Very very good argument! Infact it hits close to home because I had the same argument during development (yes my degrees are in engineering too). I was proud of myself when I remembered some of my System Dynamics and Mechanics class.

I was then shown up by the experience in the room. They informed me for static systems or standard open paths that my logic is correct, but not in an application where firing order, runner placement, and internal flow needed specific attention. I thought to myself "Oh well", but that’s how you learn.

The spacer itself is a great idea, but it did not satisfy Doug’s quest for power. His stance was to make his car faster, and my stance was to use whatever he did because I knew what he was going for. It was far easier to make a spacer than cut up a stock piece and weld it back together. Had it been the solution to his quest we all would have more free time the past 2 years. Obviously, we are not alone in the quest for power.

 

It's interesting how someone claiming to be so objective can still come out with completely speculative claims such as that above

So you have already done flow bench testing and dyno comparisons between these exact two products? I guess not otherwise you would have posted that info. Hmmm, well then I guess you must be basing this on how the plenum looks like it would move air more efficiently? Please help me understand the basis for your claim, I really would like to know

 

maybe you hit the reply button too quick, he did explain the basis for his claim.

 

copba1t is just looking to start trouble. They are both good products.

I think the Crawford wins for form.

I think the spacer wins for economy.

I think the Crawford wins for long-term reliability.

Maybe performance is a wash, maybe not. It's tough to say either way and there is support for both sides.

I think the Crawford wins out overall, but the spacer is a good value.

 

Excellent insight by the Crawford team... That's why I stated the analogy in theory

This is also why I bought the angled spacer. It mimics, but does not equal the more expensive alternative. I am a frugal man!

In the end, it will be interesting to see which business gets the most sales!

Good luck to everyone

 

The stock plenum lets 30% less air flow to the front cylinders than the rear. That is what I read. So adding a spacer or newly designed plenum to compensate this should solve that problem. Having said that, I think only a negligable difference in HP/TQ gains could possibly exist on a stock 350Z. If the re-cast plenum/s increase air flow at the entrance and allow for better air flow in general (surface condition inside)... then perhaps the more the car is upgraded the more this may come into play. I don't even know if anyone has identified (for sure) that the stock plenum has any insufficiencies in regard to the throttle body opening size (compared to the rest of the air intake system) or air flow in general.

I am only skeptical to adding increased gaskets/connections which only double your chance of developing air leaks. So, I would rather put a plenum on a lower intake manifold (1 gasketed connected, like stock design)... instead of putting a plenum on a spacer which is on the lower intake manifold, thus creating 2 gasketed connections. But that is just my opinion, I am in no way faulting the quality of the spacer or gaskets.

On that same note, I would probably go with a Kinetix Plenum since it is cheaper than the Crawford (especially bought as a combo along with the Kinetix Resonated Test Pipes, which I don't think Crawford makes and everyone seems to think they are the best brand to use to eliminate rasp), and it won't require me to replace my stock strut bar nor modify/remove my stock engine cover. Plus it is 4 lbs. lighter than the stock plenum dunno about the crawford on weight, but weight isn't actually a concern just thought I would throw it in the mix haha

sorry so long

 

sorry, i ran the kinetix resonated tpipes, and they didn't eliminate the rasp on my setup; their cats lessened it significantly but didn't eliminate it completely on my setup, with ypipe and stock exhaust.

 

How is asking someone to back up their theory with proof starting trouble? Especially when there is already existing reproducible data showing otherwise?

Some of you Crawford cronies should really start thinking for yourselves and not take all your info via spoon-feeding.

 

Sorry to be off topic... but does your Y-pipe outlet = the mid pipe inlet? I know alot of Y-pipe outlets are 1/8-1/4 " bigger so maybe your rasp is related to air flow disruption? I know, this is very iffy... just an idea.

 

This is how you cause trouble, clown. Everyone's having a civil discussion except you.

 

Some are saying the cast plenum has better flow charecteristics than a plenum spacer but where is the evidence to support the assertion? It's an assertion based on what evidence?... There is none. In fact, the data to date shows to the contrary.

Credentials and arguments in support of one theory Vs another is just background noise. What is left to say when reality disproves a theory? In science, the disproved theory is discarded.

There was a time when some people steadfastly refused to believe the world was anything but flat. Some still think science is just a bunch of deceptive non-sense. And some will reject the facts if its not "down with the in crowd".


You are looking at real / independant test data.

 

Good, Bad or Indifferent. I promise more dynos will be posted.

 

Why would you dyno an automatic?

 

I think the fact that you claim such a huge difference over Crawford discredits your actual message to some degree. If Crawford posted gains that are that much higher over a spacer, I don't really think I'd buy it either.

Maybe if you could explain why your dynos clearly produce more horsepower by solving the same problem, some more people would accept your charts. That's just my opinion.

 

Danny I have absolutely no idea how it turned out that way. -I did not expect it- -I didn't even hope for it- Call it a Fluke. Call it Luck. It just did.

What ever its called, the results were very repeatable on that car. And I will test again on other cars to see if it is repeatable on others.

Any further comparative testing like that will be done with multiple, skeptical witnesses watching. Preferably at a 350Z Dyno Day with a lot of people. The only reason for me to be there would be to give my 2 cents on fairness. I will not F around, cheat or deciet. I personally could never do business based on a lie. I have too much of a concience for it. Besides, the world already has way too many scammers and bad business practicioners.

What ever happens on the dyno will be the real deal.

As far as doing dynos on manuals or autos, from what I have seen, they pretty much dyno the same. But even if there was a step or spectral shift, the only thing that matters for Pre/Post dyno testing is repeatability. Unless the torque converter is freaking out, the autos appear to have repeatability no different from manuals.

Otherwise, If a manual Z is available, the manual Z will be the prefered test vehicle.

Tony

 

pm sent