FuturePerfect

This question is for those who run an open air intake and vent their CRV and ABV to the atmosphere. How many of you guys have changed out the stock ABV spring? I stumbled upon a post by GARCO MOTORWORKS, stating better boost response when the stock ABV spring was replaced with, what I'm guessing, a stronger spring. It seems like this has been done very successfully in the past.

To those who've done this: Where did you get the spring from and what type of spring/part number was it? How is the result? Have you run into any problems resulting from this mod?

I spoke to David (GARCO MOTORWORKS), who suggested starting this thread so I can get some input from the guys who've done this. The end goal would be to include a "how-to" in this thread for future reference.

Thanks in advance.

Mahjik

iTrader: (1)

I haven't heard of anyone doing it but Garfinkle. TBH, most people just purchase an aftermarket BOV in place of modifying the stock ABV.

FuturePerfect

True. I guess this can be perceived as the "cheap bastard BOV."

I know there are other people (however small in population) who have done this/had this done. If I can get their input, that would be great. I might even hit up Garfinkle with a PM so that he can share his experience.

Mahjik

iTrader: (1)

Good luck. The only people I know on this forum with a modified stock ABV, had theirs done by David.

GARCO MOTORWORKS

Some one from the forum called me about this and I told them how to do it .They replied back after finding a uaeable spring from Mc Master Carr. That is the point of the thread , to find that person to get the info .I did several of these using a Yamaha motorcycle clutch spring from the old 80 cc twocycles .I am going to look to see if I have any more stored away today . I know some of the modified valves are still being used .

RX7 RAGE

iTrader: (22)

I'd be interested. I need boost sooner with my BNRs since i'm running them non sequentially.

DigDug

I changed the spring in my stock ABV as well. I got my springs from Ajax Wire. The spring I ended up using was part #C-850-072-1500. That's a 0.85" OD, 0.072" wire diameter, 1.5" free length music wire spring with ground flat ends. It was somewhere around 21-22lb/in rate IIRC. This made the ABV start to open at 14-15in/Hg.

Their website http://www.ajaxwire.com/ appears to be down but their phone is 516.935.2333. They have a minimum order of 10 units, most other places require a lot more.

FuturePerfect

This is true--I just thought to expand it a little bit.

Thanks for chiming in, David. If you have the time, would you be able to put together a "how-to" write-up? If not, it's totally understandable, and I'll see if I can work with someone else on this.

Nonetheless, thank you for the input.

DigDug--that's precisely the info I was looking for, and more. Thank you!

How long has it been since you've performed this mod and how were the after effects?

DigDug

I ran it for a few weeks before the epoxy gave way and the case popped open while driving. Fortunately I didn't lose the diaghram or spring, they landed on the crossmember and stayed put until I could get to them.

I used quick-setting plastic epoxy I found at the auto parts store, I'm sure there is better stuff out there for the job. I had some difficulty applying enough of the stuff and getting it assembled in the C-clamp quickly enough after mixing the epoxy. A longer set time would help with this, the stuff I used was actually starting to solidify in a matter of a couple minutes.

Anyways, I noticed slightly quicker spooling with my setup, but I am running sequential with RZ twins. I know most here say the RZ twins don't make much of a difference, but they do spool significantly quicker in my experience. The modified ABV will probably help more with a non-seq setup.

FuturePerfect

That's bad news, but thanks for sharing your experience.

I'm looking into buying a couple of stock BOVs to tinker with. Until then, let's see if anybody else out there has any experience with this...

FuturePerfect

Geez...I thought I did a pretty decent search, but here's a thread on this from back in '04:

https://www.rx7club.com/showthread.p...blow+off+valve

Some info in there about how Garfinkle took apart and reassembled the ABV.

kerpal

What a modified ABV???

FuturePerfect

ABV = Air Bypass Valve, as Mazda calls it on our stock FDs. More commonly referred to as Blow-Off Valve.