Daryl

Bill,
I would would swear you are describing my car exactly! I can also hear a slight difference in the exaust and not quite as smooth as before. I think the computer is working hard trying to main the 14.7 air/fuel ratio.
Please don't forget me on the throttle upgrade.
Thanks

Bill Ball

Daryl:

I've posted before that I do have a persistent IDLE roughness when the car heats up. It has been traced to a drop-out of cyl 7 ONLY AT IDLE. Once off idle, cyl 7 fires normally. I have had this since immediately after the SC install and have not found the cause. The car dynos and drives perfectly OK otherwise and has had 10K miles of care-free driving under all kinds of conditions including 100s of miles in the desert almost flat out. So, someday I will probably find a heat-expanding gap somewhere. I am going to get into this when I install the intercooler sometime this winter. Until then I just drive it daily. It's outside here at work waiting for me to drive the 40 mile trip home tonight. Guess I should get back to work for a while....

Tony

Just because its pre assembled doesn’t mean its sealed. The best way ive found is to run some masking tape around the perimeter of the seem leaving appx 1/4 inch of the seam exposed. Then take some sealant...i used "The Rightstuff" and apply a light, thin bead of it along the entire seam. then take your finger (wear a latex glove or something) and smear the bead flat and smooth..filling in any gaps or question able areas.
Once done, remove the tape and your left with a really nice neat bead of sealant along the entire perimeter.

With the nice red manifold you have you want to keep it as neat looking as possible!
Looks great!

heinrich

Tony that was my thinking too

Warren928

Thanks Shane. Its interesting how Andy goes from multiple pulleys down to one. It must be the K.I.S.S. method finally dawning on him late.

Warren928

Yes, put the SC pulley so it covers up the air pump pulley. Then the last v-groove fits the AC compressor. I think I got it.

heinrich

That's a very nice design I think, better than the one I received way back ... I'd say (eh Tony?) just make quadruply sure you get the bolt torqued and it doesn't come out.

Daryl

Bill,
I forgot to mention that when my car is cold it runs perfectly, only after it warms up does the slight roughness start.

Geeez, did you have to mention that you get to go for a 40 mile drive in your car today?? I suppose the temperature is about 70s?

Here is what I am looking at out my front door right now!

Tony

Hmmm..good idea, i will try that but The after market fuel reg i have, that was on my car NA, will only give me a max of 6-7psi gain with the line off.



I basically never new how the darn thing worked to be honest with you. Not until i tore it appart and took the time to study it a bit .

On that note...how many of the TwinScrew set ups are currently using the restrictor in the signal line?

Now that ive figured it out (i think) i dont know how you could NOT use it. It made a HUGE difference in the needle valve adjustment (final fuel pressure under boost)

Funny thing is, i think thats how i WAS doing it, when i couldnt get a response from the needle valve adjustment. On some reading, a whim and some experimenting i decided to try the restrictor ....the needle valve works as advertised now.

What is the differnce between a VORTCH FMU and the BEGI unit then?
dont they do the same thing?

Also..the 8:1 ratio...i assume that is above a stock value?
ie: 5psi boost is in acrease of 40psi fule pressure at that level over stock.
Why is the value it 8:1?

Tony

got the same issue here.

Daryl

Tony
Interesting that you have the idle issue as well. I wonder how many others are experiencing the same thing? Have tried to diagnose why?

Bill Ball

Wow. With all the resealing Tony did, if he has it, then there is something systemic. Mine is very clearly a cylinder 7 miss. When the miss starts, it is a stumble at idle in gear at stoplights. It is worse in park or neutral - a virtual complete drop of cylinder 7. You can hear it in the tail pipe and the car shakes mildly. If I pull the spark boot and/or the injector lead to 7, there is no change at all, whereas all the other cylinders show a response to a pulled lead. Swapped injectors, new plugs, wires, etc. It's always cylinder 7. Hit the gas - no problem. I keep thinking something is leaning out #7 at idle when warm - perhaps related to the bypass passage which is nearest 7. I have not gotten any further with this. As I said, the car runs so well under any kind of power, only stumbling at idle, that I have not pursued it vigorously, especially since it's such a stumper with no clear cause.

Bill Ball

Daryl:

Looks like a warm day for Saskatoon in December. When I was single I had a brief fling with a girl from Saskatoon and went to visit her one April. April, you know the month when things generally are blooming around most parts of the world? Jesus HC! I thought we had returned to the ice age! It was truly glacial weather. It was the first time I had seen these things you mount on the inside of your car door windows so you can have any hope of seeing out of them in the subzero high for the day. I'm still shivering.

Louie928

Tony,
I'm way ignorant on these voodoo fuel pressure regulator devices, but it may have something to do with the relationship between fuel injector inlet pressure difference and fuel injector flow difference. The flow through the injector isn't linear with relation to a pressure change to the injector. IIRC, it's something like the square root of the pressure ratio. Going from 40 lbs to 44 lbs = 44/40 = 1.1 ratio in pressure. Sq. root of 1.1 is 1.0488. in this case a 10% increase in fuel pressure gets less than 5% increase in fuel flow. That's why fuel pressure has to increase more than air pressure. Even then it's logarithmic, not a straight multiplication like 8:1.

BrianG

Do you mean, DO NOT disassemble the manifold 1/2's, but do this process to the perimeter of the assembled unit?