Thanks, I'll check it out

 

I also recommend the Crawford. When you get it, measure any warpage. I'm told it's rare, but if the warpage is greater than 3/16ths of an inch I would send it back. Otherwise you'll need to torque down the bolts enough where you'll most likely break off the two studs towards the front that are covered with nuts.

The Plenum with Cats seems to produce a better bang than either alone.

Neither will mess with any sensors unless you bang one up during install. Both are DIY but not easy without the right tools, and moderately difficult even with the right tools.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats/ Service Engine Soon

 

the DIY for the plenum makes it seem pretty easy to me.... i would not do my cats myself however.

2004 Black on Black g coupe 6spd.... aluminum pedals, clear corners, z tube, and pop charger. soon to have 19" volk gt-c's and PIAA xtreme whites in the clearance and corners
Houston Texas

 

If you have rhino ramps, a 2 ft driver extension, a helper that can turn a ratchet, a 1/2 in driver, a 14mm box end wrench, a 14mm socket, and a Crescent wrench, the Cats are a piece of cake.
The DIY is somewhat flawed. .....you do NOT need to remove the suspension brace OR the steering joint. You just need a 2 ft extension and a helper to hold the open ended wrench while you turn the ratchet.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats/ Service Engine Soon

 

<blockquote><font class="small">In reply to:</font><hr>

If you have rhino ramps, a 2 ft driver extension, a helper that can turn a ratchet, a 1/2 in driver, a 14mm box end wrench, a 14mm socket, and a Crescent wrench, the Cats are a piece of cake.
The DIY is somewhat flawed. .....you do NOT need to remove the suspension brace OR the steering joint. You just need a 2 ft extension and a helper to hold the open ended wrench while you turn the ratchet.


<hr></blockquote>

Keep in mind that this advice is coming from the guy who paid someone to install the drivers side cat, after installing the easier passenger side cat himself, because it is "a piece of cake". [img]/w3timages/icons/tongue.gif[/img] LOL

The installer also messed up his oxygen sensor to a tune of ~$100, so make sure who ever does the job is careful.

As far as I'm concerned, the $37.50 to have the job done for me was money well spent. I watched the process, noted the tools they used and drove off happy that I did not attempt this job.

<font color=blue>The above statements are only my take on the issue. If you disagree with anything I typed then you are 100% right!</font color=blue>

 

I agree with the cat install. I started it with some jackstands, but knew that I had to be a contortionist and have more time than I did. The install cost me $75 and it was worth it.

'04 6MT coupe

 

There are two issues here that I don't understand.

First, why does Crawford (with a reputation which I understand to be generally good) ship out warped plenums? They certainly can tell if they are warped before they ship them and could mill them flat beforehand. And, at $400 for doing a little rework on an OEM plenum, they are hardly cheap! I've looked at Crawford's site and I don't see them advertising warpage as a feature of their plenums!

From an engineer's perspective, I don't like this double gasketing business. Manufacturing goals are normally to minimize the need for gaskets, not maximize them. Further, torqueing down a warped plenum puts it in a perpetual state of stress and it is just "waiting" for a chance to leak.

Second, if Crawford insists on shipping out a warped product (that's almost an oxymoron, isn't it?), why wouldn't a recipient take it to a machine shop and have it milled flat? I mean, why put on a warped plenum?

 

I have not made this comment in public because you don't want to criticize the best thing going in the plenum world, but exagorazo brings up some very good points.

1. Pre-inspection. Don't ship out warped plenums!
2. There is absolutely no final machining of any kind on any of the mating/interface surfaces.
3. #2 is the reason for the double gasket

The correct answer is to make an SLA, and a "hipped" casting for a plenum. Generate some hard tooling and create a casting process to make new plenums. You'd have 2 machining setups that could be done on any 4 axis machine. You'd machine the interface with the throttle body (drill and tap holes at this setup) and then rotate the part and machine the manifold interface. If done properly the thru holes could be cast into the plenum.

This product would be a bargain if it were in the $700 - $800 price range. It would be a reliable, good product that would produce MORE horsepower than any exhaust (at least any exhaust for the coupe) and would be in the same price range.

A slight modification to the process and you could duplicate the same process for the 350Z, keeping their "swoop" for their OEM strut bar (I think it's called a strut bar???).

Anyway, until this is done by someone I don't think it's a good idea to go bad mouthing Crawford. Their product works and that's the best thing we've got going at this point...

<font color=blue>The above statements are only my take on the issue. If you disagree with anything I typed then you are 100% right!</font color=blue>

 

Neff,
I called no less than a dozen shops and only 2 would even replace the cats, both quoted around $50-$75 an hour and it's at LEAST a one hour job. I don't know what wages are down in FL but here in Memphis, $37.50 is a non-sequitor.

Looking back on it, with another person this install would have been a piece of cake. Out of the 3 hours it took me, I spent two hours trying to figure out how to get one nut to stay put while I torqued the bolt. Once I gave in and got my better half to hold the wrench it was a piece of cake.

When it comes time to changing them back to stock, I'll definitely tackle BOTH sides myself, with the help of a buddy. I'm never letting another hack touch my car, that's for sure. You had a true anomaly, paying what you did AND they let you watch.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats/ Service Engine Soon

 

Exagorazo,

I agree with you. We made these points months ago.
These things are not cheap for warpage/cracking issues.

I'm still hoping for a better alternative. Eventually. Maybe.

At least something that looks nicer.

2004 G35C 6MT Black. Killer.

 

I'm probably going to get flamed for this but... "9 peak horsepower", for roughly $350. Umm.. My lawnmower produces 9 hp. And it weighs in at about 15 pounds. How, exactly, does a 9 hp increase on a 3,000 pound car affect anything? Given the weight of the vehicle, an increase of 9 hp would be.. nothing?? If I'm wrong, I'm wrong. But the math, guys.... be realistic.

 

The following is not ment to belittle or make anyone feel bad, as can happen, I respectfully disagree as follows.

No one is forcing anyone to buy the products, the dyno's have been done, independently on both and Crawford did their own dyno's. Some mods I've done to my car didn't do much for power and that's how I report on them when asked. No one is this community is served by fluffy false talk about a mod you know full well didn't benefit you. When asked about my Crawford, my story has alway's been the same (it's on page one).

You can tell me all you want that I can't sense 9hp peak or that the pleneum doesn't prevent as much power curve fall off from peak to redline (Crawford say's it add's 20hp at redline vs the hp at redline with oem), that the mod doesn't do anything worthwhile. Sorry, the mod made a noticeable difference and is a enhancement that is worth every penny. They have sound engineering reason's to have been created, unlike all the question's floating around surrounding intake systems. And I HATE spending money if I don't have too. Grounding kit did zip nothing, and the $900 I spent on my oem VLSD conversion was a waste of money that I advise people against. BUT, when it works, when it does as advertised, I will be the eternal flame that cannot be put out so that others that might share my love for these cars can know to. And like anything made for these cars, if you buy it and you don't aggree, that's what the classified section is for.

"All that's necessary for the forces of evil to win in the world is for enough good men to do nothing.”
Edmund Burke

G35 6mt

 

It seems to me that apples and oranges are in the same bin here.

There are at least two separate questions. First, does the plenum mod increase power. Second is the quality/workmanship what it should be?

The first question can be answered subjectively by user impressions and objectively by dynos and 1/4 mile runs.

User impressions seem decidedly mixed. Dyno results seem to show and increase in power, but none of the results I've seen posted are nearly as large as those claimed on Crawford's site.

The second question involves quality/workmanship. The plenums are either shipped warped or they are not and those who claim they have received warped plenums are either providing accurate information or they are not.

If plenums are being shipped warped, they shouldn't be and don't need to be. If Crawford does not ship warped plenums, then warping is a non issue and some people are posting false information.

 

Doing the math, 9 HP will knock off nearly a tenth of a second on a QM for this car.

Regarding Crawford...Doug is adminant that the warpage is the nature of the beast. He has taken warped plenums that another has sent back and installed it on his own car. I believe I got the worst one ever shipped. I suppose he could have a completely flat plenum if he follows the procedure that Neff has outlined, but then again we may be looking at a $1000 plenum now instead of $400. Doug is not getting rich off these things....he's an enthusiast making a living and loves his work.

I am not mistaken in the degree of warpage, I took careful measurements. I feel that this was an exception and that 95% of the time Doug ships plenums that have no more than 1/16th of an inch warpage which is enough to torque to factory specs and have a plenty tight seal.

To put things in perspective, I have banned well over 250 businesses and I keep a list of them in my Palm Pilot. They have been banned for a variety of reasons but it's pretty easy to get banned by me. Despite getting a fairly warped plenum I still recommend Crawford products to everyone. That's how happy I am with Crawford's product and Doug's attention to me as a customer. If I have the time, I will drive the 3 hours to Nashville whenever I have a service issue rather than let the hacks at my local dealership even touch my car.

I'm one happy customer even though I had to clean my drawers the first time I heard that whistle. I took controlled measurements in controlled conditions and found the plenum to be useful from a performance standpoint and among the leader in bang for your buck, particularly when combining with the cats.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats/ Service Engine Soon

 

Your pic shows an intake I've never seen before. What is it?

2003 TwBlue 5AT Sedan, sunroof,
Graphite Leather, splashguards, HKS exhaust,
14 wire Grounding kit, 350Z duct, Stillen CAI
Underbody rear diffusers, Drilled alum pedals