nuttyprof

iTrader: (1)

so what you're saying is that to address both issues, we would require both the spacer and the crawford plenum.......

also, why wouldnt raising the whole plenum fix the uneven flow issue. although the front is still sloping down, the increased area under the plenum would allow enough air to flow over the rear cylinders to the front cylinders. thats how I am picturing it. does that make sense?

copba1t

iTrader: (2)

The point of my posts is to get to the truth of what these spacers can do, and stop the mis-information that I believe we may be seeing. If that comes across as being cynical then so be it, I prefer to think of myself as more of a realist though =)

In any case, these spacers will either prove themselves as a worthwhile product and will most certainly get cheaper as more companies offer their versions, or the whole thing may turn out to be a bunch of hype as someone else suggested. Only time will tell, but that requires patience which I know first hand is certainly difficult to muster sometimes!

Zivman

iTrader: (19)

I look at it like this. Yes, I believe crawford offers the best gains, but at a price. When I was looking at headers, I believe 100% that the crawfords were the ones to get for the best gains. problem is, I couldn't justify the price when I could get the topspeed headers for a fraction of the price and maybe get 1/2-2/3 the gains. Same applies to the plenum, only the price difference isn't as significant.

randyshemin@comcast.

There's a saying...
If you buy the best, you'll never be disappointed.

In the case of the headers, if you're going to go through the expense of having them installed or if you're doing it yourself, it is a one-time investment to get the best product out there. If your budget doesn't allow it, it might be better to wait or not do it at all. Just read the posts from those that bought products only to be disappointed in the marginal results they got. Unfortunately to get real gains from a modern, highly tweaked engine like the one in the 350Z, takes time and a lot of R&D, which equals money.

Doug spent over one year developing the headers that he designed, and almost gave up on the project several times because he initially could not find anyone to produce them. Several companies said they could, but due to their complexity, could not. The guy building them now spent untold hours working with Doug to develop the jigs needed to build these to fit in the space available, and to be able to reproduce them over and over again given those tolerances. Remember, these are hand built, one at a time, and not by a major header manufacturer. Why has no one else come out with a comparable product, including those major manufacturers? Long tube, equal length is easier said than done in the case of the VQ application, and the results gained by the Crawford headers are noted time and again on this forum, including by those who tried less expensive brands with major reputations, only to "trade up" later.

The same effort went into the design of the original plenums. It has been 8 months since Doug initially contracted for the casting of the new cast aluminum plenum. There has been prototype after prototype built, only to be scrapped and done again, due to casting, fitment or finishing issues. Why do you think the APS plenum is nowhere to be found, except in what appears to be an artist's rendering? Look at the issues Kinetix faced and dealt with admirably to their credit, but again, at great expense, both financially to be sure and to their reputation as well.

This stuff is not easy, and the development is extremely time consuming and costly. Remember, the companies providing these products have neither the resources or funding that a major car builder like Nissan would have at their disposal. These are small companies trying to improve on an already great design.

Doug's major business at Crawford Z Car Service is the repair and service of Nissan products, which he's been doing for 25 years. (he's been working on my 240Z since we moved to Nashville in 1987.) He bought a 350Z when they first came out to specifically design and build the best possible performance products available for the car. His car spends more time torn down than it does on the street.

The same engine in 2002 in the Altima put out 240 hp, 260 in the new Maxima, 287 when the Z was introduced, and in 2005, 300, with a premium attached as far as price.

There's another saying...
You get what you pay for.

copba1t

iTrader: (2)

Thanks for the company history, and the shameless plug, but let's get realistic and put things into perspective. "The best" to you might not necessarily be someone else's best. Maybe you are only considering performance, but price and other things are also factors that you seem so quick to ignore.

Like in this case for example, if this spacer idea can get say 75% of the performance of your plenum, at 1/3 of the cost (assuming they drop in price once released) then for ME that may be "The best" option to go for.

I can understand your position though, you have invested man hours and dollars in your products, and to see someone come along with an alternate product that is much easier to design and produce, that would certainly explain why Crawford is getting so worked up over this stuff. Otherwise why would you even care, if you knew the spacer was simply just "snake oil" like one of your guys mentioned, because it would surely be disproven on the dyno and in real world tests. Unless of course there is more to the spacer than you care to admit which is what I believe to be the case...

copba1t

iTrader: (2)

Isn't it also funny how we're hearing all sorts of different things from Crawford, one says "snake oil" then another says "NO GAINS" then another admits there are some gains to be had but not as much as their plenum (of course). Well which is it guys? =)

Wouldn't it be funny if in the end there was actually something to this spacer thing, and Crawford ends up coming out with thier own version? From snake oil to reality before your very eyes!

nuttyprof

iTrader: (1)

oh yeah, btw, there is a group buy for the spacer on g35driver.com

its about 150 i think. probably like 40 people signed up for it i think.

ReavTek

iTrader: (1)

I think that gasket idea is a bit out there... Obviously, a smoothed out spacer wll both look and perform better. With that said, I agree with the good folks at Crawford. If there is one thing I learned from this car is that it costs serious bank to get the most out of it. I had a Mustang GT before my Z... Looking through magazines I saw Borla Pipes that produced +12 hp for $300. Once I began looking through import mags I nearly soiled myself. $600 was a bargain.. I paid about $700 for my Tanabe SMR.

Well, before I go too far off on a tangent let me just say: It takes money to make power. These torquey little V6s have been "optimized" considerably from the factory so it takes alot of time and effort to squeeze even more NA power out of em.

Btw, Any chance on a group buy rate for these Cast plenums?

randyshemin@comcast.

And thanks for: It takes money to make power.

Sorry, no group buy. However.....

The introductory price of $350 is good on orders placed by February 4. After that, the price goes to $395. Plus shipping of course.

Expected ship date: mid-late February.

Call Crawford Z Car at 615-327-4159, or email crawfordzcar@comcast.net with your name, ship to address and a phone number we can call to get your credit card info when plenum is ready to ship.
More info here: http://www.crawfordz.com/plenum-qanda.htm
____________________________________________________
The three questions regarding engine mods are:

How fast do you want to go?
How much do you want to spend?
How reliable do you want it to be?
____________________________________________________

Remember, a Timex and a Rolex both do the same thing.
Which would you rather have on your wrist?

Brandon@Forged

I did a search and came up with two dyno's of the Crawford headers, I just can't see how they have been proved time and time again.

BTW, we are getting way off topic.

randyshemin@comcast.

What's funny is that all 9 of your posts on this board are in this thread, and in this one, you're even starting to sound like PHOENIX INX (Chris).

I think we're done here.

zzzya

iTrader: (2)

It is too bad most of the "spacer" supporters haven't been around the forums long enough to remember the full history behind these products. Espirit came out with one a long long time ago and it simply went no-where. People were spending money and gaining very little. The spacer design would have to be tapered with the front being thicker than the back to try acheiving equal plenum volume front to back. With a tapered approach one has to question bolt alignment and the ability to get a good gasket seal. To lift the front of the plenum enough to create even volume, there is no way the factory strut bar will fit, unless you make some compromises to the plenum much the way Kinetix did. The spacer may seem to "make sense" to a lot of newer 350Z owners who are hearing that plenums are one of the first things you should do, but those that know the history should know better. Also, you do not want to polish the inside of the plenum for better flow unless you do it right, which is not totally smooth.

By adding a spacer you simply increase the volume in both the front and the back of the plenum space. The best design would create equal volume over all runners. To make sure flow characteristics are appropriate for the engine, one must do some R&D using a flow bench. In N/A form the engine will be pulling air from the plenum space, so some of the poor flow characteristics of a poor plenum design will be overcome, but there must still be balance to get good performance and even air flow to all cylinders. One can see on the dyno that the aftermarket plenums really help in the upper rpms, which makes sense because the engine is asking for more air at higher rpms and the stock plenum starves the front cylinders. The real question in my mind is "What volume of air should the plenum hold for an N/A application?" There is definately a point in which overall volume would allow fairly equal air flow to front and back. But even then, too much volume could hurt flow characteristics for an N/A engine since the air still has to be pulled in through the entire intake. Think of sucking something through a straw, if the straw is to small you have to work hard to pull the substance into and through the straw. On the same token, if the straw is too large you also have to work hard to pull the substance into and through the straw and chances are you will be less likely to pull anything through the straw if the straw is too big, so you want to error on the smaller side. It would be interesting to see, spacer vs Crawford or Kinetix, what is occuring at the MAF sensor. I have often thought that the plenum may be too big for an N/A car and that the Crawford plenum with a more balanced front to back design could be decreased in overall height. This may allow an N/A engine to pull more air through the intake and in effect increase the engines ability to pump more air. Of course it all comes down to balance, and making changes such as cams, headers, and so on will make a big difference in what "volume" the plenum design should be. The fact that the only real gains we see with a plenum on a stock car is in the upper rpms make me think a decrease in overall volume might be a better fit for an N/A application. The increases we see on a dyno may simply be the front cylinders not being starved at higher rpms. It would be interesting to see the dynos on a car with cams, headers, HF cats, catback with stock plenum, then aftermarket plenum to see if the plenum impacts more than just the upper rpms. That would give us a clue as to if the plenum volume is too much for our engines.

In the end, I want a plenum that is balanced in volume front to back yet has enough total volume to maintain proper airflow characteristics, but not too much volume for an N/A application. The spacers increase volume to the front, they also increase total volume which may not be a good thing, and they do not create an even volume from front to back. I personally would never buy one.

2003z

iTrader: (7)

Jeez, this is getting out of hand. I think what Chris was saying is that if you want the spacer, try a stack of gaskets first and see for yourself if there are any gains. He wasn't suggesting it as a permanent solution.

Brandon@Forged

Esprit plenum spacer is $600. I'm not really a supporter of anything other than what works. BTW, been a member since fall '02, not on this name though.


And, about all this plenum stuff, keep in mind that Performance Motorsports is still using the stock plenum and running over 1300hp. Apparently, the design isn't that bad, otherwise they would have upgraded, or, it would cost too much for the performance you would get to make a plenum more effective than stock.

uro279

That's interesting, because in the latest Sports Z mag, they interviewed someone from performance Nissan's team, and he said that he would have liked the stock plenum to have been more like Crawford's. (Great tech info.. It's the same interview where they talked about the stock fuel pumps not be able to handle much more that stock HP/TQ, therefore making this a potential prob for reliability).

zzzya

iTrader: (2)

An FI application is so much different as it relates to air flow. FI "forces" the air through the system. A normally aspirated engine pulls and pushes the air out. To get higher boost numbers you would not want to increase plenum volume too much or it would require your turbine to spin faster. FI reduces the need for the plenum volume to be consistent from front to back because you are using force to overcome the shortcomings of the plenum design. That doesn't mean a plenum with even volume from front to back wouldn't be beneficial. It would allow for easier tuning if you don't have a sophisticated standalone system. If they put a Crawford plenum or spacer on the car, they would loose boost due to the increase in plenum volume, which may not be what they want since they have such good control over fuel management and/or they may be turning their turbines as fast as they can.

Brandon@Forged

Yeah i've read that article. I'm not too sure about that guy, others have proved the fuel system for more than 300hp n/a is fine.

uro279

good post. Agree with the overall theme of 'balance'. I think that this is what alot of folks forget about.

The Z came stock with very good balance. But when you increase HP/TQ, ie FI, you must upgrade alot of other things to compensate for the change. This can be seen in many motors being blown because the internals not upgraded, fuel not sufficient, A/F ratio off, etc..

I'm not even including up grading the suspension, brakes, tires, etc., to compensate for the increase in power.

Anyways, went off topic again.

Back to spacer. Let's give it a chance and let it prove itself. If it works-good. If not, good thought, but no go.

uro279

Not to be a stickler but since we're using the scientific approach:

1). Who are 'others'?
2). What have they actually proved? How is it documented? I have been on this board since '02, and have not seen actual reports on this. I've heard people state this and that, but no actual hard numbers.

Also, 300hp is not that far off from 287. You could almost include it within the margin of error. But I acknowledge your point.

Regardless of our feeling about the interviewer, at least he had credentials, whereas many other's state claims. And with all the motors blowin up, and all the FI have upgraded fuel pumps, at what point do you actually NEED to upgrade and still be safe? That has also never been answered.

uro279

Agreed about FI. But no where in the article was it mentioned FI. I stated it in another example on this thread, but as an extreme example to demonstrate what is happening. We still do not know long term what level of increase in power is 'safe'.

Having said that, we may never know, and have to assume some risk. That's life. But what we need to do is realize what we don't know and willing to accept the consequences.

That's why warranty's don't last forever, because after a certain time, they can't guarantee something won't go wrong.

Did it again. I love intellectual debates, but gotta stay on topic. Good discussion BTW