GlennP, what is GP? You said you got your spacer for less than $200.

 

yeah.. I was wodering for the same question. The Idea is to have a bigger intake plenum to get more HP. So is it possible to combine crawford plenum and the motordyne spacer? will it be too high to fit under the hood?

 

I have the spacer and can definitely feel the difference in power throughourt the powerband. Throttle response is much better as well. There is a video two coups doing two runs against each other. One coupe is a stock 056MT and the other was a stock 04 5AT (other than the 19" aftermarket wheels and a subwoofer)which was later modded wih the spacer. In the first run the 05 edged out the 04 pulling ahead in 3rd gear. In the 2nd run the 04 edged out the 05 throughout the powerband in each gear. Good evidence that the spacer works and I would expect the plennum mods to likewise work the same.

 

i have the 1/2" motordyne spacers. results before and after... Here

 

Not GP but GB (group buy).

 

That would be overkill unnecessary if you have one or the other. It will do the same thing except the plenum will produce about 1-3 hp more than the spacer. The plenum however is a much more expensive setup than the spacer. If you go with CP you have to core your original plenum otherwise you pay even more. Kinetix is a bit cheaper but you have to be careful installing it over tighten it and it may crack.

 

http://www.crawfordz.com/350zengineperformance.htm

are these both the same xcept ones polished?

 

There is soooo much mis-information in this post, I just have to reply.

1. There is NO CORE EXCHANGE necessary for any plenum mod any more. For the last 5-6 months Doug has ONLY sold cast plenums. This allows you to keep your stock plenum since the new Crawford design is made the EXACT SAME WAY your stock intake manifold cover is made. It's an aluminum casting.

2. Any dyno that shows one mod gaining 1-3rwhp over another mod is pointless. Too many variables to argue over, so the safe bet is to say that both of these mods BY THEMSELVES are close to equivalent.

Also, the plenum BY ITSELF is not a "great mod" (neither is just the plenum spacer or just the h/f cats), but when you combine the plenum and the h/f cats you get a "great mod". There is more than one restricion in the stock intake/exhaust design and unless you remove a restriction on each side of the intake/exhaust equation, you're not going to see/feel a big gain if you stay NA. For those of you that tried a plenum or a spacer and didn't feel much, I STRONGLY recommend changing the stock cats to h/f's and giving us your "new opinion" of the two mods combined.

 

Well there you go no more core exchange so it got a little better. So how much is Crawford asking for in price now? You are right aguing over 1-3 hp gain is pointless that's why I went with the spacer. See when I bought my spacer the CF was about 400 w/ core and 700 w/o something like that I forgot already. The spacer was less than two hundred bucks and for the same kind of gain so no argument there. The H/F cats alone is a good mod get rid of the Y pipe and go true dual is even better.

 

Crawford is currently $350, alteratmoshpere has a cast plenum for $250.
I think I will go for the spacer but the company is not responding to email.

 

The only dyno that I know of that compared the spacer to the Crawford, with the car never being unhooked from the dyno going from one setup to another was the one I did with Hydrazine back in January. The car was warmed up to the same coolant temp each time, the car had the same tank of gas. All the runs were done within 1.5 hours of each other, with the same dyno operator. The ambient temps ranged from 68-72, the humidity pretty much constant at 54%.

We did about 6-8 runs with the Crawford, and 4 runs with the spacer (1/4").

On average, the spacer had 5 HP more at redline. I say on average, because too many people/companies just tell you the worst run with one setup, and overlay the best run with another setup on top of that.

Last month I redynoed on the same machine with the Crawford AND 1/4" spacer. Keep in mind that it was warmer this time around. The combo was about 1-2 HP better than the Crawford alone, but 3-4 worse than the spacer.

I've still kept my Crawford though.

(numbers are on the dynapack, a stock 350z 6MT gets about 255 WHP).

 

I'd like some evidence for your claims. ESPECIALLY about the headers. I don't want BS about how they are equal length, "should" make more power, are "better" designed, etc. Bottom line, I haven't seen a single dyno pre and post Crawford headers. And yes, I searched on my350z as well. I'd like you to point me to one. In fact, the only one I could find of the Crawford headers at all is Lowrider's, which was only AFTER the installation of ALL of the following: Crawford headers, Plenum, Crawford Cats, Invidia G200 Dual exhaust, Technosquare ECU, Ground wires, and lightweight 18" Nismo wheels. You'd think that all that would dyno at LEAST 40 hp at peak, wouldn't you? After all, that is what Crawford claims for just the headers, cats, and plenum per their website...and the ECU, exhaust, and wheels surely aren't hurting his power numbers. Either Crawford's claims are B.S. (likely) or Lou has an extremely weak engine. 248 hp peak is not very impressive when most 6mt's are dynoing 225-230 hp bone stock. Maybe 20 hp is what he made, some of which no doubt is from other mods. That's a far cry from 40 with Crawford mods alone. By the way, a stock '05 dynoed against him, and made nearly the same power, so it wasn't a bogus dyno machine. Pretty sad that all that can only net him BARELY more than a stock '05, which we know to not be stronger except up top. Nothing against him at all, but this is simply the only evidence I can find that show me "Support Crawford!" This in comparison with an Alphawerks headers dyno that showed 17 hp, roughly what Lou is getting. How is the Crawford nearly $1000 better (when considering up-front and install extra costs)? It isn't, plain and simple. I'll let you know when I get my Alpha's installed how much of a "butt dyno" increase I had. After all, that's all you're going on with your Crawfords when you make such ridiculous claims.

 

I want the crawford plenium just dont know how to install it, and if its worth 400+

 

See the post above my previous (post #26). That should tell you whether it's worth $400 when the spacer is half that....

 

The spacer has to be one of the most dynoed mods on this board. When Motordyne first came out with them they were bombarded with "give me dyno results" requests and healthy skepticism. Rightly so. Motordyne dyno days as well as independent dyno contributions have shown proven gains time and again, at least as much as any upper plenum replacement for half the cost.

As for headers, maybe there are more dynos to be had on one of the 350Z sites but I've not seen a lot here (any?) where it was the single mod changed. Since you're talking some significant coin to purchase and install headers it'd be nice to see the same scrutiny applied to the header mods as the spacer. The spacer is a no-brainer IMO.