JoeMag

Where is the fuel pin that controls what the control pressure drops to under boost?

I've read about people modifying these things to make pressure drop lower, but I have no idea where it is...

thx.

nathanUK '81 930 G50

Is this it ?

http://www.pelicanparts.com/techarti...warmup_reg.htm

JoeMag

Can someone confirm is what's mentioned above is the right thing...

PorschePhD

Yes, that is it.

DonE

If you do this mod, you MUST use an AFR meter and fuel pressure gauges. You CAN NOT rely on fuel pressures only, if you are going to use this method. Moving that pin one or two mm could mean the difference in a full point on the AFR. On the other hand, if you want to try, I can tell you how to tune the WUR under idle, cruise, and enrichment.

JoeMag

Thanks Gents... Yes, I have innovate WB AFR that I started using last year. I love it. Looks like the andial FE is coming off!

" On the other hand, if you want to try, I can tell you how to tune the WUR under idle, cruise, and enrichment. " -- Don, I'm all ears for what ever you want to tell me!

nathanUK '81 930 G50

Would be a great read Don.

Spill the beans buddy.

JoeMag

Hey Gents -- managed to get ahold of graphic that was not in pelican tech article. for those interested, here it is. ....frankly I don't like the whole idea of tapping the pin in to make it go down, so I'm going to make something that will pull it up and push it down.

Brent 930

That is isn't going to do anything under boost. Actually that mod is pretty much a band aid for a weak bi metallic strip but it does give you some flexibility to tune like Don said. It's the other pem that will get you more fuel under boost.

JoeMag

Hey Brent!! How do I make control pressure drop more under boost other than FE? I recall you posted how to do that a while ago, but can not find any info....

Brent 930

There are 3 sections to the WUR. The bottom plate has a gold pem you can see from underneath the WUR. To get more fuel under boost which happens @>5 psi, you need to knock it down. This means you need to take it appart to do this. If your WUR is good then there is no need to mess with anything else, I wouldn't. Like Don mentioned you really need a WB to monitor your AFR. Most people fail to have this on board which is critical in conjunction with an EGT. Anyhow it doesn't take but a mm to decrease the fuel pressure as you will see using your CIS tester and mity vac when checking the on boost enrichment. Just a heads up though, while you can decrease the pressure down to like 1.5bar you will run into some issues if you do this without changing the spring. Otherwise where the pem will knock down and seat @ around 2.4bar should be a good starting point. Then it just depends what your AF is doing when you test drive. I test it in 2nd gear to redline and look for no higher than 12:1 or 12.5:1 in the winter. So you might have to take the WUR apart x amount of times to get it where you want. Of course if make any engine mods related to hp then it could change again. Let me know if you need anymore help.

Brent

Brent 930

Oh, one more thing. With my setup I could run down to 0% CO or 14.7 AFR but it would vary some with CIS. Sometimes 13.5 and cruise was about 14. In any case you can do some tweaking with the fuel mixture adjustment after you change the WUR if it isn't already set right. But, changing the gold pem won't affect this.

JoeMag

Thanks. Going to take this thing aprt this weekend and see what it looks like on inside. i recall long time ago reading a post of yours of something like 450hp to ground with other mods too. What underboost control pressure were you running there?

Help me here on what you mean by "changing spring".

btw-- started using innovate wb last year. what a great tool.

sand_man

I'm gonna ask the WORLD'S STUPIDEST question (I'm sure to be banned for this one), but is the WUR and the AAR and anything other than the freaking fuel head/fuel distrubotor really needed for a moderate climate? I mean what happens if this stuff were just removed? I like simplicity, and it seems to me that it's only a matter of time before one of these cursed things fails leading a non-certified CIS fuel injection technician on a wild goose chase in trying to figure out what's going on?

Brent 930

Joe, don't worry about the spring for now. That change is needed if you go for max enrichment.

Sand, short answer is all of those components should be kept. All you need is a CIS tester and a mityvac (shop book would be nice) to do it yourself. Some people have elimated the AAR, but I wouldn't, but go ahead and see for yourself.