I just got back from my first run with the Crawford plenum installed...AMAZING. The car has been transformed. The previous 'dead' area past ~5k rpm is completely gone. The car is significantly faster in the upper RPM's...just pulls and pulls and pulls all the way to redline. I really wasn't expecting this much of a difference in performance to be honest...kind of got used to that dead area. Of course it's not FI...but it's a definite big bang for the buck mod!! .

This plenum does make a 'different' noise that I wasn't expecting...kind of disconcerting when your not expecting it, but after speaking to Doug he verified it was normal for the mod (I held the phone up to the engine )...its kind of a higher pitched hollow sounding 'werrring' noise that oscillates a bit. I can definitely live with the sound change considering the increase in performance I got (yeah I know, butt dyno sorry....). Doug is great though, very easy to get on the phone, and he seems to know the Z inside and out.

The install:

The install took me a while (3 hrs... ) and was frustrating at times...but I am not an experienced 'modder'...besides the grounding kit, this is my first real mod. The biggest PITA during the install was freeing up the 4 5mm bolts that hold the throttle body onto the plenum...I nearly broke my hand/wrench they were put on so tight...ended up chewing one up pretty good. Relocating the wiring harnesses to clear the new strut bar also took a while...and I managed to mess up the gasket inside the plenum a little bit while tightening down the 2 'plug' screws, but nothing serious...all in all it went well, but to anyone attempting this, read the directions doug gives you very carefully, make sure you use a really strong allen wrench to get those throttle body bolts off, and try your best not to strip the ever loving crap out of them. Oh and those hose clamps are pretty tough to put on/take off also...

I'll post pics later on...thanks Doug!

 

That's real good to hear and thanks for sharing. I will probably do this mod in the future when I save money for it. I think it's the next thing I want for the Z. That and high flow cat's.

 

Thanks for sharing! Good to hear the mod is living up to its reputation. Looking forward to mine from Doug, hopefully by the end of next week .

 

I ordered mine thursday. Doug gave me a 2 week time line, allot of the guys that got their's aren't turning their core's back in, in a timely manner. Pleeeeeeaaaaase turn them in guys.

 

Glad you like it. If the instruction manual needs tweaking PM me with what you think needs more elaboration, I will see that it gets included. Thanks for the post.

By the way, the noise you hear, Chris and I refer to it as the Woo Woo!

 

What is the contact info for Crawford Z?

 

http://www.crawfordzcar.com/

 

Great post glad you like it, ya those throttle body bolts are torqued pretty tight from the factory

 

Silly question, but, how will that affect the warranty? I have included a 7 year A-Z warranty for my Z.

Thanks
G

 

Ask yourself... what problems COULD this plenum cause??? (None that I can think of off the top of my head) Regardless, unless the plenum itself causes the issue... it will not begin to effect your warranty. This is a law out stating exactly this.

 

Will this wherring (excuse me, "woo-woo" ) subside if you plug the hole on top?

 

Its quieter with the center bolt and spacer installed. Chris does not have this. I do. You can definitely tell his is louder.

On mine it was noticeable at first cause it was different. Now I don’t really notice it much at all. It is not louder than stock Just different. Like the difference between a stock air box and a CAI.

 

Hahahahahaahhaha, dude... that's great!

 

VandyZ,

How do you get this center bolt/spacer? Is it included in the package? Why is there a hole there in the first place?

 

The bolt and spacer comes with the kit.

The holes are there originally for the plenum itself. The plenum uses six bolts from the top. Now it uses only four, the remaining two are filled from the inside.

 

Oh, I see . So why didn't Doug fill this one too? That way, you don't even need the bolt and spacer.

 

i'm guessing without the center spacer it gets very noisy...mine was fairly noisy so I tightened up the bolt w/spacer and the noise was greatly reduced. The aluminum Crawford used is thinner than the stock plenum thickness, and I think the noise/vibration insulating properties might be a bit less. I also have a feeling that placing spacers/bolts in the two unused screw holes would further reduce noise/vibration...also the bolt head would be outside of the plenum so there is no chance they could get sucked into the engine if they vibrated out of their holes and you could see if they were getting loose...that is my only paranoia with this mod (even though I used locktite..still worried)...Crawford guys, any thoughts on this?

 

zeroday,

Interesting insight. I too would like feed back on this by the Crawford guys . Now, the other 2 holes are already filled, so how are you going to install the bolts/spacers?

 

take the whole plenum off again and remove the two 'plug' bolts I guess...I'm not actually considering doing this, I just thought it could be a future design change if the idea has any merit. On a side note, I'm also trying to figure out a way to put the plastic engine cover back on by cutting out some of the plastic where the new plenum gets in the way. I have an idea that might look pretty cool if it works out.

 

We used loc-tite in ours... there is NO WAY they are going to come out.

We dyno'd the original plenum on mine, and when we took it off for further development it took a LOT of leverage to break the bolts off with the loc-tite applied... trust me, you're fine!