Installed my 3/8" plenum spacer today, polished the upper while it was off. Quality of product was top-notch, I must have been an early recipient as I had to get the washers that others referred to. I haven't noticed much of a change in sound, the Borla TD exhaust on my G dominates that sense. Butt dyno says more torque down low, pulls noticeably harder from 4K to redline. I can't wait until the ECU fully adapts to the improvement in air flow.

 

Question... should I be noticing a loss of HP from this mod?
It was a dog after the install, so I reset the ECU. It seemed to be better, but still weaker. I might have noticed an increase above 5000 RPMs, but my guess is that since the car runs rich at that point, the more air flow evens it out??? It seems to have a harder time breathing at low RPMs. I seems to have lost a considerable amount of torque. Am I smoking crack or is it going to take a few days before this sinks in???

 

That's not the results others posted. Check if everything is tightened properly. Misalligned gasket could be the cause too.

I've been driving for 3 days already and have yet to notice a single thing that I don't like about this mod.

My gas mileage is up too. Anyone else noticed that?

 

You definitly should not notice a loss in power. Try it on a dyno and check pre/post results. HP and TQ should only go up.

Tony

 

Ya, I love the spacer!! As copbait stated, the growl gets louder and louder with each day!!

 

and of course that's the most important aspect of the mod.

 

LOL....Exactly
What are you doing.....rolling the windows down a little more each day???
You better check your bolts...cause there is NO reason it should sound any different from the first time you cranked it up after the install.

 

I think it has to do with break-in of both the intake and exhaust systems adjusting to the increased flow, as well as the ECU adjusting.

 

It's very possible to loose low to midrange power if the air velocity is disrupted. Air velocity is much more important than high volume. The same kind of losses can occur when adding too large of exhaust piping. The air velocity goes down and causes turbulence therefore you get a lack of power until the air velocity starts to pick up in the upper rpms. This is one of the fears I have with the plenums and spacers because these mods do change velocity and if done incorrectly, you can hurt low to midrange power which is the worst place you want to loose power. The car will be lethargic around town and will need to be revved hard to get any real performance out of it.

I don't think it's the bolts or a vacuum leak because these motors will sputter, surge, and stall if there is a vacuum leak anywhere in the intake tract after the MAF.

 

This is what I've been experiencing ever since I put the Stillen CAI on my ride.

 

I doubt this will develop into a banwagon because one guy percieves power losses. The crawford plenum adds power to entire power band and doesn't lose any anywhere on the line that I recall so your statement may be valid on the spacer. Based on what I've seen people think it works but no real proof. Try not to wish these things don't work too hard or you may sound biased and subjective about something you don't even own...LOL.

My Injen CAI made the power down low a bit weaker and then stronger up high so what you desribed actually makes sense i.e disrupted airflow causing a lower output until you start to wind it up. I think all CAI's are hard on low end that's why people love the Z tube and there are several of us converts. Also there are too many people with plenums that have proven results to really allow anyone to be convinced that there is so much of a disruption as to lose any power.

Crawford doesn' F around and stake his reputation on things like the 300 hp package without making it real. It's real and it soundslike the spacer just may be real - find out this weekend in so cal!

 

Thats obviously not the reason I purchased the spacer, only for performance, I never expected or knew it would change the sound. I was just being sarcastic about the sound aspect, as if someone would really pay $170 just to have a louder growl from under the hood! But as far as pick up I do feel a lil sumin on the butt dyno. It also seems to rev through RPM's faster than before. But after install the sound level was normal and I was only listening for it b/c a few members w/ early installs stated you get a louder 'growl'. Not until yesterday which makes it 5 days now I have had mine installed did I actually notice the noise. Alot of times after a mod you wanna compare your mod to the other members whether it be sound/performance etc so you can rest assured the mod is doing what everyone elses is, which is why I mentioned it!!

 

I had the same experience. That factor and the added noise (not a good noise in my opinion) resulted in me going back to the stock box. I've been a happy clam with a more muffled, deeper engine note, a quicker off the line punch, and an overall smoother engine.

 

All these haters slamming those of us that are reporting on the sound changes, let me ask you this, what else is there to really report on until we get some actual dyno runs?

Do you guys honestly put any value on someone's butt-dyno report? I can tell you that I don't even trust my own butt-dyno, much less someone else's. If you think you can detect a loss or gain of ~ 5 torque or HP then you are fooling yourself. That's like a 2% change

So until I see some more dynos, the only useful chatter in this thread to me are reports about sound changes and any other useful install tips.

 

well said!