Just installed the Crawford Plenum this afternoon. Not too hard, just boring without someone to talk shop with. Installs are always more fun with a friend. Plus, I've been feeling under the weather which made me all thumbs... took about an hour and a half (30 minutes of which was spent looking for the solenoid assy screw that I dropped!)







Not done with the engine dress up yet.. still have the TechFlex covers to install and the SAMCO hoses are scheduled to come in next week. I will probably also add some more Earl's Pro-Lite 350 hoses too. And don't forget that set of GroundingGear!

Cheers, ted

Nice work Ted. Are you going to mod the engine cover to fit over the new plenum?

nah... I'm gonna leave the cover off. I might get a coupe cover and modify... that's if I go with the full paint job of all the engine compartment bits...

Cheers, Ted

Who do you order your pro lite hoses from?

Excuse my ignorance, but I've never seen this mod. What exactly is the difference between this plenum and the stock one? I'd assume maybe it flows better but what do they do to achieve this? I'm curious...

GeeThreeFive wrote:Who do you order your pro lite hoses from?

I actually got them from Earl's in Lawndale, CA. My dad knows "Earl", the old gent who sold his company to Holley Carbs. He still runs his store front together with his electronics salvage store.

I rolled my car in and they assisted with coming out, pulling hoses, cutting/fitting and then installing them. Great guys.. if you are local, you can go there yourselves...it is not the place directly off the 405 at Hawthorne... that is not "Earl's shop". That is some auto store that now sells earl's hoses and gets advertising $$ from Holley to put an Earl's sign out there.

Here the addy:Earl's Performance Plumbing Address: 15827 Hawthorne Blvd, Lawndale, CA 90260 Phone: (310) 542-6435

C-Kwik wrote:What is this mod?

The Crawford plenum is an altered oem plenum by Doug at Crawford Z Cars

From his website...here's what he says (p.s. there are also other products out there...one is a spacer that raises the stock plenum and another plastic plenum made by Kinetix)

Anyone should know one of the largest contributors to performance loss, is the starvation of air to the engine. While the majority of people would never notice such a loss, we began looking for causes of the sharp decrease in power within the upper part of the powerband.

There was our problem! That attractively molded plenum tucked under a plastic cover.

We still don't know why such an aggressive angle was incorporated into the design, perhaps to fit under the hood? Regardless, after flowbench testing we found a 30% difference in flow between the rear cylinders and the front due to the dip at the front of the plenum which allows for the oem strut bar to fit.

In taking the current design, and raising the forward portion by nearly one inch... we reduced that difference to less than 5%. This was a HUGE discovery and one that has proven itself already on the dynos, and in the hands of MANY Z owners.

On average the VQ with our plenum is making 9 hp at the original peak, and a solid 17-20 at redline

===> go to this page: Explanation of plenum with video to read more and see a video where doug explains and puts the stock and his mod side by side. This is a mod for 350z's and G35's.

Cheers, Ted

Interesting.