I’ve searched the forums and gotten good info on the Crawford cast plenum $350 and the Motordyne spacer $215 but was wondering which was better and/or gave more of a power increase. Guys who have bought Crawford seem happy with it and guys who have bought the spacer seem happy as well. It seems the spacer is more popular on this forum but is that because of the price or the performance?

I’ve read the spacer raises the existing top plenum up for more volume and is not detectable where the Crawford cast plenum uses a redesigned plenum
to gain more volume. With the Crawford do you re-install the plastic engine cover?

 

I wanna get one too cant decide which one

 

good question...........im wondering the same

 

i havent installed mine yet but i went w/ the 1/2 spacer. i bought it a while ago, i did my research then and from what i can remember they were showing similar results maybe 1-3 hp differnce. so for the price as well. i started a group buy from Motordyne. got good deals for everyone that got one. but i ended up getting a new one from a member on here for 160 shipped. needless to say i could not turn that down.

 

I'd go with the Crawford Products ALL DAY LONG. It has been proven over and over that the Crawford Headers and Crawford Cats are the best (hands down) parts for our cars period.

Headers- 100% equal length primaries, 25" long, hand made, thick wall steel and powder coated. Best gains of any header available for our cars.

Crawford High Flow Cats - simply amazing, you can get them with a bung for a wideband gauge just by asking, they last forever and many have passed the sniffer test for carb certification with them. Gains are pretty much equivalent to test pipes and there is no rasp and they don't collapse like the RT's!

Crawford Plenum - has been around for several years and gone through several iterations of design, has been dyno proven time and time again, it presently is an aluminum casting with a black powdercoat that makes the engine bay look much better than having a heat trapping plastic shield in the way.

Doug Stewart is a pioneer in modifying our G's and Z's and he really knows what makes them work. He has a loyal following for his knowlegde of the VQ and I say support Crawford and you won't be sorry!

 

both are good MODs

Spacer is cheaper and it works! also its easyer to go back to stock and if you get the 5/6" u can keep your engine cover on. although it does not increase peak hp as much but if you compair the curve between a stock and one with a spacer then you'll see what it really does.

Crawford Plenum is just swaping the whole plenum out.. but it costs more and gains should be around the same as a spacer.. you can only do so much to the intake alone anyways.. but i've never seen a dyno between crawford plenum and spacer or stock before.

 

The spacer is a good mod because it improves the distribution of the air/fuel mixture to the front cylinders, but it does nothing to correct the mismatch problem. The plenum top is slanted, so the rear cylinders receive more of the mixture than the fronts. The reason it is slopped is so it can fit under the hood of a "Z" along with the strut bar. The Crawford plenum corrects the mismatch problem because it equalizes the mixture distribution between the fronts and the rears. Go with the Crawford plenum.

Lou

 

Just installed my Crawford plenum today. Call I can say is wow. As soon as I pulled out of the driveway for a testdrive, I was all grins...

 

I have the Crawford cast plenum (pics on my home page) and the gains are there. You can't put the plastic cover back on, but the engine looks better without it.

 

Heres my thoughts. I bought a spacer a few months back. Never used it so I sold it to my best friend. He also did the Injen exhaust at the same time. We took a ride in his car and both of us think the car feels slower, sounds better but slower. With exhaust and spacer your not going to see much of a HP gain. The best advice I could give anyone would be to save for headers, highflow cats, exhaust. OR start to save for FI. Ill never do bolt ons again. I feel they are a waste of $$.

 

So your saying spacers dont have much HP gain if not at all? I was thinking about getting one but if it really is going to end up as a waste of money, better not to buy it then?

 

I had the crawford cast plenum.. and honestly.. I didn't really feel a difference at all.. in speed and sound. So I ended up selling it. I previously had the kinetix plenum, and that provided more sound than the crawford did, but again yielded little gains for me. Maybe I was just expecting too much with all the "wow" comments, but take it for what it's worth.

 

I have the 1/2 inch spacer on mine and I love it. I have the Stillen CAI setup and I feel that the car has definite gains specially at WOT. How people can say that they don't feel a difference is beyond me. The install was a breeze it took about 35mins try doing that with any plenum replacement. If you have the coupe you cannot put the engine cover back on with the 1/2 spacer. The sizes of the spacers are 3/8, 1/4 and 1/2. Dyno from stock setup to 1/2 spacer resulted an 8-9hp gain. Best bang for the buck I spent on my car I got mine on GB for less than 200. Goodluck.

 

stupid question- Can you get both??

 

can you go FI with a 1/2 inch spacer?