TOPIC: 2008 Honda Ridgeline 3.5L Grooved by Mail

Here is the story so far, on a Groove By Mail job on a 2008 Honda Ridgeline 3.5L V6 VTEC TB. It's a DBW type throttle body, with a small black MAP sensor down on it's side. There was the black carbon stain at the throttle plate, and this TB has a factory set idle stop screw with yellow paint on it. It looks like the Mfg. of this TB sets the plate to the normally closed hot engine idle position, and that's the plate's default/engine off position. The plate is just open from being totally closed, like the way a carburetor or cable drive TB is.

But to be on the safe side, I put paper and a business card on the opposite side of the Groove, to hold the plate several degrees open from it's stop position. This will prevent idle RPM issues. The Groove power increase will kick in just a bit off idle.

I used the new large size Carbide Super bit, as included in the new PL Kits. IT's amazing how much easier these new bits cut! I still stop the Dremel after each cut and submerge the bit in oil, but the Super bit just doesn't get as hot as the old ones.

I epoxied the outside expecting the bit to cut through, and it did. Another area of concern is the thin spot at the MAP sensor well, I marked this area in the bore with Sharpie pen, and switched over to the medium super bit for this area. It broke through to the MAP well anyway, leaving a tiny pencil point hole. I switched back to the large bit to finish the right side, but held back from going full depth here, as it is over the electric motor section, a breakthrough here would be a real problem.

I put a small bit of epoxy into the bottom of the MAP well and filled the hole OK, making sure to leave enough room for the MAP sensor to fully seat in the well. Worked out fine! The large bit breakthroughs into epoxy, and the black dot of MAP well fill are visible in my usual mediocre pics.

Careful examining of any TB you are Grooving is uber important. And again, the new carbide Super Bits are the bomb for Grooving!

This TB goes out to Michael K, along with the complete instructions for install and the Power System mods. I'll post up any feedback Michael gives.

Tracy G

HI TRACY! I am the FNG to groove land and I just re-grooved my 2007 Acura MDX 3.7 and had to do the same kind of patch work. I am still getting my confidence up to do my other vehicle. I was wondering if you had any results from this groove? I want to compare my cut to make sure I am on the correct path.Thanks for your time and hopefully I will get to hear from you soon. Stay groovey!

Hi, I have groove on my Ridgeline for few months. There is no improvement on mpg. Do you have or know anyone who can share experience and performance tips? Thanks Joe.

Joe, have you also applied the PCV re-route? What about opening up your spark plug gaps?
With Ice and snow on the roads in winter, it may be difficult to keep your right foot from using the extra power; might that have something to do with your mileage?
What about your tire pressure? Cooler weather can have an effect on that, and softer tires can affect mileage too, as can long warm-up idling in the driveway. Another possibility is the engine’s cooling system - if there isn’t enough coolant reaching proper temperature for the engine to get to closed loop operation, you won’t see an improvement in mileage.
Just a few ideas for you to explore...

I have done everything properly. I deleted Pcv valve, recap spark plugs, there is no evap leaks. Everything is in top condition. I do all maintenance my self. Timing belt service at 95,000 k, current mileage 114,000. I just spent so much time with this! I would say there is more power, but no improvement on Mpg. I would like find another owner of the Honda Ridgeline and get his opinion.

Deleted PVC valve may not be good thing. Do re-route PCV line to inbound air before TB and cap PCV valve in intake manifold.

Joe - as Gerald mentioned above me, we don't delete the PCV, we cap @ the manifold and re-route the vapours to the breather line so that they go back into the engine.

Now, if you FEEL more power, you're probably using it...maybe a bit too much: if you're being aggressive on the gas pedal, that's where your improved mileage might be going.
That said, I'm going to point out that you're probably doing pretty well to have not lost mileage in the cold winter we've been having here in North America; winter usually causes mileage to fall because the air the engine breathes is so dense and the computer sees that as as an opportunity to burn more fuel. I have faith that once Spring comes, you're going to see some gains, possibly better than you expect.

Hello brother Josef! I have now a history with the Honda/Acura vehicles. On my 07 Mdx the intake,tb,and pcv system are very close in design with your ridgeline. I noticed its absolutely important to do the ecu relearn and sometimes more than once. When I started with my personal licence kit I grooved the Acura Mdx first. In my case I had redo the groove to the correct angle and depth. With doing that i noticed a awesome increase in the torque curve. The main and huge problem in our intake design is that there is a valve on the passenger side middle of the intake that controls the intake runner length during variable rpm. This causes a major disturbance to the wave form and especially during stop and go driving and short in town trips. I did noticed that mpg mostly went up during highway driving. I do have a couple questions. 1) How old are your A/F sensors? 2) What grade of fuel are you using? 3) When you did your timing belt service, did you adjust your valves? I hope I can help in anyway so I ask these questions since you answered the other questions form Greg. Hope to hear from you soon!