Tom's B6 Build Thread

[TominMO]

Some more pics.

These two are of the filters I bought at Auto Zone for $7.80. I cut off the hose on the fuel line at the bottom of the charcoal canister, stuck on of the filters on and secured it with Gorilla duct tape. Also closed up the other end the same way. The second pic shows it in its natural habitat. Gonna do my Aspire the same way.





My Innovate MTX-L wideband. The white piece (which I will paint flat black) is an adaptor I made to match the small 52mm gauge to the large-gauge bracket. I found it at Lowes; it is used to cover a doorknob hole. Second pic shows the angle ring I have on the wb, but not on the oil pressure gauge. It's getting one tmw.

[TominMO]

Now to go for a drive and check out the wb reading on WOT, to see if I'm getting an anomaly like the dyno guys did. The problem could either be too little air or fuel. If the wb sez it's going to 12.5-13.0 AFR, then I'm thinking it needs the intake opened up (not surprisingly). If it's not getting the AFR it needs at WOT, then the AFPR is the next step, set at ~60 psi.

[TominMO]

Just got back from running my errands. Did a couple of pulls at WOT, and sure enough the AFR wouldn't go below around 14.0. My theory du jour is that the motor draws so much more air than stock, even with the stock intake, that the EFI system can't keep up. Getting the fuel rail adaptor tmw, so I should be able to slap the AFPR on and start tweaking the FP.

[Flyin4stroke]

[emoji15]

[TominMO]

OK, installed the AFPR today, to tune pressure so's I could get down to 12.5ish at WOT.

First, a WARNING. DO NOT USE the Teflon (PTFE) pipe dope from the hardware store on threaded fuel connections! It pretty much instantly melts thru and leaks. No idea why Matt thought this was a good idea. I even let it cure for a couple of days. It leaked at both locations I used it. Slow drip.

But I wanted to get some data. So I covered the leaks with paper shop towels and duct taped 'em on. I went for a short drive, just enough to get two passes in. Reasoning that with the still-restrictive stock intake, I didn't need 60 PSI, I set it at 50. Had no problem getting to 11-12 AFR. For the return trip I set it at 45 and got the same result, so it really didn't need much more than stock FP to get the job done. I can feel the extra kick too! Back to the dyno.

I think Matt reommended 60ish because when he had his shop B3, it needed 60 psi to run well at the HP numbers he was making, esp. when he had it turboed, and with the custom intake's larger plenum volume. If 45 psi does the trick, which it looks like it will, then my gas mileage shouldn't suffer too much at cruising speed.

When I got home I took the Aspire to Advance and picked this up, and put it on the threads that were leaking. It's thick and brown, and says put it on both threads and let it get tacky for a few minutes. Even tho it says fast-hardening, I'm gonna give it a few hours to set up before cranking it over and checking for leaks. The Permatex part # (not shown) is 80008. Says it's "for all common shop fuels", and cost under $5. There was another one that said gasoline-resistant, but it was ~$14.

[Dragonhealer]

Permatex PX # 56521 works well also. Glad you have it solved!

[TominMO]

Permatex PX # 56521 works well also. Glad you have it solved!

Interesting. Here's the info on this product. It also contains PTFE, but under Automotive it says it is for fuel fittings. My other option at Advance was product # 80016, which remains soft and is for both permanent and semi-permanent use. The counter guy tried to steer me to Permatex Ultra Grey, which is a good general gasket product, but has no claims of fuel resistance.

EDIT: Just went outside and fired it up to check for leakage. Only ran it for a minute, but none seen. I'll keep an eye on it and report back if it starts leaking again. It does look like it's hardened up, and I expect it to work permanently. Maybe Matt was talking about something else, similar but different enough to matter, at the hardware store. He didn't specify the brand.

Data sheet for 80008. Usable in two hours, fully cured in 24. This info is not on the packaging or tube. Brown paste.
Data sheet for 80016. Usable in four hour, fully cured in 24. This one remains flexible, unlike the 80008, and is black.

[Movin]

Permatex is awesome stuff. It is aircraft quality. For aircooled VW engines permatex rocks. It stays stable around fuel vapors, oil vapors keeping all that nasty stuff inside where it belongs. For really tuff stuff that might require GM warranty quality like the teflon that works sometimes, this is the stuff that works.

http://www.rectorseal.com/index.php/rectorseal-no-5-special/

[TominMO]

Drove the Festy ~50 miles today. Stopped after a couple miles and checked for fuel leaks, and again at 25 miles and after getting back home. No leaks.

I called my local dyno place to get an appt for next week, but they had just closed apparently. I'll try again Monday. Hopefully it will get dynoed on Thurs or Fri. Really curious to see what numbers it makes now that the WOT AFR is fixed.

[bhazard]

I would think you would want around 13.5 afr at WOT. 12.5 is better for boost.

[TominMO]

I would think you would want around 13.5 afr at WOT. 12.5 is better for boost.

With the greater airflow, it's kinda like boost maybe? I don't kow much about what it "should" be. The dyno guy mentioned 12.5, and that's what it's doing at WOT, once it warms up.

[bhazard]

How many passes you getting on the dyno? You could do something like an A-B-A run and try both numbers.

[Advancedynamix]

With the greater airflow, it's kinda like boost maybe? I don't kow much about what it "should" be. The dyno guy mentioned 12.5, and that's what it's doing at WOT, once it warms up.

12.5 isn't for power, it's a buffer to protect the engine. Even highly tuned turbo engines run best (generally speaking) at 13.5 ish to 1. I ran an engine dyno test cell for 4 years, tuning everything from V12 jags, to Air cooled Porsche, to Robbie Gordons AM General Hummer engines for Paris to Dakar. Setting a modern engine to 12.5 to 1 is a precaution to cool the cumbustion chambers and reduce the chance of detonation in 80 percent of the modern engines I tested. If 12.5 to 1 nets you more power than 13.5 then your combustion chamber design is about as efficient as a Briggs and Struggle lawnmower engine.

Pedro pulls harder under partial throttle than full throttle. Partial throttle it always tries to maintain that 14.5 to 1 target.

[TominMO]

How many passes you getting on the dyno? You could do something like an A-B-A run and try both numbers.

What is this A-B-A of which you speak?

[bhazard]

Do a run at 12.5, another at 13.5, then another at 12.5.