 2-3k and then pull hard.

Now it just kinda pulls evenly up until like 5k+ and then finally pulls hard.

Is any of this normal? I know I installed it perfectly, there is no CEL or leak sounds and ive had it on for 2 days, do I need to reset the ECU or something? Its kinda crappy because I was told it would make my car sound "meaner" and pull harder.

You said:
Doesn’t a faster increase in RPMs mean you are developing more power more quickly?

The power curve might remain flatter (more linear) making you feel as though there is less torque, especially at the points where you noticed this before the installation.

After you run for awhile, come back here and let us know what your think about the plenum spacer.

--Spike

what other mods do you have??? might need a tune, i am willing to bet that you are lean....really lean

I am 99% sure the RPM's raise a LOT faster, it was sooo sluggish before it took like 2 minutes to get to 6k lol.

Maybe thats it. But for some reason I feel more "umph" at lower RPM's before. Or maybe im just going crazy. I can try and record a 0-60 and you guys can tell me if it looks strange.

I have no other mods. Accept a K&N drop in air filter. What do you mean lean? Like my body? Lol I am 5'9" 160 pounds, is that what you mean by lean?

no goober.... your air fuel ratio.

Oh, how would I fix that? Or check it?

My gf is comming over now ill have her ride with me and ill do a 0-60 and she can record my cluster

Well there goes that extra hp

Shes like 120 pounds lol, I dunno how else to record it, I cant hold my cell and shift at the same time lol maybe I could, ill give it a shot.

I'm gona assume you got iOS or droid phone? You can get accelerometers or impromptu gps dynos. Do it safe though, don't be doing 0-60 in a school zone or nothing. Also if you put the plenum spacer on and having a 1/4 tank of gas, then filling up. The car will feel the same. It's roughly 10lbs of static weight = 1hp. Rotational weight is different, wheels brakes, flywheel, and drive shaft you get the hint. So you put an an intake with 1/2 a tank, go out and fill up before the test drive. The butt dyno lies. And most people cant tell more than a 2%-3% difference, on a 300hp engine that's 6-9hp you'd never notice.

Deleted.

Am I the only one that found this funny? Lol


Op make sure you don't have a vacuum leak.

Every 10 pounds she weighs you lose 1 hp. Weight is very important which is why people do weight reduction. BTW in that vid your car seems extremely slow. I bearly heard any wheel spin at all. If I did that lil stop and go my rear would be all over the place even from a 20 roll.

I never noticed anything much with mine besides the supercharger-ish sound that gets louder at higher rpms. It does get more vicious at higher rpms than before but below 3k-ish it felt the same as it did before. After I get exhaust upgrades i'll get a tune to put more hidden horses in the stable like what most people see after getting a tune. I suggest finishing your breather and fart mods to see a good increase in power like what i'm doing.

czirrfb, I have the notion that you may believe that adding the plenum spacer makes a very noticeable difference in your engine’s performance.

In fact the change is positive but subtle and requires a fine measurement to show its performance difference.

All the na upgrades are subtle...till your stomping on coyote 5.0s

Id scan and see if you have an issue w the knock sensor sub harness or knock sensor after messing w things back there. P0327 and p0328. Won't throw a code but will make it feel sluggish like you are stating. Just a quick start..could be loose clip or harness gone bad and poss the sensor(most likely not KS tho).

Ok here is the other video. It was very hard to drive and record at the same time so the first run I wasnt able to keep an eye on my RPMs so I have no idea when I was shifting at

What's the glowing light in there? It looks like you have a check engine light.